The document presents a numerical investigation of exhaust gas emissions from a dual fuel engine configuration using hydrogen and compressed natural gas (CNG). A simulation program was developed using MATLAB to calculate mole fractions of various exhaust species like NOx, CO, and CO2 based on input parameters like hydrogen fraction, equivalence ratio, combustion temperature and pressure. Simulations were conducted to analyze the effects of these parameters on emissions. Results showed that CO emissions increased with equivalence ratio and temperature due to incomplete combustion. CO2 emissions decreased with increasing hydrogen fraction and temperature due to dissociation.
The document presents an experimental study on the effects of substituting Compressed Natural Gas (CNG) for diesel fuel in a compression ignition engine. Experiments were conducted at different CNG substitution levels of 2.5 LPM, 7.5 LPM, and 12.5 LPM and compression ratios of 16.5, 17.5, and 18.5. Performance parameters like brake thermal efficiency, brake specific fuel consumption, volumetric efficiency, and brake specific energy consumption were calculated. The results showed that as CNG substitution increased, performance parameters like brake thermal efficiency and volumetric efficiency decreased while brake specific fuel consumption and brake specific energy consumption increased. The highest performance was achieved at a compression ratio of 17.5. Ex
The document discusses the effects of adding HHO gas produced through water electrolysis on the performance of a single cylinder, four stroke spark ignition engine. Three key findings are presented:
1) The addition of 2.57-2.74% HHO gas to the intake air decreased fuel consumption by 1.95-3.58% compared to petrol alone, with greater decreases at higher compression ratios and higher percentages of HHO gas.
2) Brake thermal efficiency increased by 0.34-0.74% with the addition of HHO gas at compression ratios of 7-9, indicating improved engine performance.
3) Mechanical efficiency increased with both higher compression ratios and higher percentages of added H
Browning_Daimler Research Thesis_Summer 2015Eric Browning
This thesis examines the effects of hydrocarbon mixtures and exhaust gas recirculation (EGR) on laminar flame speeds through one-dimensional reaction kinetic simulations. The simulations calculated laminar flame speeds for mixtures of methane with ethane and propane, as well as for Daimler fuels and natural gas with varying levels of EGR. It was found that adding larger hydrocarbons like ethane and propane increased flame speeds, while EGR decreased flame speeds. The research aims to determine an optimal combination of mixture and EGR level to reduce emissions most efficiently.
Greenhouse Gas Emissions From Land Applied Swine Manure: Development of Metho...LPE Learning Center
For more: http://www.extension.org/67579 A new method was used at the Ag 450 Farm Iowa State University (41.98N, 93.65W) from October 24, 2012 through December 14, 2012 to assess GHG emission from land-applied swine manure on crop land. Gas samples were collected daily from four static flux chambers. Gas method detection limits were 1.99 ppm, 170 ppb, and 20.7 ppb for CO2, CH4 and N2O, respectively. Measured gas concentrations were used to estimate flux using four different models, i.e., (1) linear regression, (2) non-linear regression, (3) non-equilibrium, and (4) revised Hutchinson & Mosier (HMR). Sixteen days of baseline measurements (before manure application) were followed by manure application with deep injection (at 41.2 m3/ha), and thirty seven days of measurements after manure application.
The problem of power system optimization has become a deciding factor in electrical power system engineering practice with emphasis on cost and emission reduction. The economic emission dispatch (EED) problem has been addressed in this paper using a Biogeography-based optimization (BBO). The BBO is inspired by geographical distribution of species within islands. This optimization algorithm works on the basis of two concepts-migration and mutation. In this paper a non-uniform mutation operator has been employed. The proposed technique shows better diversified search process and hence finds solutions more accurately with high convergence rate. The BBO with new mutation operator is tested on ten unit system. The comparison which is based on efficiency, reliability and accuracy shows that proposed mutation operator is competitive to the present one.
Optimization of performance and emission characteristics of dual flow diesel ...eSAT Journals
Abstract
Depleting sources of fossil fuels coupled with after effects of exhaust gases on environment i.e. global warming and climate change has necessitated the need for development and use of alternate biodegradable fuels. In this present study optimization of performance and emission characteristics has been carried out using dual flow of CNG and Diesel with varying EGR under varying load by Taguchi method. Optimum values of output response parameters have been calculated with the help of regression equation and influence of various factors on output response has carried out with the help of analysis of variance.
Keywords: Taguchi method, CNG, EGR, biodegradable fuels
Numerical analysis of confined laminar diffusion flame effects of chemical ...IAEME Publication
The document summarizes a numerical analysis of a confined laminar diffusion flame using two chemical kinetic mechanisms - a 1-step global reaction mechanism and a 4-step mechanism. The flame structure is modeled using conservation equations for mass, momentum, species, and energy. The equations are solved using the finite volume method in Fluent. Results from the 4-step mechanism are compared to previous numerical studies and experimental data, showing very good agreement. The implementation of the 4-step mechanism into Fluent via a user-defined function is also described.
Absorber Models for absorption of Carbon dioxide from sour natural gas byMeth...IJERA Editor
Mathematical models of the absorber for the absorption of carbon dioxide (CO2)from sour natural gas in Methyl-diethanol Amine (MDEA)solution were developed. The resulting ordinary differential model equations were solved numerically using theode45 solver of MATLAB 7.5. The accuracy of the models was ascertained using industrial plant data from the carbon dioxide absorber of the Obiafu/Obrikom Gas Treatment plant in Rivers State, Nigeria. The models predicted the CO2 concentration in the sweet gas, gas and solvent (MDEA) temperature progressions along the packed absorber. The results obtained from solutions to the models compared favorably with the plant outputs with a maximum deviation between models predictions and industrial plant outputs of 0.44%. The models were used to simulate the influence of sour gas flow rates and solvent (MDEA) concentration in solution on the performance (absorption rates of CO2) of the absorber.The results show that the absorption rate of CO2 increases with increasing gas flow rate and solvent concentration.
