High quality syngas production from pressurized K_2CO_3 catalytic coal gasification with in-situ CO_2 capture

摘要

The enhanced K-catalytic coal gasification by CO2 sorption reaction (EKcSG) was proposed to produce syngas with high content of H-2 and CH4 and perform in-situ CO2 capture. CO2 is reduced dramatically with the introduction of the CaO into the reactor under typical K-catalytic coal gasification condition (3.5 MPa, 700 degrees C). The carbonation reaction of CaO can promote the syngas production by improving the equilibrium of the water-gas shift reaction and supplying heat for coal gasification reaction. In the presence of the CaO sorbent (Ca/C = 0.5), the CO2 concentration in the product gas decreased from 25.61% to 12.80% compared with that without CaO. Correspondingly, the total concentration of H-2 and CH4 is improved from 65.61% to 82.99% and the carbon conversion reached above 95%. The effect of Ca/C ratio and reaction temperature was investigated during the EKcSG process. It is considered that Ca/C ratio of 0.5 is the best proportion in terms of carbon conversion and CO2 absorption in our experimental conditions. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.