Thermodynamic analysis of a new chemical looping process for syngas production with simultaneous CO_2 capture and utilization

摘要

Since typical CO2 capture technologies lack the consideration of a reliable CO2 storage method or integration with CO2 utilization, this study proposes a new chemical looping reforming process for syngas production with simultaneous CO2 capture and utilization. It integrates chemical looping, mixed reforming (i.e. CO2 reforming and partial oxidation) and calcium looping using CO2 carriers (CCs) and oxygen carriers (OCs). This novel process implements energy-efficient operation, attains flexible H-2/CO ratio, and captures CO2 with immediate CO2 conversion. Through thermodynamic screening, Fe- and Cu-based metal/metal oxides and CaO and MnO are identified as the potential OCs and CCs. For process characteristics, almost full CO2 capture is achieved, CH4 conversion rate is over 92.11%, maximum CO2 utilization rate is 99.18%, H-2/CO ratio is close to 2, and energy consumption is reduced by 40.74% and 68.62% compared to that of conventional mixed reforming and trireforming processes, respectively. Steam addition, low pressure and high temperature are benefit to enhance system performance. From experiment results, gas product distribution, solid reactivity and crystalline phases for solid demonstrate the feasibility of this novel process. More importantly, this process provides a new route to achieve integrated CO2 capture and conversion with the clean usages of carbonaceous energy sources.