The document presents an experimental study on the effects of substituting Compressed Natural Gas (CNG) for diesel fuel in a compression ignition engine. Experiments were conducted at different CNG substitution levels of 2.5 LPM, 7.5 LPM, and 12.5 LPM and compression ratios of 16.5, 17.5, and 18.5. Performance parameters like brake thermal efficiency, brake specific fuel consumption, volumetric efficiency, and brake specific energy consumption were calculated. The results showed that as CNG substitution increased, performance parameters like brake thermal efficiency and volumetric efficiency decreased while brake specific fuel consumption and brake specific energy consumption increased. The highest performance was achieved at a compression ratio of 17.5. Ex
The document discusses the effects of adding HHO gas produced through water electrolysis on the performance of a single cylinder, four stroke spark ignition engine. Three key findings are presented:
1) The addition of 2.57-2.74% HHO gas to the intake air decreased fuel consumption by 1.95-3.58% compared to petrol alone, with greater decreases at higher compression ratios and higher percentages of HHO gas.
2) Brake thermal efficiency increased by 0.34-0.74% with the addition of HHO gas at compression ratios of 7-9, indicating improved engine performance.
3) Mechanical efficiency increased with both higher compression ratios and higher percentages of added H
Browning_Daimler Research Thesis_Summer 2015Eric Browning
This thesis examines the effects of hydrocarbon mixtures and exhaust gas recirculation (EGR) on laminar flame speeds through one-dimensional reaction kinetic simulations. The simulations calculated laminar flame speeds for mixtures of methane with ethane and propane, as well as for Daimler fuels and natural gas with varying levels of EGR. It was found that adding larger hydrocarbons like ethane and propane increased flame speeds, while EGR decreased flame speeds. The research aims to determine an optimal combination of mixture and EGR level to reduce emissions most efficiently.
Greenhouse Gas Emissions From Land Applied Swine Manure: Development of Metho...LPE Learning Center
For more: http://www.extension.org/67579 A new method was used at the Ag 450 Farm Iowa State University (41.98N, 93.65W) from October 24, 2012 through December 14, 2012 to assess GHG emission from land-applied swine manure on crop land. Gas samples were collected daily from four static flux chambers. Gas method detection limits were 1.99 ppm, 170 ppb, and 20.7 ppb for CO2, CH4 and N2O, respectively. Measured gas concentrations were used to estimate flux using four different models, i.e., (1) linear regression, (2) non-linear regression, (3) non-equilibrium, and (4) revised Hutchinson & Mosier (HMR). Sixteen days of baseline measurements (before manure application) were followed by manure application with deep injection (at 41.2 m3/ha), and thirty seven days of measurements after manure application.
The problem of power system optimization has become a deciding factor in electrical power system engineering practice with emphasis on cost and emission reduction. The economic emission dispatch (EED) problem has been addressed in this paper using a Biogeography-based optimization (BBO). The BBO is inspired by geographical distribution of species within islands. This optimization algorithm works on the basis of two concepts-migration and mutation. In this paper a non-uniform mutation operator has been employed. The proposed technique shows better diversified search process and hence finds solutions more accurately with high convergence rate. The BBO with new mutation operator is tested on ten unit system. The comparison which is based on efficiency, reliability and accuracy shows that proposed mutation operator is competitive to the present one.
Optimization of performance and emission characteristics of dual flow diesel ...eSAT Journals
Abstract
Depleting sources of fossil fuels coupled with after effects of exhaust gases on environment i.e. global warming and climate change has necessitated the need for development and use of alternate biodegradable fuels. In this present study optimization of performance and emission characteristics has been carried out using dual flow of CNG and Diesel with varying EGR under varying load by Taguchi method. Optimum values of output response parameters have been calculated with the help of regression equation and influence of various factors on output response has carried out with the help of analysis of variance.
Keywords: Taguchi method, CNG, EGR, biodegradable fuels
Numerical analysis of confined laminar diffusion flame effects of chemical ...IAEME Publication
The document summarizes a numerical analysis of a confined laminar diffusion flame using two chemical kinetic mechanisms - a 1-step global reaction mechanism and a 4-step mechanism. The flame structure is modeled using conservation equations for mass, momentum, species, and energy. The equations are solved using the finite volume method in Fluent. Results from the 4-step mechanism are compared to previous numerical studies and experimental data, showing very good agreement. The implementation of the 4-step mechanism into Fluent via a user-defined function is also described.
Absorber Models for absorption of Carbon dioxide from sour natural gas byMeth...IJERA Editor
Mathematical models of the absorber for the absorption of carbon dioxide (CO2)from sour natural gas in Methyl-diethanol Amine (MDEA)solution were developed. The resulting ordinary differential model equations were solved numerically using theode45 solver of MATLAB 7.5. The accuracy of the models was ascertained using industrial plant data from the carbon dioxide absorber of the Obiafu/Obrikom Gas Treatment plant in Rivers State, Nigeria. The models predicted the CO2 concentration in the sweet gas, gas and solvent (MDEA) temperature progressions along the packed absorber. The results obtained from solutions to the models compared favorably with the plant outputs with a maximum deviation between models predictions and industrial plant outputs of 0.44%. The models were used to simulate the influence of sour gas flow rates and solvent (MDEA) concentration in solution on the performance (absorption rates of CO2) of the absorber.The results show that the absorption rate of CO2 increases with increasing gas flow rate and solvent concentration.
This document discusses formulas for calculating the heating value of coal and coal char based on their composition. It describes the development of several existing formulas and presents the results of tests of four formulas on a database of 775 coal samples. A new formula is developed through regression analysis of the database that shows less bias and a lower standard deviation than the existing formulas tested. The accuracy of the new formula is comparable to a more complex existing formula but does not require determining pyritic sulfur content.
