The document studies the isomerization of desulfurized light Iraqi petroleum naphtha over two catalysts (Pt/HX and Pt/SrX) to produce high octane gasoline. It investigates the catalyst activity, selectivity, and deactivation rates. The key findings are:
1) The optimum isomerization temperature was found to be 270°C.
2) Pt/HX showed higher activity and selectivity than Pt/SrX. Both catalysts deactivated rapidly due to deposited carbon blocking pore mouths.
3) Only an average of 90% of carbon atoms in the naphtha feed were detected in the product stream due to coke deposits leading to catalyst deactivation.
1) Recent advances in continuous flow chemistry allow for safer and more efficient reactions through the use of inline monitoring techniques like ATR-FTIR.
2) A Strecker reaction was optimized in a flow reactor using ATR-FTIR to monitor the reaction in situ which allowed for safer operation and higher yields through rapid stoichiometric optimization.
3) A chemoenzymatic sequence for the stereoselective synthesis of lactones was developed using a single-operation protocol combining continuous flow hydrogenation and biocatalyzed Baeyer-Villiger oxidation which provided a safer and simpler procedure.
21st International Conference Organic Process Research & Development 2010 San...dominev
This document discusses using real-time calorimetry to improve operational efficiency. It presents case studies where ReactIR, FBRM, PVM and RTCal were used:
1) ReactIR developed kinetic models to minimize byproducts in pharmaceutical reactions and improve crystallization processes.
2) FBRM and PVM helped optimize a crystallization to reduce impurities below 0.5%.
3) RTCal validated switching to a low copper acrylamide grade for polymerization, showing a shorter induction period but similar maximum heat output. Real-time calorimetry provided process safety evaluation.
Electrocatalytic Evaluation in Methanol Oxidation Process of PtCo Nanoparticl...David Macias Ferrer
The high reactivity of methanol with platinum and the excellent catalytic activity for electro-oxidation of methanol on pure Pt especially at low temperature (below 80°C), makes this metal a suitable anodic electrocatalyst in DMFC [1]. However, it is well known that there is a series of technical problems in DMFC that limit their marketing [2]. While Pt, which is generally supported on activated carbon with large surface area such as Vulcan XC-72, is the best catalyst for the electro-oxidation of methanol, it rapidly becomes poisoned because of the intermediate species formed during the oxidation of methanol, mainly CO, since CO molecules can be chemically adsorbed on the surface of Pt and block the active sites, producing a poor kinetic of anodic methanol oxidation due to CO poisoning and a low electrocatalytic activity of electrocatalysts [3-5]. Although electrocatalysts based on Pt and Pt-Ru alloy have shown a good catalytic activity for electro-oxidation of methanol, another of the limitations in the development of DMFC for commercial applications is the high cost of both noble metals [6-7]. In this study, we report a nanocasting method of low cost to prepare NC using SBA-15 as hard template and purified sugar as carbon precursor; the inclusion of Co as a second metal, in order to reduce the amount of platinum and measure its catalytic activity in methanol oxidation process
This document evaluates various accelerators for improving the low temperature cure properties of phenalkamine epoxy systems. It presents gelation time studies at 25C and 5C for different phenalkamines cured with DGEBA resin and accelerated with nonylphenol, DMP-30, OTBP, or CNSL. The EDA phenalkamine achieved the fastest gel times with nonylphenol, while the DETA phenalkamine showed no acceleration with DMP-30. Nonylphenol performed best at 5C and did not increase water intake like DMP-30. The conclusions indicate that nonylphenol is the most effective accelerator for EDA phenalkamines,
A optimized process for the synthesis of a key starting material for etodolac...IOSR Journals
This document describes an optimized process for synthesizing 7-ethyltryptophol, a key starting material for the non-steroidal anti-inflammatory drug etodolac. The process involves reacting 2-ethylphenyl hydrazine hydrochloride with 2,3-dihydrofuran in the presence of concentrated sulfuric acid as a catalyst in a water/dimethylacetamide solvent system. This method yields 7-ethyltryptophol in 75% yield with high purity in an easy, inexpensive, and operationally simple process without the need for purification. Testing different acid catalysts and solvent systems showed concentrated sulfuric acid and a water/dimethylacetamide mixture provided the best conversion and yield.
A comparison of cardanol and its derivatives as reactiveAlexander Decker
This document discusses the use of cardanol, cardanol acetate, and cardanyl methyl ether as reactive diluents in alkyd coatings to reduce volatile organic compounds (VOCs). The compounds were characterized and evaluated as partial replacements for solvent in long oil alkyd coatings. Coatings with the reactive diluents showed lower VOC levels (up to 39% reduction), faster drying times, and better properties compared to conventional coatings. Using these cardanol derivatives from cashew nut shell liquid provides advantages over petroleum-based solvents as it is renewable and reduces pollution from burning cashew nut shells.
The document describes a simple and flexible automated library purification solution using Caliper's Zephyr Genomics Workstation. The system utilizes solid-phase paramagnetic bead technology to purify DNA fragments over 100 bp in under an hour. It processes between 8 to 96 samples using preinstalled methods without needing programming. This allows users to prepare varying molecular biology steps for next-generation sequencing library preparation while samples are purified. The system improves purification consistency and conserves reagents without sacrificing efficiency or recovery.
This document summarizes information about 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 3,3',4,4',5-pentachlorobiphenyl (PCB 126). It describes their identification, occurrence, use, human exposure including occupational exposure, and background levels found in tissues. TCDD is an unintended byproduct formed during production of chlorophenols and herbicides. PeCDF is emitted from combustion sources while PCBs were commercially produced but their manufacture stopped in 1977 due to environmental contamination. Human exposures can
1) Recent advances in continuous flow chemistry allow for safer and more efficient reactions through the use of inline monitoring techniques like ATR-FTIR.
2) A Strecker reaction was optimized in a flow reactor using ATR-FTIR to monitor the reaction in situ which allowed for safer operation and higher yields through rapid stoichiometric optimization.
3) A chemoenzymatic sequence for the stereoselective synthesis of lactones was developed using a single-operation protocol combining continuous flow hydrogenation and biocatalyzed Baeyer-Villiger oxidation which provided a safer and simpler procedure.
21st International Conference Organic Process Research & Development 2010 San...dominev
This document discusses using real-time calorimetry to improve operational efficiency. It presents case studies where ReactIR, FBRM, PVM and RTCal were used:
1) ReactIR developed kinetic models to minimize byproducts in pharmaceutical reactions and improve crystallization processes.
2) FBRM and PVM helped optimize a crystallization to reduce impurities below 0.5%.
3) RTCal validated switching to a low copper acrylamide grade for polymerization, showing a shorter induction period but similar maximum heat output. Real-time calorimetry provided process safety evaluation.
Electrocatalytic Evaluation in Methanol Oxidation Process of PtCo Nanoparticl...David Macias Ferrer
The high reactivity of methanol with platinum and the excellent catalytic activity for electro-oxidation of methanol on pure Pt especially at low temperature (below 80°C), makes this metal a suitable anodic electrocatalyst in DMFC [1]. However, it is well known that there is a series of technical problems in DMFC that limit their marketing [2]. While Pt, which is generally supported on activated carbon with large surface area such as Vulcan XC-72, is the best catalyst for the electro-oxidation of methanol, it rapidly becomes poisoned because of the intermediate species formed during the oxidation of methanol, mainly CO, since CO molecules can be chemically adsorbed on the surface of Pt and block the active sites, producing a poor kinetic of anodic methanol oxidation due to CO poisoning and a low electrocatalytic activity of electrocatalysts [3-5]. Although electrocatalysts based on Pt and Pt-Ru alloy have shown a good catalytic activity for electro-oxidation of methanol, another of the limitations in the development of DMFC for commercial applications is the high cost of both noble metals [6-7]. In this study, we report a nanocasting method of low cost to prepare NC using SBA-15 as hard template and purified sugar as carbon precursor; the inclusion of Co as a second metal, in order to reduce the amount of platinum and measure its catalytic activity in methanol oxidation process
This document evaluates various accelerators for improving the low temperature cure properties of phenalkamine epoxy systems. It presents gelation time studies at 25C and 5C for different phenalkamines cured with DGEBA resin and accelerated with nonylphenol, DMP-30, OTBP, or CNSL. The EDA phenalkamine achieved the fastest gel times with nonylphenol, while the DETA phenalkamine showed no acceleration with DMP-30. Nonylphenol performed best at 5C and did not increase water intake like DMP-30. The conclusions indicate that nonylphenol is the most effective accelerator for EDA phenalkamines,
A optimized process for the synthesis of a key starting material for etodolac...IOSR Journals
This document describes an optimized process for synthesizing 7-ethyltryptophol, a key starting material for the non-steroidal anti-inflammatory drug etodolac. The process involves reacting 2-ethylphenyl hydrazine hydrochloride with 2,3-dihydrofuran in the presence of concentrated sulfuric acid as a catalyst in a water/dimethylacetamide solvent system. This method yields 7-ethyltryptophol in 75% yield with high purity in an easy, inexpensive, and operationally simple process without the need for purification. Testing different acid catalysts and solvent systems showed concentrated sulfuric acid and a water/dimethylacetamide mixture provided the best conversion and yield.
