CeO_(2) based semiconductor are widely used in solar-driven photothermal catalytic dry reforming of methane(DRM)reaction,but still suffer from low activity and low light utilization efficiency.This study developed gra...CeO_(2) based semiconductor are widely used in solar-driven photothermal catalytic dry reforming of methane(DRM)reaction,but still suffer from low activity and low light utilization efficiency.This study developed graphite-CeO_(2) interfaces to enhance solar-driven photothermal catalytic DRM.Compared with carbon nanotubes-modified CeO_(2)(CeO_(2)-CNT),graphite-modified CeO_(2)(CeO_(2)-GRA)constructed graphite-CeO_(2) interfaces with distortion in CeO_(2),leading to the formation abundant oxygen vacancies.These graphite-CeO_(2) interfaces with oxygen vacancies enhanced optical absorption and promoted the generation and separation of photogenerated carriers.The high endothermic capacity of graphite elevated the catalyst surface temperature from 592.1−691.3℃,boosting light-to-thermal conversion.The synergy between photogenerated carriers and localized heat enabled Ni/CeO_(2)-GRA to achieve a CO production rate of 9985.6 mmol/(g·h)(vs 7192.4 mmol/(g·h)for Ni/CeO_(2))and a light-to-fuel efficiency of 21.8%(vs 13.8%for Ni/CeO_(2)).This work provides insights for designing graphite-semiconductor interfaces to advance photothermal catalytic efficiency.展开更多
This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investi...This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.展开更多
Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains unclear.In this work,the rutile/anatase ratio in supports was successfully controlled by...Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains unclear.In this work,the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO_(2).Structural characterizations revealed that a distinct TiO_(x) coating on the Ni nanoparticles(NPs)was evident for Ni/TiO_(2)-700 catalyst due to strong metal-support interaction.It is observed that the TiOx overlayer gradually disappeared as the ratio of rutile/anatase increased,thereby enhancing the exposure of Ni active sites.The exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4,which led to the much elevated catalytic activity for Ni/TiO_(2)-950 in which rutile dominated.Therefore,the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ratio.Ni/TiO_(2)-950,characterized by a predominant rutile phase,exhibited the highest DRM reactivity,with remarkable H_(2) and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h),respectively.These rates were approximately 257 and 130 times higher,respectively,compared to those obtained on Ni/TiO_(2)-700 with anatase.This study suggests that the optimization of crystal structure of TiO_(2) support can effectively enhance the performance of photothermal DRM reaction.展开更多
Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way t...Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way to control the hard limestone roof.In this study,the effects of various factors on the reaction characteristics and mechanical properties of limestone were analyzed.The results show that the acid with stronger hydrogen production capacity after ionization(pK_(a)<0)has more prominent damage to the mineral grains of limestone.When pKa increases from−8.00 to 15.70,uniaxial compressive strength and elastic modulus of limestone increase by 117.22%and 75.98%.The influence of acid concentration is manifested in the dissolution behavior of mineral crystals,the crystal defects caused by large-scale acid action will lead to the deterioration of limestone strength,and the strength after 15%concentration reformation can be reduced by 59.42%.The effect of acidification time on limestone has stages and is the most obvious in the initial metathesis reaction stage(within 60 min).The key to the strength damage of acidified limestone is the participation of hydrogen ions in the reaction system.Based on the analytic hierarchy process method,the influence weights of acid type,acid concentration and acidification time on strength are 24.30%,59.54% and 16.16%,respectively.The research results provide theoretical support for the acidification control of hard limestone roofs in coal mines.展开更多
