Comparative exergy and exergoeconomic analysis between liquid fuels production through chemical looping hydrogen generation and methane reforming with CO_2

摘要

Recently, the concept of carbon utilization has been widely investigated to reduce greenhouse gas emissions and mitigate dependence on fossil fuels. For this purpose, two different carbon capture and utilization processes to produce liquid fuels, carbon looping cyclic reforming (CCR) and carbon dioxide hydrogenation based on chemical looping hydrogen generation (CH-CLHG), are introduced. This article aims to identify which utilization method holds more potential for future technical development. To achieve it, comprehensive thermodynamic, economic and exergoeconomic assessments are implemented. The results indicate that the exergy efficiency of CH-CLHG system is 3.84% more than that of CCR system, and the cost of liquid fuels production is 36.64% less. It is also suggested that CCR system is superior to CH-CLHG system in terms of the liquid fuels output. When the electricity price is below 0.068 $/kWh, the cost of liquid fuels of CCR system is more competitive than that of CH-CLHG system. Since the higher fuel cost and larger exergy destruction, CCR system's exergy destruction cost is more significant. In addition, the exergy destruction and exergy efficiency as well as exergoeconomic performance of each main component are presented in detail to reveal the cost formation process, and to find out the measure that would improve system efficiency and cost-effectiveness.