A comparison of cardanol and its derivatives as reactiveAlexander Decker
This document discusses the use of cardanol, cardanol acetate, and cardanyl methyl ether as reactive diluents in alkyd coatings to reduce volatile organic compounds (VOCs). The compounds were characterized and evaluated as partial replacements for solvent in long oil alkyd coatings. Coatings with the reactive diluents showed lower VOC levels (up to 39% reduction), faster drying times, and better properties compared to conventional coatings. Using these cardanol derivatives from cashew nut shell liquid provides advantages over petroleum-based solvents as it is renewable and reduces pollution from burning cashew nut shells.
The document describes a simple and flexible automated library purification solution using Caliper's Zephyr Genomics Workstation. The system utilizes solid-phase paramagnetic bead technology to purify DNA fragments over 100 bp in under an hour. It processes between 8 to 96 samples using preinstalled methods without needing programming. This allows users to prepare varying molecular biology steps for next-generation sequencing library preparation while samples are purified. The system improves purification consistency and conserves reagents without sacrificing efficiency or recovery.
This document summarizes information about 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 3,3',4,4',5-pentachlorobiphenyl (PCB 126). It describes their identification, occurrence, use, human exposure including occupational exposure, and background levels found in tissues. TCDD is an unintended byproduct formed during production of chlorophenols and herbicides. PeCDF is emitted from combustion sources while PCBs were commercially produced but their manufacture stopped in 1977 due to environmental contamination. Human exposures can
Cosolvent Transesterification of Jatropha Curcas Seed OilZX7
This document presents a study on the cosolvent transesterification of Jatropha curcas seed oil. The key findings are:
1) Jatropha oil was characterized and found to contain mainly palmitic, oleic, linoleic and stearic acids.
2) Tetrahydrofuran was used as the cosolvent to create a single miscible phase for the transesterification reaction between Jatropha oil and methanol.
3) Optimum conditions for transesterification were found to be 40°C, 200 rpm, 4:1 methanol-to-oil ratio, 1:1 cosolvent-to-methanol ratio, 0.5
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes an inter-laboratory evaluation study conducted to validate the use of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay as a standard method for evaluating the antioxidant capacity of food additives. Fourteen laboratories participated in the study. Five analytical samples - four existing food additives (tea extract, grape seed extract, enju extract, and d-α-tocopherol) and Trolox - were evaluated using the DPPH assay. The results showed good repeatability for measuring antioxidant capacity within laboratories, but greater variability between laboratories. However, expressing the results as Trolox equivalent antioxidant capacity reduced inter-laboratory variability, suggesting the DPPH assay could be
Si o2 as an efficient and reusable heterogeneous catalyst for the synthesis of 5Alexander Decker
This document describes a new method for synthesizing 5-substituted 1H-tetrazoles using MoO3-SiO2 as an efficient heterogeneous catalyst. The method involves reacting various substituted benzonitriles with sodium azide in the presence of the MoO3-SiO2 catalyst. The catalyst provides high yields of the tetrazoles under mild reaction conditions. The MoO3-SiO2 catalyst can also be recycled and reused for multiple reactions without loss of activity, making the process economical and environmentally friendly.
11.si o0002www.iiste.org call for_paper as an efficient and reusable heteroge...Alexander Decker
This document describes a new method for synthesizing 5-substituted 1H-tetrazoles using MoO3-SiO2 as an efficient heterogeneous catalyst. The method involves reacting various substituted benzonitriles with sodium azide in the presence of the MoO3-SiO2 catalyst. The catalyst provides high yields of the tetrazoles under mild reaction conditions. The MoO3-SiO2 catalyst can also be recycled without loss of activity, making the process economical and environmentally friendly.
Heterogeneous solid liquid catalysis of n-glycosylation by natural phosphate ...Alexander Decker
This document describes a study that investigated using natural phosphate doped with potassium iodide (NP/KI) as a heterogeneous solid-liquid catalyst for the one-step synthesis of several β-D-ribonucleosides. The reaction of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranoside with various nucleobases including uracil, thymine, cytosine, adenine, and N-acetyl-guanine in the presence of NP/KI produced the corresponding ribonucleosides in good yields ranging from 45-55% after refluxing overnight. The use of NP/KI as the catalyst resulted in higher yields
Fourth report on human exposure to enviroment chemicalsRobson Peixoto
This document is the 2009 Fourth National Report on Human Exposure to Environmental Chemicals, published by the Department of Health and Human Services Centers for Disease Control and Prevention. It provides data on levels of environmental chemicals found in people in the United States by analyzing blood and urine samples. The report contains information on levels of over 200 chemicals or metabolites of chemicals, including pesticides, metals, phthalates, polychlorinated biphenyls, and dioxins. For each chemical or metabolite, the report provides background on the chemical and results from the national biomonitoring study, including any trends over time.
The document discusses the design and testing of a pilot plant for fast pyrolysis of sawdust to produce bio-oil using an auger reactor. Various trials were conducted to optimize operating conditions such as temperature and feed rate. Characterization of the sawdust feedstock and products was also performed to analyze the pyrolysis process and properties of the bio-oil produced.
Determination of Immobilization Process Parameters of Corynebacterium glutami...IJERA Editor
The parameters of the immobilized process of Corynebacterium glutamicum on kappa carrageenan were identified by
Plackett-Burman matrix, and the experiments were designed by response surface methodology having the central
composite designs (RSM-CCD). The maximum yield of cell immobilization on kappa carrageenan carrier reached at
78% ± 2%. Optimal parameters were 3 grams kappa carrageenan per 100 militters sterile water and 58.58 million
cfu/mL, forming gels at 100C for 25 minutes and the speed when soaking particles of 150 rpm for 120 minutes in 0.58
M potassium chlorua solvent. The immobile finished products are applied in L-lysine production, their reusing ability
is 3 times and the total yield of L-lysine was accumulated 93 g/L in medium during 96 fermented hours. The L-lysine
productivity of the batch fermentation was 0.969 g.L-1
.h-1
. And the set-up storage conditions are the mixed solvent of
CaCl2 0.5% (w/v) and KCl 0.5% (w/v); pH is 7.0 in 40C. After 60 storage days, the survival cell rate was remained
51%.
The document provides information about Schiff bases:
- Schiff bases are organic compounds formed by the condensation of carbonyl compounds with primary amines, first reported in 1864.
- There are several methods for synthesizing Schiff bases, including microwave, reflux, stirring, and grinding methods. Spectroscopic techniques like FT-IR, UV-Vis, and X-ray spectroscopy are used to characterize Schiff bases and their complexes.
- Schiff bases have applications in coordination chemistry and as intermediates in organic synthesis. They also show biological activities like antimicrobial and anticancer properties.
1. The document analyzes the degradation of PLGA and PGA-co-PDL polymeric nanoparticles (NPs) in simulated lung fluid (SLF) for pulmonary drug delivery applications.
2. Results showed PLGA NPs reduced in size over time, indicating degradation, while PGA-co-PDL NPs aggregated and increased in size.
3. PLGA NPs produced a more acidic environment as they degraded, which could potentially cause more inflammation than PGA-co-PDL NPs in vivo.
This study evaluated the biodegradability of the antioxidant diaryl-p-phenylene diamine (DAPD) using a modified inherent biodegradation test. DAPD is used in tires and rubber products. Previous studies found it was not readily biodegradable using standard tests. This study used radiolabeled DAPD (R-898) at low concentrations of 10-100 μg/L added to silica gel to enhance solubility, along with a surfactant. After 28 days, no parent compound remained. After 63 days, 37% had mineralized and 29% was incorporated into biomass, demonstrating biodegradation. The modifications enhanced the sensitivity of the test to show DAPD
Degradation of poly-L-lactide. Part 2, IMechE, 2004Dr Neill Weir
Poly-L-lactide (PLLA) specimens were degraded in phosphate-buffered solution at 50°C and 70°C to evaluate accelerated degradation compared to physiological degradation at 37°C. Molecular weight, mechanical properties, and thermal properties were analyzed over time. At both 50°C and 70°C, molecular weight decreased more rapidly than at 37°C, with over 90% reduction by 115 days at 50°C and 95% by 23 days at 70°C. Degradation mechanisms appeared similar to 37°C, though autocatalysis may be affected at higher temperatures. Increased temperature provided accelerated degradation of PLLA compared to physiological conditions.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
We follow "Rigorous Publication" model - means that all articles appear on IJERD after full appraisal, effectiveness, legitimacy and reliability of research content. International Journal of Engineering Research and Development publishes papers online as well as provide hard copy of Journal to authors after publication of paper. It is intended to serve as a forum for researchers, practitioners and developers to exchange ideas and results for the advancement of Engineering & Technology.
miniemulsion polymerization of butadiene 2015Ahmed Moustafa
The document summarizes a study on the kinetics of miniemulsion polymerization (MEP) and conventional emulsion polymerization (CEP) of butadiene. Some key findings:
1) MEP of butadiene showed a much faster initial conversion rate and propagation rate compared to CEP, due to MEP polymerizing monomer reservoirs rather than micelles.
