This paper developed a new clean continuous process for the hydrogenation of 3,5-dimethylpyridine(DPY)to 3,5-dimethylpiperidine(DPI)without solvent.A series of Ru/C catalysts were prepared by impregnation method,which...This paper developed a new clean continuous process for the hydrogenation of 3,5-dimethylpyridine(DPY)to 3,5-dimethylpiperidine(DPI)without solvent.A series of Ru/C catalysts were prepared by impregnation method,which were characterized by the BET,ICP,CO chemisorptions,XRD,SEM,EDS,TEM and TG.The effect of active species,loading,catalyst support,reaction temperature and pressure on the catalytic performance was investigated.The influence of internal and external diffusion in the trickle-bed reactor(TBR)was basically eliminated by adjusting the particle size and dosage of the Ru/C catalyst.The reaction performance of the hydrogenation of DPY to DPI in the TBR and kettle reactor(KR)was compared,and the superiority of the TBR process was analyzed.The results show that this new continuous process developed in this study is an efficient way to realize the hydrogenation of DPY to DPI,and has a good industrial application prospect.展开更多
As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapi...As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapid movement and chemical reaction.Existing evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real process.In this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under different system temperatures,running time and process factors was investigated with percent mass loss(PML),particle size-mass distribution(PSMD)and scanning electron microscope(SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization(MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise gradually.The process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature.Catalyst attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape.展开更多
The structure and composition of coal determine its fast pyrolysis characteristics,and the study of the relationship between them can play an important role in the efficient and clean utilization of coal.So,in this wo...The structure and composition of coal determine its fast pyrolysis characteristics,and the study of the relationship between them can play an important role in the efficient and clean utilization of coal.So,in this work,hydrothermal pretreatment was used to artificially change the structure and composition of Sheng Li(SL)lignite,which was used to investigate the influence of structural changes on pyrolysis.The physicochemical structure and composition of samples were characterized by X-ray diffraction,specific surface area and porosity analyzer,solid-state 13C nuclear magnetic resonance,Fourier transform infrared spectroscopy,and elemental analyzer.Pyrolysis experiments were carried out in a powderparticle fluidized bed reactor,and the distribution and composition of the pyrolysis products were analyzed.The gasification activity of char was investigated by thermogravimetric analysis with a CO_(2) atmosphere.The results show that hydrothermal pretreatment(HTP)can destroy the cross-linking structure of SL lignite,and affect its aromaticity,pore structure,functional group,and carbon structure to change the distribution and composition of pyrolysis products of SL lignite,especially the composition of tar.Finally,the structure–activity relationship between the structure,composition,and pyrolysis characteristics of coal was comprehensively studied.展开更多
An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature wa...An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature was over a range of 550–650℃ under 1.0 MPa pressure with different atmospheres.On the basis of the individual pyrolysis behavior of bituminous coal and biomass,the influences of the biomass blending ratio,temperature,pressure and atmosphere on the product distribution were investigated.The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor,especially when the condition of bituminous coal and biomass blend ratio of 70:30(w/w),600℃,and 0.3 MPa was applied.The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis.The tar yields were higher than the calculated values from individual pyrolysis of each fuel,and consequently the char yields were lower.The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel.The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.展开更多
