Conversion of Fischer-Tropsch wax into high quality synthetic crude or finished transportation fuels such as premium diesel has been studied over the past 15 years within BP. Catalyst screening and selection was carri...Conversion of Fischer-Tropsch wax into high quality synthetic crude or finished transportation fuels such as premium diesel has been studied over the past 15 years within BP. Catalyst screening and selection was carried out in dedicated micro-reactors and pilot plants, whose designs are critical to the performance selection. Variation in catalyst composition and defining the gas to oil feed ratios with the operating temperature are a few of the parameters studied. Product selection and maximizing diesel yield combined with stability （catalyst life） were the ultimate drivers. The selected catalyst was then tested under commercial conditions in a dedicated 300 barrel per day demonstration plant. The products were also tested in engines to assess their combustion characteristics.展开更多
The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium mola...The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures （25 to 30 arm） favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure （20 arm） using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.展开更多
Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels （gaso...Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels （gasoline, diesel etc.）. Selectivity of Fischer-Tropsch hydrocarbon product （green fuel） is an important issue. In this study, the experimental data has been obtained from three factors; temperature, H2/CO ratio and pressure in the fixed bed micro reactor. T = 543-618 （K）, P = 3-10 （bar）, H2/CO = 1-2 and space velocity = 4500 （l/h） were the reactor conditions. The results of product modeling for methane （CH4）, ethane （C2H6）, ethylene （C2H4） and CO conversion with experimental data were compared. The effective parameters and the interaction between them were investigated in the model. H2/CO ratio and pressure and interaction between pressure and H2/CO in ethane selectivity model and CO conversion and interaction between temperature and H2/CO ratio in methane selectivity model and ethylene gave the best results. To determine the optimal conditions for light hydrocarbons, ANOVA and RSM were employed. Finally, products optimization was done and results were concluded.展开更多
A series of nanosized Co/Zn/Mn/K composite catalysts for Fischer-Tropsch synthesis （FTS） were prepared by supercritical fluid drying （SCFD） method and common drying （CD） method. The nanosized cobalt-based cataly...A series of nanosized Co/Zn/Mn/K composite catalysts for Fischer-Tropsch synthesis （FTS） were prepared by supercritical fluid drying （SCFD） method and common drying （CD） method. The nanosized cobalt-based catalysts were characterized by XRD, TEM and BET techniques. Their catalytic performances were tested in a slurry-bed reactor under FTS reaction conditions. The drying and crystallization were carried out simultaneously during SCFD, therefore, the catalysts prepared by SCFD method have ideal structure and show the FTS performance superior to the others prepared by CD method. The FTS activity and selectivity were improved via adding Zn, Mn and K promoters, and less CH4 and CO2 as well as higher yield of C5＋ products were achieved. The optimal performance of a 92% CO conversion and a 65% C5＋ product yield was obtained over a catalyst with the component of Co/Zn/Mn/K = 100/50/10/7. Furthermore, the catalytic performance was studied under the conditions of liquid-phase and supercritical phase slurry-bed, and C5＋ product yield were 57.4% and 65.4%, respectively. In summary, better catalytic performance was obtained using the nanosized catalyst prepared by SCFD method under supercritical reaction conditions, resulting in higher conversion of CO, less CO2 byproduct, and higher yield of C5＋ products.展开更多
Vehicle exhaust and transported biomass burning emissions are important air pollution sources in many urban areas,and domestic cooking with biomass fuels causes indoor air pollution in many rural areas.Using agricultu...Vehicle exhaust and transported biomass burning emissions are important air pollution sources in many urban areas,and domestic cooking with biomass fuels causes indoor air pollution in many rural areas.Using agricultural waste-generated synthetic fuels can reduce emissions both from vehicles and biomass burning.To estimate the potential benefits of synthetic diesel in Beijing,the emission factor model for the Beijing vehicle fleet was applied to estimate exhaust emissions for the 2015-2030 period.Compared with 100%petroleum diesel,a 20%synthetic diesel blend reduced diesel fleet emissions by 24%for carbon monoxide,30%for total hydrocarbons,5.5%for nitrogen oxides,and 19%for fine particulate matter with an aerodynamic diameter of≤2.5μm(PM2.5)while using 100%synthetic diesel decreased emissions by 36%for carbon monoxide,48%for total hydrocarbons,10%for nitrogen oxides,and 34%for PM2.5.The use of biomass for producing synthetic fuels rather than burning in the field also reduces air pollution.Over 60g of PM2.5 agricultural open-field burning emissions are avoided per liter of synthetic fuel produced.Replacing solid crop residues with synthetic liquid fuels in household cooking would reduce PM2.5 emissions by more than 90%.展开更多
Thermochemical recuperation heat recovery is an advanced waste heat utilization technology that can effectively recover exhaust waste heat from oxy-fuel Stirling engines.The novel combustor of a Stirling engine with t...Thermochemical recuperation heat recovery is an advanced waste heat utilization technology that can effectively recover exhaust waste heat from oxy-fuel Stirling engines.The novel combustor of a Stirling engine with thermochemical recuperation heat recovery system is expected to utilize both reformed gas and diesel fuels as sources of combustion.In this research,the effects of various factors,including the H_(2)O addition,fuel distribution ratio(FDR),excess oxygen coefficient,and cyclone structure on the temperature distribution in the combustor,combustion emissions,and external combustion system efficiency of the Stirling engine were experimentally investigated.With the increase of steam-to-carbon ratio(S/C),the temperature difference