2) The maximum swelling of butadiene liquid into hexadecane miniemulsion droplets was achieved within 3 hours at room temperature.
3) Reducing the swelling time to 45 minutes before initiating polymerization still resulted in faster kinetics for MEP compared to CEP.
4) The propagation rate for MEP was found to
Nano ti o2 as an efficient and reusable heterogeneous catalyst for the synthe...Alexander Decker
This document summarizes a study that investigated the use of nano TiO2 as a heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles. Nano TiO2 efficiently catalyzed the [2+3] cycloaddition reaction of sodium azide with various nitriles to produce the corresponding tetrazoles in good yields. The nano TiO2 catalyst could be easily recovered and reused for multiple cycles without loss of activity. This new catalytic method provides a simple, efficient, and reusable approach for synthesizing 5-substituted 1H-tetrazoles.
The document provides guidelines for safely starting up and reducing steam reforming catalyst. It discusses warm-up procedures to avoid condensation, reducing the catalyst with hydrogen or hydrocarbons, and gradually introducing feedstock. It also summarizes a case study where overfiring during start-up led to tube failures due to much higher than normal temperatures as a result of deviations from proper procedures.
The document discusses fuels and combustion. It defines fuels and their classification based on occurrence and physical state. It describes the measurement of calorific value using a bomb calorimeter and Junkers gas calorimeter. It also discusses the gross and net calorific values, combustion calculations, proximate and ultimate analysis of solid fuels, and the theoretical calculation of a fuel's calorific value using Dulong's formula.
Revamp objectives
Revamp Philosophy
Revamp options
Semi-Regenerative Reforming Unit
Typical Flow Scheme
Continuous Reforming Unit
Typical Flow Scheme
Revamp to Hybrid Operation
What may be achieved?
Typical C5+ Yield at Decreasing Pressure
Changes Required for Full Conversion
Typical Benefits of Full Conversion
Revamping of Existing Continuous Reforming Units
Fired Heaters Revamp
Burners
Reactor Options
Regeneration Section
Summary
Cosolvent Transesterification of Jatropha Curcas Seed OilZX7
This document presents a study on the cosolvent transesterification of Jatropha curcas seed oil. The key findings are:
1) Jatropha oil was characterized and found to contain mainly palmitic, oleic, linoleic and stearic acids.
2) Tetrahydrofuran was used as the cosolvent to create a single miscible phase for the transesterification reaction between Jatropha oil and methanol.
3) Optimum conditions for transesterification were found to be 40°C, 200 rpm, 4:1 methanol-to-oil ratio, 1:1 cosolvent-to-methanol ratio, 0.5
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes an inter-laboratory evaluation study conducted to validate the use of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay as a standard method for evaluating the antioxidant capacity of food additives. Fourteen laboratories participated in the study. Five analytical samples - four existing food additives (tea extract, grape seed extract, enju extract, and d-α-tocopherol) and Trolox - were evaluated using the DPPH assay. The results showed good repeatability for measuring antioxidant capacity within laboratories, but greater variability between laboratories. However, expressing the results as Trolox equivalent antioxidant capacity reduced inter-laboratory variability, suggesting the DPPH assay could be
Si o2 as an efficient and reusable heterogeneous catalyst for the synthesis of 5Alexander Decker
This document describes a new method for synthesizing 5-substituted 1H-tetrazoles using MoO3-SiO2 as an efficient heterogeneous catalyst. The method involves reacting various substituted benzonitriles with sodium azide in the presence of the MoO3-SiO2 catalyst. The catalyst provides high yields of the tetrazoles under mild reaction conditions. The MoO3-SiO2 catalyst can also be recycled and reused for multiple reactions without loss of activity, making the process economical and environmentally friendly.
11.si o0002www.iiste.org call for_paper as an efficient and reusable heteroge...Alexander Decker
This document describes a new method for synthesizing 5-substituted 1H-tetrazoles using MoO3-SiO2 as an efficient heterogeneous catalyst. The method involves reacting various substituted benzonitriles with sodium azide in the presence of the MoO3-SiO2 catalyst. The catalyst provides high yields of the tetrazoles under mild reaction conditions. The MoO3-SiO2 catalyst can also be recycled without loss of activity, making the process economical and environmentally friendly.
Heterogeneous solid liquid catalysis of n-glycosylation by natural phosphate ...Alexander Decker
This document describes a study that investigated using natural phosphate doped with potassium iodide (NP/KI) as a heterogeneous solid-liquid catalyst for the one-step synthesis of several β-D-ribonucleosides. The reaction of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranoside with various nucleobases including uracil, thymine, cytosine, adenine, and N-acetyl-guanine in the presence of NP/KI produced the corresponding ribonucleosides in good yields ranging from 45-55% after refluxing overnight. The use of NP/KI as the catalyst resulted in higher yields
Fourth report on human exposure to enviroment chemicalsRobson Peixoto
This document is the 2009 Fourth National Report on Human Exposure to Environmental Chemicals, published by the Department of Health and Human Services Centers for Disease Control and Prevention. It provides data on levels of environmental chemicals found in people in the United States by analyzing blood and urine samples. The report contains information on levels of over 200 chemicals or metabolites of chemicals, including pesticides, metals, phthalates, polychlorinated biphenyls, and dioxins. For each chemical or metabolite, the report provides background on the chemical and results from the national biomonitoring study, including any trends over time.
The document discusses the design and testing of a pilot plant for fast pyrolysis of sawdust to produce bio-oil using an auger reactor. Various trials were conducted to optimize operating conditions such as temperature and feed rate. Characterization of the sawdust feedstock and products was also performed to analyze the pyrolysis process and properties of the bio-oil produced.
Determination of Immobilization Process Parameters of Corynebacterium glutami...IJERA Editor
The parameters of the immobilized process of Corynebacterium glutamicum on kappa carrageenan were identified by
Plackett-Burman matrix, and the experiments were designed by response surface methodology having the central
composite designs (RSM-CCD). The maximum yield of cell immobilization on kappa carrageenan carrier reached at
78% ± 2%. Optimal parameters were 3 grams kappa carrageenan per 100 militters sterile water and 58.58 million
cfu/mL, forming gels at 100C for 25 minutes and the speed when soaking particles of 150 rpm for 120 minutes in 0.58
M potassium chlorua solvent. The immobile finished products are applied in L-lysine production, their reusing ability
is 3 times and the total yield of L-lysine was accumulated 93 g/L in medium during 96 fermented hours. The L-lysine
productivity of the batch fermentation was 0.969 g.L-1
.h-1
. And the set-up storage conditions are the mixed solvent of
CaCl2 0.5% (w/v) and KCl 0.5% (w/v); pH is 7.0 in 40C. After 60 storage days, the survival cell rate was remained
51%.
The document provides information about Schiff bases:
- Schiff bases are organic compounds formed by the condensation of carbonyl compounds with primary amines, first reported in 1864.
- There are several methods for synthesizing Schiff bases, including microwave, reflux, stirring, and grinding methods. Spectroscopic techniques like FT-IR, UV-Vis, and X-ray spectroscopy are used to characterize Schiff bases and their complexes.
- Schiff bases have applications in coordination chemistry and as intermediates in organic synthesis. They also show biological activities like antimicrobial and anticancer properties.
1. The document analyzes the degradation of PLGA and PGA-co-PDL polymeric nanoparticles (NPs) in simulated lung fluid (SLF) for pulmonary drug delivery applications.
2. Results showed PLGA NPs reduced in size over time, indicating degradation, while PGA-co-PDL NPs aggregated and increased in size.
3. PLGA NPs produced a more acidic environment as they degraded, which could potentially cause more inflammation than PGA-co-PDL NPs in vivo.
This study evaluated the biodegradability of the antioxidant diaryl-p-phenylene diamine (DAPD) using a modified inherent biodegradation test. DAPD is used in tires and rubber products. Previous studies found it was not readily biodegradable using standard tests. This study used radiolabeled DAPD (R-898) at low concentrations of 10-100 μg/L added to silica gel to enhance solubility, along with a surfactant. After 28 days, no parent compound remained. After 63 days, 37% had mineralized and 29% was incorporated into biomass, demonstrating biodegradation. The modifications enhanced the sensitivity of the test to show DAPD
Degradation of poly-L-lactide. Part 2, IMechE, 2004Dr Neill Weir
Poly-L-lactide (PLLA) specimens were degraded in phosphate-buffered solution at 50°C and 70°C to evaluate accelerated degradation compared to physiological degradation at 37°C. Molecular weight, mechanical properties, and thermal properties were analyzed over time. At both 50°C and 70°C, molecular weight decreased more rapidly than at 37°C, with over 90% reduction by 115 days at 50°C and 95% by 23 days at 70°C. Degradation mechanisms appeared similar to 37°C, though autocatalysis may be affected at higher temperatures. Increased temperature provided accelerated degradation of PLLA compared to physiological conditions.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
We follow "Rigorous Publication" model - means that all articles appear on IJERD after full appraisal, effectiveness, legitimacy and reliability of research content. International Journal of Engineering Research and Development publishes papers online as well as provide hard copy of Journal to authors after publication of paper. It is intended to serve as a forum for researchers, practitioners and developers to exchange ideas and results for the advancement of Engineering & Technology.
miniemulsion polymerization of butadiene 2015Ahmed Moustafa
The document summarizes a study on the kinetics of miniemulsion polymerization (MEP) and conventional emulsion polymerization (CEP) of butadiene. Some key findings:
1) MEP of butadiene showed a much faster initial conversion rate and propagation rate compared to CEP, due to MEP polymerizing monomer reservoirs rather than micelles.