COMBUSTION OPTIMIZATION IN SPARK IGNITION ENGINESBarhm Mohamad
The blending technique used in internal combustion engines can reduce emission of toxic exhaust components and noises, enhance overall energy efficiency and reduce fuel costs. The aim of the study was to compare the effects of dual alcohols (methanol and ethanol) blended in gasoline fuel (GF) against performance, combustion and emission characteristics. Problems arise in the fuel delivery system when using the highly volatile methanol - gasoline blends. This problem is reduced by using special fuel manifold. However, the satisfactory engine performance of the dual alcohol–gasoline blends need to be proved. The test fuels were GF, blend M35g65 (35 % methanol, and 65% GF by volume), blend E40g60 (40% ethanol, and 6o% GF by volume). The blend M35g65 was selected to match the vapor pressure (VP) of GF. The test fuels were a lean mixture with excess-air ratio of λ=1.1. The reaction parameters are taken from literatures and fitting calculations. Mathematical model and Computer software AVL program were conducted on a naturally-aspirated, spark ignition engine. The results show that indicate thermal efficiency (ITE) improved whereas the exhaust gas temperature (EGT) of the blends reduced, which is a benefit that reduces compression work. The regulated emissions were also reported. The blend E40g60 was recommended in preference to use because the former had shortened combustion duration, high energy content and its VP was selectively matched to that of GF's.
Biomass is considered as a potential source of energy production.Gasification can be employed to convert
dilute biomass energy source in to gaseous products holding concentrated form of energy. A steady state model for fluidized
bed biomass gasifier is developed based on reaction kinetics and hydrodynamic aspects of fluidization. The presence of
sorbent for absorption of carbon dioxide from the product gas is also incorporated in the model.The developed model
predicts the variation of syngas composition, temperature, pressure and velocity along the height of gasifier. Experiments
were carried out in a lab scale fluidized bed biomass gasifier and the results were used to validate the model.An increase of
50.35% in H2 mole fraction and a decrease of 50.88 % in CO2 mole fraction were observed when CaO was used as the
sorbent.
Thermal regeneration of activated carbon saturated with nitrate ions from an ...IJAEMSJORNAL
The present study was initiated to help the simple and less expensive regeneration of activated carbons after saturation in rural area. In order to determine a regeneration time and the number of regeneration cycles, an adsorption test was necessary. Thus, 3h and 4 cycles of carbon regeneration are obtained after evaluation of the performance, percentage and adsorption capacity after each cycle. Regeneration percentages of 71.29, 54.05, 40.40, 28.06 % and 72.6, 69.84, 64.33, 34.98 %for respective concentrations of 30± 1.2 mg/L and 55 ± 1.6 mg/L are observed. Also, the performances of activated carbon 8.5, 10, 12, 20 g/L and capacities 24.04, 19.93, 14.9 and 10.35mg/g 35.7, 34.12, 31.43 and 17.09 mg/g respectively for dry season and rainy season were necessary to fix the number of cycles. The artisanal furnace with its ease of installation and its maximum temperature of 500±2°C is suitable for the regeneration of saturated activated carbon.
This is a lecture is a series on combustion chemical kinetics for engineers. The course topics are selections from thermodynamics and kinetics especially geared to the interests of engineers involved in combusition
1) The document discusses methods for calculating the geological reserves of natural gas, focusing on using the volumetric method.
2) It takes the S0 group in the Lamadian oilfield as an example to demonstrate how to determine parameters for the volumetric method formula, including the original gas-bearing area, effective thickness, average effective porosity, initial gas saturation, and gas volume factor.
3) By applying the volumetric method formula and using the determined parameters, the geological reserves of natural gas were calculated for different sand bodies in the S0 group, with a total reserve of 12.93×108 m3.
Performance Study of Ethanol Blended Gasoline Fuel in Spark Ignition EngineIOSR Journals
Growing energy needs and environmental concern worldwide have propelled the interest for quest
and utilization of renewable and eco friendly fuels .Various substitutes are available to be used engines with the
possibility of reducing harmful emissions. In this work gasoline is taken as reference which is blended with
ethanol. Physical properties relevant to the fuel were determined for the four blends of gasoline and ethanol. A
four cylinder, four stroke, varying rpm, Petrol engine connected to eddy current type dynamometer was run on
blends containing 5%,10%,15%,20% ethanol and performance characteristics were evaluated. In this paper it
is shown that the higher blends can replace gasoline in a SI engine, results showed that there is a reduction in
exhaust gases and increase in Mechanical efficiency, Specific Fuel Consumption and air fuel ratio on blending.
We can conclude from the result that using 10% ethanol blend is most effective and we can utilize it for further
use in SI engines with little constraint on material used to sustain little increase in pressure
The experiments successfully demonstrated the use of carbon dioxide and argon as alternative carrier gases for N/protein analyses using Elementar's new EAS REGAINER technology. Analyses were done for various solid and liquid sample matrixes, including less homogeneous food and feed samples. Excellent accuracy and precision were achieved for even the most challenging species. Both instruments easily met repeatability requirements according to international food, feed and fertilizer standards, with repeatability approximately 5 times better than required. The EAS REGAINER technology results in a five-fold increase in lifetime of reduction tube chemicals, improving efficiency and reducing consumable and lab time costs.
This document discusses a study of the kinetics of self-reducing mixtures composed of iron ore, steel mill waste (BOF dust), and biomass from elephant grass. Kinetic runs were performed using thermogravimetric analysis at temperatures from 900-1100°C and carbon contents of 15-30%. The reaction fractions over time showed good agreement with first-order kinetics. Activation energies were estimated, with the highest kinetic constants occurring at 1100°C with 30% carbon: 0.0037 s-1 for the Fe3O4→FeO reaction and 0.0258 s-1 for FeO→Fe. The kinetic behavior supported chemical reaction control over diffusion control for self-reducing pellet reactions.
This study evaluated the performance and emissions of a gasoline engine fueled with blends of gasoline and n-butanol. The engine was tested without modifications using blends with 10-25% butanol. Emissions of CO and HC decreased with butanol blending while NOx increased. Fuel consumption slightly decreased and efficiency increased, showing butanol blends can be used without engine modifications. Testing was conducted under varying load conditions and emissions/performance were measured and compared to gasoline. Results indicate butanol-gasoline blends up to 25% are a promising alternative fuel option.
This document describes an experimental study on the effect of hydrogen blending on burning velocity for different fuels. The study involved:
- Designing a constant volume combustion chamber and instrumentation to measure laminar burning velocity and flame speed.
- Investigating the impact of equivalence ratio, initial pressure, and hydrogen blending ratio on burning velocity and other combustion parameters for LPG-air and hydrogen-LPG-air mixtures.
