Coal catalytic hydrogasification(CCHG)is a straightforward approach for producing CH_(4),which shows advantages over the mature coal-to-CH_(4) technologies from the perspectives of CH_(4) yield,thermal efficiency,and ...Coal catalytic hydrogasification(CCHG)is a straightforward approach for producing CH_(4),which shows advantages over the mature coal-to-CH_(4) technologies from the perspectives of CH_(4) yield,thermal efficiency,and CO_(2) emission.The core of CCHG is to make carbon in coal convert into CH_(4) efficiently with a catalyst.In the past decades,intensive research has been devoted to catalytic hydrogasification of model carbon(pitch coke,activated carbon,coal char).However,the chemical process of CCHG is still not well understood because the coal structure is more complicated,and CCHG is a combination of coal catalytic hydropyrolysis and coal char catalytic hydrogasification.This review seeks to shed light on the catalytic process of raw coal during CCHG.The configuration of suitable catalysts,operating conditions,and feedstocks for tailoring CH_(4) formation were identified,and the underlying mechanisms were elucidated.Based on these results,the CCHG process was evaluated,emphasizing pollutant emissions,energy efficiency,and reactor design.Furthermore,the opportunities and strategic approaches for CCHG under the restraint of carbon neutrality were highlighted by considering the penetration of“green”H2,biomass,and CO_(2) into CCHG.Preliminary investigations from our laboratories demonstrated that the integrated CCHG and biomass/CO_(2) hydrogenation process could perform as an emerging pathway for boosting CH_(4) production by consuming fewer fossil fuels,fulfilling the context of green manufacturing.This work not only provides systematic knowledge of CCHG but also helps to guide the efficient hydrogenation of other carbonaceous resources such as biomass,CO_(2),and coal-derived wastes.展开更多
CO2 gasification of Fuijian high-metamorphous anthracite with black liquor （BL） and/or mixture of BL and calcium stuff （BL＋Ca） as catalyst was studied by using a thermogravimetry under 750-950℃ at ambient pressu...CO2 gasification of Fuijian high-metamorphous anthracite with black liquor （BL） and/or mixture of BL and calcium stuff （BL＋Ca） as catalyst was studied by using a thermogravimetry under 750-950℃ at ambient pressure. When the coal was impregnated with an appropriate quantity of Ca and BL mixture, the catalytic activity of CO2 gasification was enhanced obviously. With a loading of 8%Na-BL＋2%Ca, the carbon conversion of three coal samples tested reaches up to 92.9%-99.3% at 950℃ within 30min. The continuous formation of alkali surface compounds such as （[-COM], [-CO2M]） and the presence of exchanged Ca, such as calcium phenolate and calcium carboxylates （COO）2Ca, contribute to the increase in catalytic efficiency, and using BL＋Ca is more efficient than that adding BL only, The homogeneous model and shrinking-core model were applied to correlate the data of conversion with time and to estimate the reaction rate constants under different temperature. The corresponding reaction activation energy （Ea） and pre-exponential factor of three anthracites were estimated. It is found that Ea is in the range from 73.6 to 121.4kJ·mol^-1 in the case of BL＋Ca, and 74.3 to 104.2kJ·mol^-1 when only BL was used as the catalyst, both of which are much less than that from 143.5 to 181.4kJ·mol^-1 if no catalyst used. It is clearly demonstrated that both of BL＋Ca mixture and BL could be the source of cheap and effective catalyst for coal gasification.展开更多
The gasification wastewater is a kind of typical organic industrial wastewater with high chemical oxygen demand （COD） and ammonia nitrogen, which could not be completely degraded by the traditional physical, chemica...The gasification wastewater is a kind of typical organic industrial wastewater with high chemical oxygen demand （COD） and ammonia nitrogen, which could not be completely degraded by the traditional physical, chemical and biological method. So it is very important to find an effective treatment process. A combination process of catalytic oxidation with noble metal catalysts and aerobic biological fluid-bed packed with the new ultrastructure biological carriers, which was developed by ourselves, was investigated to treat the gasification wastewater. The pilot scale test with 0.5 m^3/h influent flow was carried out to investigate the performance of this new combination process. The results showed that the effluent COD was 84.02 mg/L, ammonia nitrogen was 14.15 mg/L, and total phenol was 0.20 mg/L, which could completely meet the Grade I of Wastewater Discharge Standard （GB8978-1996）, when the influent average COD was 5 564 mg/L, ammonia nitrogen was 237 mg/L, and total phenol was 1 100 mg/L. The two catalytic reactors could evidently improve the wastewater biodegradability, and the value of BOD5/COD （B/C） increased from 0.23 to 0.413 in the one-stage catalytic reactor and from 0. 