2) The maximum swelling of butadiene liquid into hexadecane miniemulsion droplets was achieved within 3 hours at room temperature.
3) Reducing the swelling time to 45 minutes before initiating polymerization still resulted in faster kinetics for MEP compared to CEP.
4) The propagation rate for MEP was found to
Nano ti o2 as an efficient and reusable heterogeneous catalyst for the synthe...Alexander Decker
This document summarizes a study that investigated the use of nano TiO2 as a heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles. Nano TiO2 efficiently catalyzed the [2+3] cycloaddition reaction of sodium azide with various nitriles to produce the corresponding tetrazoles in good yields. The nano TiO2 catalyst could be easily recovered and reused for multiple cycles without loss of activity. This new catalytic method provides a simple, efficient, and reusable approach for synthesizing 5-substituted 1H-tetrazoles.
The document provides guidelines for safely starting up and reducing steam reforming catalyst. It discusses warm-up procedures to avoid condensation, reducing the catalyst with hydrogen or hydrocarbons, and gradually introducing feedstock. It also summarizes a case study where overfiring during start-up led to tube failures due to much higher than normal temperatures as a result of deviations from proper procedures.
The document discusses fuels and combustion. It defines fuels and their classification based on occurrence and physical state. It describes the measurement of calorific value using a bomb calorimeter and Junkers gas calorimeter. It also discusses the gross and net calorific values, combustion calculations, proximate and ultimate analysis of solid fuels, and the theoretical calculation of a fuel's calorific value using Dulong's formula.
Revamp objectives
Revamp Philosophy
Revamp options
Semi-Regenerative Reforming Unit
Typical Flow Scheme
Continuous Reforming Unit
Typical Flow Scheme
Revamp to Hybrid Operation
What may be achieved?
Typical C5+ Yield at Decreasing Pressure
Changes Required for Full Conversion
Typical Benefits of Full Conversion
Revamping of Existing Continuous Reforming Units
Fired Heaters Revamp
Burners
Reactor Options
Regeneration Section
Summary
Neil Brodie has over 30 years of experience in the aircraft industry as a manufacturing engineer, designer, and technician. He has extensive experience designing aircraft structures, systems, electrical, and interiors using CAD systems like CATIA. Recent roles include senior design engineer positions at Airbus developing the A350 wing flaps and fuel systems. He has also held design roles on projects like the A380, A400M, Eurofighter, and Embraer aircraft.
This document discusses the isomerization of n-butane and aromatics. Isomerization changes the physical and chemical properties of compounds and produces isomers that are better for motor fuels and an important step in gasoline manufacture. Isomerization of aromatics uses catalysts to produce specific chemicals in the naphtha boiling range that have applications in various industries.
The document describes a catalytic isomerization unit (KIT) that increases the octane rating of gasoline. It processes light petroleum fractions to produce gasoline with an octane number of 76-83. The technological process involves reacting normal alkanes over a zeolite catalyst to isomerize the hydrocarbons. The unit is available in capacities of 24 or 48 cubic meters per day and can boost octane by 13 to 30 points. It operates continuously to convert low-octane gasoline into high-octane unleaded petrol.
Naphtha Steam Reforming Catalyst Reduction with MethanolGerard B. Hawkins
Procedure for Naphtha Steam Reforming Catalyst Reduction with Methanol
Scope
This procedure applies to the in situ reduction of VULCAN Series steam reforming catalysts using methanol cracking to form hydrogen over the catalyst in the steam reformer.
The procedure is likely to be applied to plants using only heavier feeds (e.g.: LPG and/or naphtha) and some combination of VULCAN Series catalysts.
Introduction
A small number of steam reforming plants do not have an available source of the commonly used reducing media (e.g.: hydrogen, hydrogen-rich off-gas, natural gas). These plants will usually operate on LPG and/or naphtha feed only where cracking of this hydrocarbon is not usually advised for reduction of the steam reforming catalyst ...
The document contains a list of typical process equipment used in reforming and catalyst regeneration sections of a refinery, including reactors, columns, vessels, furnaces, heat exchangers, pumps, compressors and blowers. It also provides comparisons of different reforming processes and their key parameters such as RON, reaction pressure, LHSV, H2/HC ratio, yield and cycle length. Finally, it summarizes the assessment of a recommended process/technology for criteria such as performance, reliability, safety, costs and flexibility.
This document discusses catalytic cracking, which breaks down large hydrocarbon molecules into smaller, more useful molecules. It describes the different types of cracking processes and explains that catalytic cracking is most commonly used. Catalytic cracking uses lower temperatures and pressures than thermal cracking by using a catalyst. It provides details on the catalytic cracking process, including that it occurs in three basic functions: reaction, regeneration, and fractionation. It also describes the specific fluid catalytic cracking and moving bed catalytic cracking processes.
Catalytic Reactions in Catalytic Reforming
Catalytic Reforming Reactions
Sulfur Related Problems
Effects of Sulfur in Catalytic Reforming
Reactions in Catalytic Reforming
Catalytic Reforming Catalysts
Effect of Sulfur on Catalytic Reforming Catalysts
Catalytic Reformer Efficiency
VULCAN Sulfur Guards
VULCAN Sulfur Guards for Catalytic Reformers
VULCAN Guard Installation Protects Isomerization Catalysts
Liquid Phase vs Gas Phase: Relative Advantages
Liquid Phase Treating
Which active metal is best?
Thiophenes and Nickel Sulfur Guards
Sulfiding mechanisms with reduced metals
Thiophene adsorption on nickel
Advantages of Cu/Zn Over Nickel Sulfur Guards
Copper oxide vs Nickel
Nickel Sulfur Guards
Manganese Sulfur Guards
The petroleum industry uses Reforming as a primary process for quality improvement to meet final fuel specifications as well as hydrogen and LPG production for many intermediate processing units. This course covers the core elements of Reforming technology. Key variables that affect product yields and properties are described and their impact on the optimisation of the unit operation discussed. A framework is presented for troubleshooting operating problems and, throughout this discussion, participants are encouraged to describe their specific challenges.
The document discusses octane number, which is a measure of gasoline's resistance to engine knocking. It outlines how engines needed more power, leading to higher compression ratios that risked knocking. To prevent this, the octane number scale from 0-100 was developed using single-cylinder engine tests comparing fuels to iso-octane (100) and n-heptane (0). Higher octane fuels allow for greater efficiency and power through higher compression. Additives and blending fuels can increase a gasoline's octane number to prevent knocking. The scale has been extended above 100 through additional additives.
Octane and cetane numbers measure a fuel's resistance to self-ignition or knocking. Octane numbers refer to gasoline's resistance to knocking, measured using two tests - the Research Octane Number (RON) and Motor Octane Number (MON). Cetane numbers refer to diesel fuel's ease of ignition, with higher numbers indicating easier ignition. Fuels like gasoline and diesel have different typical octane/cetane numbers and properties that affect their use in engines.
1. Isomerization is the process of converting a carbohydrate like glucose into another with the same molecular formula but different structure. Glucose isomerase catalyzes the conversion of glucose into fructose, which is used to produce high fructose corn syrup.
2. High fructose corn syrup is composed of 42% or 55% fructose and is sweeter and cheaper than sucrose, making it widely used as a sweetener in foods and beverages. It is produced through the isomerization of glucose into fructose using immobilized glucose isomerase enzymes.
3. Dextrinization is the breakdown of starch into smaller carbohydrate molecules called dextrins through enzymatic
Catalytic Reforming Process is one of the most important processes in the petroleum and petrochemical industries which produce high octane number gasoline.
03 Chemical Engineering Plant Design And Economicsguestac67362
The document is a past exam paper for a Chemical Engineering Plant Design and Economics course. It contains 8 multi-part questions testing various concepts related to plant design, economics, and capital investment analysis. Specifically, it examines topics such as batch vs continuous operation, methods for estimating capital investment, components of fixed charges, taxation, depreciation methods, rate of return analysis, and optimization of plant design. Students were required to answer any 5 of the 8 questions in the 3 hour exam.
