This document summarizes biomass gasification technology. It discusses how biomass gasification works, the types of gasifiers, and key process parameters that influence the products of gasification. Biomass is gasified through thermal conversion processes to produce a syngas fuel mixture. There are four primary gasifier types - moving bed, fluidized bed, and circulating fluidized bed - which differ in how biomass and gas contact each other within the gasifier. Important operating parameters like temperature, gasifying agent, and pressure determine the syngas composition and energy efficiency of the process.
Thermodynamic modeling and experimental study of rice husk pyrolysiseSAT Journals
Abstract Pyrolysis of agricultural waste is a promising route for waste to energy generation. Rice husk is a type of agro-waste that is available in plenty in India. It can be used as feed for pyrolysis to produce different products such as (solid) coke and silica, (liquid) tar and other organics and syngas. HSC Chemistry computer aided code for thermodynamic modeling was used to predict the products of rice-husk pyrolysis in this research study. The pyrolysis of rice husk was carried out between 100-1200°C in the pressure range of 1 – 15 bar. The pyrolysis products predicted by HSC calculations were mainly solid coke, gases like H2, CO2, CO, CH4, with small quantity of aromatic compounds like C6H6, C7H8, C8H10 (ethyl benzene), C8H10 (xylenes) and C6H5 –OH. An experimental study for product validation was also done and the results are presented. Keywords: Pyrolysis, syngas, HSC Chemistry, aromatic compounds.
Co gasification of coal and biomass – thermodynamic and experimental studyeSAT Journals
Abstract Cogasification of coal and biomass is a new area of research. Cogasification offers several advantages than individual feed gasification. A thermodynamic analysis of lignite coal and rice husk cogasification using only steam was studied by using HSC chemistry software in this paper involving the effect of temperature 500-1200°C and GaCR ratio(1-3) on the product gas composition. The study also focused on calculation of thermoneutral conditions and hundred percent carbon conversion temperature in cogasification of lignite coal and rice husk. Experimental study of co gasification of rice husk and coal was also done at fixed steam to carbon ratio. The experimental study was found to be more kinetically controlled.
Keyword: cogasification, rice husk, lignite coal, HSC chemistry software, fixed bed.
Technical challenges of utilizing biomass gasification gas for power generationAlexander Decker
This document discusses the technical challenges of utilizing biomass gasification gas for power generation. Biomass gasification produces a gas called producer gas that can be used to generate heat and power. However, commercial application of biomass gasification technology for power generation faces several technological challenges. One of the most challenging issues is gas cleaning. The producer gas contains impurities like tar and particles that must be removed to acceptable levels for applications like internal combustion engines and gas turbines. Various gas cleaning methods have been developed including physical filtration, thermal cracking, and catalytic reforming of tar, but an efficient and commercially viable solution has yet to be found. This document reviews different gas cleaning methods and how they affect the gas composition and cold gas efficiency of
SYNGAS PRODUCTION BY DRY REFORMING OF METHANE OVER CO-PRECIPITATED CATALYSTSIAEME Publication
The syngas manufacturing from the reforming of methane with carbon dioxide is tempting because of output in terms of extra pure synthesis gas and lower H2 to CO ratio than other synthesis gas production methods like either partial oxidation or steam reforming. For production of long-chain hydrocarbons though the Fischer-Tropsch synthesis, lower H2 to CO ratio is required and important, as it is a most likely feedstock. In recent decades, CO2 utilization has become more and more important in view of the emergent global warming phenomenon. On the environmental point of view, methane reforming is tantalizing due to the reduction of carbon dioxide and methane emissions as both are consider as dangerous greenhouse gases. Commercially, as cost effectively, nickel is used for methane reforming reactions due to its availability and lower cost compared to noble metals. Number of catalysts endures rigorous deactivation because of carbon deposition. Mainly carbon formation is because of methane decomposition and CO disproportionate. It is important and required to recognize essential steps of activation and conversion of CH4 and CO2 to design catalysts that minimize deactivation. Effect of promoters on activity and stability were studied in the detail. In order to develop the highly active with minimum coke formation the alkali metal oxides and ceria/zirconia/magnesia promoters were incorporated in the catalysts. The influence of ZrO2, CeO2 and MgO, in the performance of Ni-Al2O3 catalyst, prepare by co-precipitation method was studied in detailed. The XRD, FTIR, and BET and reactivity test for different promoted and unprompted catalyst was carried out.
Feasibility study: Wood gasification power plant in Belarus (2012)Dr. Petr Dudin
The feasibility study concerned wood chips gasification in Belarus and was conducted in 2012. Some data in the presentation might be outdated. However, key technology facts and macro remains very much the same in 2015
Now I am interested in building a pilot gasification plant with my own advance design tar removal system - all designed by me and manufactured by the BDC R&D company
The document discusses thermodynamic analysis of biomass gasification. It analyzes the reaction thermoneutral points (R-TNPs) for gasifying rice husk with different gasifying agents and their ratios. Key findings include:
- For CO2 alone, R-TNPs decreased with higher CO2:carbon ratios, with syngas output and CO2 conversion also decreasing. Heat requirements initially rose then fell with a heat exchanger.
- R-TNPs were not found for H2O alone at any ratio.
- With CO2+H2O, R-TNPs were only obtained at low total gasifier agent:carbon ratios. Higher ratios supported
In this project we basically studied scope of this project, its feasibility and market assessment, raw material availability, different routes to produce Syngas and their comparison, process selection and its complete description, its P&ID, and environmental consideration.
Thermodynamic modeling and experimental study of rice husk pyrolysiseSAT Journals
Abstract Pyrolysis of agricultural waste is a promising route for waste to energy generation. Rice husk is a type of agro-waste that is available in plenty in India. It can be used as feed for pyrolysis to produce different products such as (solid) coke and silica, (liquid) tar and other organics and syngas. HSC Chemistry computer aided code for thermodynamic modeling was used to predict the products of rice-husk pyrolysis in this research study. The pyrolysis of rice husk was carried out between 100-1200°C in the pressure range of 1 – 15 bar. The pyrolysis products predicted by HSC calculations were mainly solid coke, gases like H2, CO2, CO, CH4, with small quantity of aromatic compounds like C6H6, C7H8, C8H10 (ethyl benzene), C8H10 (xylenes) and C6H5 –OH. An experimental study for product validation was also done and the results are presented. Keywords: Pyrolysis, syngas, HSC Chemistry, aromatic compounds.
Co gasification of coal and biomass – thermodynamic and experimental studyeSAT Journals
Abstract Cogasification of coal and biomass is a new area of research. Cogasification offers several advantages than individual feed gasification. A thermodynamic analysis of lignite coal and rice husk cogasification using only steam was studied by using HSC chemistry software in this paper involving the effect of temperature 500-1200°C and GaCR ratio(1-3) on the product gas composition. The study also focused on calculation of thermoneutral conditions and hundred percent carbon conversion temperature in cogasification of lignite coal and rice husk. Experimental study of co gasification of rice husk and coal was also done at fixed steam to carbon ratio. The experimental study was found to be more kinetically controlled.
Keyword: cogasification, rice husk, lignite coal, HSC chemistry software, fixed bed.
Technical challenges of utilizing biomass gasification gas for power generationAlexander Decker
This document discusses the technical challenges of utilizing biomass gasification gas for power generation. Biomass gasification produces a gas called producer gas that can be used to generate heat and power. However, commercial application of biomass gasification technology for power generation faces several technological challenges. One of the most challenging issues is gas cleaning. The producer gas contains impurities like tar and particles that must be removed to acceptable levels for applications like internal combustion engines and gas turbines. Various gas cleaning methods have been developed including physical filtration, thermal cracking, and catalytic reforming of tar, but an efficient and commercially viable solution has yet to be found. This document reviews different gas cleaning methods and how they affect the gas composition and cold gas efficiency of
SYNGAS PRODUCTION BY DRY REFORMING OF METHANE OVER CO-PRECIPITATED CATALYSTSIAEME Publication
The syngas manufacturing from the reforming of methane with carbon dioxide is tempting because of output in terms of extra pure synthesis gas and lower H2 to CO ratio than other synthesis gas production methods like either partial oxidation or steam reforming. For production of long-chain hydrocarbons though the Fischer-Tropsch synthesis, lower H2 to CO ratio is required and important, as it is a most likely feedstock. In recent decades, CO2 utilization has become more and more important in view of the emergent global warming phenomenon. On the environmental point of view, methane reforming is tantalizing due to the reduction of carbon dioxide and methane emissions as both are consider as dangerous greenhouse gases. Commercially, as cost effectively, nickel is used for methane reforming reactions due to its availability and lower cost compared to noble metals. Number of catalysts endures rigorous deactivation because of carbon deposition. Mainly carbon formation is because of methane decomposition and CO disproportionate. It is important and required to recognize essential steps of activation and conversion of CH4 and CO2 to design catalysts that minimize deactivation. Effect of promoters on activity and stability were studied in the detail. In order to develop the highly active with minimum coke formation the alkali metal oxides and ceria/zirconia/magnesia promoters were incorporated in the catalysts. The influence of ZrO2, CeO2 and MgO, in the performance of Ni-Al2O3 catalyst, prepare by co-precipitation method was studied in detailed. The XRD, FTIR, and BET and reactivity test for different promoted and unprompted catalyst was carried out.
Feasibility study: Wood gasification power plant in Belarus (2012)Dr. Petr Dudin
The feasibility study concerned wood chips gasification in Belarus and was conducted in 2012. Some data in the presentation might be outdated. However, key technology facts and macro remains very much the same in 2015
Now I am interested in building a pilot gasification plant with my own advance design tar removal system - all designed by me and manufactured by the BDC R&D company
The document discusses thermodynamic analysis of biomass gasification. It analyzes the reaction thermoneutral points (R-TNPs) for gasifying rice husk with different gasifying agents and their ratios. Key findings include:
- For CO2 alone, R-TNPs decreased with higher CO2:carbon ratios, with syngas output and CO2 conversion also decreasing. Heat requirements initially rose then fell with a heat exchanger.
- R-TNPs were not found for H2O alone at any ratio.
- With CO2+H2O, R-TNPs were only obtained at low total gasifier agent:carbon ratios. Higher ratios supported
In this project we basically studied scope of this project, its feasibility and market assessment, raw material availability, different routes to produce Syngas and their comparison, process selection and its complete description, its P&ID, and environmental consideration.
Effect of Fractionation and Pyrolysis on Fuel Properties of Poultry LitterLPE Learning Center
The document summarizes research on the effect of fractionation and pyrolysis on the fuel properties of poultry litter. Key findings include:
- Pyrolyzing the coarse fraction of poultry litter at 300°C captured the most energy (68.71%) in the charcoal produced and resulted in the highest calorific value (17.39 MJ/kg).
- Pyrolysis above 500°C captured less carbon but produced a light condensate fraction that could be used as a low-grade liquid fuel.