Coal pyrolysis integrated with dry reforming of low-carbon alkane(CP-DRA)is an effective way to improve tar yield.Ni/La_(2)O_(3)-ZrO_(2) with a La/Zr ratio of 4 was a good catalyst for DRA to inhibit carbon deposition...Coal pyrolysis integrated with dry reforming of low-carbon alkane(CP-DRA)is an effective way to improve tar yield.Ni/La_(2)O_(3)-ZrO_(2) with a La/Zr ratio of 4 was a good catalyst for DRA to inhibit carbon deposition and obtain high tar yield in CP-DRA.In this study,the fraction distribution and component of tars from CP-DRA and coal pyrolysis in N_(2) atmosphere(CP-N_(2))were characterized by using several methods to understand the effect of DRA on coal pyrolysis.The isotope trace method was also used to discuss the role of low-carbon alkane in CP-DRA.The results showed that the tar from CP-N_(2)is mainly composed of aliphatic compounds with more C_(al),H_(al) and CH+CH_(2),and the tar from CP-DRA contains more Car,Har,and CH_(3),and has lower weight-average molecular weight and more light tar content than CP-N_(2).A small amount of C_(2)H_(6) addition in CP-DRA will raise the ratio of H_(β) and CH+CH_(2).Electron paramagnetic resonance(EPR)analysis shows that the tar from CP-DRA has a higher radical concentration while the corresponding char has a lower radical concentration.The isotope trace experiment showed that alkanes provide·H,·CH_(3),etc.to stabilize the radicals from coal pyrolysis and result in more alkyl aromatic compounds during CP-DRA.展开更多
In the process of transition from the rural China to modern society,the people's assessor system mainly reflects the citizens' individual participation.However,organized judicial participation has not been pai...In the process of transition from the rural China to modern society,the people's assessor system mainly reflects the citizens' individual participation.However,organized judicial participation has not been paid enough attention in either institutional design or in the actual operation.Judicial participation of social organizations has important significance not only in highlighting the value of people's assessor system,but also in getting out of the "presenting without substantive hearing"predicament in practice.Therefore,the people's court shall guide the orderly participation of social organizations in justice,and make social organizations play a more important role in people's assessor system.展开更多
Steam reforming of methanol was carried out on the copper-silica aerogel catalyst.The effects of reaction temperature,feed rate,water to methanol molar ratio and carrier gas flowrate on the H_2 production rate and CO ...Steam reforming of methanol was carried out on the copper-silica aerogel catalyst.The effects of reaction temperature,feed rate,water to methanol molar ratio and carrier gas flowrate on the H_2 production rate and CO selectivity were investigated.M ethanol conversion was increased considerably in the range of about 240-300,after which it increased at a slightly lower rate.The used feed flowrate,steam to methanol molar ratio and carrier gas flowwere 1.2-9.0 m L/h,1.2-5.0 and 20-80 m L/min,respectively.Reducing the feed flowrate increased the H_2 production rate.It was found that an increase in the water to methanol ratio and decreasing the carrier gas flowrate slightly increases the H2production rate.Increasing the water to methanol ratio causes the lowest temperature in which CO formation was observed to rise,so that for the ratio of 5.0 no CO formation was detected in temperatures lower than 375℃.In all conditions,by approaching the complete conversion,increasing the main product concentration,increasing the temperature and contact time,and decreasing the steam to methanol ratio,the CO selectivity was increased.These results suggested that CO was formed as a secondary product through reverse water-gas shift reaction and did not participate in the methanol steam reforming reaction mechanism.展开更多
With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Ni...With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Nickel-based catalysts are renowned for their outstanding activity and selectivity in this process.The impact of metal-support interaction(MSI),on Ni-based catalyst performance has been extensively researched and debated recently.This paper reviews the recent research progress of MSI on Ni-based catalysts and their characterization and modulation strategies in catalytic reactions.From the perspective of MSI,the effects of different carriers(metal oxides,carbon materials and molecular sieves,etc.)are introduced on the dispersion and surface structure of Ni active metal particles,and the effect of MSI on the activity and stability of DRM reactions on Ni-based catalysts is discussed in detail.Future research should focus on better understanding and controlling MSI to improve the performance and durability of nickel-based catalysts in CH_(4)-CO_(2)reforming,advancing cleaner energy technologies.展开更多
The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by...The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.展开更多