This document is a presentation by Group 4 of Diploma Civil "A" on the topic of fuel and combustion. It introduces different types of fuels such as solid, liquid, and gaseous fuels. Solid fuels discussed include coal, coke, and charcoal. Liquid fuels mentioned are tar, kerosene, diesel, petrol, and gas. Gaseous fuels include natural gas, coal gas, and biogas. The presentation covers the characteristics of good fuels, classification of fuels, advantages and disadvantages of different fuel types, and concepts of combustion and calorific values. In the end, the group thanks their professor Mr. Tarang Agarwal for giving them the opportunity to present.
This document provides an overview of isomerism for students. It begins by outlining the prior knowledge needed to understand isomerism and then defines the main types: structural isomerism, stereoisomerism, geometrical isomerism, and optical isomerism. For each type, examples are given to illustrate key concepts like different arrangements of carbon skeletons or functional groups (structural), restricted double bond rotation causing cis/trans forms (geometrical), and chiral centers producing non-superimposable mirror images (optical). Checklists are provided to identify isomerism possibilities in different molecules. The document aims to clearly define and differentiate the various isomerism types through detailed explanations, diagrams, and molecular
This document discusses a hydroxylamine-based wet chemistry process for removing photoresist, sidewall polymers, and other residues from plasma processing. It has been found to leave surfaces free of visual contamination. The process exhibits lower levels of mobile ionic contamination than alternatives. The development of sub-micron devices requires clean via holes for low-resistance contacts. Photoresist stripping methods must address issues like mobile ion contamination and plasma damage while simplifying processes.
Deactivation Modeling through Separable Kinetics of Coking On Ni/CZ Catalyst ...IOSR Journals
Abstract : Steam methane reforming (SMR) is a very significant technique to produce hydrogen from fossil fuels. In this particular work, nickel is used as the active metal and ceria-zirconia (CZ) bi-metallic oxide is used as the support. The foremost challenge to this process is sooting or coking over the catalyst surface and blocking the active sites. For the economic viability of the catalyst, it is very significant to make it coke deposition resistant. This is the reason that the kinetic modeling of the deactivation is very important. Therefore, this paper is aimed to model the deactivation and activity of the catalyst. A rate model of the deactivation process is also developed using separable kinetics. A comparison with commercial catalyst is also reported to show that the Ni/CZ catalyst is much more stable towards the coking. Keywords –Coking, Deactivation, Methane, Separable kinetics, Steam reforming.
The Selective Oxidation of n-Butane to Maleic Anhydride in a Catalyst Packed ...Gerard B. Hawkins
The Selective Oxidation of n-Butane to Maleic Anhydride in a Catalyst Packed Tubular Reactor
CONTENTS
0 INTRODUCTION
1 n-BUTANE OXIDATION
2 REACTION KINETICS
3 HEAT AND MASS TRANSFER PARAMETERS
4 NON-ISOTHERMAL, NON-ADIABATIC REACTOR MODELING
5 USE OF THE REACTOR MODEL IN OPERABILITY AND DESIGN STUDIES
6 BIBLIOGRAPHY
7 NOMENCLATURE
The document summarizes research on synthesizing macrocyclic chelating agents for removing and concentrating perchlorate. It discusses:
1) Background on perchlorate contamination issues and calixarenes as potential extraction reagents.
2) The objectives to synthesize and characterize calix[4]arene-based polymeric materials and apply them to remove perchlorate from water.
3) Experimental methods including synthesis, characterization techniques, and column studies to test perchlorate removal efficiency.
"SEDIMENTATION"
INTRODUCTION - THE PHENOMENON OF SEDIMENTATION
Sedimentation is the physical process whereby solid particles, of greater density than their suspending medium, will tend to separate into regions of higher concentration under the influence of gravity. As a solids/liquids separation technique it therefore possesses the great advantage of utilizing a natural, and therefore costless, driving force. This section of the suspension processing Guide is Intended to provide an Introduction to the science of the subject, and the means to judge where and how best to exploit sedimentation as a separation (or other processing) technique.
As a scientific discipline the subject of sedimentation is vast with perspectives ranging from the field of chemical engineering through to theoretical physics being covered In the literature [1-11]. Good reviews of the subject, with a bias towards the engineering aspects, have been written by Fitch and Koz [12, 13]. A short summary of some of the more relevant contributions from the literature is also provided in GBHE-SPG-PEG-302 “Basic Principles & Test Methods”, of the Suspensions Processing Guides.
.
The sedimentation process is traditionally divided into ..."
IRJET - Factorial Optimization and Peri-Kinetics of Pharmaceutical Effluent C...IRJET Journal
The document discusses optimization and kinetics of coag-flocculation of pharmaceutical industry effluent using Pleurotus tuberregium sclerotium tuber. Key findings include:
1) The optimal coag-flocculation conditions for maximum TDSS removal were determined to be pH 13, coagulant dosage of 0.3g/l, and settling time of 40 minutes, achieving 98.68% removal efficiency.
2) Kinetic models were developed and applied to experimental data to determine aggregation rate constant (K) and coagulation period (τ1/2), with maximum values of 2.491E-04 l/g.min and 7E-02 min respectively.
3
The document discusses nanocatalysts and their applications in chemical industry. It begins with definitions of catalyst and nanocatalyst. It then discusses different types of nanocatalysts including homogeneous nanocatalysts which are soluble in solvents and heterogeneous nanocatalysts which are insoluble. Methods for preparing both homogeneous and heterogeneous nanocatalysts are described. The document outlines several industrial applications of nanocatalysts such as in biodiesel production, water purification, drug delivery, and fuel cells. It concludes that nanocatalysts have advantages over traditional catalysts like high activity, selectivity, stability, and ease of separation.
This document summarizes research on the catalytic wet peroxide oxidation of olive oil mill wastewater over zeolite-based catalysts. The researchers prepared a Cu/13X catalyst by ion exchange and tested its activity and stability for reducing phenolic compounds in wastewater. Characterization showed the ion exchange did not affect zeolite structure but a post-treatment calcination at 1273K decreased surface area and increased copper oxide particles. Testing showed the catalyst reduced total phenols in wastewater by over 80% and TOC by 20% with low copper leaching. The research aims to develop an effective treatment to reduce toxicity of olive oil wastewater before conventional biological processing.
This document discusses guidelines for efficient organic synthesis. It covers topics like atom economy, redox economy, cascade reactions, protecting groups, biomimetic synthesis, and lessons from natural products. The goal is to minimize waste and maximize the formation of carbon-carbon bonds in each step. Tactics include choosing reactions with 100% atom economy, reducing non-essential oxidation/reduction steps, exploiting the reactivity of functional groups, and incorporating tandem reactions to make multiple changes in one step.
The document discusses various applications of nanomaterials in catalysis. It begins by introducing different types of catalysts and how nanocatalysts combine advantages of homogeneous and heterogeneous systems by having a high surface area like homogeneous catalysts while also being easily separable like heterogeneous catalysts. Several examples of nanocatalyst applications are then summarized in areas like water purification, biodiesel production, drug delivery, fuel cells, environmental protection, and solar cells. The document emphasizes how nanocatalysts provide benefits like high activity, selectivity, stability, and being energy efficient.
Predictive Model for Corrosion Inhibition of Mild Steel in HCl by Crushed Lea...IRJET Journal
The document presents a study on using crushed leaves of the Clerodendrum Splendens plant as a natural corrosion inhibitor for mild steel immersed in hydrochloric acid solutions. Key findings from the study include:
1) The crushed leaves reduced the corrosion rate of mild steel and improved inhibition efficiency as exposure time and leaf quantity increased, with the highest efficiency of 70.7% achieved.
2) A predictive corrosion model was developed using multiple regression and artificial neural networks to predict corrosion rates based on time, acid concentration, and leaf quantity.
3) Analysis of the steel surface suggested the leaves form a protective film associated with functional groups that inhibit corrosion.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Toxicity immobilization of refinery sludge containing heavy metals via vitrif...eSAT Journals
Abstract Heavy metals are known to be toxic to human and the environment. Despite the growing of petrochemical and refinery industries, the world is facing problems with the heavy metals contamination from the sludge by the industries. Many methods have been applied to address these issues from the refinery sludge. In this study, stabilization and solidification of refinery sludge containing heavy metals using vitrification method was utilized to solve this problem. The ashing temperature of 550oC was selected in preparing the ash of the dried sludge prior to the vitrification process at 1110oC to 1400oC. After vitrification, all samples were morphologically, thermally and toxically analyzed using Scanning Electron Microscopy, Thermogravimetric Analysis and Toxicity Characteristic Leaching Procedure. The sludge contained high amount of iron and aluminum, followed by some amount of magnesium, gold, arsenic and zinc with some traces of nickel and lead. Results showed that at maximum vitrified temperature of 1400oC, no magnesium, nickel and lead were detected in the sludge and only some traces of other heavy metals with less than 1 ppm. The vitrification method exhibits excellent output in immobilizing the transition metals leading to a reduction in environmental pollution caused by petrochemical and refinery sludge containing heavy metals. Index Terms: Vitrification, Heavy metals contamination, Refinery sludge, Toxicity, Leaching analysis
Investigations into Advanced Laboratory Deactivation Methods for the Selectio...Zachary Sample
This document discusses methods for deactivating fresh fluid catalytic cracking (FCC) catalyst in the laboratory to simulate commercial equilibrium catalyst performance. Commonly used methods like cyclic deactivation and cyclic propene steaming can accurately mimic plant catalyst but are time-consuming. Rapid deactivation methods have been proposed as alternatives that can also simulate commercial catalyst performance without extensive testing procedures. This study aims to assess one such rapid deactivation method and characterize catalyst samples using techniques like XRD, TPR and SEM/EDX to evaluate its ability to predict commercial FCC performance.
