A New Chemical Looping Process For Syngas Production With Simultaneous CO₂ Capture And Utilization

CO₂ capture,utilization and storage technology?CCUS?has been widely used to reduce the impact of the greenhouse effect.However,conventional carbon dioxide capture technology can't be supported by the reliable carbon dioxide utilization and storage methods.Therefore,searching for the approach that CO₂ capture and CO₂ utilization are combined in a single process is a solution to deal with that issue.This paper proposes a new chemical looping reforming process for syngas production with simultaneous CO₂ capture.In the new process,it integrates chemical looping mixing reforming technology?i.e.CO₂ reforming and partial oxidation reforming?,calcium looping and redox reaction using the CO₂ carrier?CC?and oxygen carrier?OC?as the intermediate circulating materials.This new process enables an energy-efficient operation,obtains the syngas with flexible H₂/CO ratios,and achieves the immediate CO₂ conversion for the captured CO₂.The?G minimization principle and entropy increase principle are firstly used to achieve the thermodynamic screening of the potential OC.The Fe-and Cu-based metal/metal oxides are determined as the potential OCs,while the CaO and MnO determined as the potential CCs.To investigate the process characteristics,a triple fluidized bed process model was established and the process simulation are conducted.It was found that CO₂ was almost completely captured,the CH₄ conversion rate exceeded 92.11%,the maximum CO₂ utilization rate was99.18%,and H₂/CO ratio can be close to 2.Besides,the energy consumption for this new process can be reduced by 40.74%and 68.62%,respectively,when compared to that of the traditional mixed-reforming and triple-reforming processes.Additional steam feed,low pressure and high temperature are helpful to improve the system performance.The experimental results from a fixed-bed facility found that the gas product distribution,solid reactivity and solid crystal phase composition variation proved the feasibility of this novel method.The variations of the phase compositions for the fresh and used solid carriers indicated that the process can realize continuous redox and CO₂ loops.Moreover,this novel process provides a route for the clean usage of carbonaceous energy sources and achieves the integrated carbon dioxide capture and conversion to reduce the carbon footprint.