Selection and preparation of CO2 sorbent for sorption-enhanced steam reforming process of raw coke oven gas

摘要

The study on CO2 sorbent to be used in the sorption-enhanced steam reforming process of raw coke oven gas (RCOG) was performed via thermodynamic and experimental analysis in this article. From the thermodynamic analysis, CaO showed the highest CO2 adsorption capacity in the SR reaction temperature zone of RCOG and the best CO2 desorption efficiency at the higher temperature among eight candidate metal-oxides, and thus was selected as the active component of CO2 sorbent. Then, the CaO-based sorbents were prepared with Ca12Al14O33 as carrier and their adsorption performances were tested via thermogravimetric experiment. Under the preparation conditions with the calcined time of 4 h, the calcined temperature of 900 degrees C and the CaO content of 75%, the sorbent sample showed the better CO2 adsorption and cycle stability than the other prepared samples and pure CaO, with its adsorption capacity reaching 47.38%. From the sorption-enhanced steam reforming experiments, the addition of the selected sorbent can obviously improve the H-2 yield, with its concentration approaching 100%, and the optimal reforming temperature was deceased, with the H-2 yield obtaining 83.76% at 800 degrees C. (c) 2018 American Institute of Chemical Engineers Environ Prog, 38: 89-97, 2019