Chemical modification of lignocellulosic materials by irradiation with Nd-YAG...NabilMabrouk6
1) Nd-YAG laser pulses were used to irradiate samples of lignin, microcrystalline cellulose, and filter paper. Lignin experienced substantial weight loss and degradation upon irradiation, while cellulose samples were unaffected.
2) Irradiation reduced the molecular weight and narrowed the molecular weight distribution of lignin. Smaller lignin fragments with increased phenolic hydroxyl content were produced.
3) Laser treatment provided a simple way to modify lignin properties without using chemical reagents. This technique could allow production of lignin samples with uniform characteristics.
DEACTIVATION OF METHANOL SYNTHESIS CATALYSTS
CONTENTS
1 INTRODUCTION
2 THERMAL SINTERING
3 CATALYST POISONING
4 REACTANT INDUCED DEACTIVATION
5 SUMMARY
TABLES
1 DEACTIVATION PROCESSES ON METHANOL SYNTHESIS CATALYSTS
2 MELTING POINT, HUTTIG AND TAMMANN TEMPERATURES OF COPPER, IRON AND NICKEL
3 SINTERING RATE CONSTANTS CALCULATED INLET AND OUTLET SIDE STREAM UNIT FOR VULCAN VSG-M101
4 COMPARISON BETWEEN CALCULATED S∞ AND DISCHARGED MEASUREMENTS ON VULCAN VSG-M101
5 EFFECT OF POSSIBLE CONTAMINANTS AND POISONS ON CU/ZNO/AL2O3 CATALYSTS FOR METHANOL SYNTHESIS
6 GUARD SCREENING TEST RESULTS ON METHANOL MICRO-REACTOR. EFFECT OF DEPOSITED METALS ON METHANOL ACTIVITY
FIGURES
1 THE HΫTTIG AND TAMMANN TEMPERATURES OF THE COMPONENTS OF A SYNTHESIS CATALYST
2 A SCHEMATIC REPRESENTATION OF TWO CATALYST SINTERING MECHANISMS
3 SIDE STREAM DATA FOR VULCAN VSG-M101. INLET TEMPERATURE 242 OC, PRESSURE 1500 PSI, GAS COMPOSITION 6% CO, 9.2% CO2, 66.9% H2, 2.5% N2 AND 15.4% CH4, SPACE VELOCITY 17,778 HR-1. MEAN OUTLET TEMPERATURE 280 OC
4 TEMPERATURE DEPENDENCE OF THE RATE OF SINTERING
5 MECHANISM OF SULFUR RETENTION
6 CORRELATION OF SULFUR CAPACITY WITH TOTAL SURFACE AREA
7 EFFECT OF DEPOSITED (NI+FE) PPM ON METHANOL SYNTHESIS CATALYST ACTIVITY
8 DISCHARGED (FE + NI) DEPOSITION LEVELS ON METHANOL SYNTHESIS PLANT SAMPLES
9 EPMA ANALYSIS OF DISCHARGED LABORATORY SAMPLE OF POISONED VULCAN VSG-M101
10 THE EFFECT OF CO2 ON SYNTHESIS CATALYST DEACTIVATION
REFERENCES
In this study, kinetics of demineralization of chitin extraction from snail shells was
investigated. Chitin was extracted from snail shells by demineralizing the
deproteinized shells in 1.2 M HCl solution. Prior to demineralization, the raw snail
shells were deproteinized using 1 M NaOH solution to remove proteins and organic
matter present in the shells. The product was dried before the demineralization
process was carried out. The results showed that based on the R2 values obtained for
each of the shrinking core models considered which include; fluid film diffusion
(FFD), ash layer diffusion (ALD), and chemical reaction control (CRC), it was noted
that the CRC model was prevalent for all the various range of particle sizes analyzed
(6.3 – 4.75 mm, 4.75 – 2 mm, 2 – 1 mm, and 600 – 300 μm). The surface morphologies
and the Fourier Transform Infra-Red (FTIR) bands of the extracted chitin were
similar to previous studies
Studies on radiation grafting of hydrophilic monomer onto chitin for ion exchange application were examined . Over the past several years , chitin has been receiving increased attention for its application such as ion exchange . They are utilized scarcely because of problems associated with poor solubility, hidrophilicity and low reactivity. Graft copolymerization induced by irradiation is one of the methods for chitin modification in order to improve its properties such as hydrophilicity and reactivity. The aim of this research is to increasing the ability of chitin as ion exchange for heavy metal adsorbent.
PerkinElmer Application Note: Monitoring volatile organic compounds in beer p...PerkinElmer, Inc.
Beer is a popular beverage produced by the fermentation of hopped malt extracted from barley and other grains. Although simple in concept, beer is a highly complex mixture of many compounds including sugars, proteins, alcohols, esters, acids, ketones, acids and terpenes. Flavor is an important quality of any beer and the chemical content of the beer is obviously responsible for that flavor. Aroma is an extremely important part of the flavor and so there is a strong interest by brewers in the volatile organic compounds (VOCs) in beer that affect it's aroma. This application note describes a system comprising a headspace trap sampler to extract and concentrate VOCs from a beer sample and deliver them to a gas chromatograph/mass spectrometer (GC/MA) for separation, identification and quantification.
International Journal of Engineering (IJE) Volume (2) Issue (4)CSCJournals
This document summarizes an experimental study on treating distillery effluent using an aerobic reactor with sewage sludge as a seed culture. Microorganisms in the sewage sludge were isolated and identified. The reactor was operated at different initial substrate concentrations and samples analyzed over time for COD, TSS, TDS and pH. The first-order and diffusional models best described the kinetic data, showing decreasing rate constants with increasing initial concentration. The Singh model provided a poor fit. Maximum COD removals of 78-88% were achieved.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
Communicating effectively and consistently with students can help them feel at ease during their learning experience and provide the instructor with a communication trail to track the course's progress. This workshop will take you through constructing an engaging course container to facilitate effective communication.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
Isome hoa pdf
1. IICPT
Inqi Journal of Chcmicel
.rd P.trolcum Enginccritrg
lraqi Chemical Petroleum
Journalof and
Vol.8No.3(September
ISSN:
Engineering
2007)43-48
1997-4884 Univcnity ofBrgbdd
Coll€c of EDtinE iog
Deactivation lsomerization
Studyof Catalysts in Process
to ProduceHigh OctaneGasoline
Khalid A. Sukkar,HayamM. Abrlul-Raheemo Amel Th. Jubern and Jabir Sh.Jurnaly'
ChemicalEngineering - University Technolog,t
Department of - Iraq
' * College Engineering *
- University Al-Nahrain Iraq
Chemical Department
Engineering of of
Abstract
In this study the isomerization desulfuerized
of light lraqi petroleumnaphtha(Al-DuraRefinery)with boilingpoint
range of 37 to 124 oC , 80.5API specificgravity and 68.2 octanenumber has beenirwestigated.Two typesof
catolystswereprepared (P1/HXand Pt/SrX) by impregnationof 0.8 wt%o on l3X-zeolite. The catalyst activity and
Pt
selectivitytowardisomerization, catalyt deactivation
and wereinvestigated.
Theisomerization consisled a vertical tubular stainless
unit of steelreactorof 2 cm internaldiameter, cm external
3
diameter and 68 cm height.Theoperating pressure was atmospheric all experimental
for runs. Theliquidflow of light-
naphtha was A.4 IJh, and the catalystweight was 50 gm, H/H.C ratio usedwas 4 for all experimental runs. The
isomerizationprocess studiedat dfurent tenperatures 250, 270, 275, 300,325, and 350oC , Itwasfound that,
was of
the optimum isomerization is
temperature 270"C
Theisomerizationactivities snd selectivities afunction of timeshowedhigh activity at the beginningof the reaction
os
ord were deactivated rapidly. This indicatesthat the deactivationof PI/HX and Pt/SrX results from the blocking of pore
nouth by the depositedcarbon. Thefollowing deaeliv;ation decreasingorder, PI/HX > Pt/SrX wasfound. On the other
,nnd, PI/HX cotalyst shows higher activity and selectivitythqn that of Pt/SrX.