273 to 0.421 in two-stage catalytic reactor. The further experiment results showed that the effluent quality of this new combination process could still meet the discharge standard, when the COD loading was 8.65 kg / （m^3· d）. Most of aromatic and heterocyclic compounds were degraded effectively in this combination process.展开更多
The regeneration of fluidized catalytic cracking(FCC)catalysts is an essential process in petroleum processing.The current study focused the regeneration reaction characteristics of spent fluidized catalytic cracking ...The regeneration of fluidized catalytic cracking(FCC)catalysts is an essential process in petroleum processing.The current study focused the regeneration reaction characteristics of spent fluidized catalytic cracking catalyst(SFCC)at different atmospheres with influences on pore evolution and activity,for a potential way to reduce emission,produce moderate chemical product(CO),and maintain catalyst activity.The results show that regeneration in air indicates a satisfaction on removing coke on the catalyst surface while giving a poor effect on eliminating the coke inside micropores.This is attributed that the combustion in air led to a higher temperature and further transformed kaolinite phase to silicaaluminum spinel crystals,which tended to collapse and block small pores or expand large pores,with similar results observed in pure O_(2)atmosphere.Nevertheless,catalysts regenerated in O_(2)/CO_(2)diminished the combustion damage to the pore structure,of which the micro porosity after regeneration increased by 32.4% and the total acid volume rose to 27.1%.The regeneration in pure CO_(2)displayed low conversion rate due to the endothermic reaction and low reactivity.The coexistence of gasification and partial oxidation can promote regeneration and maintain the original structure and good reactivity.Finally,a mechanism of the regeneration reaction at different atmospheres was revealed.展开更多
Changes are needed to improve the efficiency and lower the CO_(2)emissions of traditional coal-fired power generation,which is the main source of global CO_(2)emissions.The integrated gasification fuel cell(IGFC)proce...Changes are needed to improve the efficiency and lower the CO_(2)emissions of traditional coal-fired power generation,which is the main source of global CO_(2)emissions.The integrated gasification fuel cell(IGFC)process,which combines coal gasification and high-temperature fuel cells,was proposed in 2017 to improve the efficiency of coal-based power generation and reduce CO_(2)emissions.Supported by the National Key R&D Program of China,the IGFC for nearzero CO_(2)emissions program was enacted with the goal of achieving near-zero CO_(2)emissions based on(1)catalytic combustion of the flue gas from solid oxide fuel cell(SOFC)stacks and(2)CO_(2)conversion using solid oxide electrolysis cells(SOECs).In this work,we investigated a kW-level catalytic combustion burner and SOEC stack,evaluated the electrochemical performance of the SOEC stack in H2O electrolysis and H2O/CO_(2)co-electrolysis,and established a multiscale and multi-physical coupling simulation model of SOFCs and SOECs.The process developed in this work paves the way for the demonstration and deployment of IGFC technology in the future.展开更多