A new method for nitric oxide(NO)removal was developed by combining dielectric barrier discharge(DBD)and negative pulse corona(NPC).The effects of gas composition(O2,CO2,and H2 O)on NO removal were investigated with t...A new method for nitric oxide(NO)removal was developed by combining dielectric barrier discharge(DBD)and negative pulse corona(NPC).The effects of gas composition(O2,CO2,and H2 O)on NO removal were investigated with this method,and the effect of alcohols(methanol and ethanol)addition on NO removal was also investigated as well as the reaction mechanisms to enhance the NO removal efficiency.The experimental results showed that O2,CO2,and H2 O had obvious inhibition effects on NO removal,and the negative effects were in the following order:O2>CO2>H2 O.The addition of methanol or ethanol in the reaction system could mitigate the negative effects of O2,CO2 and H2 O on NO removal,and also eliminated the production of N02.The positive effect of alcohols addition with DBD-NPC denitration method was also validated in the simulated flue gas,in which the NOx(NO,NO2)was mainly converted into N2.展开更多
A pilot-scale methane dehydroaromatization–H_2regeneration fluidized bed system(MDARS)was developed.In the MDARS,the catalyst circulation between a fluidized bed reactor and a fluidized bed regenerator with the help ...A pilot-scale methane dehydroaromatization–H_2regeneration fluidized bed system(MDARS)was developed.In the MDARS,the catalyst circulation between a fluidized bed reactor and a fluidized bed regenerator with the help of a catalyst feeder allowed methane dehydroaromatization(MDA)and H_2regeneration to be carried out simultaneously,which is good for maintaining a stable MDA catalytic activity.A fixed bed reactor(FB)and a single fluidized bed reactor(SFB)were also used for a comparative study.The experimental results showed that the catalytic activity in the MDARS was more stable than that in the FB and SFB reactors.The effects of some parameters of MDARS on the CH_4conversion and product selectivity were investigated.To verify the feasibility and reliability of the MDARS,an eight-hour long-term test was carried out,which demonstrated that the operation of the MDARS was stable and that the catalytic activity remained stable throughout the entire experimental period.展开更多
Nitric oxide(NO) removal and sulfur dioxide(SO_2) removal by sodium persulfate(Na_2S_2O_8) were studied in a Bubble Column Reactor. The proposed reaction pathways of NO and SO_2 removal are discussed. The effects of t...Nitric oxide(NO) removal and sulfur dioxide(SO_2) removal by sodium persulfate(Na_2S_2O_8) were studied in a Bubble Column Reactor. The proposed reaction pathways of NO and SO_2 removal are discussed. The effects of temperatures(35–90 °C), Na_2S_2O_8(0.05–0.5 mol·L^(-1)), Fe SO4(0.5–5.0 m mol·L^(-1)) and H_2O_2(0.25 mol·L^(-1))on NO and SO_2 removal were investigated. The results indicated that increased persulfate concentration led to increase in NO removal at various temperatures. SO_2 was almost completely removed in the temperature range of 55–85 °C. Fe^(2+)accelerated persulfate activation and enhanced NO removal efficiency. At 0.2 mol·L^(-1) Na_2S_2O_8 and 0.5–1.0 mmol·L^(-1) Fe^(2+), NO removal of 93.5%–99% was obtained at 75–90 °C, SO_2 removal was higher than 99% at all temperatures. The addition of 0.25 mol·L^(-1) H_2O_2 into 0.2 mol·L^(-1) Na_2S_2O_8 solution promoted NO removal efficiency apparently until utterly decomposition of H2 O2, the SO_2 removal was as high as98.4% separately at 35 °C and 80 °C.展开更多
HFC-134a is a widely used environment-friendly refrigerant.At present,China is the largest producer of HFC-134a in the world.The production of HFC-134a in China mainly adopts the calcium carbide acetylene route.Howeve...HFC-134a is a widely used environment-friendly refrigerant.At present,China is the largest producer of HFC-134a in the world.The production of HFC-134a in China mainly adopts the calcium carbide acetylene route.However,the production route has high resource and energy consumption and large waste emission,and few of the studies addressed on the environmental performance of its production process.This study quantified the environmental performance of HFC-134a production by calcium carbide route via carrying out a life cycle assessment(LCA)using the CML 2001 method.And uncertainty analysis by Monte-Carlo simulation was also carried out.The results showed that electricity had the most impact on the environment,followed by steam,hydrogen fluoride and chlorine,and the impact of direct CO_(2) emissions in calcium carbide production stage on the global warming effect also could not be ignored.Therefore,the clean energy(e.g.,wind,solar,biomass,and natural gas)was used to replace coal-based electricity and coal-fired steam in this study,showing considerable environmental benefits.At the same time,the use of advanced production technologies could also improve environmental benefits,and the environmental impact of the global warming category could be reduced by 4.1%via using CO_(2) capture and purification technology.The Chinese database of HFC-134a production established in this study provides convenience for the relevant study of scholars.For the production of HFC-134a,this study helps to better identify the specific environmental hotspots and proposes useful ways to improve the environmental benefits.展开更多