The changing of flow conditions caused by construction of hydro-projects will result in river's refor- mation and development of channel pattern.In this paper,the development of channel pattern in the process of r...The changing of flow conditions caused by construction of hydro-projects will result in river's refor- mation and development of channel pattern.In this paper,the development of channel pattern in the process of reformation is studied by means of flume experiments.Influence of slope,grain size,angle-of-inflow,dis- charge and discharge process are comprehensively analyzed according to the experimental data.It was found that the channel would be widened as the river slope or discharge increased and grain s...展开更多
As a general rule of Economics of Development,economic growth and development require rational institution guarantee.Land Tenure.As a main institution factor in agricultural development,closely relates to the reform o...As a general rule of Economics of Development,economic growth and development require rational institution guarantee.Land Tenure.As a main institution factor in agricultural development,closely relates to the reform of Chinese agriculture.Based on the relevant theories of Economics of Institution and Economics of Development,and combined with the marketization process of Chinese Land Tenure of Property Rights,the article studied the effects of institutional factors and put forward some choices in the development of agriculture,which is of both significant and practical importance.展开更多
Hydrogen was produced from partial oxidation reforming of DME （dimethyl ether） by spark discharge plasma at atmospheric pressure. A plasma-catalyst reformer was designed. A series of experiments were carried out to ...Hydrogen was produced from partial oxidation reforming of DME （dimethyl ether） by spark discharge plasma at atmospheric pressure. A plasma-catalyst reformer was designed. A series of experiments were carried out to investigate its performance of hydrogen-rich gas production. The effects of reaction temperature, catalyst and flow rate on gas concentrations （volume fraction）, hydrogen yield, DME conversion ratio, specific energy consumption and thermal efficiency were investigated, respectively. The experimental results show that hydrogen concentration and the flow rate of produced H2 are improved when temperature increases from 300 ℃ to 700 ℃. Hydrogen yield, hydrogen concentration and the flow rate of produced H2 are substantially improved in the use of Fe-based catalyst at high temperature. Moreover, hydrogen yield and thermal efficiency are improved and change slightly when flow rate increases. When catalyst is 12 g, and flow rate increases from 35 mL/min to 210 mL/min, hydrogen yield decreases from 66.4% to 57.7%, and thermal efficiency decreases from 35.6% to 30.9%. It is anticipated that the results would serve as a good guideline to the application of hydrogen generation from hydrocarbon fuels by plasma reforming onboard.展开更多
In this work,hydrogen is produced from partial oxidation reforming of dimethyl ether （DME） by a plasma-catalyst hybrid reformer under atmospheric pressure.The plasma-catalyst hybrid reformer which includes both plas...In this work,hydrogen is produced from partial oxidation reforming of dimethyl ether （DME） by a plasma-catalyst hybrid reformer under atmospheric pressure.The plasma-catalyst hybrid reformer which includes both plasma and catalyst reactors is designed.A spark discharge is used as a non-equilibrium plasma source,and it is used to ionize the mixture of DME and air.The performances of the reformer are characterized experimentally in terms of gas concentrations,hydrogen yield,DME conversion ratio,and specific energy consumption.The effects of discharge frequency,reaction temperature,air-to-DME ratio and space velocity are investigated.The experimental results show that the plasma-catalyst hybrid reformer enhances hydrogen yield when reaction temperature drops below 620 ℃.At 450 ℃,hydrogen yield of hybrid reforming is almost three times that of catalyst reforming.When space velocity is 510 h-1,hydrogen yield is 67.7%,and specific energy consumption is 12.2 k J/L-H2.展开更多
India's economic reform started from the realm of finance, which is within the category of soft power of a country. The wax and wane of the overall power of a country is largely determined by the interplay of hard...India's economic reform started from the realm of finance, which is within the category of soft power of a country. The wax and wane of the overall power of a country is largely determined by the interplay of hard and soft pwers in question. India's soft power has its own characteristics and advantages, which chiefly manifest in its culture, parliamentary democracy, education and finance. In the 21st century, these advantages will continue to have significant play.展开更多