It waseoncluded that,only an cverage 90 wt% of the carbonatoms
of feed into thereactor(light naphtha)is detected
in theproductstreamduetoformation of cokedeposits which leadsto cqtalystdeactivation. resultsclearlyshowed
The
thot hydrogenis necessary the ltydrogenation olefinsin order to preventoligonerizationreactionthat leadslo
for of
coke formation and catalystdeactivation.
light-napgtha,PIJHX PVSrXcatalysts,
Icywortls; catalyticisomerization, and deactivation.
lnboduction In general,a catalystmay lose its activity or its
selectivity to poisoning,
due fouling,sintering lossof
and
Due to a heightened awareness the environrnental
of activespecies Oneof the mostchallenging
[], tasksin
poblem worldwide,expectations cleanand unleaded
of the designand operation industrialcatalyticprocesses
of
gasoline and world demand for gasoline have been is the prevention,or at least the control, of catalyst
ircreasing.Catzl5'ticisomerization regardedoneof the
is deactivation. Loss of catalyst activity is often
mostimportantprocesses oil refineries
in which produce accompaniedby a loss in selectivity. This leads to
cleanand high octanegasoline. Isomerization convefts n- greater formation of undesired by-products such as
butane, n-pentaneand n-hexaneinto their respective wasteof
carbonoxides,poor utilizationof raw rnaterials,
boparaffinsof substantiallyhigher octanenumber.The energy,and increased pollution [3,4]. Thus, solving
oommon feedstocke isomerization
for process the light
is problems of paramount
deactivation is importance the
for
saight run naphtha, which consists the lighter fraction
of economicand ecologic performance the process
of
cs tc6Lt,2l. industry.Understanding deactivation mechanisms could
Vol.8No.3(September
IJCPE 2007) 43
2. otin,
ultimately lead to the design of inherently stable diameter,3 cm externaldiameter
and 68 cm height
catalysts, considerable
with benefits.Solvine deactivation (reactor volume 214 cm3).The reactor was heated
-of
problems requiresa detailedknowledge th. ,uny uniformlyusingan electrical furnace.Thetemperarure at
causes mechanisms
and involved [6,7,gJ. the reactorcenterof the catalystbed and at different
, On theotherhand,foulingformation regarded of
is one points in reactor and system were determinedby
the most importanttypes of catalystdeictivationin manufacturingan interface system, (Computerized
isomerization process.Generally,the kinetics of a Temperature Measurement System) which has ten
catalyst deactivation a functionof temperature,
is time, calibrated thermocouple sensors K (iron-constantan).
type
pressure and the concentrations of different Theinterface programmed is andrun by a computer (p4).
substances l0].
[9, The reactoris fittsd with accurate meansfor controlof
The principal differences between the various pressure, and liquid flow rates. The experiments
gas
industrial processes isomerization
of relate thecatalyst were conducted atmospheric
to at pressure.Feedmixtures
used; this will in turn affectthe feedpretreatment steps of hydrogenand hydrocarbon were preheated reactor
to
and spent catalyst characterization. The two principal temperature beforeentering bed.
the
typesof catalystidentifiedin the industry areiplatinum
on zeolite,which operates temperatures
at above2OO oC,
and platinum chloride on alumina, which operates at
temperatures below200 oCIll, l2]. Themainadvantage
of zeolites overplatinum chlorinated
on alumina.atalyJtt
is that they have a much betterresistance againstfeed
impurities such as water, which obviates need for
the
expensive drying facilities.Moreover,in zeolitebased
processesit is unnecessary to continuouslyadd
chlorinating agents, remove hydrogen chloride from
effluent steams and take precautions againstcorrosion.
Manyauthon haveinvestigated catalyst
the deactivation
phenomenon over PVA|2O3 catalystusingn-pentane, n-
hexane,and n-heptane a feedstock isomerization
as for
reaction 13,l4].
[ll,
In order to designand optimize catalysts, detailed
a
undentanding of the reaction mechanism,kinetic,
deactivation and catalyst properties is of primary
interesl The combination between catalystperformance
and understanding catalystdeactivation will enable
of
the designof a new catalystwith reduceddeactivation
and increased acrivity and selectivity for desired
products. Therefore, present
the work aimsto:
- providea substantiated Fig.(1)General view of experimental apparatus
knowledge the isomerization
of
reaction based on bifunctional zeolite catalystsby
using light-naphthaas a feed and determiningthe
optimumproc€ss conditions. Materials
- test the performance, deactivationrates and catalyst Two typesof catalysts namedPt/HX and pt/SrX were
stabilityunder optimum process conditions prepared. preparation the catalysts were carried
The of
out by impregnation extrudates x 5) mm of sodium
of (3
Experimental Work typel3X zeolite, SilAl = 2.8 ( Linde Company) with 0.8
wt% platinum.
Catalytic unit Dried and desulfurized Iraqi light petroleum naphtha
The experimental study was carriedout to investigate deliveredby Al-Dura Refinery-Baghdad used as a
was
the catalysts activity, selectivity and catalysts feedstock. Hydrogengas was suppliedfrom Al-Mansour
deactivation rate by building an experimental rig plant (purity is 99.9 %). Various rypes of chemical
specifiedfor isomerization reaction,as shown in Figure compounds wereused.Hexachloroplatonic H2ptCl6acid
(l) whichrepresents general view of experirnental unit. (40%wtPt), strontium chloride, ammonium chloridewere
Figure(2) showsa schematic diagramof a fixed bed obtained from FlukaAG.
flow-typeapparatus. isomerization consists a
The unit of The properties chemical
and analysis light-naphtha
of
vertical tubular stainless steelreactor 2 cm internal
of are tabulated Tables(l) and (2) respectively. the
in On
otherhand,according G.C, analysis
to shownin Table
44 IJCPE
Vol.B
No.3(September
2007)
3. Khalid A. Suk*ar et oI
bt
d 1-lI eteringburette
tr 3-Dosiug putry
I
3-Liquid meter
flon
U
d J- I iddelralt'e
tr 5- IIJ flon'meter
t 6-5AlloletularSiete
j- Onewa.vtalve
f
8-II iringsettisr
t
3
9-feed preheatiug zone
I 10- Temperamre controls)-stem
1I- Pressure toutt'olsf$em
12- Smiuless reattor
steel
13- eatiug
II fiu'uace
1.1- Tbermocouples
15-Co uterizetl
mp iuterfares.Ystem
16-P4conp ilter
l?- Cooliug sl'srem
18-Gas ChronatograPhY
Fig. (2) Schematic of apparatus'
diagram the experimental
(2), the main components the light-naphthafeed are
of analysis light-Iraqipetroleum
Table(2) Chemical of
n-hexane (35.70 and - 40'8 volYo naphtha
n-pentane and
reipectively) which indicates that, the catalytic ComDosition wl%o
process' n-Pentane 35.70
isomerization suchfeed may be a dominant
for 40.80
n-Hexane
Therefore,such processcan be used to improve the MethvlCvcloPentane l l l3
octanenumberwhen optimum operatingconditionsare Bertzene 1,40
applied. Cvclohexane 2.82
n-HeDtane 3.15
leum n-Octane 1.88
Table( I ) TheproPerlies I
of t-l i
t.54
Property Data Toluene
t{ 604 0.665 1.22
80.5 Total 99.64
API
Distillation
I,B.P, 3? oc Modification 13X-Zeolite'
of
5 Vol.7o distilled 42'C
l0 Vol.o/odistilled 48"C NaX
In orderto modify the NaX zeolitespecification,
20 Vol.%distilled 52'c zeolite were exchangedwith two type of cations
30 Vot.%distilled 560C
40 Vol.% distilled 60.oc (Ammonium and Strontium). The Na+ ions were
50 Vol.%distilled 550C ixchanged for NH4+ ions to obtain the HX by ion
60 Vol,%distilled 68"C exchangingthe original NaX zeolite with (3 N )
70 Vol.% distilled 760c
g20c u*rotiiurn chloride-solution [4]' Thus ?8'75gm of
80 Vol.%distilled
90 Vol.o/odistilled 86'C ammonium chloride in 500m1 distillate water was
95Yol.%distilled 920C contacted with 50gmof NaX zeolitewith stirringfor I hr
124'C oC . Then,the exchangingprocess continued 4
for
E.B.P. at 50 oC.'The exchange
TotaldistiUate 96 Vol.% temperature
laboratory of25
daysat
Totalrecovery Residue 0.7 Yol.o/o
["oss J.3 ol.Yo reiult shows % of exchanging ofNa* by Sr-'
82 rate
68.2 On other hand,SrX form zeolite was prepared ion
by
SulfurContent < 3 ppm(Desulfurized) exchangingthe original NaX zeolite with (3 N )
KinematicViscosity 5.4x10'' m'ls strontium chloride solution [5, 6]' Thus 80gn of
at 25oC
IJCPEVol.8No.3(SePtember
2007) 45
4. Study of catalysts dea9lry!!!9n in isomerizationprocess Io produce high octane gasoline
strontium chloride in 500m1 distillate water were aromatizationand cracking selectiviqr are low, while
contacted with 50gm of NaX zeolite with stirr.ing l hr
for isomerization light-naphtha relativelyhigh. So that,asrhe
of is
at 50oC. Then, the exchanging processcontinued 4for reaction temperature increases above 300 oC the
days at laboratory temperatureof 25 oC with 85% of hydrocracking aromatization
and reactions accelerated
are and
exchanging rate of Na* by Sr*. isomerizationactivity and selectivity startedby,decreasing.