The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed reactor.Under the same reduction conditions(300°C in H_(2)),the catalytic activity of the non-...The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed reactor.Under the same reduction conditions(300°C in H_(2)),the catalytic activity of the non-in-situ reduced Ru/C-n catalyst was higher than that of the in-situ reduced Ru/C-y catalyst.Therefore,an in-situ H_(2)reduction and moderate oxidation method was developed to increase the catalyst activity.Moreover,the influence of oxidation temperature on the developed method was investigated.The catalysts were characterized by Brunauer–Emmett–Teller method,hydrogen temperature programmed reduction H_(2)-TPR,hydrogen temperature-programmed dispersion(H_(2)-TPD),X-ray diffraction,energy dispersive spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,O2 chemisorption and oxygen temperature-programmed dispersion(O2-TPD)analyses.The results showed that there existed an optimal Ru/RuO_(x)ratio for the catalyst,and the highest 3,5-dimethylpyridine conversion was obtained for the Ru/C-i1 catalyst prepared by in-situ H_(2)reduction and moderate oxidation(oxidized at 100°C).Excessive oxidation(200°C)resulted in a significant decrease in the Ru/RuO_(x)ratio of the in-situ H_(2)reduction and moderate oxidized Ru/C-i2 catalyst,the interaction between RuO_(x)species and the support changed,and the hard-to-reduce RuO_(x)species was formed,leading to a significant decrease in catalyst activity.The developed in-situ H_(2)reduction and moderate oxidation method eliminated the step of the non-in-situ reduction of catalyst outside the trickle bed reactor.展开更多
China is the largest producer and consumer of HFC-134a(1,1,1,2-tetrafluoroethane)in the world.Coal-based route is mainly adopted to produce HFC-134a,which suffers from large waste and CO_(2) emissions.Natural gas is a...China is the largest producer and consumer of HFC-134a(1,1,1,2-tetrafluoroethane)in the world.Coal-based route is mainly adopted to produce HFC-134a,which suffers from large waste and CO_(2) emissions.Natural gas is a low-carbon and clean energy resource,and no research has been found on the environment and economy of producing HFC-134a from natural gas.In this study,CML 2001 method was used to carry out the life cycle assessment of natural gas(partial oxidation)-based and natural gas(plasma cracking)-based routes(abbreviated as gas(O)-based and gas(P)-based routes,respectively),and their environmental performances were compared with coal-based and oil-based routes.Meanwhile,considering that China is vigorously promoting the transformation of energy structure,and the application of electric heating equipment to replace fossil-based heating equipment in industrial field,which has a great impact on the environmental performance of the production processes,the authors conducted a scenario analysis.The results showed that the gas(O)-based route had the most favourable environmental benefits.However,the gas(P)-based route had the highest potential for reducing environmental burdens,and its environmental benefit was the most favourable in scenario 2050.Additionally,the economic performance of the gas(P)-based route was significantly better than that of gas(O)-based and coal-based routes.展开更多
To reasonably utilize the coal direct liquefaction residue(DLR), contrasting research on the co-pyrolysis between different low-rank coals and DLR was investigated using a TGA coupled with an FT-IR spectrophotometer a...To reasonably utilize the coal direct liquefaction residue(DLR), contrasting research on the co-pyrolysis between different low-rank coals and DLR was investigated using a TGA coupled with an FT-IR spectrophotometer and a fixed-bed reactor. GC–MS, FTIR, and XRD were used to explore the reaction mechanisms of the various co-pyrolysis processes. Based on the TGA results, it was confirmed that the tetrahydrofuran insoluble fraction of DLR helped to catalyze the conversion reaction of lignite. Also, the addition of DLR improved the yield of tar in the fixed-bed, with altering the composition of the tar. Moreover, a kinetic analysis during the co-pyrolysis was conducted using a distributed activation energy model. The co-pyrolysis reactions showed an approximate double-Gaussian distribution.展开更多
基金supported by the National Natural Science Foun-dation of China(21536009)the Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03).