Catalytic coal gasification technology shows prominent advantages in enhancing coal gasification reactivity and is restrained by the cost of catalyst.Two typical biomass ash additions,corn stalk ash(CSA,high K–Na and...Catalytic coal gasification technology shows prominent advantages in enhancing coal gasification reactivity and is restrained by the cost of catalyst.Two typical biomass ash additions,corn stalk ash(CSA,high K–Na and low Si)and poplar sawdust ash(PSA,high K–Ca and high Si),were employed to study the influence of biomass ash on pyrolysis process and char gasification reactivity of the typical anthracite.Microstructure characteristics of the char samples were examined by X-ray diffraction(XRD).Based on isothermal char-CO2 gasification experiments,the influence of biomass ash on reactivity of anthracite char was determined using thermogravimetric analyzer.Furthermore,structural parameters were correlated with different reactivity parameters to illustrate the crucial factor on the gasification reactivity varied with char reaction stages.The results indicate that both CSA and PSA additives hinder the growth of adjacent basic structural units in a vertical direction of the carbon structure,and then slow down the graphitization process of the anthracite during pyrolysis.The inhibition effect is more prominent with the increasing of biomass ash.In addition,the gasification reactivity of anthracite char is significantly promoted,which could be mainly attributed to the abundant active AAEM(especially K and Na)contents of biomass ash and a lower graphitization degree of mixed chars.Higher K and Na contents illustrate that the CSA has more remarkable promotion effect on char gasification reactivity than PSA,in accordance with the inhibition effect on the order degree of anthracite char.The stacking layer number could reasonably act as a rough indicator for evaluating the gasification reactivity of the char samples.展开更多
The present study aims to explore the physico-chemical structure evolution characteristic during Yangchangwan bituminous coal(YCW)gasification in the presence of iron-based waste catalyst(IWC).The catalytic gasificati...The present study aims to explore the physico-chemical structure evolution characteristic during Yangchangwan bituminous coal(YCW)gasification in the presence of iron-based waste catalyst(IWC).The catalytic gasification reactivity of YCW was measured by thermogravimetric analyzer.Scanning electron microscope–energy dispersive system,nitrogen adsorption analyzer and laser Raman spectroscopy were employed to analyze the char physico-chemical properties.The results show that the optimal IWC loading ratio was 5 wt%at 1000°C.The distribution of IWC on char was uneven and Fe catalyst concentrated on the surface of some chars.The specific surface area of YCW gasified semi-char decreased significantly with the increase of gasification time.i.e.,the specific surface area reduced from 382 m2/g(0 min)to 192 m2/g(3 min),meanwhile,the number of micropores and mesopores decreased sharply at the late gasification stage.The carbon microcrystalline structure of YCW gasified semi-char was gradually destroyed with the increase of gasification time,and the microcrystalline structure with small size was gradually generated,resulting in the decreasing order degree of carbon microcrystalline structure.IWC can catalyze YCW gasification which could provide theoretical guidance for industrial solid waste recycling.展开更多
Catalytic steam gasification of fine coal char particles was carried out using a self-made laboratory reactor to determine the intrinsic kinetics and external diffusion under varying pressures (0.1-0.5 MPa) and superf...Catalytic steam gasification of fine coal char particles was carried out using a self-made laboratory reactor to determine the intrinsic kinetics and external diffusion under varying pressures (0.1-0.5 MPa) and superficial gas flow velocities (GF Vs) of 13.8- 68.8 cm· s^-1. In order to estimate the in-situ gas release rate at a low GFV, the transported effect of effluent gas on the temporal gasification rate pattern was simulated by the Fluent computation and verified experimentally. The external mass transfer coefficients(kmam) and the effectiveness factors were determined at lower GF Vs, based on the intrinsic gasification rate obtained at a high GFV of 55.0 cm·s^-1. The kmamwas found to be almost invariable in a wider carbon conversion of 0.2-0.7. The variations of kmam at a median carbon conversion with GFV, temperature and pressure were found to follow a modified Chilton-Colburn correlation:Sh=0.311Re^2.83Sc1/3(P/P0)^-2.07 (0.04<Re<0.19), where P is total pressure and Po is atmospheric pressure. An intrinsic kinetics/extemal diffusion integrating model could well describe the gasification rate as a function of GFV, temperature and pressure over a whole gasification process.展开更多
