Simulation of the calcium looping process (CLP) for hydrogen, carbon monoxide and acetylene poly-generation with CO2 capture and COS reduction

In this paper, a novel poly-generation system is proposed for hydrogen, carbon monoxide, and acetylene production with inherent CO2 capture and COS reduction. It is based on calcium looping coal gasification and oxygen-thermal CaC2 preparation. The system is comprised of calcium looping gasification reactors, preheaters, oxygen-thermal CaC2 furnace, and carbide slag modifier. Modified carbide slag and fresh CaCO3 are used as raw materials for sorption enhanced hydrogen production (SEHP). The cycled CaO-based sorbent is fed into oxygen-thermal CaC2 furnace for CaC2 production after calcination. CO-rich gas is generated from the furnace simultaneously. A portion of CO-rich gas which includes COS is fed into calcium looping gasification system to generate extra hydrogen. In addition, CO2 and COS are captured through the CaO-based sorbent. To maintain the heat balance of the system, a portion of CO-rich gas is fed into the regenerator for combustion. The entire process is modeled and simulated using Aspen Plus software. The proposed system efficiency could reach 81.62%. Parameters that affect the target products (H2, CO, C2H2, and CaC2) are investigated in the sensitive analysis, including steam/CO/CaO ratio, riser temperature, coke/CaO/O2 ratio, and coal species.