- Developing empirical correlations between studied variables using a FORTRAN program to calculate mixture properties.
Results showed that hydrogen blending increased adiabatic flame temperature and burning velocity. Burning velocity increased with higher equivalence ratios and hydrogen percentages, but decreased with initial pressure. Experimental data agreed well with previous
Heating Value Estimation for Natural Gas ApplicationsVijay Sarathy
For natural gas custody transfer applications, the gross calorific or gross heating value is necessary for both the buyer and seller to estimate the sales price of natural gas. In case of fuel suppliers, heat content is expressed in terms of Higher Heating value (HHV) to estimate fuel charges in kWh. Whereas Lower Heating Value (LHV) is employed to estimate fuel requirements since the total energy input for a specific power output is already fixed. To understand how fuel heating values are affected, LHV and HHV is explained as,
Natural Gas Compressibility Factor Correlation Evaluation for Niger Delta Gas...IOSR Journals
This document presents a new natural gas compressibility factor correlation developed specifically for Niger Delta gas fields in Nigeria. Laboratory PVT reports from 22 gas reservoirs in the Niger Delta were compiled into a database and used to evaluate existing compressibility factor correlations. A new correlation was then developed using the database. The performance of the new correlation was found to have the lowest standard error and absolute error compared to other evaluated correlations when calculating z-factors for different Niger Delta reservoir systems. Statistical analysis also showed the new correlation had the highest correlation coefficients and best matched experimental and other estimated z-factor values. It was concluded that the new developed correlation and that of Papay correlation are the most appropriate for calculating natural gas compressibility factors in Niger Delta gas fields
This document presents an experimental investigation into the effects of adding HHO gas (produced via electrolysis of water) and varying the compression ratio on the performance characteristics of a constant speed diesel engine. The HHO gas was added at a constant flow rate while testing compression ratios of 16, 17, and 18 at varying loads. Test results showed that adding HHO gas decreased fuel consumption and increased indicated thermal efficiency compared to diesel alone. Fuel savings of up to 6.5% were observed. Brake thermal efficiency was not significantly affected by HHO gas addition. Mechanical efficiency increased with higher compression ratio and load. Overall, a compression ratio of 18 showed the most improvement in engine performance when HHO gas was added.
Key Thermo-Physical Properties of Light Crude OilsVijay Sarathy
1) The document discusses methods for estimating key thermo-physical properties of light crude oils, such as latent heat of vaporization, using correlations based on distillation data and critical properties.
2) It provides examples of the Katz-Firoozabadi and Riazi-Daubert correlations that can be used to calculate properties like molecular weight, specific gravity, critical pressure and temperature.
3) The document works through a case study to estimate the latent heat of vaporization of a light crude oil at 325°K using distillation data, volume average boiling point, and the provided property correlations.
CO2 Reduction in a Calciner Reactor at a Cement Factory MemorandumAlfonso Figueroa
• Extensive research in a team of four on how to reduce CO2 emissions from a cement factory
• Focused on reducing CO2 emissions from the calciner reactor by using substitute reactant materials and running a simulation on Aspen HYSYS to determine the least CO2 produced
This document summarizes a study that used the SAFT-VR Mie equation of state to model transport properties like viscosity and interfacial tension of CO2-rich systems relevant to carbon capture and storage. The SAFT-VR Mie EoS was used to calculate densities, from which a viscosity model and density gradient theory were used to predict viscosity and interfacial tension, respectively. Results for five binary mixtures and two multicomponent mixtures were compared to experimental data and showed good agreement, supporting the capabilities of the models.
This document summarizes a study that measured the kinetics of carbon dioxide absorption into aqueous solutions of lithium, sodium, and potassium hydroxides and blends of hydroxides and carbonates over a range of temperatures and concentrations. The researchers derived an infinite dilution second order rate constant for the reaction of carbon dioxide with hydroxide ions as an Arrhenius temperature function. They also validated a model for the ionic strength dependency of the second order rate constant using refitted parameters. The model with the new parameters represented the experimental data with less than 12% average absolute relative deviation.
El documento describe un proyecto de innovación docente en dibujo, imagen y artes plásticas. El proyecto busca cumplir con los objetivos del currículo a través de actividades cotidianas que ayuden a los estudiantes a entender conceptos como color, composición y textura. El proyecto también fomenta la cooperación entre estudiantes y genera un espacio común para que aprendan en grupo.
A arte eletrónica envolve o espectador de forma interativa, respondendo aos seus movimentos e estímulos. As obras caracterizam-se por serem altamente interativas e dependentes da participação do público. Este tipo de arte distingue-se pelo diálogo entre a obra e o participante, que é habilitado a agir e interagir com a peça.
The document lists the names, years of study, majors, and hometowns of 27 orientation leaders. It provides basic biographical information about each student leader, including their class year, area of study, and place of origin.
This document discusses formulas for calculating the heating value of coal and coal char based on their composition. It describes the development of several existing formulas and presents the results of tests of four formulas on a database of 775 coal samples. A new formula is developed through regression analysis of the database that shows less bias and a lower standard deviation than the existing formulas tested. The accuracy of the new formula is comparable to a more complex existing formula but does not require determining pyritic sulfur content.
COMBUSTION OPTIMIZATION IN SPARK IGNITION ENGINESBarhm Mohamad
The blending technique used in internal combustion engines can reduce emission of toxic exhaust components and noises, enhance overall energy efficiency and reduce fuel costs. The aim of the study was to compare the effects of dual alcohols (methanol and ethanol) blended in gasoline fuel (GF) against performance, combustion and emission characteristics. Problems arise in the fuel delivery system when using the highly volatile methanol - gasoline blends. This problem is reduced by using special fuel manifold. However, the satisfactory engine performance of the dual alcohol–gasoline blends need to be proved. The test fuels were GF, blend M35g65 (35 % methanol, and 65% GF by volume), blend E40g60 (40% ethanol, and 6o% GF by volume). The blend M35g65 was selected to match the vapor pressure (VP) of GF. The test fuels were a lean mixture with excess-air ratio of λ=1.1. The reaction parameters are taken from literatures and fitting calculations. Mathematical model and Computer software AVL program were conducted on a naturally-aspirated, spark ignition engine. The results show that indicate thermal efficiency (ITE) improved whereas the exhaust gas temperature (EGT) of the blends reduced, which is a benefit that reduces compression work. The regulated emissions were also reported. The blend E40g60 was recommended in preference to use because the former had shortened combustion duration, high energy content and its VP was selectively matched to that of GF's.