With the accelerated reform of the state-owned industry,deregulation and competition continues,but integrated layout and regulation reconstruction are more and more expected.Through analyzing power,telecom,and tobacco...With the accelerated reform of the state-owned industry,deregulation and competition continues,but integrated layout and regulation reconstruction are more and more expected.Through analyzing power,telecom,and tobacco industry’s reform model,this paper advances a general model of deepening monopoly reform,which applies regulation reconstruction to industry restricting and monitoring regulation improvement,promoting the harmonious development of the central and local industries and promoting the vitality,influence,control force as well as anti-risk capability of the state-owned economy comprehensively.展开更多
The effect of oxidation pretreatment temperature(500 ~ 1 000 ℃) on the catalytic activity of Kovar applied on hydrocarbon CO2reforming was examined. Catalytic performance evaluation using tetradecane at 800 ℃ with ...The effect of oxidation pretreatment temperature(500 ~ 1 000 ℃) on the catalytic activity of Kovar applied on hydrocarbon CO2reforming was examined. Catalytic performance evaluation using tetradecane at 800 ℃ with 70 μmol/s CO2revealed 700 and 1 000 ℃ as the best pre-oxidation temperature in producing CO and H2,respectively. XRD and SEM-EDX analyses showed that a separate metal oxide layer composed of iron oxide(Fe2O3and F3O4),nickel,cobalt,and possibly their respective oxides started to form when oxidation was conducted at 700 ℃ or higher.The presence of iron enhanced the stability of nickel in the structure while the compact structure of Fe3O4resulted into the formation of a thick and rigid metal oxide layer on the surface of the Kovar tube. The strong physical bond between the metal oxide layer and Kovar tube provided the catalyst good mechanical strength and consequently good catalytic activity.展开更多
In the current study simultaneous reactions of hydrodesulfurization(HDS) of dibenzothiophene(DBT) and reforming of methanol in a micro-autoclave reactor were studied over bi-metallic(Co-Mo/Al2O3 and Ni-Mo/Al2O3) and t...In the current study simultaneous reactions of hydrodesulfurization(HDS) of dibenzothiophene(DBT) and reforming of methanol in a micro-autoclave reactor were studied over bi-metallic(Co-Mo/Al2O3 and Ni-Mo/Al2O3) and tri-metallic(Pd-Co-Mo/Al2O3 and Pd-Ni-Mo/Al2O3) catalyst systems which were prepared by incipient impregnation method.In situ hydrogen utilization and low Pd loadings were the major targets of this study.For comparison purpose,catalytic activity was separately determined for both the methanol reforming and HDS of DBT reactions as well.Ni based catalysts were confirmed with better activity than Co ones for both the reactions with Pd promoted ones ranking at the top i.e.Pd-Ni-Mo/Al2O3 > Ni-Mo/Al2O3 > Pd-Co-Mo/Al2O3 > Co-Mo/Al2O3 where Pd-Ni-Mo/Al2O3 showed 91% DBT conversion at 380 ℃ and 12 h reaction time.Some of the selected organic additives on catalytic activity were tested for their effect toward HDS reaction which was unique with close relation to their chemical nature.Reaction products were quantitatively and qualitatively analyzed via HPLC and GC-MS techniques respectively which helped in elucidating reaction mechanism.展开更多
文摘CeO_(2) based semiconductor are widely used in solar-driven photothermal catalytic dry reforming of methane(DRM)reaction,but still suffer from low activity and low light utilization efficiency.This study developed graphite-CeO_(2) interfaces to enhance solar-driven photothermal catalytic DRM.Compared with carbon nanotubes-modified CeO_(2)(CeO_(2)-CNT),graphite-modified CeO_(2)(CeO_(2)-GRA)constructed graphite-CeO_(2) interfaces with distortion in CeO_(2),leading to the formation abundant oxygen vacancies.These graphite-CeO_(2) interfaces with oxygen vacancies enhanced optical absorption and promoted the generation and separation of photogenerated carriers.The high endothermic capacity of graphite elevated the catalyst surface temperature from 592.1−691.3℃,boosting light-to-thermal conversion.The synergy between photogenerated carriers and localized heat enabled Ni/CeO_(2)-GRA to achieve a CO production rate of 9985.6 mmol/(g·h)(vs 7192.4 mmol/(g·h)for Ni/CeO_(2))and a light-to-fuel efficiency of 21.8%(vs 13.8%for Ni/CeO_(2)).This work provides insights for designing graphite-semiconductor interfaces to advance photothermal catalytic efficiency.
基金supported by the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(2023yjrc51)the National Natural Science Foundation of China(22172184)+2 种基金the Foundation of State Key Laboratory of Coal Conversion(J24-25-603)the Fundamental Research Project of ICC-CAS(SCJC-DT-2023-01)Weiqiao-UCAS Special Projects on Low-Carbon Technology Development(GYY-DTFZ-2022-015)。
文摘This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.