文摘This paper developed a new clean continuous process for the hydrogenation of 3,5-dimethylpyridine(DPY)to 3,5-dimethylpiperidine(DPI)without solvent.A series of Ru/C catalysts were prepared by impregnation method,which were characterized by the BET,ICP,CO chemisorptions,XRD,SEM,EDS,TEM and TG.The effect of active species,loading,catalyst support,reaction temperature and pressure on the catalytic performance was investigated.The influence of internal and external diffusion in the trickle-bed reactor(TBR)was basically eliminated by adjusting the particle size and dosage of the Ru/C catalyst.The reaction performance of the hydrogenation of DPY to DPI in the TBR and kettle reactor(KR)was compared,and the superiority of the TBR process was analyzed.The results show that this new continuous process developed in this study is an efficient way to realize the hydrogenation of DPY to DPI,and has a good industrial application prospect.
基金supported by Hydrocarbon High-efficiency Utilization Technology Research Center of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,China(Contract No.HCRC-C13-010)the National Natural Science Foundation of China(No.21536009)。
文摘As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapid movement and chemical reaction.Existing evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real process.In this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under different system temperatures,running time and process factors was investigated with percent mass loss(PML),particle size-mass distribution(PSMD)and scanning electron microscope(SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization(MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise gradually.The process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature.Catalyst attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape.
基金supported by the National Natural Science Foundation of China(21536009)Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03)。
文摘The structure and composition of coal determine its fast pyrolysis characteristics,and the study of the relationship between them can play an important role in the efficient and clean utilization of coal.So,in this work,hydrothermal pretreatment was used to artificially change the structure and composition of Sheng Li(SL)lignite,which was used to investigate the influence of structural changes on pyrolysis.The physicochemical structure and composition of samples were characterized by X-ray diffraction,specific surface area and porosity analyzer,solid-state 13C nuclear magnetic resonance,Fourier transform infrared spectroscopy,and elemental analyzer.Pyrolysis experiments were carried out in a powderparticle fluidized bed reactor,and the distribution and composition of the pyrolysis products were analyzed.The gasification activity of char was investigated by thermogravimetric analysis with a CO_(2) atmosphere.The results show that hydrothermal pretreatment(HTP)can destroy the cross-linking structure of SL lignite,and affect its aromaticity,pore structure,functional group,and carbon structure to change the distribution and composition of pyrolysis products of SL lignite,especially the composition of tar.Finally,the structure–activity relationship between the structure,composition,and pyrolysis characteristics of coal was comprehensively studied.
基金Supported by Hydrocarbon High-efficiency Utilization Technology Research Center of Yanchang Petroleum(Group)Co.Ltd.,China(ycsy2013ky-A-30)
文摘An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature was over a range of 550–650℃ under 1.0 MPa pressure with different atmospheres.On the basis of the individual pyrolysis behavior of bituminous coal and biomass,the influences of the biomass blending ratio,temperature,pressure and atmosphere on the product distribution were investigated.The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor,especially when the condition of bituminous coal and biomass blend ratio of 70:30(w/w),600℃,and 0.3 MPa was applied.The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis.The tar yields were higher than the calculated values from individual pyrolysis of each fuel,and consequently the char yields were lower.The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel.The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.
基金Supported by the National Natural Science Foundation of China(21536009)the Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03).
文摘A new method for nitric oxide(NO)removal was developed by combining dielectric barrier discharge(DBD)and negative pulse corona(NPC).The effects of gas composition(O2,CO2,and H2 O)on NO removal were investigated with this method,and the effect of alcohols(methanol and ethanol)addition on NO removal was also investigated as well as the reaction mechanisms to enhance the NO removal efficiency.The experimental results showed that O2,CO2,and H2 O had obvious inhibition effects on NO removal,and the negative effects were in the following order:O2>CO2>H2 O.The addition of methanol or ethanol in the reaction system could mitigate the negative effects of O2,CO2 and H2 O on NO removal,and also eliminated the production of N02.The positive effect of alcohols addition with DBD-NPC denitration method was also validated in the simulated flue gas,in which the NOx(NO,NO2)was mainly converted into N2.
