Reducing CO_(2) to produce methane through microbial electrolytic cell(MEC)is one of the important methods of CO_(2) resource utilization.In view of the problem of low methanogenesis rate and weak CO_(2) conversion ra...Reducing CO_(2) to produce methane through microbial electrolytic cell(MEC)is one of the important methods of CO_(2) resource utilization.In view of the problem of low methanogenesis rate and weak CO_(2) conversion rate in the reduction process,theflowfield environment of the cathode chamber is changed by changing the upper gas cir-culation rate and the lower liquid circulation rate of the cathode chamber to explore the impact on the reactor startup and operation and products.The results showed that under certain conditions,the CO_(2) consumption and methane production rate could be increased by changing the upper gas recirculation rate alone,but the increase effect was not obvious,but the by-product hydrogen production decreased significantly.Changing the lower liquid circulation rate alone can effectively promote the growth of biofilm,and change the properties of biofilm at the later stage of the experiment,with the peak current density increased by 16%;The methanogenic rate decreased from the peak value of 0.561 to 0.3 mmol/d,and the CO_(2) consumption did not change signifi-cantly,which indicated that CO_(2) was converted into other organic substances instead of methane.The data after coupling the upper gas circulation rate with the lower liquid circulation rate is similar to that of only changing the lower liquid circulation rate,but changing the upper gas circulation rate can alleviate the decline of methane pro-duction rate caused by the change of biofilm properties,which not only improves the current density,but also increases the methane production rate by 0.05 mmol/d in the stable period.This study can provide theoretical and technical support for the industrial application scenario offlowfield regulation intervention of microbial elec-trolytic cell methanogenesis.展开更多
As a new generation fuel cell,solid oxide fuel cell(SOFC)has become a hot spot in the industry due to its unique advantages.In order to improve energy utilization and prevent carbon deposition in the reformer,the ejec...As a new generation fuel cell,solid oxide fuel cell(SOFC)has become a hot spot in the industry due to its unique advantages.In order to improve energy utilization and prevent carbon deposition in the reformer,the ejector is usually used to recover the cell anode exhaust.In this paper,the applications related to ejector in SOFC are reviewed,including the ejector design and optimization methods,the ejector performance verification experiment and the performance of ejector in SOFC systems.Besides,in order to adapt to the wide power output characteristics of the stack,a study on extending the working range of the ejector is also introduced.On the one hand,the theory of optimal design of ejector used in SOFC system is obtained,including the influence of main structure parameters of ejector on the performance of the whole system and the theoretical model of performance monitoring of ejector used in SOFC.On the other hand,it is proved that the ejector used in SOFC power system can prevent the occurrence of carbon deposition problems,while the recovery of exhaust heat can improve the energy utilization of the system.Finally,suggestions for future related research work are given,aiming to promote the ejector-based SOFC system to provide higher and more stable performance in the future.展开更多
基金This paper is supported by Shanghai Science and Technology Development Fund,China,No.19DZ1205604.
文摘Reducing CO_(2) to produce methane through microbial electrolytic cell(MEC)is one of the important methods of CO_(2) resource utilization.In view of the problem of low methanogenesis rate and weak CO_(2) conversion rate in the reduction process,theflowfield environment of the cathode chamber is changed by changing the upper gas cir-culation rate and the lower liquid circulation rate of the cathode chamber to explore the impact on the reactor startup and operation and products.The results showed that under certain conditions,the CO_(2) consumption and methane production rate could be increased by changing the upper gas recirculation rate alone,but the increase effect was not obvious,but the by-product hydrogen production decreased significantly.Changing the lower liquid circulation rate alone can effectively promote the growth of biofilm,and change the properties of biofilm at the later stage of the experiment,with the peak current density increased by 16%;The methanogenic rate decreased from the peak value of 0.561 to 0.3 mmol/d,and the CO_(2) consumption did not change signifi-cantly,which indicated that CO_(2) was converted into other organic substances instead of methane.The data after coupling the upper gas circulation rate with the lower liquid circulation rate is similar to that of only changing the lower liquid circulation rate,but changing the upper gas circulation rate can alleviate the decline of methane pro-duction rate caused by the change of biofilm properties,which not only improves the current density,but also increases the methane production rate by 0.05 mmol/d in the stable period.This study can provide theoretical and technical support for the industrial application scenario offlowfield regulation intervention of microbial elec-trolytic cell methanogenesis.
基金supported by the National Natural Science Foundation of China(Grant No.51776110)。
文摘As a new generation fuel cell,solid oxide fuel cell(SOFC)has become a hot spot in the industry due to its unique advantages.In order to improve energy utilization and prevent carbon deposition in the reformer,the ejector is usually used to recover the cell anode exhaust.In this paper,the applications related to ejector in SOFC are reviewed,including the ejector design and optimization methods,the ejector performance verification experiment and the performance of ejector in SOFC systems.Besides,in order to adapt to the wide power output characteristics of the stack,a study on extending the working range of the ejector is also introduced.On the one hand,the theory of optimal design of ejector used in SOFC system is obtained,including the influence of main structure parameters of ejector on the performance of the whole system and the theoretical model of performance monitoring of ejector used in SOFC.On the other hand,it is proved that the ejector used in SOFC power system can prevent the occurrence of carbon deposition problems,while the recovery of exhaust heat can improve the energy utilization of the system.Finally,suggestions for future related research work are given,aiming to promote the ejector-based SOFC system to provide higher and more stable performance in the future.