基金The project was supported by the National Key R&D Program of China(2021YFF0500702)Natural Science Foundation of Shanghai(22JC1404200)+3 种基金Program of Shanghai Academic/Technology Research Leader(20XD1404000)Natural Science Foundation of China(U22B20136,22293023)Science and Technology Major Project of Inner Mongolia(2021ZD0042)the Youth Innovation Promotion Association of CAS。
文摘Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains unclear.In this work,the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO_(2).Structural characterizations revealed that a distinct TiO_(x) coating on the Ni nanoparticles(NPs)was evident for Ni/TiO_(2)-700 catalyst due to strong metal-support interaction.It is observed that the TiOx overlayer gradually disappeared as the ratio of rutile/anatase increased,thereby enhancing the exposure of Ni active sites.The exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4,which led to the much elevated catalytic activity for Ni/TiO_(2)-950 in which rutile dominated.Therefore,the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ratio.Ni/TiO_(2)-950,characterized by a predominant rutile phase,exhibited the highest DRM reactivity,with remarkable H_(2) and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h),respectively.These rates were approximately 257 and 130 times higher,respectively,compared to those obtained on Ni/TiO_(2)-700 with anatase.This study suggests that the optimization of crystal structure of TiO_(2) support can effectively enhance the performance of photothermal DRM reaction.
基金Project(2021YFC2902102)supported by the National Key Research and Development Program of ChinaProject(52374142)supported by the National Natural Science Foundation of ChinaProject(JSTU-2022-066)supported by the Young Talent Support Project of Jiangsu Association for Science and Technology,China。
文摘Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way to control the hard limestone roof.In this study,the effects of various factors on the reaction characteristics and mechanical properties of limestone were analyzed.The results show that the acid with stronger hydrogen production capacity after ionization(pK_(a)<0)has more prominent damage to the mineral grains of limestone.When pKa increases from−8.00 to 15.70,uniaxial compressive strength and elastic modulus of limestone increase by 117.22%and 75.98%.The influence of acid concentration is manifested in the dissolution behavior of mineral crystals,the crystal defects caused by large-scale acid action will lead to the deterioration of limestone strength,and the strength after 15%concentration reformation can be reduced by 59.42%.The effect of acidification time on limestone has stages and is the most obvious in the initial metathesis reaction stage(within 60 min).The key to the strength damage of acidified limestone is the participation of hydrogen ions in the reaction system.Based on the analytic hierarchy process method,the influence weights of acid type,acid concentration and acidification time on strength are 24.30%,59.54% and 16.16%,respectively.The research results provide theoretical support for the acidification control of hard limestone roofs in coal mines.
基金supported by the National Natural Science Foundation of China(21576046)the Innovation Team Support Program in Key Areas of the Dalian Science and Technology Bureau(2019RT10).
文摘Coal pyrolysis integrated with dry reforming of low-carbon alkane(CP-DRA)is an effective way to improve tar yield.Ni/La_(2)O_(3)-ZrO_(2) with a La/Zr ratio of 4 was a good catalyst for DRA to inhibit carbon deposition and obtain high tar yield in CP-DRA.In this study,the fraction distribution and component of tars from CP-DRA and coal pyrolysis in N_(2) atmosphere(CP-N_(2))were characterized by using several methods to understand the effect of DRA on coal pyrolysis.The isotope trace method was also used to discuss the role of low-carbon alkane in CP-DRA.The results showed that the tar from CP-N_(2)is mainly composed of aliphatic compounds with more C_(al),H_(al) and CH+CH_(2),and the tar from CP-DRA contains more Car,Har,and CH_(3),and has lower weight-average molecular weight and more light tar content than CP-N_(2).A small amount of C_(2)H_(6) addition in CP-DRA will raise the ratio of H_(β) and CH+CH_(2).Electron paramagnetic resonance(EPR)analysis shows that the tar from CP-DRA has a higher radical concentration while the corresponding char has a lower radical concentration.The isotope trace experiment showed that alkanes provide·H,·CH_(3),etc.to stabilize the radicals from coal pyrolysis and result in more alkyl aromatic compounds during CP-DRA.
文摘In the process of transition from the rural China to modern society,the people's assessor system mainly reflects the citizens' individual participation.However,organized judicial participation has not been paid enough attention in either institutional design or in the actual operation.Judicial participation of social organizations has important significance not only in highlighting the value of people's assessor system,but also in getting out of the "presenting without substantive hearing"predicament in practice.Therefore,the people's court shall guide the orderly participation of social organizations in justice,and make social organizations play a more important role in people's assessor system.