- The medium condensate fraction captured 27.54% of nitrogen and could be used as fertilizer.
- Pyrolysis significantly reduced nutrients like ammonium
Proximate and ultimate analysis of cotton pod used in the updraft gasifierIaetsd Iaetsd
This document provides an overview of cotton pod gasification. It discusses the gasification process, which involves drying, pyrolysis, combustion, and reduction to produce a producer gas. The document then reviews the characteristics of cotton pod as a biomass fuel, including particle size, moisture content, and ash content, and how these properties affect the gasification process. It also examines various process parameters like temperature, heating rate, equivalence ratio, and gasification agents and how they impact gas composition and energy output. The goal is to investigate cotton pod's potential as an energy source and evaluate its properties for gasification applications.
4.15 - "Technologies of Biomass Gasification" - Aleksander Sobolewski, Sławom...Pomcert
This document summarizes technologies for biomass gasification. It provides background on the Institute for Chemical Processing of Coal, which conducts research on gasification. Biomass gasification is described as converting biomass into a gaseous fuel through thermochemical processes. Different types of biomass gasification reactors are presented, along with examples of small and large-scale biomass gasification technologies. Challenges associated with biomass gasification include ensuring a continuous biomass supply and dealing with gas contamination.
Fabrication and Performance Analysis of Downdraft Biomass Gasifier Using Suga...IJSRD
The process by which biomass can be converted to a producer gas by supplying less oxygen than actually required for complete combustion of the fuel is known as gasification. It is a thermo-chemical process and it is performed by a device known as gasifier. For executing the gasification experiments nowadays single throated gasifier uses sugarcane industry waste. In the present study we get to know that sugarcane briquettes are manufactured from residue of sugarcane which is used as a biomass material for the gasification process. Briquettes are formed by extruding the sugar which is extracted from the residue of sugarcane (bagasse) dried in the sun. Equivalence ratio, producer gas composition, calorific value of the producer gas, gas production rate and cold gas efficiency are certain grounds for estimating the performance of the biomass gasifier. The experiential results are compared with those reported in the literature.
V. Belgiorno et al. / Waste Management 23 (2003) 1–15
1. Gasification is a process that converts solid waste or biomass into a combustible gas through partial oxidation at high temperatures. It has regained popularity due to increasing demand for renewable energy sources.
2. There are three main types of gasifiers - fixed bed, fluidized bed, and indirect gasifiers. Fixed bed gasifiers include updraft and downdraft designs. Fluidized bed gasifiers have bubbling or circulating bed designs. Indirect gasifiers use steam or combusted gas to provide heat.
3. Gasification produces syngas, tar, and char as outputs. The syng
Production of Syngas from biomass and its purificationAwais Chaudhary
This document summarizes a project proposal for a biomass gasification plant in Pakistan. It discusses the motivation, basic chemistry, advantages of syngas, availability of raw materials, effects of temperature and residence time on syngas production, particulate matter, tars, sulfur, nitrogen compounds in biomass gasification. It also describes the gasification process selected, purification of syngas using hot gas cleanup technology, equipment list, environmental considerations, and concludes with recommendations for syngas production from biomass.
1) Gasification, pyrolysis, and hydrothermal carbonization (HTC) are three thermal conversion processes that can be used to treat solid wastes and produce combustible gases, liquid fuels, and solids like char.
2) Gasification involves partial oxidation at high temperatures to produce syngas, while pyrolysis uses thermal decomposition without oxygen to produce bio-oil. HTC uses hydrothermal conditions to produce "hydrochar".
3) Each process has advantages - gasification produces a high-quality syngas, pyrolysis flexibility to produce liquid fuels, and HTC higher solid yields than dry pyrolysis. Overall, these carbonization methods have potential for environmentally-friendly conversion of biomass into
This document provides an overview of thermochemical conversion processes for biomass, focusing on combustion, gasification, and pyrolysis. It defines each process and describes the basic stages and reactions involved. Combustion aims to release all chemical energy as heat through complete oxidation. Gasification produces a synthetic gas (syngas) through partial oxidation. Pyrolysis thermally decomposes biomass in the absence of oxygen to produce bio-oil, biochar, and syngas. The document discusses process applications and outputs, as well as considerations like emissions and efficiency. Overall, it concisely introduces the key thermochemical conversion options for biomass energy.
Increasing Calorific Value of Biogas using Different Techniques: A Reviewijsrd.com
The use of fossil fuel is increasing day by day and is going to deplete soon. Biogas is a clean environment friendly fuel. Biogas produced from anaerobic digestion of organic waste cannot be utilized straight off as a vehicle fuel. The gases produced from anaerobic digestion are CH4 and trace components like CO2, H2O, H2S, Siloxanes, Hydrocarbons, NH3, O2, CO and N2. To use biogas as fuel, its CV should be about equal to CV of natural gas. Hence CV of biogas can be improved by removing CO2 and trace components from biogas. These gases are not completely combustible and will harm engine parts. For transforming biogas to bioCNG two steps are performed: (1) cleaning process to remove trace components and (2) upgrading process to increase CV of biogas. This paper reviews the attempt made to increase CV of a biogas by different methods for cleaning and upgrading.
The use of Cooking Gas as Refrigerant in a Domestic RefrigeratorIJERA Editor
The application of cooking gas refrigerants in refrigeration system is considered to be a potential way to improve
energy efficiency and to encourage the use of environment-friendly refrigerants. Refrigeration operation has
been met with many challenges as it deals with environmental impact, how it affects humans and how it
contributes to the society in general. Domestic refrigerators annually consume several metric tons of traditional
refrigerants, which contribute to very high Ozone Depletion Potential (ODP) and Global Warming Potential
(GWP). The experiment conducted employs the use of two closely linked refrigerants, R600a (Isobutene) and
cooking gas which is varied in an ideal refrigerant mixture of 150 g of refrigerant and 15 ml of lubricating oil (to
a rating of 40 wt % expected in the compressor). The Laboratory process involved the use of Gas
Chromatography machine to ascertain the values of the mole ratio, molecular weight and critical temperatures.
Prode properties and Refprop softwares were used to ascertain other refrigerant properties of the mixture. The
results indicated that the mixture of R600a with lubricant confirm mineral oil as being the most appropriate for
the operation. The experimental results indicated that the refrigeration system with cooking gas refrigerant
worked normally and was found to attain high freezing capacity and a COP value of 2.159. It is established that
cooking gas is a viable alternative refrigerant to replace R600a in domestic refrigerators. Hence, its application
in refrigerating systems measures up to the current trend on environmental regulations with hydrocarbon
refrigerants
An examination surface morphology and in situ studies of metalIAEME Publication
The document examines surface morphology and in situ studies of metal dusting that leads to external pits on ASTM A516 Gr60 carbon steel exposed to flare gas in an MTBE plant. Metal dusting is a form of high-temperature corrosion that begins with carbon deposition on the metal surface and diffusion into the metal, eventually leading to superficial carbon deposition. Experiments were conducted on ASTM A516 Gr60 steel and chromium-based steel exposed to flare gas. The poorer alloy composition experienced a higher carbon formation rate. Methanol in the gas increased carbon formation. Field experiments also studied limits for carbon-free operation.
This document provides information about various mass transfer unit operations including drying, crystallization, and extraction. It discusses drying methods and mechanisms. It also defines psychrometric terms and describes psychrometric charts. Crystallization involves nucleation and crystal growth from supersaturated solutions. Different types of crystallizers are identified. Extraction involves transferring an active agent from a solid or liquid mixture into a solvent. The key types of extraction are solid-liquid, liquid-liquid, and gas-liquid. The document provides details on each of these mass transfer unit operations.
Methanol synthesis from industrial CO2 sourcesKishan Kasundra
Kishan Kasundra presented on methanol synthesis from industrial CO2 sources. Two case studies were analyzed: direct CO2 to methanol (d-CTM) and synthesis gas to methanol (sg-CTM). The d-CTM process consumed more utilities and CO2 per ton of methanol but emitted slightly more CO2. The sg-CTM process optimized methanol production at high hydrogen-carbon ratios and was less resource intensive. Both achieved high methanol yields but differed in raw material use and carbon emissions. The presentation concluded the sg-CTM route may be preferable due to lower resource use and carbon emissions per ton of methanol produced.
Paper: Trophy Hunting vs. Manufacturing Energy: The PriceResponsiveness of Sh...Marcellus Drilling News
Discussion paper from researchers at Resources for the Future (RFF), a nonpartisan think tank devoted exclusively to natural resource and environmental issues, taking a look at how the "new way" of drilling multiple wells from a single pad, which is akin to a manufacturing process, is flattening out the supply curve. That, in turn, means far less price volatility for natgas.
Episode 3 : Production of Synthesis Gas by Steam Methane ReformingSAJJAD KHUDHUR ABBAS
Episode 3 : Production of Synthesis Gas by Steam Methane Reforming
History of Synthesis Gas
In 1780, Felice Fontana discovered that combustible gas develops if water vapor is passed over carbon at temperatures over 500 °C. This CO and H2 containing gas was called water gas and mainly used for lighting purposes in the19th century.
As of the beginning of the 20th century, H2/CO-mixtures were used for syntheses of hydrocarbons and then, as a consequence, also called synthesis gas.
Haber and Bosch discovered the synthesis of ammonia from H2 and N2 in 1910 and the first industrial ammonia synthesis plant was commissioned in 1913.
The production of liquid hydrocarbons and oxygenates from syngas conversion over iron catalysts was discovered in 1923 by Fischer and Tropsch.
Much of the syngas conversion processes were being developed in Germany during the first and second world wars at a time when natural resources were becoming scare and alternative routes for hydrogen production, ammonia synthesis, and transportation fuels were a necessity.
In 1943/44, this was applied for large-scale production of artificial fuels from synthesis gas in Germany.
Chemical Looping Combustion of Rice HuskIJERA Editor
A thermodynamic investigation of direct chemical looping combustion (CLC) of rice husk is presented in this paper. Both steam and CO2 are used for gasification within the temperature range of 500–1200˚C and different amounts of oxygen carriers. Chemical equilibrium model was considered for the CLC fuel reactor. The trends in product compositions of the fuel reactor, were determined. Rice husk gasification using 3 moles H2O and 0 moles CO2 per mole carbon (in rice husk) at 1 bar pressure and 900˚C was found to be the best operating point for hundred percent carbon conversion in the fuel reactor. Such detailed thermodynamic studies can be useful to design chemical looping combustion processes using different fuels.
