Experimental studies of CO2 capture by a hybrid catalyst/adsorbent system applicable to IGCC processes

This paper presents experimental results about CO2 capture in a hybrid adsorbent/catalyst system at both laboratory and bench scale. The proposed novel system consists of a homogeneous mixture of a K-doped hydrotalcite and a high temperature Fe–Cr WGS catalyst in a single reactor, which was selected in previous works. Tests were performed using simulated syngas compositions (CO, CO2, H2, N2, H2O) and simplified binary mixtures (N2/CO and N2/CO2) at temperatures in the range of 300 °C–500 °C and pressures up to 15 bar. The effect of contact time, process temperature and feed gas composition in the CO2 capture capacity of the sorbent was investigated and main results are presented. Moreover, the sorbent showed catalytic activity towards the WGS reaction which was highly dependent on process temperature. Details on the influence of temperature in the catalytic activity of the sorbent are also described in this paper. The influence of temperature and volume ratio adsorbent/catalyst (Vads/Vcat) in the performance of the hybrid system proposed is discussed in terms of CO conversion and CO2 capture capacity of the sorbent.