文摘Steam reforming of methanol was carried out on the copper-silica aerogel catalyst.The effects of reaction temperature,feed rate,water to methanol molar ratio and carrier gas flowrate on the H_2 production rate and CO selectivity were investigated.M ethanol conversion was increased considerably in the range of about 240-300,after which it increased at a slightly lower rate.The used feed flowrate,steam to methanol molar ratio and carrier gas flowwere 1.2-9.0 m L/h,1.2-5.0 and 20-80 m L/min,respectively.Reducing the feed flowrate increased the H_2 production rate.It was found that an increase in the water to methanol ratio and decreasing the carrier gas flowrate slightly increases the H2production rate.Increasing the water to methanol ratio causes the lowest temperature in which CO formation was observed to rise,so that for the ratio of 5.0 no CO formation was detected in temperatures lower than 375℃.In all conditions,by approaching the complete conversion,increasing the main product concentration,increasing the temperature and contact time,and decreasing the steam to methanol ratio,the CO selectivity was increased.These results suggested that CO was formed as a secondary product through reverse water-gas shift reaction and did not participate in the methanol steam reforming reaction mechanism.
基金supported by the Natural Science Foundation of Shanxi Province(202203021221155)the Foundation of National Key Laboratory of High Efficiency and Low Carbon Utilization of Coal(J23-24-902)。
文摘With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Nickel-based catalysts are renowned for their outstanding activity and selectivity in this process.The impact of metal-support interaction(MSI),on Ni-based catalyst performance has been extensively researched and debated recently.This paper reviews the recent research progress of MSI on Ni-based catalysts and their characterization and modulation strategies in catalytic reactions.From the perspective of MSI,the effects of different carriers(metal oxides,carbon materials and molecular sieves,etc.)are introduced on the dispersion and surface structure of Ni active metal particles,and the effect of MSI on the activity and stability of DRM reactions on Ni-based catalysts is discussed in detail.Future research should focus on better understanding and controlling MSI to improve the performance and durability of nickel-based catalysts in CH_(4)-CO_(2)reforming,advancing cleaner energy technologies.
基金Project(2010CB227103) supported by the National Basic Research Program of ChinaProjects(50930007,50836005) supported by the Key Program of the National Natural Science Foundation of ChinaProject(U1034005) supported by the National Natural Science Foundation of China
文摘The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.
基金Supported by National Key Basic Research and Development Program(973 Program) (2003CB415205),the National Natural Science Foundation of China(50479036)
文摘The changing of flow conditions caused by construction of hydro-projects will result in river's refor- mation and development of channel pattern.In this paper,the development of channel pattern in the process of reformation is studied by means of flume experiments.Influence of slope,grain size,angle-of-inflow,dis- charge and discharge process are comprehensively analyzed according to the experimental data.It was found that the channel would be widened as the river slope or discharge increased and grain s...
文摘As a general rule of Economics of Development,economic growth and development require rational institution guarantee.Land Tenure.As a main institution factor in agricultural development,closely relates to the reform of Chinese agriculture.Based on the relevant theories of Economics of Institution and Economics of Development,and combined with the marketization process of Chinese Land Tenure of Property Rights,the article studied the effects of institutional factors and put forward some choices in the development of agriculture,which is of both significant and practical importance.
基金Project(21106002)supported by the National Natural Science Foundation of ChinaProject(2010DFA72760)supported by the Collaboration on Cutting-Edge Technology Development of Electric Vehicle,China
文摘Hydrogen was produced from partial oxidation reforming of DME （dimethyl ether） by spark discharge plasma at atmospheric pressure. A plasma-catalyst reformer was designed. A series of experiments were carried out to investigate its performance of hydrogen-rich gas production. The effects of reaction temperature, catalyst and flow rate on gas concentrations （volume fraction）, hydrogen yield, DME conversion ratio, specific energy consumption and thermal efficiency were investigated, respectively. The experimental results show that hydrogen concentration and the flow rate of produced H2 are improved when temperature increases from 300 ℃ to 700 ℃. Hydrogen yield, hydrogen concentration and the flow rate of produced H2 are substantially improved in the use of Fe-based catalyst at high temperature. Moreover, hydrogen yield and thermal efficiency are improved and change slightly when flow rate increases. When catalyst is 12 g, and flow rate increases from 35 mL/min to 210 mL/min, hydrogen yield decreases from 66.4% to 57.7%, and thermal efficiency decreases from 35.6% to 30.9%. It is anticipated that the results would serve as a good guideline to the application of hydrogen generation from hydrocarbon fuels by plasma reforming onboard.