Catalytic coal gasification for methane production is a promising technology in the clean coal utilization field.In this review,the technologies for coal-derived natural gas production,the catalytic coal gasification ...Catalytic coal gasification for methane production is a promising technology in the clean coal utilization field.In this review,the technologies for coal-derived natural gas production,the catalytic coal gasification processes and the used reactors were compared.The compared catalysts mainly included single-component,composite,and disposable catalysts.The effects of catalyst properties included composition,preparation method,supporter and loading amount were further illustrated.The influences of coal properties included char preparation method,particle size,and ash content on catalytic performance were investigated.The effects of temperatures and pressures on gasification performance were discussed in details.The evaporation,melting,decomposition,and inactivation of catalyst under various temperatures and pressures were also analyzed.It is expected to provide comprehensive information on the researches of catalytic coal gasification for methane production.展开更多
Catalytic coal gasification is an efficient way to achieve high conversion rates at low temperatures.Catalyst loss due to the reaction between the inherent mineral matter in the coal and the catalyst is a major hurdle...Catalytic coal gasification is an efficient way to achieve high conversion rates at low temperatures.Catalyst loss due to the reaction between the inherent mineral matter in the coal and the catalyst is a major hurdle for its practical application.The problem may be overcome by removing the mineral matter from the coal before use.Two demineralizing approaches,acid-washing and solvent-extraction methods are investigated for demineralizing the coals.Elemental analysis,XRD analysis,NMR analysis,and N_(2)adsorption analysis were made to compare the demineralization efficiency,crystallographic carbon microstructure,chemical structure,and micro-porosity,respectively.Solvent-extraction method was found be more efficient for demineralization.Difference was observed in the chemical structure and micro-porosity while crystallographic carbon-microstructure was found to be similar.Non-catalytic and catalytic gasification reactivity of the chars obtained by the two methods was compared.Gas composition and gas evolution profiles were also obtained and found to be influenced by the degree of demineralization.展开更多
基金National Natural Science Foundation of China(22308170)A Project Supported by Scientific Research Fund of Zhejiang Provincial Education Department(Y202250270)+2 种基金Key research and development project of Shanxi Province(202102090301029)Scientific Research Incubation Program of Ningbo University of Technology(2022TS12)Scientific Research Project Funded by Ningbo University of Technology(2022KQ04).
文摘Coal catalytic hydrogasification(CCHG)is a straightforward approach for producing CH_(4),which shows advantages over the mature coal-to-CH_(4) technologies from the perspectives of CH_(4) yield,thermal efficiency,and CO_(2) emission.The core of CCHG is to make carbon in coal convert into CH_(4) efficiently with a catalyst.In the past decades,intensive research has been devoted to catalytic hydrogasification of model carbon(pitch coke,activated carbon,coal char).However,the chemical process of CCHG is still not well understood because the coal structure is more complicated,and CCHG is a combination of coal catalytic hydropyrolysis and coal char catalytic hydrogasification.This review seeks to shed light on the catalytic process of raw coal during CCHG.The configuration of suitable catalysts,operating conditions,and feedstocks for tailoring CH_(4) formation were identified,and the underlying mechanisms were elucidated.Based on these results,the CCHG process was evaluated,emphasizing pollutant emissions,energy efficiency,and reactor design.Furthermore,the opportunities and strategic approaches for CCHG under the restraint of carbon neutrality were highlighted by considering the penetration of“green”H2,biomass,and CO_(2) into CCHG.Preliminary investigations from our laboratories demonstrated that the integrated CCHG and biomass/CO_(2) hydrogenation process could perform as an emerging pathway for boosting CH_(4) production by consuming fewer fossil fuels,fulfilling the context of green manufacturing.This work not only provides systematic knowledge of CCHG but also helps to guide the efficient hydrogenation of other carbonaceous resources such as biomass,CO_(2),and coal-derived wastes.