ASSESSMENT OF SAPLINGS OF MANGOSTEEN (GARCINIA MANGOSTANA L) IN ABSORBING CAR...IAEME Publication
Carbon dioxide is a gas needed by plants in its growth. Plants use CO2 for
photosynthesis in producing food ingredients. Research topics related to carbon
dioxide uptake are still open to study because there are still many potential types of
plants, especially in Central Kalimantan. Plants that have not been studied are mainly
plant saplings that are easily found and widely known by the people of Central
Kalimantan. The plant species is Mangosteen (Garcinia mangostana L.). The study
aims to (a) measure the ability of the mangosteen seedlings' CO2 uptake (b) measure
the fluctuations in seedlings of mangosteen plant CO2 uptake during the measurement
period of 06.00-06.30, 12.00-12.30 and 15.00-15.30 WIB, (c) analyze biomass / dry
weight reserves and organic carbon stored in mangosteen seedlings. The mangosteen
seedlings used in this study were 3-5 months old. Measurements of CO2 absorption
using a containment method measuring 50 cm x 50 cm x 30 cm and CO2 gas analysis
using Gas Cromatography. The time period for measuring CO2 uptake is carried out
at 06.00-06.30, 12.00-12.30 and 15.00-15.30 WIB with a time interval of 5, 10, 15,
20, 25 and 30 for 4 (four) weeks. Analysis of biomass / dry weight reserves, percent
and organic carbon content of saplings of mangosteen plants using the gravimetric
method. The results showed that the average CO2 absorption rate of the mangosteen
seedlings was 0.119 mg / m2 / minute. The CO2 absorption rate of saplings of
mangosteen plants fluctuated, where the highest CO2 uptake occurred at 12.00-12.30
WIB, followed by 15.00-15.30 WIB and the lowest CO2 uptake occurred at 06.00-
06.30 WIB. The average biomass / dry weight of saplings of Mangosteen plants is
9.24 grams, the average percent of organic carbon ranges from 55.65% and the
organic carbon content is 5.14 grams
Synthetic gas (syngas) can be produced from gasification of biomass, coal, or natural gas reforming and contains mainly carbon monoxide (CO) and hydrogen (H2). The key properties that affect combustion include the flammability limits and laminar flame velocity. Syngas is commonly produced via gasification processes involving partial oxidation of carbon-based feedstocks with oxygen, steam, or carbon dioxide at high temperatures. The syngas can then be used to produce fuels and chemicals through processes like Fischer-Tropsch synthesis, which converts syngas into liquid hydrocarbons. Removal of impurities from the raw syngas produced is typically required before it can be used as a chemical
The document discusses bio gasified coupled engines which convert bio/organic fuel into producer gas or syngas that can be used to power engines. It describes the process of biomass gasification where biomass is converted into combustible gases like carbon monoxide, hydrogen, and methane through incomplete combustion. This producer gas can then be used to power gas engines or for heat applications. The document outlines the various zones in a gasifier where different chemical reactions occur during gasification and discusses reaction chemistry and technologies used.
Thermochemical conversion of biomass involves processes that use heat to convert biomass into other forms. This includes combustion, gasification, and pyrolysis. Gasification converts biomass into a gaseous fuel called producer gas through a series of chemical reactions at high temperatures. It has advantages like efficiency and being carbon neutral, but requires precise control and feedstock preparation. Pyrolysis thermally decomposes biomass into solid, liquid, and gaseous products depending on temperature and residence time.
Effect of Fractionation and Pyrolysis on Fuel Properties of Poultry LitterLPE Learning Center
The document summarizes research on the effect of fractionation and pyrolysis on the fuel properties of poultry litter. Key findings include:
- Pyrolyzing the coarse fraction of poultry litter at 300°C captured the most energy (68.71%) in the charcoal produced and resulted in the highest calorific value (17.39 MJ/kg).
- Pyrolysis above 500°C captured less carbon but produced a light condensate fraction that could be used as a low-grade liquid fuel.
- The medium condensate fraction captured 27.54% of nitrogen and could be used as fertilizer.
- Pyrolysis significantly reduced nutrients like ammonium
Proximate and ultimate analysis of cotton pod used in the updraft gasifierIaetsd Iaetsd
This document provides an overview of cotton pod gasification. It discusses the gasification process, which involves drying, pyrolysis, combustion, and reduction to produce a producer gas. The document then reviews the characteristics of cotton pod as a biomass fuel, including particle size, moisture content, and ash content, and how these properties affect the gasification process. It also examines various process parameters like temperature, heating rate, equivalence ratio, and gasification agents and how they impact gas composition and energy output. The goal is to investigate cotton pod's potential as an energy source and evaluate its properties for gasification applications.
4.15 - "Technologies of Biomass Gasification" - Aleksander Sobolewski, Sławom...Pomcert
This document summarizes technologies for biomass gasification. It provides background on the Institute for Chemical Processing of Coal, which conducts research on gasification. Biomass gasification is described as converting biomass into a gaseous fuel through thermochemical processes. Different types of biomass gasification reactors are presented, along with examples of small and large-scale biomass gasification technologies. Challenges associated with biomass gasification include ensuring a continuous biomass supply and dealing with gas contamination.
Fabrication and Performance Analysis of Downdraft Biomass Gasifier Using Suga...IJSRD
The process by which biomass can be converted to a producer gas by supplying less oxygen than actually required for complete combustion of the fuel is known as gasification. It is a thermo-chemical process and it is performed by a device known as gasifier. For executing the gasification experiments nowadays single throated gasifier uses sugarcane industry waste. In the present study we get to know that sugarcane briquettes are manufactured from residue of sugarcane which is used as a biomass material for the gasification process. Briquettes are formed by extruding the sugar which is extracted from the residue of sugarcane (bagasse) dried in the sun. Equivalence ratio, producer gas composition, calorific value of the producer gas, gas production rate and cold gas efficiency are certain grounds for estimating the performance of the biomass gasifier. The experiential results are compared with those reported in the literature.
V. Belgiorno et al. / Waste Management 23 (2003) 1–15
1. Gasification is a process that converts solid waste or biomass into a combustible gas through partial oxidation at high temperatures. It has regained popularity due to increasing demand for renewable energy sources.
2. There are three main types of gasifiers - fixed bed, fluidized bed, and indirect gasifiers. Fixed bed gasifiers include updraft and downdraft designs. Fluidized bed gasifiers have bubbling or circulating bed designs. Indirect gasifiers use steam or combusted gas to provide heat.
3. Gasification produces syngas, tar, and char as outputs. The syng
Production of Syngas from biomass and its purificationAwais Chaudhary
This document summarizes a project proposal for a biomass gasification plant in Pakistan. It discusses the motivation, basic chemistry, advantages of syngas, availability of raw materials, effects of temperature and residence time on syngas production, particulate matter, tars, sulfur, nitrogen compounds in biomass gasification. It also describes the gasification process selected, purification of syngas using hot gas cleanup technology, equipment list, environmental considerations, and concludes with recommendations for syngas production from biomass.
1) Gasification, pyrolysis, and hydrothermal carbonization (HTC) are three thermal conversion processes that can be used to treat solid wastes and produce combustible gases, liquid fuels, and solids like char.
2) Gasification involves partial oxidation at high temperatures to produce syngas, while pyrolysis uses thermal decomposition without oxygen to produce bio-oil. HTC uses hydrothermal conditions to produce "hydrochar".
3) Each process has advantages - gasification produces a high-quality syngas, pyrolysis flexibility to produce liquid fuels, and HTC higher solid yields than dry pyrolysis. Overall, these carbonization methods have potential for environmentally-friendly conversion of biomass into
This document provides an overview of thermochemical conversion processes for biomass, focusing on combustion, gasification, and pyrolysis. It defines each process and describes the basic stages and reactions involved. Combustion aims to release all chemical energy as heat through complete oxidation. Gasification produces a synthetic gas (syngas) through partial oxidation. Pyrolysis thermally decomposes biomass in the absence of oxygen to produce bio-oil, biochar, and syngas. The document discusses process applications and outputs, as well as considerations like emissions and efficiency. Overall, it concisely introduces the key thermochemical conversion options for biomass energy.
Increasing Calorific Value of Biogas using Different Techniques: A Reviewijsrd.com
The use of fossil fuel is increasing day by day and is going to deplete soon. Biogas is a clean environment friendly fuel. Biogas produced from anaerobic digestion of organic waste cannot be utilized straight off as a vehicle fuel. The gases produced from anaerobic digestion are CH4 and trace components like CO2, H2O, H2S, Siloxanes, Hydrocarbons, NH3, O2, CO and N2. To use biogas as fuel, its CV should be about equal to CV of natural gas. Hence CV of biogas can be improved by removing CO2 and trace components from biogas. These gases are not completely combustible and will harm engine parts. For transforming biogas to bioCNG two steps are performed: (1) cleaning process to remove trace components and (2) upgrading process to increase CV of biogas. This paper reviews the attempt made to increase CV of a biogas by different methods for cleaning and upgrading.
The use of Cooking Gas as Refrigerant in a Domestic RefrigeratorIJERA Editor
The application of cooking gas refrigerants in refrigeration system is considered to be a potential way to improve
energy efficiency and to encourage the use of environment-friendly refrigerants. Refrigeration operation has
been met with many challenges as it deals with environmental impact, how it affects humans and how it
contributes to the society in general. Domestic refrigerators annually consume several metric tons of traditional
refrigerants, which contribute to very high Ozone Depletion Potential (ODP) and Global Warming Potential
(GWP). The experiment conducted employs the use of two closely linked refrigerants, R600a (Isobutene) and
cooking gas which is varied in an ideal refrigerant mixture of 150 g of refrigerant and 15 ml of lubricating oil (to
a rating of 40 wt % expected in the compressor). The Laboratory process involved the use of Gas
Chromatography machine to ascertain the values of the mole ratio, molecular weight and critical temperatures.
Prode properties and Refprop softwares were used to ascertain other refrigerant properties of the mixture. The
results indicated that the mixture of R600a with lubricant confirm mineral oil as being the most appropriate for
the operation. The experimental results indicated that the refrigeration system with cooking gas refrigerant
worked normally and was found to attain high freezing capacity and a COP value of 2.159. It is established that
cooking gas is a viable alternative refrigerant to replace R600a in domestic refrigerators. Hence, its application
in refrigerating systems measures up to the current trend on environmental regulations with hydrocarbon
refrigerants
An examination surface morphology and in situ studies of metalIAEME Publication
The document examines surface morphology and in situ studies of metal dusting that leads to external pits on ASTM A516 Gr60 carbon steel exposed to flare gas in an MTBE plant. Metal dusting is a form of high-temperature corrosion that begins with carbon deposition on the metal surface and diffusion into the metal, eventually leading to superficial carbon deposition. Experiments were conducted on ASTM A516 Gr60 steel and chromium-based steel exposed to flare gas. The poorer alloy composition experienced a higher carbon formation rate. Methanol in the gas increased carbon formation. Field experiments also studied limits for carbon-free operation.
This document provides information about various mass transfer unit operations including drying, crystallization, and extraction. It discusses drying methods and mechanisms. It also defines psychrometric terms and describes psychrometric charts. Crystallization involves nucleation and crystal growth from supersaturated solutions. Different types of crystallizers are identified. Extraction involves transferring an active agent from a solid or liquid mixture into a solvent. The key types of extraction are solid-liquid, liquid-liquid, and gas-liquid. The document provides details on each of these mass transfer unit operations.