between the upper and lower heating tubes reduces and the circumferential temperature fluctuation decreases,and the combustion of diesel and reformed gas remains close to complete combustion.At S/C=2,the external combustion efficiency is 80.6%,indicating a 1.6%decrease compared to conventional combustion.With the increase of FDR,the temperature uniformity of the heater tube is improved,and the CO and HC emissions decrease.However,the impact of the FDR on the maximum temperature difference and temperature fluctuation across the heater is insignificant.When the FDR rises from 21%to 38%,the external combustion efficiency increases from 87.4%to92.3%.The excess oxygen coefficient plays a secondary role in influencing temperature uniformity and temperature difference,and the reformed gas and diesel fuel can be burned efficiently at a low excess oxygen coefficient of 1.04.With an increase in the cyclone angle,the heater tube temperature increases,while the maximum temperature difference at the lower part decreases,and the temperature fluctuation increases.Simultaneously,the CO and HC emissions increase,and the external combustion efficiency experiences a decrease.A cyclone angle of 30°is found to be an appropriate value for achieving optimal mixing between reformed gas and diesel fuel.The research findings present valuable new insights that can be utilized to enhance the performance optimization of Stirling engines.展开更多
Green hydrogen is anticipated to play a major role in the decarbonization of the mobility sector.Its chemical storage in CO_(2)-neutral synthetic liquid fuels is advantageous in terms of safety and reliability compare...Green hydrogen is anticipated to play a major role in the decarbonization of the mobility sector.Its chemical storage in CO_(2)-neutral synthetic liquid fuels is advantageous in terms of safety and reliability compared to other hydrogen storage developments,and thus represents a complementary building block to developments in electric and hydrogen mobility for the low-carbon transition in the mobility sector.Its development is especially relevant for transport sectors which will have no alternatives to liquid fuels in the foreseeable future.In this paper,three alternative technological routes for the chemical storage of hydrogen in CO_(2)-neutral synthetic liquid fuels are identified and comparatively evaluated in terms of feedstock potential,product potential,demand for renewable electricity and associated costs,efficiency as well as expected market relevance.While all three routes exhibited similar levels of overall efficiencies,electricity-based liquid fuels in Germany are currently limited by the high cost and limited supply of renewable electricity.In contrast,liquid fuels generated from biogenic waste have a constant supply of biogenic feedstock and are largely independent from the supply and cost of renewable electricity.展开更多
文摘Conversion of Fischer-Tropsch wax into high quality synthetic crude or finished transportation fuels such as premium diesel has been studied over the past 15 years within BP. Catalyst screening and selection was carried out in dedicated micro-reactors and pilot plants, whose designs are critical to the performance selection. Variation in catalyst composition and defining the gas to oil feed ratios with the operating temperature are a few of the parameters studied. Product selection and maximizing diesel yield combined with stability （catalyst life） were the ultimate drivers. The selected catalyst was then tested under commercial conditions in a dedicated 300 barrel per day demonstration plant. The products were also tested in engines to assess their combustion characteristics.
文摘The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures （25 to 30 arm） favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure （20 arm） using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.
文摘Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels （gasoline, diesel etc.）. Selectivity of Fischer-Tropsch hydrocarbon product （green fuel） is an important issue. In this study, the experimental data has been obtained from three factors; temperature, H2/CO ratio and pressure in the fixed bed micro reactor. T = 543-618 （K）, P = 3-10 （bar）, H2/CO = 1-2 and space velocity = 4500 （l/h） were the reactor conditions. The results of product modeling for methane （CH4）, ethane （C2H6）, ethylene （C2H4） and CO conversion with experimental data were compared. The effective parameters and the interaction between them were investigated in the model. H2/CO ratio and pressure and interaction between pressure and H2/CO in ethane selectivity model and CO conversion and interaction between temperature and H2/CO ratio in methane selectivity model and ethylene gave the best results. To determine the optimal conditions for light hydrocarbons, ANOVA and RSM were employed. Finally, products optimization was done and results were concluded.
基金supported by Research Fund for the Doctoral Program of Higher Education (China,No.20050010014)
文摘A series of nanosized Co/Zn/Mn/K composite catalysts for Fischer-Tropsch synthesis （FTS） were prepared by supercritical fluid drying （SCFD） method and common drying （CD） method. The nanosized cobalt-based catalysts were characterized by XRD, TEM and BET techniques. Their catalytic performances were tested in a slurry-bed reactor under FTS reaction conditions. The drying and crystallization were carried out simultaneously during SCFD, therefore, the catalysts prepared by SCFD method have ideal structure and show the FTS performance superior to the others prepared by CD method. The FTS activity and selectivity were improved via adding Zn, Mn and K promoters, and less CH4 and CO2 as well as higher yield of C5＋ products were achieved. The optimal performance of a 92% CO conversion and a 65% C5＋ product yield was obtained over a catalyst with the component of Co/Zn/Mn/K = 100/50/10/7. Furthermore, the catalytic performance was studied under the conditions of liquid-phase and supercritical phase slurry-bed, and C5＋ product yield were 57.4% and 65.4%, respectively. In summary, better catalytic performance was obtained using the nanosized catalyst prepared by SCFD method under supercritical reaction conditions, resulting in higher conversion of CO, less CO2 byproduct, and higher yield of C5＋ products.