基金Supported by the National Natural Science Foundation of China （No.20376014） and Fujian Science and Technology Council Grant （HG99-01）.
文摘CO2 gasification of Fuijian high-metamorphous anthracite with black liquor （BL） and/or mixture of BL and calcium stuff （BL＋Ca） as catalyst was studied by using a thermogravimetry under 750-950℃ at ambient pressure. When the coal was impregnated with an appropriate quantity of Ca and BL mixture, the catalytic activity of CO2 gasification was enhanced obviously. With a loading of 8%Na-BL＋2%Ca, the carbon conversion of three coal samples tested reaches up to 92.9%-99.3% at 950℃ within 30min. The continuous formation of alkali surface compounds such as （[-COM], [-CO2M]） and the presence of exchanged Ca, such as calcium phenolate and calcium carboxylates （COO）2Ca, contribute to the increase in catalytic efficiency, and using BL＋Ca is more efficient than that adding BL only, The homogeneous model and shrinking-core model were applied to correlate the data of conversion with time and to estimate the reaction rate constants under different temperature. The corresponding reaction activation energy （Ea） and pre-exponential factor of three anthracites were estimated. It is found that Ea is in the range from 73.6 to 121.4kJ·mol^-1 in the case of BL＋Ca, and 74.3 to 104.2kJ·mol^-1 when only BL was used as the catalyst, both of which are much less than that from 143.5 to 181.4kJ·mol^-1 if no catalyst used. It is clearly demonstrated that both of BL＋Ca mixture and BL could be the source of cheap and effective catalyst for coal gasification.
基金the Key Project in Science and Technology of Heilongjiang Province , China (No. GB06C20401)
文摘The gasification wastewater is a kind of typical organic industrial wastewater with high chemical oxygen demand （COD） and ammonia nitrogen, which could not be completely degraded by the traditional physical, chemical and biological method. So it is very important to find an effective treatment process. A combination process of catalytic oxidation with noble metal catalysts and aerobic biological fluid-bed packed with the new ultrastructure biological carriers, which was developed by ourselves, was investigated to treat the gasification wastewater. The pilot scale test with 0.5 m^3/h influent flow was carried out to investigate the performance of this new combination process. The results showed that the effluent COD was 84.02 mg/L, ammonia nitrogen was 14.15 mg/L, and total phenol was 0.20 mg/L, which could completely meet the Grade I of Wastewater Discharge Standard （GB8978-1996）, when the influent average COD was 5 564 mg/L, ammonia nitrogen was 237 mg/L, and total phenol was 1 100 mg/L. The two catalytic reactors could evidently improve the wastewater biodegradability, and the value of BOD5/COD （B/C） increased from 0.23 to 0.413 in the one-stage catalytic reactor and from 0. 273 to 0.421 in two-stage catalytic reactor. The further experiment results showed that the effluent quality of this new combination process could still meet the discharge standard, when the COD loading was 8.65 kg / （m^3· d）. Most of aromatic and heterocyclic compounds were degraded effectively in this combination process.
基金supported by the National Natural Science Foundation of China(21908063)the Shanghai Pujiang Program(21PJ1402300)the Fundamental Research Funds of the Central Universities(JKB01211715 and JKB01221677)。
文摘The regeneration of fluidized catalytic cracking(FCC)catalysts is an essential process in petroleum processing.The current study focused the regeneration reaction characteristics of spent fluidized catalytic cracking catalyst(SFCC)at different atmospheres with influences on pore evolution and activity,for a potential way to reduce emission,produce moderate chemical product(CO),and maintain catalyst activity.The results show that regeneration in air indicates a satisfaction on removing coke on the catalyst surface while giving a poor effect on eliminating the coke inside micropores.This is attributed that the combustion in air led to a higher temperature and further transformed kaolinite phase to silicaaluminum spinel crystals,which tended to collapse and block small pores or expand large pores,with similar results observed in pure O_(2)atmosphere.Nevertheless,catalysts regenerated in O_(2)/CO_(2)diminished the combustion damage to the pore structure,of which the micro porosity after regeneration increased by 32.4% and the total acid volume rose to 27.1%.The regeneration in pure CO_(2)displayed low conversion rate due to the endothermic reaction and low reactivity.The coexistence of gasification and partial oxidation can promote regeneration and maintain the original structure and good reactivity.Finally,a mechanism of the regeneration reaction at different atmospheres was revealed.