Methanol synthesis from industrial CO2 sourcesKishan Kasundra
Kishan Kasundra presented on methanol synthesis from industrial CO2 sources. Two case studies were analyzed: direct CO2 to methanol (d-CTM) and synthesis gas to methanol (sg-CTM). The d-CTM process consumed more utilities and CO2 per ton of methanol but emitted slightly more CO2. The sg-CTM process optimized methanol production at high hydrogen-carbon ratios and was less resource intensive. Both achieved high methanol yields but differed in raw material use and carbon emissions. The presentation concluded the sg-CTM route may be preferable due to lower resource use and carbon emissions per ton of methanol produced.
Paper: Trophy Hunting vs. Manufacturing Energy: The PriceResponsiveness of Sh...Marcellus Drilling News
Discussion paper from researchers at Resources for the Future (RFF), a nonpartisan think tank devoted exclusively to natural resource and environmental issues, taking a look at how the "new way" of drilling multiple wells from a single pad, which is akin to a manufacturing process, is flattening out the supply curve. That, in turn, means far less price volatility for natgas.
Episode 3 : Production of Synthesis Gas by Steam Methane ReformingSAJJAD KHUDHUR ABBAS
Episode 3 : Production of Synthesis Gas by Steam Methane Reforming
History of Synthesis Gas
In 1780, Felice Fontana discovered that combustible gas develops if water vapor is passed over carbon at temperatures over 500 °C. This CO and H2 containing gas was called water gas and mainly used for lighting purposes in the19th century.
As of the beginning of the 20th century, H2/CO-mixtures were used for syntheses of hydrocarbons and then, as a consequence, also called synthesis gas.
Haber and Bosch discovered the synthesis of ammonia from H2 and N2 in 1910 and the first industrial ammonia synthesis plant was commissioned in 1913.
The production of liquid hydrocarbons and oxygenates from syngas conversion over iron catalysts was discovered in 1923 by Fischer and Tropsch.
Much of the syngas conversion processes were being developed in Germany during the first and second world wars at a time when natural resources were becoming scare and alternative routes for hydrogen production, ammonia synthesis, and transportation fuels were a necessity.
In 1943/44, this was applied for large-scale production of artificial fuels from synthesis gas in Germany.
Chemical Looping Combustion of Rice HuskIJERA Editor
A thermodynamic investigation of direct chemical looping combustion (CLC) of rice husk is presented in this paper. Both steam and CO2 are used for gasification within the temperature range of 500–1200˚C and different amounts of oxygen carriers. Chemical equilibrium model was considered for the CLC fuel reactor. The trends in product compositions of the fuel reactor, were determined. Rice husk gasification using 3 moles H2O and 0 moles CO2 per mole carbon (in rice husk) at 1 bar pressure and 900˚C was found to be the best operating point for hundred percent carbon conversion in the fuel reactor. Such detailed thermodynamic studies can be useful to design chemical looping combustion processes using different fuels.
ASSESSMENT OF SAPLINGS OF MANGOSTEEN (GARCINIA MANGOSTANA L) IN ABSORBING CAR...IAEME Publication
Carbon dioxide is a gas needed by plants in its growth. Plants use CO2 for
photosynthesis in producing food ingredients. Research topics related to carbon
dioxide uptake are still open to study because there are still many potential types of
plants, especially in Central Kalimantan. Plants that have not been studied are mainly
plant saplings that are easily found and widely known by the people of Central
Kalimantan. The plant species is Mangosteen (Garcinia mangostana L.). The study
aims to (a) measure the ability of the mangosteen seedlings' CO2 uptake (b) measure
the fluctuations in seedlings of mangosteen plant CO2 uptake during the measurement
period of 06.00-06.30, 12.00-12.30 and 15.00-15.30 WIB, (c) analyze biomass / dry
weight reserves and organic carbon stored in mangosteen seedlings. The mangosteen
seedlings used in this study were 3-5 months old. Measurements of CO2 absorption
using a containment method measuring 50 cm x 50 cm x 30 cm and CO2 gas analysis
using Gas Cromatography. The time period for measuring CO2 uptake is carried out
at 06.00-06.30, 12.00-12.30 and 15.00-15.30 WIB with a time interval of 5, 10, 15,
20, 25 and 30 for 4 (four) weeks. Analysis of biomass / dry weight reserves, percent
and organic carbon content of saplings of mangosteen plants using the gravimetric
method. The results showed that the average CO2 absorption rate of the mangosteen
seedlings was 0.119 mg / m2 / minute. The CO2 absorption rate of saplings of
mangosteen plants fluctuated, where the highest CO2 uptake occurred at 12.00-12.30
WIB, followed by 15.00-15.30 WIB and the lowest CO2 uptake occurred at 06.00-
06.30 WIB. The average biomass / dry weight of saplings of Mangosteen plants is
9.24 grams, the average percent of organic carbon ranges from 55.65% and the
organic carbon content is 5.14 grams
Synthetic gas (syngas) can be produced from gasification of biomass, coal, or natural gas reforming and contains mainly carbon monoxide (CO) and hydrogen (H2). The key properties that affect combustion include the flammability limits and laminar flame velocity. Syngas is commonly produced via gasification processes involving partial oxidation of carbon-based feedstocks with oxygen, steam, or carbon dioxide at high temperatures. The syngas can then be used to produce fuels and chemicals through processes like Fischer-Tropsch synthesis, which converts syngas into liquid hydrocarbons. Removal of impurities from the raw syngas produced is typically required before it can be used as a chemical
The document discusses bio gasified coupled engines which convert bio/organic fuel into producer gas or syngas that can be used to power engines. It describes the process of biomass gasification where biomass is converted into combustible gases like carbon monoxide, hydrogen, and methane through incomplete combustion. This producer gas can then be used to power gas engines or for heat applications. The document outlines the various zones in a gasifier where different chemical reactions occur during gasification and discusses reaction chemistry and technologies used.
Thermochemical conversion of biomass involves processes that use heat to convert biomass into other forms. This includes combustion, gasification, and pyrolysis. Gasification converts biomass into a gaseous fuel called producer gas through a series of chemical reactions at high temperatures. It has advantages like efficiency and being carbon neutral, but requires precise control and feedstock preparation. Pyrolysis thermally decomposes biomass into solid, liquid, and gaseous products depending on temperature and residence time.
Fundamental Review and Analysis of Gasifier Performance and Gasification ModelAI Publications
A reliable, affordable and clean energy supply is of major importance for society, economy and the environment. The modern use of biomass is considered a very promising clean energy option for reduction of greenhouse gas emission and energy dependency. Biomass gasification has been considered as the enabling technology for modern biomass utilization. However, challenges remains in biomass gasifier design and gasification model for viable commercial application through reliable model prediction and optimization of the process condition to obtain quality product compositions and maximal efficiencies. Bubbling fluidized bed gasifier and Apen Plus gasification model can salvage the undue complex processes and aims to develop the simplest possible model using the process simulator or Aspen Plus that incorporates the key gasification reaction and gasifier design.
The document discusses biomass gasification and different types of gasifiers. Gasification is a process that converts carbonaceous materials into a combustible gas. There are two main types of gasification gases - producer gas produced at low temperatures, and syngas produced at high temperatures. Fixed bed gasifiers like updraft, downdraft and crossdraft gasifiers as well as fluidized bed gasifiers are described. Producer gas contains more hydrocarbons while syngas contains mainly CO and H2. The applications and advantages of biomass gasification are also summarized.
The document discusses different types of biomass gasifiers. It explains that gasifiers convert carbon-containing materials into a combustible gas through a thermo-chemical process with a restricted oxygen supply. The two main types are fixed bed and fluidized bed gasifiers. Fixed bed gasifiers include updraft, downdraft, and crossdraft types, which differ in gas and air flow directions. Updraft gasifiers produce a low-quality gas suitable only for heating while downdrafts generate a cleaner gas for engines. Fluidized beds, including bubbling and circulating types, produce higher-quality syngas but are more complex and expensive.
The document discusses various processes for producing synthesis gas (syngas), which is a mixture of hydrogen and carbon monoxide, from natural gas through reforming reactions. It describes the main reforming processes - steam reforming, partial oxidation, autothermal reforming, dry reforming, and their operating conditions. Catalysts used and reactor designs for the different reforming reactions are also summarized.
This document reviews various techniques for optimizing biogas production and upgrading biogas quality through CO2 removal. It discusses pretreatment of substrates, co-digestion, use of serial digesters, and different methods for biogas upgrading including pressure swing adsorption, membrane separation, and CO2 absorption to purify biogas. The optimization of biogas production and upgrading is important as biogas can be a substitute for conventional fossil fuels but the presence of CO2 and other components can reduce its quality and economic feasibility for certain applications.
Carbon black from thermal Decomposition.pdfTHESEZAR1
The document investigates the production of hydrogen and carbon black through the thermal decomposition of sub-quality natural gas containing methane and hydrogen sulfide without requiring hydrogen sulfide separation. A computational model is developed to simulate the chemical reactions and effects of process parameters like feedstock flow rate and reactor temperature. The results show that reactor temperature strongly influences methane and hydrogen sulfide conversion, with over 100% methane conversion and increasing hydrogen sulfide conversion at higher temperatures. Carbon monoxide formation also plays a role, with lower carbon black yields at lower feedstock flow rates where methane conversion to carbon monoxide is higher. Hydrogen yield increases with feedstock flow rate up to a maximum point then decreases with further increases in flow rate.
Fabrication and Performance Analysis of Downdraft Biomass Gasifier Using Suga...IJSRD
The process by which biomass can be converted to a producer gas by supplying less oxygen than actually required for complete combustion of the fuel is known as gasification. It is a thermo-chemical process and it is performed by a device known as gasifier. For executing the gasification experiments nowadays single throated gasifier uses sugarcane industry waste. In the present study we get to know that sugarcane briquettes are manufactured from residue of sugarcane which is used as a biomass material for the gasification process. Briquettes are formed by extruding the sugar which is extracted from the residue of sugarcane (bagasse) dried in the sun. Equivalence ratio, producer gas composition, calorific value of the producer gas, gas production rate and cold gas efficiency are certain grounds for estimating the performance of the biomass gasifier. The experiential results are compared with those reported in the literature.
This document summarizes a study on using biomass gasification to capture CO2 from engine exhaust. Experiments were conducted introducing 0-15% CO2 into a gasifier along with oxygen and nitrogen. Higher CO2 fractions decreased bed temperature but increased CO production from 13.1% to 16.3% due to the endothermic reaction of char and CO2. Over 55% of input CO2 was converted. Cold gas efficiency increased 30% with higher char conversion. Using engine exhaust eliminates the cost of separating and storing CO2, as condensing water and mixing with oxygen is sufficient. The paper addresses using biomass gasification to capture CO2 from engine exhaust via recycling into the gasification process.
