Experimental Study of an Intensified Water–Gas Shift Reaction Process Using a Membrane Reactor/Adsorptive Reactor Sequence

Abstract

We present here a preliminary experimental study of a novel reactor configuration, consisting of a membrane reactor (MR) followed by two adsorptive reactors (ARs) in parallel, operating alternately, utilized for the production of high-purity hydrogen with simultaneous CO2 capture during the water–gas shift (WGS) reaction treating a coal gasifier off-gas. In the study, we used a commercial sour-shift WGS catalyst (Co/Mo/Al2O3) in both the MR and the AR. A carbon molecular sieve (CMS) membrane was used in the MR, and a hydrotalcite adsorbent was used in the AR. The experimental results show that membrane, catalyst, and adsorbent all operated stably under the integrated gasification combined cycle (IGCC)-relevant conditions. The MR–AR reactor sequence displayed performance superior to that of a conventional packed-bed reactor (PBR) with near 100% conversions attained while the ARs are functional (with an ultrapure hydrogen stream exiting the AR and permeate-side hydrogen purities from the MR of ∼75–80%). Thus, these findings manifest the ability of the hybrid MR–AR process configuration to operate properly under the desired conditions and to intensify the efficiency of the WGS reaction, as well as to validate its potential to function as a high-efficiency, ultra-compact process for incorporation into IGCC power plants for environmentally benign power generation with pre-combustion CO2 capture.