Biomass is considered as a potential source of energy production.Gasification can be employed to convert
dilute biomass energy source in to gaseous products holding concentrated form of energy. A steady state model for fluidized
bed biomass gasifier is developed based on reaction kinetics and hydrodynamic aspects of fluidization. The presence of
sorbent for absorption of carbon dioxide from the product gas is also incorporated in the model.The developed model
predicts the variation of syngas composition, temperature, pressure and velocity along the height of gasifier. Experiments
were carried out in a lab scale fluidized bed biomass gasifier and the results were used to validate the model.An increase of
50.35% in H2 mole fraction and a decrease of 50.88 % in CO2 mole fraction were observed when CaO was used as the
sorbent.
Thermal regeneration of activated carbon saturated with nitrate ions from an ...IJAEMSJORNAL
The present study was initiated to help the simple and less expensive regeneration of activated carbons after saturation in rural area. In order to determine a regeneration time and the number of regeneration cycles, an adsorption test was necessary. Thus, 3h and 4 cycles of carbon regeneration are obtained after evaluation of the performance, percentage and adsorption capacity after each cycle. Regeneration percentages of 71.29, 54.05, 40.40, 28.06 % and 72.6, 69.84, 64.33, 34.98 %for respective concentrations of 30± 1.2 mg/L and 55 ± 1.6 mg/L are observed. Also, the performances of activated carbon 8.5, 10, 12, 20 g/L and capacities 24.04, 19.93, 14.9 and 10.35mg/g 35.7, 34.12, 31.43 and 17.09 mg/g respectively for dry season and rainy season were necessary to fix the number of cycles. The artisanal furnace with its ease of installation and its maximum temperature of 500±2°C is suitable for the regeneration of saturated activated carbon.
This is a lecture is a series on combustion chemical kinetics for engineers. The course topics are selections from thermodynamics and kinetics especially geared to the interests of engineers involved in combusition
1) The document discusses methods for calculating the geological reserves of natural gas, focusing on using the volumetric method.
2) It takes the S0 group in the Lamadian oilfield as an example to demonstrate how to determine parameters for the volumetric method formula, including the original gas-bearing area, effective thickness, average effective porosity, initial gas saturation, and gas volume factor.
3) By applying the volumetric method formula and using the determined parameters, the geological reserves of natural gas were calculated for different sand bodies in the S0 group, with a total reserve of 12.93×108 m3.
Performance Study of Ethanol Blended Gasoline Fuel in Spark Ignition EngineIOSR Journals
Growing energy needs and environmental concern worldwide have propelled the interest for quest
and utilization of renewable and eco friendly fuels .Various substitutes are available to be used engines with the
possibility of reducing harmful emissions. In this work gasoline is taken as reference which is blended with
ethanol. Physical properties relevant to the fuel were determined for the four blends of gasoline and ethanol. A
four cylinder, four stroke, varying rpm, Petrol engine connected to eddy current type dynamometer was run on
blends containing 5%,10%,15%,20% ethanol and performance characteristics were evaluated. In this paper it
is shown that the higher blends can replace gasoline in a SI engine, results showed that there is a reduction in
exhaust gases and increase in Mechanical efficiency, Specific Fuel Consumption and air fuel ratio on blending.
We can conclude from the result that using 10% ethanol blend is most effective and we can utilize it for further
use in SI engines with little constraint on material used to sustain little increase in pressure
The experiments successfully demonstrated the use of carbon dioxide and argon as alternative carrier gases for N/protein analyses using Elementar's new EAS REGAINER technology. Analyses were done for various solid and liquid sample matrixes, including less homogeneous food and feed samples. Excellent accuracy and precision were achieved for even the most challenging species. Both instruments easily met repeatability requirements according to international food, feed and fertilizer standards, with repeatability approximately 5 times better than required. The EAS REGAINER technology results in a five-fold increase in lifetime of reduction tube chemicals, improving efficiency and reducing consumable and lab time costs.
This document discusses a study of the kinetics of self-reducing mixtures composed of iron ore, steel mill waste (BOF dust), and biomass from elephant grass. Kinetic runs were performed using thermogravimetric analysis at temperatures from 900-1100°C and carbon contents of 15-30%. The reaction fractions over time showed good agreement with first-order kinetics. Activation energies were estimated, with the highest kinetic constants occurring at 1100°C with 30% carbon: 0.0037 s-1 for the Fe3O4→FeO reaction and 0.0258 s-1 for FeO→Fe. The kinetic behavior supported chemical reaction control over diffusion control for self-reducing pellet reactions.
This study evaluated the performance and emissions of a gasoline engine fueled with blends of gasoline and n-butanol. The engine was tested without modifications using blends with 10-25% butanol. Emissions of CO and HC decreased with butanol blending while NOx increased. Fuel consumption slightly decreased and efficiency increased, showing butanol blends can be used without engine modifications. Testing was conducted under varying load conditions and emissions/performance were measured and compared to gasoline. Results indicate butanol-gasoline blends up to 25% are a promising alternative fuel option.
This document describes an experimental study on the effect of hydrogen blending on burning velocity for different fuels. The study involved:
- Designing a constant volume combustion chamber and instrumentation to measure laminar burning velocity and flame speed.
- Investigating the impact of equivalence ratio, initial pressure, and hydrogen blending ratio on burning velocity and other combustion parameters for LPG-air and hydrogen-LPG-air mixtures.
- Developing empirical correlations between studied variables using a FORTRAN program to calculate mixture properties.