Water Gas Shift Reaction Characteristics Using Syngas from Waste Gasification inventionjournals
The characteristics of a high temperature water gas shift reaction over a commercial Fe-based catalyst using syngas from waste gasification were investigated using lab equipment tests and found to be feasible for producing valuable chemical products. The CO conversion and H2/CO ratio were observed using various values for the gas hourly space velocity(GHSV), steam/CO ratio, and temperature. The CO conversion and H2/CO ratio increased with increasing temperature, increasing steam/CO ratio and decreasing SV. The CO conversion values were 32.95% and 46.84% and the H2/CO ratios were 1.8 and 2.09 with temperatures of 350 C and 400C, respectively, when the steam/CO ratio was 2.4 and SV was 458 h-1 . The H2/CO ratio and CO conversion were 1.42 and 30.14%, respectively, when the steam/CO ratio was 1.45, and increased with an increase in the steam/CO ratio. The H2/CO ratio increased to 2.36 and the CO conversion increased to 51.70% when the steam/CO ratio was 3.44. However, the increase in the CO conversion was insignificant when the steam/CO ratio was greater than 2.9.
PRESENTATION ON PLANT DESIGN FOR MANUFACTURING OF HYDROGENPriyam Jyoti Borah
Steam reforming or steam methane reforming is a method for producing syngas (hydrogen and carbon monoxide) by reaction of hydrocarbons with water. Commonly natural gas is the feedstock. The main purpose of this technology is hydrogen production.The reaction is conducted in a reformer vessel where a high pressure mixture of steam and methane are put into contact with a nickel catalyst. Catalysts with high surface-area-to-volume ratio are preferred because of diffusion limitations due to high operating temperature. Examples of catalyst shapes used are spoked wheels, gear wheels, and rings with holes. Additionally, these shapes have a low pressure drop which is advantageous for this application.
This document discusses coal gasification, which involves converting coal into a gaseous fuel called synthesis gas (syngas) through a process of partial oxidation. Syngas is composed primarily of carbon monoxide and hydrogen. There are three main types of gasifiers - moving bed, entrained flow, and fluidized bed. Catalytic gasification uses catalysts to lower operating temperatures and enhance reaction rates. Applications of syngas include power generation, chemical production, hydrogen production, and byproducts like ash for construction materials. Further research is needed to develop carbon capture technologies and more efficient oxygen separation methods to enable cleaner coal gasification processes.
Biomass gasification converts biomass into a gaseous mixture through a partial oxidation process in a gasifier. The process involves upstream processing of the biomass feedstock, the gasification reaction in the gasifier reactor, and downstream processing of the produced gas. Key factors that affect the gasification include the biomass characteristics, moisture content, equivalence ratio, temperature, gasifying agent, and residence time. Common biomass gasification technologies are downdraft, updraft and fluidized bed gasifiers.
Biomass and Sludge Gasification for Syngas Synthesis and CHP - FinalJad Halawi
This document discusses a project to produce energy from municipal solid waste and wastewater treatment sludge in Lebanon via gasification and combined heat and power generation. It describes the gasification process which involves dehydration, pyrolysis and char gasification to produce syngas. A fluidized bed gasifier is selected for its suitability with Lebanon's high moisture waste. Syngas is purified using activated carbon adsorption to remove acidic gases before being used in a gas turbine to power a steam turbine for combined heat and power generation. Simulation results show the process can effectively recover energy from waste while addressing Lebanon's solid waste and energy crises.
PRODUCTION OF ALTERNATIVE FUEL USING GASIFICATION BY SYNTHESIS OF FISCHER-TRO...IAEME Publication
The solid carbonaceous fuel is converted into combustible gas (energy) using limited amount of air it is called Gasification process the gases which evolve are known as “producer gas”. This is more suitable than the direct combustion of biomass gases. In this paper an updraft gasifier is construct and is used to carry out the experiment. updraft gasifier is one of the boiler. The waste material like coconut shells, sugarcane waste, and wood particles are used for the generation of producer gas. The sense of this paper is to study the effect of waste products (coconut shells, sugarcane waste, and wood particles) in form of biomass. The performance of the gasifier is evaluated in terms of zone temperature with different air velocity. By taking the different fuels and varying the air flow rate the temperature of the zones are analysed. The arrangement of tar is also seen in this apparatus. After analysis the maximum temperature give for coconut shell (waste) all three place as compare to other two .so coconut shell is the best suitable material for this gasifier.
The document discusses a method for producing synthesis gas (syngas) from gasification of bagasse. Bagasse is a waste product from sugar production that is abundant in India. Syngas produced from bagasse gasification can be used as an alternative fuel source for power generation and other industrial processes. The method involves pyrolyzing bagasse in a free-fall reactor to produce char, and then gasifying the char in a packed bed reactor to produce syngas, which consists mainly of carbon monoxide and hydrogen. Experimental results show that syngas yield increases with higher temperature and smaller bagasse particle size during pyrolysis.
Syngas is a mixture of hydrogen and carbon monoxide produced through gasification processes. It can be used directly as fuel or to synthesize other fuels and chemicals. The main industrial processes for syngas production are steam reforming, autothermal reforming, and partial oxidation of hydrocarbons. Partial oxidation involves reacting hydrocarbons with oxygen without steam, producing syngas at lower costs but higher temperatures than steam reforming. Catalytic partial oxidation uses catalysts to control the reaction and reduce heat generation. Research continues to improve catalyst heat resistance and prevent coking while reducing costs of syngas production.
An improved modulation technique suitable for a three level flying capacitor ...IJECEIAES
This research paper introduces an innovative modulation technique for controlling a 3-level flying capacitor multilevel inverter (FCMLI), aiming to streamline the modulation process in contrast to conventional methods. The proposed
simplified modulation technique paves the way for more straightforward and
efficient control of multilevel inverters, enabling their widespread adoption and
integration into modern power electronic systems. Through the amalgamation of
sinusoidal pulse width modulation (SPWM) with a high-frequency square wave
pulse, this controlling technique attains energy equilibrium across the coupling
capacitor. The modulation scheme incorporates a simplified switching pattern
and a decreased count of voltage references, thereby simplifying the control
algorithm.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Rainfall intensity duration frequency curve statistical analysis and modeling...bijceesjournal
Using data from 41 years in Patna’ India’ the study’s goal is to analyze the trends of how often it rains on a weekly, seasonal, and annual basis (1981−2020). First, utilizing the intensity-duration-frequency (IDF) curve and the relationship by statistically analyzing rainfall’ the historical rainfall data set for Patna’ India’ during a 41 year period (1981−2020), was evaluated for its quality. Changes in the hydrologic cycle as a result of increased greenhouse gas emissions are expected to induce variations in the intensity, length, and frequency of precipitation events. One strategy to lessen vulnerability is to quantify probable changes and adapt to them. Techniques such as log-normal, normal, and Gumbel are used (EV-I). Distributions were created with durations of 1, 2, 3, 6, and 24 h and return times of 2, 5, 10, 25, and 100 years. There were also mathematical correlations discovered between rainfall and recurrence interval.
Findings: Based on findings, the Gumbel approach produced the highest intensity values, whereas the other approaches produced values that were close to each other. The data indicates that 461.9 mm of rain fell during the monsoon season’s 301st week. However, it was found that the 29th week had the greatest average rainfall, 92.6 mm. With 952.6 mm on average, the monsoon season saw the highest rainfall. Calculations revealed that the yearly rainfall averaged 1171.1 mm. Using Weibull’s method, the study was subsequently expanded to examine rainfall distribution at different recurrence intervals of 2, 5, 10, and 25 years. Rainfall and recurrence interval mathematical correlations were also developed. Further regression analysis revealed that short wave irrigation, wind direction, wind speed, pressure, relative humidity, and temperature all had a substantial influence on rainfall.
Originality and value: The results of the rainfall IDF curves can provide useful information to policymakers in making appropriate decisions in managing and minimizing floods in the study area.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Applications of artificial Intelligence in Mechanical Engineering.pdf
Gasification ieee4
1. Biomass gasification technology: The state of the art
overview
Marta Trninić
University of Belgrade, Faculty of Mechanical Engineering,
Department for Processing Engineering and Environmental
Protection
Belgrade, Serbia
mtrninic@mas.bg.ac.rs
Dragoslava Stojiljković
University of Belgrade, Faculty of Mechanical Engineering,
Department for Material Technology
Belgrade, Serbia
dstojiljkovic@mas.bg.ac.rs
Aleksandar Jovović
University of Belgrade, Faculty of Mechanical Engineering,
Department for Processing Engineering and Environmental
Protection
Belgrade, Serbia
ajovovic@mas.bg.ac.rs
Goran Jankes,
University of Belgrade, Faculty of Mechanical Engineering,
Innovation Center
Belgrade, Serbia
gjankes@mas.bg.ac.rs
Abstract— The reduction of imported forms of energy, and
the conservation of the limited supply of fossil fuels, depends up
on the utilization of all other available fuel energy sources.
Biomass is a renewable energy source and represents a valid
alternative to fossil fuels. The abundance of biomass ranks it as
the third energy resource after oil and coal. Moreover, when
compared to fossil fuels, biomass fuels possess negligible sulphur
concentrations, produce less ash, and generate far less emissions
in to the air. In other words, biomass can deliver significant
greenhouse gas reductions in electricity, heat and transport fuel
supply. The energy in biomass may be realized by different
thermochemical technologies of which gasification is most
promising alternative routes to convert biomass to power/heat
generation and production of transportation fuels and chemical
feedstock. This paper deals with the state of the art biomass
gasification technologies, evaluating advantages and dis-
advantages, the potential use of the syngas and the application of
the biomass gasification. Also, this paper provides short overview
of the current status of the biomass gasification in Serbia.
Keywords— biomass; gasification technology
I. INTRODUCTION
Ever increasing energy demand and the climate change
problem caused by anthropogenic greenhouse gas emissions
have resulted in the worldwide effort to find a sustainable and
environmentally friendly alternative to today`s fossil fuels
dominated energy supply. The potential offered by biomass for
solving some of the world's energy and environmental
problems is widely recognized as environmentally friendly and
renewable energy source. Biomass can meet different kinds of
energy needs, including fuelling vehicles, providing process
heat for industrial facilities, generating electricity and
providing heat for household heating. Through energy
thermochemical conversion, biomass can be used in three
different processes: gasification, pyrolysis, and direct
combustion. Gasification of biomass has proved itself a highly
efficient way to utilize biomass for a series of different
purposes in processes with one or several useful outputs that is
applicable on small or medium scale. The combination of
flexibility and efficiency in biomass conversion has attracted
increasing attention to the gasification technology platform in
recent years [2]. This article has the objective of surveying the
current applications of gasification technology.