基金This work was financially supported by the National Key R&D Program of China(2017YFB0601904).
文摘Changes are needed to improve the efficiency and lower the CO_(2)emissions of traditional coal-fired power generation,which is the main source of global CO_(2)emissions.The integrated gasification fuel cell(IGFC)process,which combines coal gasification and high-temperature fuel cells,was proposed in 2017 to improve the efficiency of coal-based power generation and reduce CO_(2)emissions.Supported by the National Key R&D Program of China,the IGFC for nearzero CO_(2)emissions program was enacted with the goal of achieving near-zero CO_(2)emissions based on(1)catalytic combustion of the flue gas from solid oxide fuel cell(SOFC)stacks and(2)CO_(2)conversion using solid oxide electrolysis cells(SOECs).In this work,we investigated a kW-level catalytic combustion burner and SOEC stack,evaluated the electrochemical performance of the SOEC stack in H2O electrolysis and H2O/CO_(2)co-electrolysis,and established a multiscale and multi-physical coupling simulation model of SOFCs and SOECs.The process developed in this work paves the way for the demonstration and deployment of IGFC technology in the future.
基金This work was financial supported by Natural Science Foundation of Shanxi Province(Grant Number 201801D12105)Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant Number 2017006)Shanxi Scholarship Council of China(Grant Number 2017-086).
文摘Catalytic coal gasification technology shows prominent advantages in enhancing coal gasification reactivity and is restrained by the cost of catalyst.Two typical biomass ash additions,corn stalk ash(CSA,high K–Na and low Si)and poplar sawdust ash(PSA,high K–Ca and high Si),were employed to study the influence of biomass ash on pyrolysis process and char gasification reactivity of the typical anthracite.Microstructure characteristics of the char samples were examined by X-ray diffraction(XRD).Based on isothermal char-CO2 gasification experiments,the influence of biomass ash on reactivity of anthracite char was determined using thermogravimetric analyzer.Furthermore,structural parameters were correlated with different reactivity parameters to illustrate the crucial factor on the gasification reactivity varied with char reaction stages.The results indicate that both CSA and PSA additives hinder the growth of adjacent basic structural units in a vertical direction of the carbon structure,and then slow down the graphitization process of the anthracite during pyrolysis.The inhibition effect is more prominent with the increasing of biomass ash.In addition,the gasification reactivity of anthracite char is significantly promoted,which could be mainly attributed to the abundant active AAEM(especially K and Na)contents of biomass ash and a lower graphitization degree of mixed chars.Higher K and Na contents illustrate that the CSA has more remarkable promotion effect on char gasification reactivity than PSA,in accordance with the inhibition effect on the order degree of anthracite char.The stacking layer number could reasonably act as a rough indicator for evaluating the gasification reactivity of the char samples.
基金The present work was supported by the National Natural Science Foundation of China (21968024)the Project of Key Research Plan of Ningxia (2019BCH01001)The authors also gratefully thank Professor Junzhuo Fang for his help in taking SEM–EDS photos.
