Constructed by a solar chimney power plant(SCPP)and a honeycomb photocatalytic reactor(HPCR),the system can remove non-CO_(2)greenhouse gases on a large scale.A mesoscopic-scale fluid flow heat transfer model of the p...Constructed by a solar chimney power plant(SCPP)and a honeycomb photocatalytic reactor(HPCR),the system can remove non-CO_(2)greenhouse gases on a large scale.A mesoscopic-scale fluid flow heat transfer model of the photocatalytic reaction region within the SCPP-HPCR system has been established based on the Lattice Boltzmann method(LBM).Multiple distribution functions have been introduced to simulate the distribution of flow,temperature,and concentration of the photocatalytic region.The performance of photocatalytic methane in the SCPP-HPCR system has been analyzed under the influence of different operating and structural parameters.The results show that increasing the inlet methane flow rate can improve the efficiency of photocatalytic and purification rate of CH4,and lead to the increase in carbon dioxide generation rate.When the solar radiation Gr=857 W/m^(2) and the inlet flow rate Q_(p)=750 mL/min,the photocatalytic efficiency can reach 30.67%.Furthermore,decreasing the aperture size results in enhanced photocatalytic efficiency,purification rate of CH4,and equivalent CO_(2)reduction rate.When the inlet flow rate Q_(p)=1000 mL/min and the aperture size Dp=0.5 mm,the photocatalytic efficiency can reach 40.23%.Conversely,an increase in the temperature leads to a slight decrease in all evaluated criteria,and the highest photocatalytic efficiency is 24.79%at a temperature of 298 K.These findings provide valuable insights and guidance for subsequent simulation studies on a more microscopic scale.展开更多
The methane concentration in the atmosphere is far lower than that of carbon dioxide,but it is more potent,accounting for 30%of the global greenhouse effect.Although removing atmospheric methane would be an effective ...The methane concentration in the atmosphere is far lower than that of carbon dioxide,but it is more potent,accounting for 30%of the global greenhouse effect.Although removing atmospheric methane would be an effective way to mitigate climate change,no practical methods have been identified.The enhancement of the oxidative capacity of ecosystems to remove atmospheric methane is a green approach.This paper presents the novel concept of utilizing a solar chimney power plant(SCPP)associated with a solar pond to remove atmospheric methane.In the proposed system,the production of both hydroxyl radicals from ozone photolysis and chlorine atoms from converting Fe(Ⅲ)to Fe(Ⅱ)under optimized conditions degrades the atmospheric methane.The results reveal that a 200 MW SCPP associated with a solar pond could eliminate 0.22 million tons of atmospheric methane per year.The construction of 5400 systems worldwide could remove 1.19 billion tons of atmospheric methane per year,achieving the climate goal of a temperature rise of less than 2℃this century.The devices require an investment of about 3.5748×10^(12)EUR.Although the proposal seems a promising way to mitigate the effects of a warming climate,a comprehensive model must be developed to evaluate its feasibility.展开更多
基金supported by the National Key Research and Development Plan(Grant No.2019YFE0197500)the European Commission H2020Marie Curie Research and Innovation Staff Exchange(RISE)award(Grant No.871998)the National Natural Science Foundation of China(Grant Nos.52278123 and 52208124)。
文摘Constructed by a solar chimney power plant(SCPP)and a honeycomb photocatalytic reactor(HPCR),the system can remove non-CO_(2)greenhouse gases on a large scale.A mesoscopic-scale fluid flow heat transfer model of the photocatalytic reaction region within the SCPP-HPCR system has been established based on the Lattice Boltzmann method(LBM).Multiple distribution functions have been introduced to simulate the distribution of flow,temperature,and concentration of the photocatalytic region.The performance of photocatalytic methane in the SCPP-HPCR system has been analyzed under the influence of different operating and structural parameters.The results show that increasing the inlet methane flow rate can improve the efficiency of photocatalytic and purification rate of CH4,and lead to the increase in carbon dioxide generation rate.When the solar radiation Gr=857 W/m^(2) and the inlet flow rate Q_(p)=750 mL/min,the photocatalytic efficiency can reach 30.67%.Furthermore,decreasing the aperture size results in enhanced photocatalytic efficiency,purification rate of CH4,and equivalent CO_(2)reduction rate.When the inlet flow rate Q_(p)=1000 mL/min and the aperture size Dp=0.5 mm,the photocatalytic efficiency can reach 40.23%.Conversely,an increase in the temperature leads to a slight decrease in all evaluated criteria,and the highest photocatalytic efficiency is 24.79%at a temperature of 298 K.These findings provide valuable insights and guidance for subsequent simulation studies on a more microscopic scale.
基金supported by the National Natural Science Foundation of China(Grant No.52278123)the National Key R&D Program of China(Grant No.2019YFE0197500)the European Commission H2020 Marie Curie Research and Innovation Staff Exchange(RISE)award(Grant No.871998)。
文摘The methane concentration in the atmosphere is far lower than that of carbon dioxide,but it is more potent,accounting for 30%of the global greenhouse effect.Although removing atmospheric methane would be an effective way to mitigate climate change,no practical methods have been identified.The enhancement of the oxidative capacity of ecosystems to remove atmospheric methane is a green approach.This paper presents the novel concept of utilizing a solar chimney power plant(SCPP)associated with a solar pond to remove atmospheric methane.In the proposed system,the production of both hydroxyl radicals from ozone photolysis and chlorine atoms from converting Fe(Ⅲ)to Fe(Ⅱ)under optimized conditions degrades the atmospheric methane.The results reveal that a 200 MW SCPP associated with a solar pond could eliminate 0.22 million tons of atmospheric methane per year.The construction of 5400 systems worldwide could remove 1.19 billion tons of atmospheric methane per year,achieving the climate goal of a temperature rise of less than 2℃this century.The devices require an investment of about 3.5748×10^(12)EUR.Although the proposal seems a promising way to mitigate the effects of a warming climate,a comprehensive model must be developed to evaluate its feasibility.