II. THEPRINCIPLE OF BIOMASS GASIFICATION
Gasification is the conversion of biomass, or any solid fuel,
into gas as a prime product. Due to the process, it also results
in variable quantities of charcoal, pyroligneous acids, tars and
ash [3]. The gasification process is performed in the presence
of a gasifying agent (for example air, pure oxygen, or steam,
or mixtures of these components) at elevated temperatures
between 500 and 1400 °C and at atmospheric or elevated
pressures up to 33 bar [1, 2]. The produced gas is a fuel gas
mixture consisting primarily of carbon monoxide (CO),
hydrogen (H2), methane (CH4), small quantities of other light
hydrocarbons (CnHm), carbon dioxide (CO2), steam (H2O),
besides the nitrogen (N2) present in the air and supplied for the
reaction [1,3,4]. The gas produced may be classified as
product gas (producer gas) or biosyngas (syngas), depends on
the further gas application. In general, producer gas is formed
at temperatures less than 1000 o
C, and syngas is formed at
temperatures higher than 1200 o
C [5]. Syngas has a higher
content of CO and H2 than producer gas as it is used for the
synthesis of hydrocarbons. The producer gas can be converted
into syngas by thermal cracking or reforming (CO and H2
content is increased) [5]. The lowest heating value (LHV) of
the gas produced by biomass gasification ranges from 4 to 13
MJ/Nm3
depending on the feedstock, the gasification
technology and the operational conditions [6].
The principal reactions of the gasification are endothermic
and the necessary energy for their occurrences, generally,
generated by the oxidation of part of the biomass, through an
allothermal or an auto-thermal phase [6]. In the auto-thermal
process, the gasifier is internally heated through partial
combustion, while in the allothermal process the energy
required for the gasification is supplied externally [6].
Considering the autothermal system, gasification can be
generally seen as a sequence of several stages: drying
2. (endothermic stage), pyrolysis (endothermic stage), oxidation
(exothermic stage) and reduction (endothermic stage). An
additional step, consisting in ash cooling, can be also included
[7].
A. Gasification products
The gasification end products may be distinct in a solid
phase and gas phase (condensable and noncondensable). The
solid phase, ash, consists of the inert material formed of the
mineral matter present in the feedstock and the unreacted
carbon. The carbon in the ashes is in a very low percentage of
the total ash amount as the transformation of the carbon matrix
in gas being the objective of the overall process. The gas phase
is a gas mixture that contains the gases that are incondensable
at ambient temperature. If air is used in the oxidization step as
a gasifying carrier, then inert N2 is present in the gas phase.
Also, minor components such as NH3 and inorganic acid gases
(H2S and HCl) can be found in gas depending on the biomass
composition. According to Molino [6], depending on
gasification technology chosen and the operating variables, the
amount of syngas which can be produced from biomass may
range in 1–3 Nm3
/kg on a dry basis, with a LHV spanning over
4–15 MJ/Nm3
. The condensable phase, tar, is a complex
mixture of condensable hydrocarbons, which includes single
ring to 5 - ring aromatic compounds along with other oxygen-
containing hydrocarbons and complex high molecular weight
polynuclear aromatic hydrocarbons (PAH). The composition
depends on the biomass feedstock, the gasification technology
used and on the chosen operating parameters chosen. The
formation of tar is one of the biggest problems faced during the
gasification of biomass. Tar is undesirable because of various
problems associated with condensation, formation of tar
aerosols and polymerization to form more complex structures.
That can cause problems in the process equipment, primarily in
operation of engines and turbines used in application of the
producer gas.
B. Types of gasifiers
All the gasifiers fall into basically four primary gasifier
types: moving bed (downdraft and updraft), circulating and
fluidized bed, as shown in Figure 1. Each of these types is
defined according to on the contact of the biomass and the gas
phase in the gasifier. A summary of the gasifier types is
presented in Table I.
Fig. 1 The typical gasifier types [12]
TABLE I. SUMMARY OF SELECTED BIOMASS GASIFIER TYPES [12]
Gasifier
Type
Scale
Typical
temp.
(°C)
Fuel
moisture
content (%)
Gas
Characteristics
Downdraft
Fixed Bed
5 kWth -
2 MWth
800 -
1000
<20%
Very low tar,
Moderate
particulates,
charcoal at low
temperatures
Updraft <10 800 - up to 50%-
Very high tar
(10% to 20%),
Fixed Bed MWth 1000 55% Low particulates,
High methane
Bubbling
Fluidized
Bed
<25
MWth
850 <5 to 10%
Moderate tar,
Very high in
particulates
Reduced
charcoal,
Ash does not
melt,
Circulating
Fluidized
Bed
A few
MWth
up to
100
MWth
850 <5 to 10%
Low tar,
Very high in
particulates
Reduced
charcoal,
Ash does not melt
C. Gasification process parameters
The products of gasification process depend on the design
of the gasifier, the characteristics of the biomass and important
operating parameters (temperature, pressure, gasifying agent,
air to fuel ratio) and type of bed materials (presence or absence
of catalytically active substances).
1)Effect of the temperature - The temperature profile is the
most important aspect of operational control for gasification
processes. Temperature has an important effect on the
conversion, the product distribution, and the energy efficiency
of a gasifier. Higher temperature results in increased gas yield
because of higher conversion efficiency. Influence of
gasification temperature on product distribution is shown in
Fig 2.
Fig. 2 Typical gasification temperature for various feedstock and influence of
temperature change on some critical factors [20]
2)Effect of gasifying agent - As gasifying agents, air, steam,
carbon dioxide and pure oxygen are commonly being used the
selection of gasifying agent entirely depends on the
requirement of the product gas quality for different
downstream applications. Under steam gasification conditions,
a H2-rich gas (30–60 vol %) with a heating value of 10–16
MJ/m3
is produced [13]. Addition of external steam with air
increases the H2 concentration, because of the water gas shift
3. reaction. It contributes to balance CO and H2 ratio for Fischer
– Tropsch synthesis . Biomass gasification with pure oxygen
produces, produces a higher quality, nitrogen - free gas with a
LHV of 10 – 18 MJ/m3
[14]. Pure oxygen is suitable for
producing gases with high concentration of CO and H2 and
low concentration of tar; however, pure oxygen itself is an
expensive gasifying agent. When CO2 is set under non-
catalytic conditions, it acts mainly as a diluent of the producer
gas, but also slightly higher carbon conversion and lower tar
release. With increasing CO2 to biomass mass ratio, more
oxygen would be available for the exothermic oxidation
reactions, resulting in higher producer gas temperature, and
higher mole fractions of CO in the producer gas, but lower
mole fractions of H2 and CO2. The influence of gasification
medium on characteristics of gas and tar production is shown
in Table II.
TABLE II. EFFECT OF GASIFICATION MEDIUM ON CHARACTERISTICS OF
GAS AND TAR PRODUCTION [8]
Medium Operating condition
Tar Yield
(g/Nm3
)
LHV
(MJ/Nm3
dry)
Steam
Steam to biomass ratio–
0.9
30-80 12.7 – 13.3
steam/oxygen Steam to oxygen ratio-3 4-30 15.5 – 13
Air ER=0.3 2-20 4.5 – 6.5
3)Effect of equivalence ratio - According to Güell et al.
[14] the optimal equivalence ratio (or excess air ratio) applied
in biomass air gasification is in the range 0.2–0.45. Lower
values than 0.2 led to a decrease of the gasification
temperature and therefore higher amounts of tar, whereas
higher values than 0.45 resulted in a decrease in the heating
value and the energy content of the produced gas [14]. Also, at
temperatures between 750 o
C and 850 o
C, an increase in
equivalence ratio from 0.2 to 0.45 resulted in higher gas
yields, lower amounts of tar and lower heating value of the gas
[14]. An equivalence ratio of 0.25 - 0.3 was proposed as the
optimal value to obtain a good gas quality [7].
4)Effect of the pressure - Depending on the downstream
application of the product gas, gasification of biomass is often
conducted under atmospheric and high pressures. Performing
biomass gasification in pressurized reactors has two main
advantages. First, the size of the gasifier can be reduced to a
large extent [14]. Second, gas compression steps can be
avoided in the production of biofuels, as most of the processes
namely Fischer – Tropsch synthesis depending on the pressure
applied methanol and dimethylether synthesis are carried out
at high pressures [14]. In addition, an increase in the gasifier
pressure reduces the tar yield in the product gas. As pressure
increases, H2, CO2, and CH4 yield increased (enhancing the
water-gas shift reaction), whereas the CO yield decreased
[14]. The evolution of H2, CO, and CO2 with pressure was
attributed to an increase of the apparent experimental water-
gas shift constant. It is due to an acceleration of the reaction
kinetics with pressure and an enhanced catalytic effect of the
charcoal, which increased its hold-up rate in the bed with
increasing pressure, on the reaction [14]. However, some
investigations conducted in the fluidized bed gasifier have
shown that the concentration of tar, mainly naphthalene,
increased with increasing gasifier pressure from 0.1 to 0.5
MPa, and thus the concentration of CO decreased, while CH4
and CO2 increased]. The disadvantage of high pressure
gasification is the expensive technology.
5)Effect of residence time - According to Kinoshita et al.
[15] residence time has little influence on the tar yield, but it
significantly influences the tar composition. Amounts of O2 -
containing compounds tend to decrease with increasing
residence time. Also, yields of 1- and 2-ring compounds
(except benzene and naphthalene) decrease whereas that of 3-
and 4-ring compounds increases in the total tar fraction [8,
11].
6)Effect of the catalysts - Catalysts used in gasification
processes can be categorized into natural catalysts and
synthetic catalysts. Among natural catalysts, dolomite and
olivine are the most widely investigated catalysts [7].
Dolomite has attracted much attention as it is inexpensive and
it reduces the tar content effectively. However, it undergoes
attrition relatively easy, resulting in a loss of catalyst activity.
Ekstrom et al. [16] have achieved almost 100% conversion of
tar at 700–800 °C using Malaga dolomite under steam
reforming conditions. However, they also observed a marked
increase in CH4 and C2H4 at lower temperatures and showed
that calcinad dolomite was 10 times more active than the
uncalcined material. Olivine, in contrast, is reported to be less
active in tar removal but more attrition-resistant than dolomite
thus, being more suitable for fluidized bed biomass
gasification. Devi et al. [17] reported that pre-treatment of
olivine at high temperatures could improve the catalytic
performance as bed material. This increased activity was
explained by the increased iron concentration at the surface of
the catalyst. The presence of dolomite and olivine increased
the production of gas by more than 50 %, resulting in a 20 -
fold reduction in tar content and over 30% reduction in
charcoal. In terms of gas composition, H2, CO, and CO2
increased, related to the decrease in tar and charcoal [23]. On
the other hand, the concentration of CH4 in the gas mixture
remained rather constant, indicating that none of the catalyst is
active for CH4 conversion. Alkali metal catalysts are premixed
with biomass before they are fed into the gasifier [8]. Unlike
dolomite, alkali catalysts can reduce methane in the product
gas, but it is difficult to recover them after use. Many
commercial nickel catalysts are available in the market for
reduction of tar as well as CH4 and NH3 in the product gas [8].