基金Project(21106002)supported by the National Natural Science Foundation of ChinaProject(2010DFA72760)supported by Collaboration on Cutting-Edge Technology Development of Electric Vehicle,China
文摘In this work,hydrogen is produced from partial oxidation reforming of dimethyl ether （DME） by a plasma-catalyst hybrid reformer under atmospheric pressure.The plasma-catalyst hybrid reformer which includes both plasma and catalyst reactors is designed.A spark discharge is used as a non-equilibrium plasma source,and it is used to ionize the mixture of DME and air.The performances of the reformer are characterized experimentally in terms of gas concentrations,hydrogen yield,DME conversion ratio,and specific energy consumption.The effects of discharge frequency,reaction temperature,air-to-DME ratio and space velocity are investigated.The experimental results show that the plasma-catalyst hybrid reformer enhances hydrogen yield when reaction temperature drops below 620 ℃.At 450 ℃,hydrogen yield of hybrid reforming is almost three times that of catalyst reforming.When space velocity is 510 h-1,hydrogen yield is 67.7%,and specific energy consumption is 12.2 k J/L-H2.
文摘India's economic reform started from the realm of finance, which is within the category of soft power of a country. The wax and wane of the overall power of a country is largely determined by the interplay of hard and soft pwers in question. India's soft power has its own characteristics and advantages, which chiefly manifest in its culture, parliamentary democracy, education and finance. In the 21st century, these advantages will continue to have significant play.
基金the staged achievement of the key project of soft science of the Science and Technology Agency of Sichuan-On the Risk Identification and Risk Management System of the International Operation of China’s Petroleum Enterprises(2014ZR0075)
文摘With the accelerated reform of the state-owned industry,deregulation and competition continues,but integrated layout and regulation reconstruction are more and more expected.Through analyzing power,telecom,and tobacco industry’s reform model,this paper advances a general model of deepening monopoly reform,which applies regulation reconstruction to industry restricting and monitoring regulation improvement,promoting the harmonious development of the central and local industries and promoting the vitality,influence,control force as well as anti-risk capability of the state-owned economy comprehensively.
基金Supported by a research grant(K2106)from the Ministry of Environment of Japan
文摘The effect of oxidation pretreatment temperature(500 ~ 1 000 ℃) on the catalytic activity of Kovar applied on hydrocarbon CO2reforming was examined. Catalytic performance evaluation using tetradecane at 800 ℃ with 70 μmol/s CO2revealed 700 and 1 000 ℃ as the best pre-oxidation temperature in producing CO and H2,respectively. XRD and SEM-EDX analyses showed that a separate metal oxide layer composed of iron oxide(Fe2O3and F3O4),nickel,cobalt,and possibly their respective oxides started to form when oxidation was conducted at 700 ℃ or higher.The presence of iron enhanced the stability of nickel in the structure while the compact structure of Fe3O4resulted into the formation of a thick and rigid metal oxide layer on the surface of the Kovar tube. The strong physical bond between the metal oxide layer and Kovar tube provided the catalyst good mechanical strength and consequently good catalytic activity.
基金Fundamental Research Foundation of Sinopec(X505015)
文摘In the current study simultaneous reactions of hydrodesulfurization(HDS) of dibenzothiophene(DBT) and reforming of methanol in a micro-autoclave reactor were studied over bi-metallic(Co-Mo/Al2O3 and Ni-Mo/Al2O3) and tri-metallic(Pd-Co-Mo/Al2O3 and Pd-Ni-Mo/Al2O3) catalyst systems which were prepared by incipient impregnation method.In situ hydrogen utilization and low Pd loadings were the major targets of this study.For comparison purpose,catalytic activity was separately determined for both the methanol reforming and HDS of DBT reactions as well.Ni based catalysts were confirmed with better activity than Co ones for both the reactions with Pd promoted ones ranking at the top i.e.Pd-Ni-Mo/Al2O3 > Ni-Mo/Al2O3 > Pd-Co-Mo/Al2O3 > Co-Mo/Al2O3 where Pd-Ni-Mo/Al2O3 showed 91% DBT conversion at 380 ℃ and 12 h reaction time.Some of the selected organic additives on catalytic activity were tested for their effect toward HDS reaction which was unique with close relation to their chemical nature.Reaction products were quantitatively and qualitatively analyzed via HPLC and GC-MS techniques respectively which helped in elucidating reaction mechanism.