Results showed that hydrogen blending increased adiabatic flame temperature and burning velocity. Burning velocity increased with higher equivalence ratios and hydrogen percentages, but decreased with initial pressure. Experimental data agreed well with previous
Heating Value Estimation for Natural Gas ApplicationsVijay Sarathy
For natural gas custody transfer applications, the gross calorific or gross heating value is necessary for both the buyer and seller to estimate the sales price of natural gas. In case of fuel suppliers, heat content is expressed in terms of Higher Heating value (HHV) to estimate fuel charges in kWh. Whereas Lower Heating Value (LHV) is employed to estimate fuel requirements since the total energy input for a specific power output is already fixed. To understand how fuel heating values are affected, LHV and HHV is explained as,
Natural Gas Compressibility Factor Correlation Evaluation for Niger Delta Gas...IOSR Journals
This document presents a new natural gas compressibility factor correlation developed specifically for Niger Delta gas fields in Nigeria. Laboratory PVT reports from 22 gas reservoirs in the Niger Delta were compiled into a database and used to evaluate existing compressibility factor correlations. A new correlation was then developed using the database. The performance of the new correlation was found to have the lowest standard error and absolute error compared to other evaluated correlations when calculating z-factors for different Niger Delta reservoir systems. Statistical analysis also showed the new correlation had the highest correlation coefficients and best matched experimental and other estimated z-factor values. It was concluded that the new developed correlation and that of Papay correlation are the most appropriate for calculating natural gas compressibility factors in Niger Delta gas fields
This document presents an experimental investigation into the effects of adding HHO gas (produced via electrolysis of water) and varying the compression ratio on the performance characteristics of a constant speed diesel engine. The HHO gas was added at a constant flow rate while testing compression ratios of 16, 17, and 18 at varying loads. Test results showed that adding HHO gas decreased fuel consumption and increased indicated thermal efficiency compared to diesel alone. Fuel savings of up to 6.5% were observed. Brake thermal efficiency was not significantly affected by HHO gas addition. Mechanical efficiency increased with higher compression ratio and load. Overall, a compression ratio of 18 showed the most improvement in engine performance when HHO gas was added.
Key Thermo-Physical Properties of Light Crude OilsVijay Sarathy
1) The document discusses methods for estimating key thermo-physical properties of light crude oils, such as latent heat of vaporization, using correlations based on distillation data and critical properties.
2) It provides examples of the Katz-Firoozabadi and Riazi-Daubert correlations that can be used to calculate properties like molecular weight, specific gravity, critical pressure and temperature.
3) The document works through a case study to estimate the latent heat of vaporization of a light crude oil at 325°K using distillation data, volume average boiling point, and the provided property correlations.
CO2 Reduction in a Calciner Reactor at a Cement Factory MemorandumAlfonso Figueroa
• Extensive research in a team of four on how to reduce CO2 emissions from a cement factory
• Focused on reducing CO2 emissions from the calciner reactor by using substitute reactant materials and running a simulation on Aspen HYSYS to determine the least CO2 produced
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IJCER (www.ijceronline.com) International Journal of computational Engineering research
1. I nternational Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 7
N UMERICAL IN VESTIG ATION F OR E XHAUST G AS E MISSIONS F OR A
D UAL F UEL E NG INE C ONFIG URATION U SING H YDROG EN A ND
C OMPRESSED N ATURAL G AS (CNG)
PREMAKUMARA. G1, AKHIL THOMAS2, JAYAKRISHNAN .K3,ANIRUDH VUYYALA4
,L.M. DAS5
1
(CENT RE FOR ENERGY ST UDIES, INDIAN INSTITUTE OF TECHNOLOGY, DELHI , INDIA)
2
(DEPARTMENT OF M ECHANICAL ENGINEERING, INDIAN INSTITUTE OF TECHNOLOGY, BHUBANESWAR, INDIA)
ABS TRACT
A simulat ion for numerical analysis of internal co mbustion engines, bot h spark-ignited and compression-
ignited systems, running on duel fuel of Hydrogen and any hydrocarbon developed is presented in this report. The
program coded using Matlab is used to simulate various engine conditions and discern its effect on the emissions. The
engine emissions, including species like NOx, CO, and CO2 , in accordance with the extent of hydrogen fraction, the
equivalence fuel-air rat io, co mbustion equilib riu m temperature and pressure are simulated. The paper focuses on
simu lation of exhaust emissions while using H-CNG blend. Simu lation attempts to find an optimu m extent of dual-
fuelling, equivalence ratio, co mbustion temperature with regard to quality of emissions.
Key words:Hydrogen,Matlab,CNG,emissions etc
1. Introduction
Our history tells us one thing that all along the past men was consistently tending to go wrong, as if he always
beholds to the Murphy‟s Law wh ich says, „if anything can go wrong, then it will‟. Such an error made by man was his
incorrect assessment on availability of petroleum fuels. Till the early 1970s, petroleum was considered as the eternal
fuel source when it was realized that the petroleum-based fuels were dwindling fast and at the same time, the rate of
consumption of these fuels was increasing at a much faster rate and this presents the trillion dollar quest today, for the
best alternative fuel [1].Loo king at this problem, we have a broader aim than just an alternative to the present fuels, but
a better one in terms of its emissions. Considering the effect of global warming which has already made big impact
giving us serious warning of its effects has led to the need for an alternative fuels which produce minimu m emissions.
But there also lies another big problem in terms of econo mic v iability. So, taking all these factors, we look for an
environment friendly, economically viab le alternative fuel for the existing internal combustion engines.Over the years,
liquefied petroleum gas (LPG), alcohols (both ethanol and methanol), compressed natural gas (CNG), Bio -fuels
(including biodiesel), hydrogen and so many other fuels has been investigated as alternative fuels for both the spark
ignition (SI) and co mpression ignition (CI)engines[1]. Performance studies were done in engines running on these fuels
and many methods have been implemented to imp rove the emissions as well as engine performance. CNG is one fuel
which had been able to replace gasoline in spark ignited engines. In order to reduce the emissions from these engines,
lean burn strategy is being implemented. But this has a setback on the engine power output. It is clear that the lower
flame speed of CNG significantly reduce the power output available. It has additional drawbacks as they are difficu lt to
ignite, which results in misfire and increases un-burned hydrocarbon emissions, and wastes fuel. Adding hydrogen as a
blend with CNG helps in reducing these defects. Hydrogen‟s high flame speed (high burning speed), low ignition
energy makes the hydrogen-CNG mixture easier to ignite, thus avoiding misfire and imp rov ing the emissions [7]. It also
improves the mixture‟s energy density at lean zone wh ich imp roves the power output.