Catalyst activity is influenced by temperature, space time,
particle size, and composition of the gas atmosphere. Wang
and his coworkers [18] reported 95% conversion of NH3 along
with 89% conversion of light hydrocarbons, which they
defined as C2H6, C6H6; C7H8 and C9H8. Use of dolomite or
alkali as the primary catalyst and nickel as the secondary
catalyst has been successfully demonstrated for tar and
4. methane reduction [8]. Steam-reforming nickel catalysts for
heavy hydrocarbons are effective for reduction of tar while
nickel catalysts for light hydrocarbons are effective for
methane reduction [8]. Charcoal, a carbonaceous product of
pyrolysis, also catalyzes tar reforming when used in the
secondary reactor [8]. Chembukulam et al [19] obtained a
nearly total reduction in tar with this.
7) Effect of biomass particle size and shape - The size and
shape of the biomass particles are important to determining the
diffuculty of handeling and transport the biomass, as well as
the behavior of the biomass once it is in the gasifier. Gasifiers
friquently have problems with bridging and channeling of the
biomass. The size and size distribution of the biomass
determine the thickness of the gasification zone, the pressure
drop through the bed, and the minimum and maximum heart
load for satisfactory operation. Smaller particle sizes
contributed to higher total gas yields, higher H2
concentrations, and lower charcoal and tar yields , but also
cause problems of bridging and channeling and bigger
pressure drop. Larger feedstock particle size increase the
temperature gradient inside the particle, so that at a given time
the core of the particle has lower temperature compared to the
particle surface, which resulted to the increase of the charcoal
and liquids yields and decrease in gase. Smaller particles can
obtain faster heating rate due to larger surface area. High
heating rates produce more light gases and less charcoal and
condensate [22].
III. BIOMASS GASIFICATION PROCESS CHALLENGES
Gasification is considered as one of the most attractive
options to convert biomass into mechanical energy and
electricity or to produce high quality synthetic liquid and
gaseous fuels. However, the biomass gasification process
requires optimization to minimize the energy efficiency loss
stemming from a few main problems: biomass must be dried
before conversion; expensive equipment is required to clean
the produced gas from contaminants, then further prevent
pollution during combustion; despite special equipment and
treatments, tar remains a part of the synthesis gas [5].
A. Ash agglomeration mechanism and its reduction
Ash related problems including sintering, agglomeration,
deposition, erosion and corrosion are the main obstacles to
economical and viable applications of biomass gasification
technologies. In general, potassium plays an important role in
forming of the ash melts during the thermochemical processes
of biomass. Potassium will react with Cl, S, Si and P through
different reaction paths. Partial products from these reactions
have low melting temperatures (even lower than 700 o
C); these
are potassium salts, silicates, phosphates and mixtures of them.
These potassium containing compounds or eutectics will be
present as molten phases, leading to adhesion/aggregating of
charcoal and ash grains and further ash sintering to large and
heavy blocks. The alkali silicates and sulfates tend to deposit
on the reactor walls and leave a sticky deposit on the surface of
the bed particles, causing bed sintering and defluidization].
Furthermore, the presence of ash such as alkali in syngas can
cause problems of deposition, corrosion and erosion for
equipment that utilizes syngas (gas engines and turbines).
Methods which can be used for reduction of the ash-related
problems are: leaching, fractionation and use of additives (e.g.,
kaolin and calcite).
B. Tar
The presence of tars in the produced gas may be considered
as the weakest point of biomass gasification affecting the final
use of the produced gas itself: energy production and/or
chemical utilization. Tars removal or their conversion is the
great technical challenge to overcome and develop a successful
application of biomass-derived gas. Several approaches are
available for tar reduction and they can be categorized in two
types depending on the location where tar is removed; either in
the gasifier itself (known as primary method) or outside the
gasifier (known as secondary method) [8]. Primary methods
include: the proper selection of the specific operational
parameters, the use of a proper bed additives or a catalyst
during gasification, and a proper gasifer design/modification of
the gasifier [3]. Another way to realize increased tar conversion
is to create areas of high temperatures in the product gas
usually by adding a post gasification section or in a secondary
gasification reactor put in series with the primary gasifier.
Secondary methods can be chemical or physical treatment as:
tar cracking downstream the gasifier (either thermally or
catalytically), mechanical methods (use of cyclone, baffle,
ceramic filter, fabric filter, rotating particle separator,
electrostatic filter, scrubber and alkali remover).
C. Biomass moisture
The water content in biomass absorbs a considerable
amount of sensible heat for evaporation and heating up inside
the gasifier and this way it adversely affects the gasification
efficiency, more biomass has to be fully combusted to provide
the required heat. Moreover, the maximum temperature inside
the gasifier is reduced, which affects tar and charcoal
conversion negatively. On the other hand, a small amount of
moisture in the biomass is favorable for satisfactory gasifier
performance as water is used in the gasification and (steam)
cracking reactions. The moisture content limits for gasifier
feedstock depend on the type of gasifier used. The highest
moisture content for a downdraft gasifier is generally
considered to be 25 % wet basis and not higher than 50 % for
an updraft gasifier [3]. Predrying of the biomass to <25 wt %
moisture (w.b.) is therefore required.
D. Secondary equipment
The greatest challenge for biomass gasification for energy
production may be the costliness of secondary, or auxiliary,
equipment needed make gas clean and relatively contaminants
free [3]. Auxiliary systems are operations supplemental to the
basic process of gasification and generally are placed into one
of two categories: preparation of the fuel and its introduction in
the gasifier, or cleaning of the produced gas [3]. The need for
cleaning syngas depends on the intended use of the gas, being
particularly important in cases when gas will be used to
synthesize liquid fuel. Typical equipment for dry gas cleaning
are cyclones, baffle filter, bag filter, ceramic filter, candle filter,
5. and separators. Wet gas cleaning use scrubbers, spray towers
and wet electrostatic precipitators [3]. This greatly drives up
the cost of the entire process, accounting for more than half of
the final price of produced biofuel [3].
IV. APPLICATIONS OF BIOMASS GASIFICATION PRODUCTS
The gaseous products can be combusted to generate heat or
electricity, or they can be used in the synthesis of liquid
transportation fuels, H2, or chemicals [4]. On the other hand,
the tar can be used as fuel in boilers, gas turbines or diesel
engines, both for heat or electric power generation [4].
Furthermore, the composition of the gasification gas is very
dependent on the type of gasification process, gasifying agent
and the gasification temperature. Based on the general
composition and the typical applications, two main types of
gasification gas can be distinguished, i.e. syngas and product
gas.
A. Utilisation of product gas
The main application of product gas from gasification is
found in direct or indirect combustion to generate power with
co-production of heat.
1)Co-combustion – The primary products obtained by the
thermochemical conversion of biomass may be added to
conventional fuels (coal, heavy oil or biomass) in power plants
for co-combustion processes. According to Boerrigter and
Rauch [20] the most straightforward application of product
gas is co-firing in existing coal power plants by injecting the
product gas in the combustion zone of the coal boiler. Co-
firing percentages up to 10% (on energy basis) are feasible
without the need for substantial modifications of the coal
boiler [20]. The overall electrical efficiency of these plants is
about 35% [47]. Critical issue in co-firing is the impact of the
biomass ash on the quality of the boiler fly and bottom ash .
Examples of biomass co-firing plants are the AMER 85 MWth
circulating fluidised bed (CFB) gasifier in the Essent power
plant in Geertruidenberg (the Netherlands) and the Foster
Wheeler CFB gasifiers in Lahti (Finland) and Ruien
(Electrabel power plant, Belgium) [45].
2)Combined heat and power (CHP) - Biomass gasification
is one of the most suitable processes for combined heat and
power (CHP) production, being a direct route to utilizeenergy
from renewable resources efficiently. The product gas in CHP
plants the product gas is fired on a gas engine [4, 20].
Modified gas engines can run without problems on most
product gases even those from air-blown gasification that have
calorific values of approximately 5 - 6 MJ/Nm3
[20].
Typically, the energetic output is one-third electricity and two-
third heat [20]. The main technical challenge in the
implementation of integrated biomass gasification CHP plants
has been, and still is, the removal of tar from the product gas.
The use of biomass for district heating and CHP has been
expanding rapidly in countries such as Austria and Germany,
e.g. the plants in Güssing (Austria) and Harboøre (Denmark).
They have in common that they result from long development
trajectories and that the technologies are neither simple nor
cheap [20]. In Finland, biomass-based fuels are used nearly
completely in heat and CHP production. The number of large
scale CHP plants in Finland is nearly 100MW and the total
capacity is over 1500 MW [4]. The Alholmens Kraft CHP
plant in Pietarsaari, Finland, is the largest biofuelled power
plant in the world [4].
3)Biomass Integrated gasification combined cycle (BIGCC)
– this technology holds the promise of efficient, clean and
cost-effective power generation from biomass. A typical
biomass integrated gasification combined cycle (BIGCC)
involves combustion of the hot gas from a gasifier in a gas
turbine to generate electricity in a topping cycle. As a gas
turbine requires a pressurised feed gas the biomass
gasification should be carried out at the pressure of the turbine
(typically 5-20 bar) or the atmospherically generated gas must
be pressurised [20]. The first route is preferred as in that case
only dedusting of the gas and cooling to the turbine inlet
temperature (400-500 °C) is required, whereas in the
alternative route the gas must be completely cleaned and
cooled down to allow compression [20]. Miccio [21] reported
that the overall efficiency of the BIGCC system was 83 % and
the electrical efficiency was 33 %. However, this technology
is not yet commercially available, there are experiments with
gasification for use in high efficiency combined-cycle power
plants, which are in the demonstration phase [4]. Several
projects have been initiated for IGCC applications over the
last decade, however, only two have been implemented, the
SYDKRAFT plant at Värnamo (Finland) and the ARBRE
plant at South of Selby, (North Yorkshre, UK). In general the
operational costs related to the inert gas consumption and
electricity consumption for pressurisation of the inert gas for
solids feeding and the gasification air are a major drawback
for pressurised gasification [20].
4)Biomass gasification fuel cell (BGFC) systems -
electrochemical systems for electricity production via
chemical energy conversion [6]. FC have the advantage of
providing clean, near zero emission conversion of reformed
fuels to electricity, with high conversion efficiency in
relatively small units. In theory, fuel cells have the potential to
achieve higher electrical efficiencies (greater than 40% [6])
compared to simple combustion systems and gas engines. A
fuel cell (such as solid oxide fuel cells (SOFC) and molten
carbonate fuel cells (MCFC)) uses H2 and O2 to produce
electricity and the by-product of heat in the presence of an
electrically conductive electrolyte material. However, the
application of gas in fuel cells for the production of electricity
is still in its early development [20].