基金Supported by Hydrocarbon High-efficiency Utilization Technology Research Center of Yanchang Petroleum(Group)Co.Ltd,China(Contract No.HCRC-C13-010)by the National Natural Science Foundation of China(21536009)
文摘A pilot-scale methane dehydroaromatization–H_2regeneration fluidized bed system(MDARS)was developed.In the MDARS,the catalyst circulation between a fluidized bed reactor and a fluidized bed regenerator with the help of a catalyst feeder allowed methane dehydroaromatization(MDA)and H_2regeneration to be carried out simultaneously,which is good for maintaining a stable MDA catalytic activity.A fixed bed reactor(FB)and a single fluidized bed reactor(SFB)were also used for a comparative study.The experimental results showed that the catalytic activity in the MDARS was more stable than that in the FB and SFB reactors.The effects of some parameters of MDARS on the CH_4conversion and product selectivity were investigated.To verify the feasibility and reliability of the MDARS,an eight-hour long-term test was carried out,which demonstrated that the operation of the MDARS was stable and that the catalytic activity remained stable throughout the entire experimental period.
基金Supported by the National Natural Science Foundation of China(21536009)Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03)
文摘Nitric oxide(NO) removal and sulfur dioxide(SO_2) removal by sodium persulfate(Na_2S_2O_8) were studied in a Bubble Column Reactor. The proposed reaction pathways of NO and SO_2 removal are discussed. The effects of temperatures(35–90 °C), Na_2S_2O_8(0.05–0.5 mol·L^(-1)), Fe SO4(0.5–5.0 m mol·L^(-1)) and H_2O_2(0.25 mol·L^(-1))on NO and SO_2 removal were investigated. The results indicated that increased persulfate concentration led to increase in NO removal at various temperatures. SO_2 was almost completely removed in the temperature range of 55–85 °C. Fe^(2+)accelerated persulfate activation and enhanced NO removal efficiency. At 0.2 mol·L^(-1) Na_2S_2O_8 and 0.5–1.0 mmol·L^(-1) Fe^(2+), NO removal of 93.5%–99% was obtained at 75–90 °C, SO_2 removal was higher than 99% at all temperatures. The addition of 0.25 mol·L^(-1) H_2O_2 into 0.2 mol·L^(-1) Na_2S_2O_8 solution promoted NO removal efficiency apparently until utterly decomposition of H2 O2, the SO_2 removal was as high as98.4% separately at 35 °C and 80 °C.
基金supported by the National Natural Science Foun-dation of China(22008198)and(21536009)Science and Technol-ogy Plan Projects of Shaanxi Province,China(2017ZDCXL-GY-10-03)Industrialization Cultivation Project of Education Ministry of Shaanxi province,China(19JK0854).
文摘HFC-134a is a widely used environment-friendly refrigerant.At present,China is the largest producer of HFC-134a in the world.The production of HFC-134a in China mainly adopts the calcium carbide acetylene route.However,the production route has high resource and energy consumption and large waste emission,and few of the studies addressed on the environmental performance of its production process.This study quantified the environmental performance of HFC-134a production by calcium carbide route via carrying out a life cycle assessment(LCA)using the CML 2001 method.And uncertainty analysis by Monte-Carlo simulation was also carried out.The results showed that electricity had the most impact on the environment,followed by steam,hydrogen fluoride and chlorine,and the impact of direct CO_(2) emissions in calcium carbide production stage on the global warming effect also could not be ignored.Therefore,the clean energy(e.g.,wind,solar,biomass,and natural gas)was used to replace coal-based electricity and coal-fired steam in this study,showing considerable environmental benefits.At the same time,the use of advanced production technologies could also improve environmental benefits,and the environmental impact of the global warming category could be reduced by 4.1%via using CO_(2) capture and purification technology.The Chinese database of HFC-134a production established in this study provides convenience for the relevant study of scholars.For the production of HFC-134a,this study helps to better identify the specific environmental hotspots and proposes useful ways to improve the environmental benefits.