Far sighting the potential of H-CNG dual fuelling, studies have been done on various fields in view of
developing this concept. It is, however a necessity that we have to optimize all the factors that affects the performance
of the engine. Conducting experiments is the obvious way of doing this, but it always has its own limitations as many of
the possible combination of factors may not be brou ght up practically. So, an intelligent way of doing this is by
theoretical analysis.There was a time when analytical methods were time consuming and extremely challenging. But
today, the scenario is different. With the development of technology, there are enormous and effective ways of
theoretically analyzing situations. This paper attempt to numerically analyze the exhaust gas emissions from an engine
run on duel fuel involving Hydrogen-CNG b lends. The paper involves an indigenously developed simulat ion program
with graphical user interface which is capable of calculating the mole fraction of different components in exhaust
emission.
2. THE P ROGRAM
The developed program is capable of simu lating the effects of various factors, such as extent of dual-fuelling,
the equivalence fuel-air ratio, co mbustion equilibriu m temperature and pressure, on the emission properties as well as
calculating the emission properties for a specific set of input values. The species which could be analyzed in the exhaust
are CO, NO, CO2 , H2 O, O2 , H2 , O, H, OH and N2 .
Issn 2250-3005(online) November| 2012 Page 140
2. I nternational Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 7
For simu lating the effects of input parameters on exhaust emissions, we considered three main input
parameters, Temperature, equivalence ratio, and extent of dual fuelling, on the exhaust species CO, NO, and CO2 . Out
of the different methods possible of simulat ing the effect, we found three-dimensional surface plots as the apt one in our
analysis. In two-dimensional plots, when simulating the effect of t wo factors on output, there is a limitation that there
can be only one variable factor and the effect of other has to be analyzed for various constant values. Surface plots give
a wider scope of simulation, since in addition to what is possible in two-dimensional plots, we can simu late the effect of
two factors, both being variables at a time on the exhaust properties. And this approach makes it more co mparable with
real engine simu lations.
Table 1.Notations used
p Nu mber of carbon atoms in primary fuel
q Nu mber of hydrogen atoms in primary fuel
r Nu mber of o xygen atoms in primary fuel
s Nu mber of n itrogen atoms in primary fuel
t Temperature (K)
x Fraction of Hydrogen in blend
Pres Pressure ( atm )
equ Equivalence ratio
sto Stoichio metric fuel-air ratio
K Equilibriu m constant
ni Concentration of „i‟th product
2.1 PROGRAM INTERFACE
A user friendly interface is given to the program as seen in Fig.1 that enables the user to control the
hydrocarbon fuel data (the number of Carbon, Hydrogen, Nitrogen, and Oxygen atoms), fraction of Hydrogen in the
fuel b lend, co mbustion conditions including equilibriu m co mbustion temperature and pressure, and the equivalence
fuel-air rat io. According to the user‟s choice, the output will be the mole fractions of the compounds CO 2 , H2 O, N2 , O2 ,
CO, H2 , H, O, OH, and NO corresponding to the input set of values or the simulated change in mole fraction of the
species with the change in input parameters.
Fig.1: Interface of the program
3. SIMULATIONS
Mole fract ions of NO, CO, H2 O, N2 and CO2 can be simu lated against varying
Extent of blending (fract ion of hydrogen in blend) for five d ifferent values of co mbustion temperature with
equivalence fuel-air ratio kept as a constant in a 2- dimensional p lot.
Extent of blending for five different values of equivalence fuel-air rat io with combustion temperature kept as a
constant.
Equivalence fuel-air ratio for five different values of combustion temperature with extent of blending kept as a
constant.
Equivalence fuel-air ratio for five different values of extent of blending with combustion temperature ke pt as a
constant.
Issn 2250-3005(online) November| 2012 Page 141
3. I nternational Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 7
Equivalence fuel-air ratio and extent of blending for a constant value of temperature in a three dimensional surface
plot.
Equivalence fuel-air ratio and Temperature for a constant value of composition of hydrogen in a three dimensional
surface plot.
Temperature and composition of hydrogen for a constant value of equivalence fuel-air ratio in a three dimensional
surface plot.
4. Formation Of Equations
The program uses a modified version of equilibriu m constant method applied by Olikara and Borman to find
the solution for the properties of equilibriu m gas phase products of combustion of Hydrocarbon fuels. [3] The coding is
done for any general dual fuel b lend involving hydrogen. The reactant mixture is a blend of a primary fuel of formula
CpHq OrNs and H2 and air.Lagrange mult iplier approach [3] is done with the help of NASA simulation program [5] to
restrict the number o f species to be considered in the equilibriu m constant method. The data showed that if fuel-air rat io
is less than 3, the only species of importance because of dissociation are O, H, OH, and NO. In accordance with the
results, we considered only 10 products of combustion.