文摘The present study aims to explore the physico-chemical structure evolution characteristic during Yangchangwan bituminous coal(YCW)gasification in the presence of iron-based waste catalyst(IWC).The catalytic gasification reactivity of YCW was measured by thermogravimetric analyzer.Scanning electron microscope–energy dispersive system,nitrogen adsorption analyzer and laser Raman spectroscopy were employed to analyze the char physico-chemical properties.The results show that the optimal IWC loading ratio was 5 wt%at 1000°C.The distribution of IWC on char was uneven and Fe catalyst concentrated on the surface of some chars.The specific surface area of YCW gasified semi-char decreased significantly with the increase of gasification time.i.e.,the specific surface area reduced from 382 m2/g(0 min)to 192 m2/g(3 min),meanwhile,the number of micropores and mesopores decreased sharply at the late gasification stage.The carbon microcrystalline structure of YCW gasified semi-char was gradually destroyed with the increase of gasification time,and the microcrystalline structure with small size was gradually generated,resulting in the decreasing order degree of carbon microcrystalline structure.IWC can catalyze YCW gasification which could provide theoretical guidance for industrial solid waste recycling.
基金the National Natural Science Foundation of China (Grand No.21376080).
文摘Catalytic steam gasification of fine coal char particles was carried out using a self-made laboratory reactor to determine the intrinsic kinetics and external diffusion under varying pressures (0.1-0.5 MPa) and superficial gas flow velocities (GF Vs) of 13.8- 68.8 cm· s^-1. In order to estimate the in-situ gas release rate at a low GFV, the transported effect of effluent gas on the temporal gasification rate pattern was simulated by the Fluent computation and verified experimentally. The external mass transfer coefficients(kmam) and the effectiveness factors were determined at lower GF Vs, based on the intrinsic gasification rate obtained at a high GFV of 55.0 cm·s^-1. The kmamwas found to be almost invariable in a wider carbon conversion of 0.2-0.7. The variations of kmam at a median carbon conversion with GFV, temperature and pressure were found to follow a modified Chilton-Colburn correlation:Sh=0.311Re^2.83Sc1/3(P/P0)^-2.07 (0.04<Re<0.19), where P is total pressure and Po is atmospheric pressure. An intrinsic kinetics/extemal diffusion integrating model could well describe the gasification rate as a function of GFV, temperature and pressure over a whole gasification process.
基金financially supported by Shangrao Natural Science Foundation(No.2020L001)Natural Science Foundation of China(No.51976226)Science Foundation of North University of China(No.XJJ201923).
文摘Catalytic coal gasification for methane production is a promising technology in the clean coal utilization field.In this review,the technologies for coal-derived natural gas production,the catalytic coal gasification processes and the used reactors were compared.The compared catalysts mainly included single-component,composite,and disposable catalysts.The effects of catalyst properties included composition,preparation method,supporter and loading amount were further illustrated.The influences of coal properties included char preparation method,particle size,and ash content on catalytic performance were investigated.The effects of temperatures and pressures on gasification performance were discussed in details.The evaporation,melting,decomposition,and inactivation of catalyst under various temperatures and pressures were also analyzed.It is expected to provide comprehensive information on the researches of catalytic coal gasification for methane production.
文摘Catalytic coal gasification is an efficient way to achieve high conversion rates at low temperatures.Catalyst loss due to the reaction between the inherent mineral matter in the coal and the catalyst is a major hurdle for its practical application.The problem may be overcome by removing the mineral matter from the coal before use.Two demineralizing approaches,acid-washing and solvent-extraction methods are investigated for demineralizing the coals.Elemental analysis,XRD analysis,NMR analysis,and N_(2)adsorption analysis were made to compare the demineralization efficiency,crystallographic carbon microstructure,chemical structure,and micro-porosity,respectively.Solvent-extraction method was found be more efficient for demineralization.Difference was observed in the chemical structure and micro-porosity while crystallographic carbon-microstructure was found to be similar.Non-catalytic and catalytic gasification reactivity of the chars obtained by the two methods was compared.Gas composition and gas evolution profiles were also obtained and found to be influenced by the degree of demineralization.
基金supported by National Key Research and Development Program of China(2022YFC2905900)Xuzhou Science and Technology Plan Project(KC20190)+1 种基金the National Natural Science Foundation of China(21903087,22201243)Experimental technology research and development project of China University of Mining and Technology(S2021Y006)。