文摘The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed reactor.Under the same reduction conditions(300°C in H_(2)),the catalytic activity of the non-in-situ reduced Ru/C-n catalyst was higher than that of the in-situ reduced Ru/C-y catalyst.Therefore,an in-situ H_(2)reduction and moderate oxidation method was developed to increase the catalyst activity.Moreover,the influence of oxidation temperature on the developed method was investigated.The catalysts were characterized by Brunauer–Emmett–Teller method,hydrogen temperature programmed reduction H_(2)-TPR,hydrogen temperature-programmed dispersion(H_(2)-TPD),X-ray diffraction,energy dispersive spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,O2 chemisorption and oxygen temperature-programmed dispersion(O2-TPD)analyses.The results showed that there existed an optimal Ru/RuO_(x)ratio for the catalyst,and the highest 3,5-dimethylpyridine conversion was obtained for the Ru/C-i1 catalyst prepared by in-situ H_(2)reduction and moderate oxidation(oxidized at 100°C).Excessive oxidation(200°C)resulted in a significant decrease in the Ru/RuO_(x)ratio of the in-situ H_(2)reduction and moderate oxidized Ru/C-i2 catalyst,the interaction between RuO_(x)species and the support changed,and the hard-to-reduce RuO_(x)species was formed,leading to a significant decrease in catalyst activity.The developed in-situ H_(2)reduction and moderate oxidation method eliminated the step of the non-in-situ reduction of catalyst outside the trickle bed reactor.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.22078266 and 22008198)the Youth Innovation Team construction scientific research Project of Education Ministry of Shaanxi province,China(Grant No.22JP090)+1 种基金the Youth Talent Promotion Program of Shaanxi Association for Science and Technology(Grant No.20220602)Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2021JQ-555).
文摘China is the largest producer and consumer of HFC-134a(1,1,1,2-tetrafluoroethane)in the world.Coal-based route is mainly adopted to produce HFC-134a,which suffers from large waste and CO_(2) emissions.Natural gas is a low-carbon and clean energy resource,and no research has been found on the environment and economy of producing HFC-134a from natural gas.In this study,CML 2001 method was used to carry out the life cycle assessment of natural gas(partial oxidation)-based and natural gas(plasma cracking)-based routes(abbreviated as gas(O)-based and gas(P)-based routes,respectively),and their environmental performances were compared with coal-based and oil-based routes.Meanwhile,considering that China is vigorously promoting the transformation of energy structure,and the application of electric heating equipment to replace fossil-based heating equipment in industrial field,which has a great impact on the environmental performance of the production processes,the authors conducted a scenario analysis.The results showed that the gas(O)-based route had the most favourable environmental benefits.However,the gas(P)-based route had the highest potential for reducing environmental burdens,and its environmental benefit was the most favourable in scenario 2050.Additionally,the economic performance of the gas(P)-based route was significantly better than that of gas(O)-based and coal-based routes.
基金Supported by National High-tech Research and Development Program of China(2011AA05A2021)the National Natural Science Foundation of China(21536009)Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03).
文摘To reasonably utilize the coal direct liquefaction residue(DLR), contrasting research on the co-pyrolysis between different low-rank coals and DLR was investigated using a TGA coupled with an FT-IR spectrophotometer and a fixed-bed reactor. GC–MS, FTIR, and XRD were used to explore the reaction mechanisms of the various co-pyrolysis processes. Based on the TGA results, it was confirmed that the tetrahydrofuran insoluble fraction of DLR helped to catalyze the conversion reaction of lignite. Also, the addition of DLR improved the yield of tar in the fixed-bed, with altering the composition of the tar. Moreover, a kinetic analysis during the co-pyrolysis was conducted using a distributed activation energy model. The co-pyrolysis reactions showed an approximate double-Gaussian distribution.