Then, the exchangedsamples(HX and SrX) were Therefore, according to Figure (4) the optimum reaction
.l10 oC
filtered, washedand dried at for l0 hours.The temperature isomerizationis at 270 oC for such type of
for
preparedsample was washedwith deionizedwater to be catalystsand feed composition. the other hand,Figure(3)
On
free of chloride ions, and drying procedureswere indicates that, the PI/HX catalystshows higher selectiviry
repeated twice. The obtained zeoliteswere calcined air
in toward isomen than that of Pr/SrX.This is amribured high
to
at 5000C for 6 hoursto obtainthe HX and SrX forms. surfaceareaand the eflect of cationfvne that forms the final
catalyst.
Preparation PVHX
of andPt/SrXcatalysts
Table (3) Characterization
dataofprepared catalysts.
The exchangedzeolires(HX and SrX) were loaded
with Pt at concentrations 0.8 wt % by impregnation Characteri;atron Pt/HX Pt/SrX
of
process riith aqueous Source Prepared Preparcd
solutionof hexachloroplatonic acid
($t%o)
Platinumcontent 0.8wt% 0.8wt%
H2PIC16 The prepared
. solutionwas added dropwiseto
t h e z e o l i r e i i h m i x i n g f o r 4 h o u r sa t 2 5 ' C . T h e m i x t u r e Area(m'lg)
Surface 340 325
u
ChlorineContent(wt7o) 0.25 0 .r 8
was then left at room temperaturefor 24 hours, it was (si/Ai) 2.8 2.8
stined interme,liately during this time. The mixture was
then slo*lr eraporatedto drynessover a period of 8
Catalystdeactivation definedas a phenomenon which
is in
hours ar rsmperarure of 75oC. The resultingcatalysts
the sffuctureand stateof the catalystchange,leadingto the
u'ere driec in air ar I l0'C for an additional 12 hours.
loss of active sites on the catalyst'ssuface thus causing a
Then. the sanples riere calcinedin air at 500oCfor l0
decrease catalyst
in performance,Therefore,eachcatalystwas
hours lincreaslrg ro that temperaturewith a rate of
subjected an aging period.After a pretreatrnent 350 "C in
to at
0.5"C mir I ar: i'rnaili reducedat 350oCin flowing H2
flowing hydrogen the catalyst was submitted to l0 hr of
fcrr-l rtrurs ,1. 5,. Then. the samples are referred as to standard reaction conditions (T=270 oC and atmospheric
P t H X a n dP : S : X c a t a l , s t s .
pressure).The catalytic activity, expressed in terms of
percentage iso-butanes,
iso-pentanes iso-hexanes
and yield, is
Procedure plonedas a functionof onsffeam time as shown in Figure(4).
B e t o r et : e e r p e r i r n e n t sh e c a t a l y s w a s d r i e d a t l l 0
t, t Both catalyss showedgood stability,however,the activity of
'C in ii:rc:e; Pt/HX fell rapidly and it was even lower after l0 hr than that
Jlsruicr one hour and then reduced 350 at
"C in hl crLrser florv for three hours. The operating of Pt/SrX. The fast catalystdeactivation that was notedafter
pressure ',r:;e he,,j constant I bar for all experimental
at few hours of reaction time can be attributed to a high
runs. Th: ii.:.riJ t-lo* of light-naphtha was 0.4 Llhr , hydrogenation-dehydrogenationcapacity of platinum
and rhe Brnrrr.rnr of catalyst was 50 gm. A according the conclusions
to submitted the work of Tomp
by
hrdrogerhrC:o;arbon molar ratio used was 4 for all et al. Il l] andJorgeet al. u2l. Also,Figure(4) indicates thar,
experimerui i-u:rs. The isomerization process carriedout both catalysts loseapproximately35% of their initial activity.
a t a r a n i e r . f : 3 n F e i a t J r ev a r i e d e f w e e n 2 5 0 , 2 7 5 , 3 0 0 ,
s b
Ji). ano _.-'(_'-L 80
The feec a:c :he effluent reactor were analyzed in a
gas chromatogiaph(Shimadzu GC-2014) FID using
coiumn ( S.G.E., length=25 mm, l.D.= 0.22
capillar_r 70
mm, film=0.iun: t and usingN2 as a carriergas. I
U)
Results
and Discussion 60
N
Table (3) shous the rnain characterizes prepared
of
catalysts (PtlHX and Pr Sr.. Ir is clearrhat,Pr/HXcaralyst
fU
showsa total surfaceareagieaterthanthat of Pt'SrX.
200 22s 2s0 27s 300 325 350
The reaction temperature uences
infl isomerization !'iN
acti
T e m p e r a t u r e( o C )
and selectivity the catalvst a higler ertenl Figure(3)
of to
shows the effect of reaction temper"arure isomerzation
on
selectivitytoward branchedisomers hrdrocarbons. is noted
lt (3)
Fi_s. The influence reaction
of temperature
on
that, at low reaction temperatures ll,<. 2-0. l-5 oC the isomerizationselectivity
46 I J C P E o l . 8N o . 3( S e p t e r n b e r 0 7 )
V 20
l
5. Khalid A. Sukko a aI
show fast catalystdeactivation causedby deposition of
carbonaceous materials (coke)on the catalyst surface and
s 8 0 pores.The major productformedin the beginning the of
reactionwas iso-butane. Higher contents iso-hexane
of
'! were detectedin the course of the deactivationrun.
; 6 0 However,the presence hydrogenin the reactionzone
of
(Hydroisomerization) essential to minimize coke
is
5 5 0
formation 12,13].
[2,
N
Figure(6) showsaromatization selectivity a function
as
4 4 0
of reactiontime. In this figure, Pt/SrX catalystshows
3 3 0 higher aromatizationselectivity than that of PI/HX
This is attributed high concentration active
catalyst. to of
acid sitesin this type of catalysts, which promoted
in
aromatizationreaction take. This conclusion is in
agreement theworkof Donket al. [14].
with
Fig.(a)Deactivation PVHXandPVSrX
of catalysts
Conclusions
90
x In this paper the isomerization light-naphtha
of for
producing of branchedisomershas been investigated.
Normal paraffin isomerization presence hydrogen
in of
8 7 0
€) (hydroisomerization) an equilibrium
is limitedreaction,
E 6 0 in which branched paraffin isomersare favoredby low
ternperatures, Therefore, was concluded
it that, in order
5 5 0 to prevent the undesiredreactions of cracking and
N
aromatization,the isomerization process should be
b 4 0 oC as an optimum operating
carried out at 270
A 3 0 temperature both PI/HX andPt/SrXcatalysts.
for
6 l0 t2 It was concluded that only an average 90% wt of
of
Time(hr) the carbonatomsfeedinto the reactor(light-naphtha) are
detected in the productstream. This loss(- 10%) is due
with agingtime to formation of coke depositswhich lead to catalyst
selectivity
Fig.(5)Loses catalysts
of
deactivation. the otherhand,the resultscleartyshow
On
that hydrogen is necessary for the hydrogenation of
c 25 olefins in order to preventoligomerization reactionthat
leads cokeformation catalyst
to and deactivation.
.: 20 In spite of the presence cske deposits
of poisoningof
t) the metalsites,cokedeposits alsoblock the acidsitesof a
.{)9 l s zeolite.The followingdeactivation decreasing order of
O
catalysts Pt/HX > PVSrXwas found.On the otherhand'
o l 0 PI/HX catalystshowedhigher activity and selectivity
N thanof PVSTX.
Acknowledgment
L ( )
The authors gratefully acknowledgethe financial
supportprovided for this work by Ministry of Higher
Education and Scientific Research/ Scientists and
selectivity a function reaction
as of Deparrment-Baghdad.
Creators
Fig.(6)
Aromatization
time
On the otherhandFigure(5) showsthe isomerization References
selectivity toward paraffin isomers.The isomerization l- Maloncy, J.C.,
M.L., Gora,L., Mcleary, E.E.,Jansen,
selectivitywas reducedfrom 85% to 55o/o PtlHX
for
and Maschmeyeq "Hydroisomerisation Hexane
T. of
catalystand from 74Yo 46Ysfor Pt/SrXunder l0 hours
to within a ReactorComposedof a Tubular Silicalite
of reactiontime. Both catalystsusedin the present
work
Vol.B
IJCPE No.3(SePtember
2007) 47
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Catalyst", Commun.,
Cat, (2004). Hydroisomerization of n-Hexane on platinum Zeolite,'
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IJCPE
Vol.B
No.3(September
2007)