A new solar energy and biomass-based distributed energy system using H_(2)O/CO_(2)hybrid gasification is proposed,and their complementarity to enhance the system's energy efficiency is investigated and shown.In th...A new solar energy and biomass-based distributed energy system using H_(2)O/CO_(2)hybrid gasification is proposed,and their complementarity to enhance the system's energy efficiency is investigated and shown.In the system,concentrated solar energy is used to provide heat for biomass gasification;two gasifying agents(H_(2)O and CO_(2))are adopted to enhance syngas yields,and the produced solar fuel is further burned for power production in a combined cycle plant.Results show that CO share in gasification products is remarkably increased with the increment of CO_(2)/H_(2)O mole ratio caused by the boudouard reaction with the consumption of fixed carbon,while the H_(2)share is decreased;the optimal solar-to-fuel efficiency,27.88%,is achieved when the temperature and CO_(2)/H_(2)O mole ratio are 1050℃and 0.45,respectively.The emission reduction rate of CO_(2)in the system under design conditions is reduced by 2.31%compared with that using only H_(2)O agent.The annual power production of the system is increased by 1.39%,and the thermodynamic and environmental performances are significantly improved.Moreover,an economic assessment is conducted to forecast the technical feasibility of the hybrid gasification technology.This work provides a promising route to improving the thermochemical utilization efficiency of solar energy and solid fuel.展开更多
Energy systems with multi-energy product outputs driven by renewable energy sources are becoming increasingly popular.To satisfy the diversification of energy use forms in China,this study proposes a new thermochemica...Energy systems with multi-energy product outputs driven by renewable energy sources are becoming increasingly popular.To satisfy the diversification of energy use forms in China,this study proposes a new thermochemical energy system driven by solar energy and biomass for natural gas and power production.In this system,syngas from solar-driven biomass gasification is used to synthesize natural gas,whereas the unreacted syngas is burned directly in a combined cycle for power generation.To adjust the production capacity of the system,a shift reaction was used to change the H_(2)/CO ratio in the syngas.The biomass gasification model was experimentally verified,and the thermodynamic performance of the system was studied numerically.The results showed that the production rate of natural gas,with a heat value of 714.88 k J/mol,was approximately 0.306 m^(3)-SNG/kg-bio,and the primary energy efficiency was 47%.The new system showed a good energy-saving potential of 15.29%.Parametric analysis indicated that an increase in the gasification temperature led to a reduction in the natural gas production and an increase in the power output of the system,with a maximum energy efficiency of 66.72%at gasification temperature of 1050°C.With an increase in the syngas share entering the transfer reactor,the natural gas production rate and energy efficiency of the system were improved with an optimum share of approximately 0.55,thereby facilitating the development and optimization of operation strategies.This study provides a promising way to increase the share of renewable energy instead of fossil fuels.展开更多
基金supported by the National Natural Science Foundation of China(No.52306220)Major Program of the National Natural Science Foundation of China(No.52090061)。
文摘A new solar energy and biomass-based distributed energy system using H_(2)O/CO_(2)hybrid gasification is proposed,and their complementarity to enhance the system's energy efficiency is investigated and shown.In the system,concentrated solar energy is used to provide heat for biomass gasification;two gasifying agents(H_(2)O and CO_(2))are adopted to enhance syngas yields,and the produced solar fuel is further burned for power production in a combined cycle plant.Results show that CO share in gasification products is remarkably increased with the increment of CO_(2)/H_(2)O mole ratio caused by the boudouard reaction with the consumption of fixed carbon,while the H_(2)share is decreased;the optimal solar-to-fuel efficiency,27.88%,is achieved when the temperature and CO_(2)/H_(2)O mole ratio are 1050℃and 0.45,respectively.The emission reduction rate of CO_(2)in the system under design conditions is reduced by 2.31%compared with that using only H_(2)O agent.The annual power production of the system is increased by 1.39%,and the thermodynamic and environmental performances are significantly improved.Moreover,an economic assessment is conducted to forecast the technical feasibility of the hybrid gasification technology.This work provides a promising route to improving the thermochemical utilization efficiency of solar energy and solid fuel.
基金supported by the Major Program of the National Natural Science Foundation of China(Grant No.52090061)the Beijing University of Civil Engineering and Architecture Scientific Research Ability Improvement Plan of Young Teachers(Grant No.Z21045)the Guangdong Provincial Key Laboratory of Distributed Energy Systems(Grant No.2020B1212060075)。
文摘Energy systems with multi-energy product outputs driven by renewable energy sources are becoming increasingly popular.To satisfy the diversification of energy use forms in China,this study proposes a new thermochemical energy system driven by solar energy and biomass for natural gas and power production.In this system,syngas from solar-driven biomass gasification is used to synthesize natural gas,whereas the unreacted syngas is burned directly in a combined cycle for power generation.To adjust the production capacity of the system,a shift reaction was used to change the H_(2)/CO ratio in the syngas.The biomass gasification model was experimentally verified,and the thermodynamic performance of the system was studied numerically.The results showed that the production rate of natural gas,with a heat value of 714.88 k J/mol,was approximately 0.306 m^(3)-SNG/kg-bio,and the primary energy efficiency was 47%.The new system showed a good energy-saving potential of 15.29%.Parametric analysis indicated that an increase in the gasification temperature led to a reduction in the natural gas production and an increase in the power output of the system,with a maximum energy efficiency of 66.72%at gasification temperature of 1050°C.With an increase in the syngas share entering the transfer reactor,the natural gas production rate and energy efficiency of the system were improved with an optimum share of approximately 0.55,thereby facilitating the development and optimization of operation strategies.This study provides a promising way to increase the share of renewable energy instead of fossil fuels.
