Tech-economic and environmental analysis of energy-efficient shale gas and flue gas coupling system for chemicals manufacture and carbon capture storage and utilization

Abstract

Shale gas and flue gas complementary co-conversion for simultaneous value added chemicals synthesis and carbon capture, utilization and storage are crucial way to energy source utilization and carbon emission mitigation. This paper put forward a novel process design converting shale gas and flue gas into value added chemicals including sulfur, urea and methanol. Three scenarios, urea and methanol parallel, urea priority and methanol priority cases, are placed to make comparison. Process simulation and pinch analysis are employed to simulate the whole process and synthesize heat exchange network. Waste heat recovery and reuse of ready-made CO2 and N2 in flue gas greatly reduce the total energy consumption under same amount of chemicals production and CO2 capture over individual production basis. Tech-economic and environmental analysis results indicate that the urea priority scenario process is superior in economic performance and its net present value is 109.5 MM$, the methanol-urea parallel scenario has the lowest greenhouse gas emission, 367.7 kton CO2-Eq/year while the methanol priority process has highest CO2 utilization proportion 55.57%. This work is great progress for shale gas energy-efficient and economical conversion to chemicals and lower energy penalty of flue gas CCUS of coal-based power plant.