文摘Vehicle exhaust and transported biomass burning emissions are important air pollution sources in many urban areas,and domestic cooking with biomass fuels causes indoor air pollution in many rural areas.Using agricultural waste-generated synthetic fuels can reduce emissions both from vehicles and biomass burning.To estimate the potential benefits of synthetic diesel in Beijing,the emission factor model for the Beijing vehicle fleet was applied to estimate exhaust emissions for the 2015-2030 period.Compared with 100%petroleum diesel,a 20%synthetic diesel blend reduced diesel fleet emissions by 24%for carbon monoxide,30%for total hydrocarbons,5.5%for nitrogen oxides,and 19%for fine particulate matter with an aerodynamic diameter of≤2.5μm(PM2.5)while using 100%synthetic diesel decreased emissions by 36%for carbon monoxide,48%for total hydrocarbons,10%for nitrogen oxides,and 34%for PM2.5.The use of biomass for producing synthetic fuels rather than burning in the field also reduces air pollution.Over 60g of PM2.5 agricultural open-field burning emissions are avoided per liter of synthetic fuel produced.Replacing solid crop residues with synthetic liquid fuels in household cooking would reduce PM2.5 emissions by more than 90%.
基金supported by the Ministry of Science and Technology of China(Grant No.2022YFE0209000)the Shanghai Rising-Star Program(Grant No.21QB1403900)Shanghai Municipal Commission of Science and Technology(Grant No.22170712600)。
文摘Thermochemical recuperation heat recovery is an advanced waste heat utilization technology that can effectively recover exhaust waste heat from oxy-fuel Stirling engines.The novel combustor of a Stirling engine with thermochemical recuperation heat recovery system is expected to utilize both reformed gas and diesel fuels as sources of combustion.In this research,the effects of various factors,including the H_(2)O addition,fuel distribution ratio(FDR),excess oxygen coefficient,and cyclone structure on the temperature distribution in the combustor,combustion emissions,and external combustion system efficiency of the Stirling engine were experimentally investigated.With the increase of steam-to-carbon ratio(S/C),the temperature difference between the upper and lower heating tubes reduces and the circumferential temperature fluctuation decreases,and the combustion of diesel and reformed gas remains close to complete combustion.At S/C=2,the external combustion efficiency is 80.6%,indicating a 1.6%decrease compared to conventional combustion.With the increase of FDR,the temperature uniformity of the heater tube is improved,and the CO and HC emissions decrease.However,the impact of the FDR on the maximum temperature difference and temperature fluctuation across the heater is insignificant.When the FDR rises from 21%to 38%,the external combustion efficiency increases from 87.4%to92.3%.The excess oxygen coefficient plays a secondary role in influencing temperature uniformity and temperature difference,and the reformed gas and diesel fuel can be burned efficiently at a low excess oxygen coefficient of 1.04.With an increase in the cyclone angle,the heater tube temperature increases,while the maximum temperature difference at the lower part decreases,and the temperature fluctuation increases.Simultaneously,the CO and HC emissions increase,and the external combustion efficiency experiences a decrease.A cyclone angle of 30°is found to be an appropriate value for achieving optimal mixing between reformed gas and diesel fuel.The research findings present valuable new insights that can be utilized to enhance the performance optimization of Stirling engines.
基金funded by the German Federal Ministry of Education and Research(BMBF)through the research project grant no.01LN1713A.All opinions,results and conclusions in the text are those of the authors and do not necessarily reflect the opinion of the BMBF.
文摘Green hydrogen is anticipated to play a major role in the decarbonization of the mobility sector.Its chemical storage in CO_(2)-neutral synthetic liquid fuels is advantageous in terms of safety and reliability compared to other hydrogen storage developments,and thus represents a complementary building block to developments in electric and hydrogen mobility for the low-carbon transition in the mobility sector.Its development is especially relevant for transport sectors which will have no alternatives to liquid fuels in the foreseeable future.In this paper,three alternative technological routes for the chemical storage of hydrogen in CO_(2)-neutral synthetic liquid fuels are identified and comparatively evaluated in terms of feedstock potential,product potential,demand for renewable electricity and associated costs,efficiency as well as expected market relevance.While all three routes exhibited similar levels of overall efficiencies,electricity-based liquid fuels in Germany are currently limited by the high cost and limited supply of renewable electricity.In contrast,liquid fuels generated from biogenic waste have a constant supply of biogenic feedstock and are largely independent from the supply and cost of renewable electricity.