5)Synthetic Natural Gas (SNG) - Synthetic Natural Gas
(SNG) is a gas with similar properties as natural gas but
produced by synthesis of methan from H2 and CO from
gasification product gas. Methanation is the catalytic (nickel-
based catalyst) reaction of carbon monoxide and/or carbon
dioxide with hydrogen, forming methane and water. The
methanation reactions of both carbon monoxide and carbon
dioxide are highly exothermic. Such high heat releases
6. strongly affect the process design of the methanation plant
since it is necessary to prevent excessively high temperatures
in order to avoid catalyst deactivation and carbon deposition
[20]. The highly exothermic reaction generally creates a
problem for the design of methane synthesis plants: either the
temperature increase must be limited by recycling of reacted
gas or steam dilution, or special techniques such as isothermal
reactors or fluidised beds, each with indirect cooling by
evaporating water, must be used [20].
B. Utilisation of syngas
1)Transportation fuels production via biomass gasification -
Use of biomass based syngas for liquid fuel generation –
biomass to liquid (BTL), can help lower the economic and
environmental problems caused by the natural gas or coal.
Biomass to liquid (BTL) is suggested to be a positive route to
reducing the inclination towards fossil transportation fuels and
is also a key to keeping the environment clean. For 20% of the
total liquid fuels produced from carbon neutral sources, like
biomass, 15% CO2 emissions reduction could be achieved –
just by fuel replacement. As of now, there are no commercial
scale BTL plants, like those installed for coal to liquid (CTL)
or gas to liquid (GTL) plants. Most of the documented BTL
plants are either on demonstration scale or experimental scale.
2)Synthesis of Fischer–Tropsch fuels - The production of
liquid fuels from syngas has a long history, which goes back
to the pioneering work of Fisher and Tropsch to synthesize
hydrocarbon fuels in Germany in the 1920s. The Fischer-
Tropsch synthesis (FTS) is a process by which gasoline, diesel
oil, wax, and alcohols are produced from CO and H2 gas
mixture [4]. Typical operation conditions for FTS are
temperatures of 200 - 350 °C and pressures between 25 and 60
bar [20]. In the exothermic FTS reaction about 20% of the
chemical energy is released as heat [20]. Several types of
catalysts can be used for the FTS, the most important are
based on iron (Fe) or cobalt (Co). Co catalysts have the
advantage of a higher conversion rate and a longer life (over
five years). The Co catalysts are in general more reactive for
hydrogenation and produce therefore less unsaturated
hydrocarbons (olefins) and alcohols compared to iron catalysts
. Iron catalysts have a higher tolerance for sulphur and
produce more olefin products and alcohols. One of FTS
technical issues is the reduction of inert gases, such as CO2
and contaminants, such as H2S, because the inert gases and
contaminants can lower catalyst activity due to catalyst
poisoning [36].
3)Synthesis of methanol and dimethyl ether from syngas -
Methanol and dimethyl ether (DME) are promising clean
liquid fuels because they are storable and would be
alternatives to gasoline and diesel fuels. Methanol can be
produced by means of the catalytic reaction of CO and some
CO2 with H2 [20]. These reactions are exothermic and proceed
with volume contraction; and a low temperature and high
pressure consequently favours them [20]. Side reactions, also
strongly exothermic, can lead to formation of by-products
such as methane, higher alcohols, or dimethyl ether (DME)
[20]. Methanol is currently produced on an industrial scale
exclusively by catalytic conversion of synthesis gas [20].
Processes are classified according to the pressure used: high-
pressure process (250-300 bar) with uses of zinc-chromium
oxide catalysts, medium-pressure process (100-250 bar) with
uses of copper-zinc-chromium catalyst and low-pressure
process (50–100 bar) [20]. The low-pressure processes are
dominant currently and their main advantages are lower
investment and production costs, improved operational
reliability, and greater flexibility in the choice of plant size
20]. DME can be obtained from methanol via catalytic
dehydration using catalysts based on silica-alumina or using
bifunctional catalysts such as copper-ZSM-5 zeolite and
hybrid copper-allumina based catalysts [6].
4)Ethanol production - According to Xu et al. [522] three
major research areas using lignocellulosic biomass for biofuels
are: enzymatic hydrolysis of cellulose followed by sugar
fermentation, gasification followed by raw syngas
fermentation and gasification followed by Fisher Tropsch
catalysis. Biosyngas fermentation is a microbial process where
syngas is used as carbon and energy source by certain
anaerobic microorganisms (act as biocatalysts) and then
converted into fuels or chemicals (acetic acid, ethanol, 2,3
butanediol, butyric acid, and butanol) [6]. A fermentation
process using a biocatalyst has several advantages in
converting syngas into chemicals and fuels compared with a
thermochemical route (FTS). Griffin and Schultz [23] pointed
out that a biosyngas fermentation route profits from low
temperature, low pressure, the tolerance of a biocatalyst to
several impurities in syngas, and the ability to use flexible
syngas compositions. Thus, the need for an extensive gas
clean up was eliminated. However, relatively low rates of
growth and production by anaerobes, difficulties in
maintaining anaerobic conditions and mass transfer between
gas phase (especially CO and H2) and liquid phase, and
product inhibition have been identified as the main barriers to
commercializing syngas fermentation technology.
5)Synthetic Natural Gas (SNG) - can also be produced from
syngas, however, in that case the biomass to SNG yield is
significantly lower, as no advantage is taken from already
present amounts of methane [20].
6)Chemical synthesis - Syngas is one of the main sources
for hydrogen used in refineries. Biomass gasification followed
by water reforming of CH4 to H2 and CO, water–gas shift
reaction of CO to H2 and CO2 with catalysts such as copper–
zinc, and CO2 adsorption using an adsorbent such as CaO can
produce pure H2. In refineries, hydrogen is used for the hydro-
treating and hydro-processing operations.
V. STATUS OF THE EUROPEAN BIOMASS GASIFICATION
PLANTS
In the last decades, the presence of the gasification process
in the European market has increased. According to IEA
Bioenergy, in Europe there are 77 gasification plants [24] from
7. which 49 are power generation or combined heat and power
generation plants, 15 are co-combustion plants and 13 plants
are dedicated to the production of chemicals.
VI. STATUS OF THE SERBIAN BIOMASS GASIFICATION
PLANTS
In Serbia, several experimental small scale laboratory
gasifiers were designed and tested with different kind of
gasification processes using biomass and waste material at the
Department for Process Engineering of the Faculty of
Mechanical Engineering, University of Belgrade in the
seventies and eighties. Low energy prices and the lack of the
support for R&D work were the reasons for no commercial
application and interest. The importance of the use of biomass
as an energy source was recognized by the study supported by
NPEE and completed in 2007 (NPEE ev.no. 273 020) has
determined that it was economically feasible to build
approximately 400-500 MWe of CHP pants with solid biomass
as a fuel in units of 500 kW to several MW in Serbia. Also,
according to the National Renewable Energy Action Plan
(NREAP) established by Ministry of Energy, Development and
Environmental Protection of the Republic of Serbia in 2013,
until 2020, it is planned to build biomass CHP plants with total
power of 100 MW (640 GWh of electricity and 49 ktoe of
heat). The future investments for these capacities were
estimated to be in total 1 billion EUR. If the development of
domestic equipment would be supported, nearly 70% of this
amount could be covered by equipment and engineering from
domestic companies (it was assumed that it is not economically
reasonable to finance domestic development of gas engines, or
turbines which takes about 30% of plant investments). This
made a good basis for R&D projects in this field. The Faculty
of Mechanical Engineering, University of Belgrade proposed in
2011. Project “Development of CHP demonstration plant with
Biomass Gasification” started with support of the Ministry of
Science and Technological Development of the Republic of
Serbia in 2011. This Project is a continuation of the previous
project “Technologies for using biomass for combined heat and
power generation” (ЕЕ 18026). The aims of project are: a) to
build a demonstration CHP plant with biomass gasification, b)
optimize the gasification processes in terms of maximum
utilization of energy from biomass, c) to determine conditions
for gas engine to gasification coupling. The gas cleaning and
heat recuperation will be tasted, and necessarily testing will be
done in order to determine pollutants emissions of the plant,
and if it is necessarily, segments of equipment will be
improved. The new project will determine possible ways of
development of the future commercial plant. The CHP Facility
with Biomass Gasification is based on down-draft fixed bed
gasifier with use of corn cob (HHV app. 18.6 MJ/kg d. b.) and
with thermal output of 0.5 MWth, PBH regenerative heat
exchanger (for gas cleaning), and gas engine. The location of
the plant is planned to be nearby Belgrade. The available
amount of biomass of the Company (corn cobs) is app. 1000
t/year. Produced gas in demonstration phase will be used as
additional fuel for the existing hot water boilers of the
company, or alternatively, after cooling and dust separation, for
electricity production. The expected electrical power is 150-
180 kW. After introducing Feed-in tariff in Serbia in 2009,
production of electricity with biomass as a fuel became
commercially interesting. The analysis of the efficiency of
investments in development and operation of demonstration
CHP plant was based on “Feed-in” tariff of 13.26 EURc/ kWh
(for electricity produced in biomass CHP plant less than 1
MW) and price of LNG which can be replaced by heat from the
CHP. The Simple pay-back period of 5-6 years is expected.
VII. CONCLUSION
Biomass gasification can be considered as one of the
competitive ways of converting biomass to fuel gas for
combined heat and power generation, fuel cell and synthetic
fuel production. This review leads to the following
conclusions: 1) The parameters with the greatest impact on
the gasification process are the gasification reaction
temperature and the equivalent ratio. The control of these
parameters ensures that a syngas with an acceptable content
of tars and particles is produced and that ash sintering effects
caused by high temperatures in the reactor not appears. 2)
Biomass moisture content is an operating parameter that
reduces gasification efficiency, as part of the energy is used
for drying the biomass. Moisture contents above 15% can
lead to unstable process and reduction of the produced gas
calorific value. 3) The presence of tars in the produced gas is
one of the main technology barriers to the development of
gasification. Several approaches available for tar reduction
can be categorized in two types depending on the location
where tar is removed; either in the gasifier itself (known as
primary method and include gasifier design, optimal settings
of the operating parameters and use of catalysts) or outside
the gasifier (known as secondary method). Once the gas has
been obtained, it is difficult and costly to ensure that it meets
the optimal conditions required for the energy of fuel
production.
At the Department for Process Engineering of the
Faculty of Mechanical Engineering, University of Belgrade,
several experimental laboratory gasifiers have been designed
and tested with different kinds of gasification processes
using downdraft gasifier design biomass and waste material.
According to results of biomass and waste gasification
experiments carried out several years ago at laboratory scale
reactors at the Department, but also according to results of
many projects recently presented in literature, the concept of
downdraft demonstration unit has been developed and the
downdraft gasification unit of thermal power 0.5-07 MW is
designed. After demonstration phase, it is expected that the
plant will be commercialized and used for heat production or
combined heat and electricity production in small-scale
plants. Biomass gasification is important because of the
amount of available biomass in Serbia and because it offers
the possibility of increasing the share of renewable energy
sources in energy balance of Serbia.
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