The combustion reaction is hence written as:
equ sto {(1-x) Cp Hq Or Ns +(x H2 )} + (0.21 O2 ) +(0.79 N2 ) n 1 CO2 + n 2 H2 O + n 3 N2 + n 4 O2 +n 5 CO + n 6 H2 + n 7 O
+ n 8 H + n 9 OH + n 10 NO (1)
Here, stoichiometric fuel-air rat io:
sto = 0.21 ( (2)
Balancing of ato ms leads to:
C: equ sto (1-x) p = n 1 + n 5 (3)
H: equ sto (1-x) q + 2x = 2n 2 + 2n 6 +n 8 +n 9 (4)
O: equ sto (1-x) r + 0.42 = 2n 1 + n 2 +2n 4 + n 5 + n 7 + n 9 + n 10 (5)
N: equ sto (1-x) s + 1.58 = 2n 3 + n 10 (6)
Applying the following appro ximations, we developed the equations:
For equ < 1: n 5 = 0 (7)
For equ > 1: n 4 = 0 (8)
The equations of products for equivalence fuel-air rat io < 1 are:
n1 = (1-x) p equ sto (9)
n2 = (10)
n3 = 1 0.79 + (1-x) s equ sto/2 (11)
n4 = (1) 0.21 (1-equ) (12)
n5 = 0 (13)
n6 = 0.42x (14)
And for equivalence fuel-air rat io > 1;
In this case, considering the equilibriu m constant for the water gas reaction [3] and taking values fro m JANAF tables
[7] we get the following equations:
K= (15)
a = 1 (1-K) (16)
b = (1-x) (0.42-equ sto (2-r) + k (0.42 (equ-1)) + p equ sto) + x (0.42-2 equ sto +
K 0.42 (equ-1)) (17)
c = - (1-x) (0.42 equ sto p (equ-1) k) (18)
n5 = (19)
n 1 = (1-x) (p equ sto – n5 ) + x n 5 (20)
n 2 = (1-x) (0.42+equ sto (2p -r) + n 5 ) - x (0.42+n 5 ) (21)
n 3 = (1-x) (0.79+s equ sto/2) + 0.79x (22)
n4 = 0 (23)
n 6 = (1-x) (0.42 (equ-1)-n 5 ) + 0.42x (24)
Mole fract ions of these products are found out using the equation:
y i = n i / ∑n i (25)
The six gas-phase reactions are introduced which include the dissociation of hydrogen, oxygen, water, carbon dio xide,
and equilibriu m OH and NO formation [3]. The equilibriu m constants of these reactions [3] had been curve fitted to
JANAF table by Olikara and Borman fo r 600 < t < 4000 K. Their expressions are of the form:
Issn 2250-3005(online) November| 2012 Page 142
4. I nternational Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue. 7
log 10 Ki = A i + + Ci + Di t + Ei (26)
The values of A, B, C, D, E are obtained fro m JANAF table [7].
The mo le fraction of rest species are found out using these equilibriu m constant values in accordance with the following
equations:
y7 = (27)
y8 = (28)
y 9 = K3 (29)
y 10 = K4 (30)
5. RES ULTS
Simu lations are done for CNG – H2 fuel blend emissions under various conditions as discussed before. The
results are presented below:
5.1 CO EMISSIO NS
Fig.2: Effect of Temperature and equivalence rat io on mole fraction of CO for x=0.3
Fig.2 shows that for lean mixtures (equ<1), the CO emissions are negligib le which is due to complete co mbustion of
fuel. On the other hand for rich mixtures (equ>1), it can be observed that mole fraction of CO increases with increasing
equivalence ratio. Th is can be attributed to the occurrence of incomp lete co mbustion.
It can also be observed that CO emissions increase with increase in temperature. This result is due to the increase in
dissociation of CO2 at higher temperatures which boosts the format ion of CO. It can be noted that the emissions of CO
are more prevalent for T=2500K and equ=1.4 in the plot.
5.2 CO2 EMIS S IONS
Fig.3: Variation of Mo le fraction of CO2 with change in Temperature and Hydrogen fraction at equ=0.3
In Fig.3, with increase in hydrogen fraction, CO2 emissions decrease as the carbon content in the fuel (CNG fraction) is
decreasing, for a lean mixture (equ=0.3). This trend was found to be the same for all other values of equ less than one.
For the hydrogen fraction of 0.2, the value of CO2 mole fraction is 0.06, and for 0.9 the value of mo le fract ion is 0.01,
which gives an average decrease of 83%.
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Fig.4: Effect of equivalence ratio and temperature on the mole fract ion of CO2 at x=0.3
In Fig.4, it can be observed that for lean mixtures, the mole fraction of CO 2 is almost independent on temperature.
However, for rich mixtures it is seen that the mole fraction decreases with increase in temperature. Fro m the plot, the
mo le fraction for T= 2500K is much less than T= 500K. This can be explained as temperature increases, dissociation of
CO2 increases which, on the other hand leads to the increase in mo le fraction of CO, a product due to incomplete
combustion of rich mixtures. It is also noticeable that mole fract ion of CO2 shows an increasing trend with increase in
equivalence ratio, which can be accredited to the increase in carbon content (due to increased fuel content).
NOX EMISSIO NS
Fig.5: Effect of Temperature and Hydrogen fract ion on mo le fraction of NO x at equ=0.6
The Fig.7 shows that for all hydrogen fractions, mole fract ion of NO increases with increase in temperature. This is due
to the very high dissociation energy of N2 atoms which demands higher temperatures for its dissociation, which is in
turn essential for NO formation. It can also be observed that for a fixed temperature, NO emissions show a slightly
decreasing trend with increase in hydrogen fraction.
Fig.6: Effect of Temperature and equivalence rat io on mole fraction of NO x
Fro m the Fig.8, it is clear that effect of temperature on NO emission is consistent with the earlier result. It can also be
observed that as equivalence ratio increases for a given temperature, NO x emissions decrease. This can be explained by
the decrease in availability of Oxygen with increase in equivalence rat io.
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6. CONCLUS IONS
The results from the simulat ion were successfully verified with experimental values, wh ich give credibility to
the algorithm used. But there are many limitations to the program as it cannot be used for simulating very high
temperatures (T> 3000K) due to the assumptions involved in derivation of the formu la.
The effects of equivalence ratio, Temperature and Hydrogen fraction o n emission of different species in an H-CNG
blend can be concluded as follows:
The emission of CO is negligib le for lean mixtures and increases with equivalence ratio for rich mixtures. Also for
rich mixtures, the CO emissions increase with increase in co mbustion equilibriu m temperature.
For lean mixtures, CO2 emissions decrease with increase in hydrogen fraction and increase with increase in
equivalence ratio. It is also independent on temperature for lean mixtures, but decrease with increase in temperatu re
for rich mixtu res.
The emission of NO is neglig ible for rich mixtures and decreases with equivalence ratio for lean mixtu res. NO
emissions also decrease slightly with increase in hydrogen fraction. Also, the emissions increase with increase in
temperature.
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[4] Svehla, R.A and Mcbridge, B.J. “Fo rtran IV co mputer program for calcu lation of thermodynamic and transport
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