The natural gas(NG)reforming is currently one of the low-cost methods for hydrogen production.However,the mixture of H2 and CO_(2) in the produced gas inevitably includes CO_(2) and necessitates the costly CO_(2) sepa...The natural gas(NG)reforming is currently one of the low-cost methods for hydrogen production.However,the mixture of H2 and CO_(2) in the produced gas inevitably includes CO_(2) and necessitates the costly CO_(2) separation.In this work,a novel double chemical looping involving both combustion(CLC)and sorption-enhanced reforming(SE-CLR)was proposed towards the co-production of H2 and CO(CLC-SECLRHC)in two separated streams.CLC provides reactant CO_(2) and energy to feed SECLRHC,which generates hydrogen in a higher purity,as well as the calcium cycle to generate CO in a higher purity.Techno-economic assessment of the proposed system was conducted to evaluate its efficiency and economic competitiveness.Studies revealed that the optimal molar ratios of oxygen carrier(OC)/NG and steam/NG for reforming were recommended to be 1.7 and 1.0,respectively.The heat integration within CLC and SECLRHC units can be achieved by circulating hot OCs.The desired temperatures of fuel reactor(FR)and reforming reactor(RR)should be 850C and 600C,respectively.The heat coupling between CLC and SECLRHC units can be realized via a jacket-type reactor,and the NG split ratio for reforming and combustion was 0.53:0.47.Under the optimal conditions,the H2 purity,the H2 yield and the CH4 conversion efficiency were 98.76%,2.31 mol mol-1 and 97.96%,respectively.The carbon and hydrogen utilization efficiency respectively were 58.60% and 72.45%in terms of the total hydrogen in both steam and NG.The exergy efficiency of the overall process reached 70.28%.In terms of the conventional plant capacity(75 × 103 t y^(-1))and current raw materials price(2500$t^(-1)),the payback period can be 6.2 years and the IRR would be 11.5,demonstrating an economically feasible and risk resistant capability.展开更多
The use of hydrogen as an energy carrier could help address our concerns about energy security,global cli mate change,and air quality.Fuel cells are ani mportant enablingtechnologyfor the Hydrogen Future and have the ...The use of hydrogen as an energy carrier could help address our concerns about energy security,global cli mate change,and air quality.Fuel cells are ani mportant enablingtechnologyfor the Hydrogen Future and have the potential torevolutionize theway we power our nation,offering cleaner,more-efficient alternatives to the combustion of gasoline and other fossil fuels.For over 45 years,GTI has been activein hydrogen energy research,development and demonstration.The Institute has ex-tensive experience and on-going workin all aspects of the hydrogen energy economyincluding production,delivery,infrastructure,use,safety and public policy.This paper discusses the recent GTI programsin hydrogen production,hydrogenstorage,and protonexchange membrane fuel cells(PEMFC) and solid oxide fuel cells(SOFC).展开更多
基金supported by National Natural Science Foundation of China(U1810205)The authors would also like to thank the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20220003)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2021L002)for their support.
文摘The natural gas(NG)reforming is currently one of the low-cost methods for hydrogen production.However,the mixture of H2 and CO_(2) in the produced gas inevitably includes CO_(2) and necessitates the costly CO_(2) separation.In this work,a novel double chemical looping involving both combustion(CLC)and sorption-enhanced reforming(SE-CLR)was proposed towards the co-production of H2 and CO(CLC-SECLRHC)in two separated streams.CLC provides reactant CO_(2) and energy to feed SECLRHC,which generates hydrogen in a higher purity,as well as the calcium cycle to generate CO in a higher purity.Techno-economic assessment of the proposed system was conducted to evaluate its efficiency and economic competitiveness.Studies revealed that the optimal molar ratios of oxygen carrier(OC)/NG and steam/NG for reforming were recommended to be 1.7 and 1.0,respectively.The heat integration within CLC and SECLRHC units can be achieved by circulating hot OCs.The desired temperatures of fuel reactor(FR)and reforming reactor(RR)should be 850C and 600C,respectively.The heat coupling between CLC and SECLRHC units can be realized via a jacket-type reactor,and the NG split ratio for reforming and combustion was 0.53:0.47.Under the optimal conditions,the H2 purity,the H2 yield and the CH4 conversion efficiency were 98.76%,2.31 mol mol-1 and 97.96%,respectively.The carbon and hydrogen utilization efficiency respectively were 58.60% and 72.45%in terms of the total hydrogen in both steam and NG.The exergy efficiency of the overall process reached 70.28%.In terms of the conventional plant capacity(75 × 103 t y^(-1))and current raw materials price(2500$t^(-1)),the payback period can be 6.2 years and the IRR would be 11.5,demonstrating an economically feasible and risk resistant capability.
文摘The use of hydrogen as an energy carrier could help address our concerns about energy security,global cli mate change,and air quality.Fuel cells are ani mportant enablingtechnologyfor the Hydrogen Future and have the potential torevolutionize theway we power our nation,offering cleaner,more-efficient alternatives to the combustion of gasoline and other fossil fuels.For over 45 years,GTI has been activein hydrogen energy research,development and demonstration.The Institute has ex-tensive experience and on-going workin all aspects of the hydrogen energy economyincluding production,delivery,infrastructure,use,safety and public policy.This paper discusses the recent GTI programsin hydrogen production,hydrogenstorage,and protonexchange membrane fuel cells(PEMFC) and solid oxide fuel cells(SOFC).
