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.

Integration of Membrane Separation with Nonthermal Plasma Catalysis: A Proof-of-Concept for CO2 Capture and Utilization

“…Specifically, the MS with two membrane units achieved the highest CCE of ∼91.8% at feed total flow rate of <30 mL min −1 , which achieved the present CCE target set by the U.S. Department of Energy (DOE) for the gasifier off-gas (i.e., >90%). 3 The system with two membrane units showed the considerably improved performance of separating CO 2 from the mixture, which is reflected by the comparison of the CO 2 concentration in the permeate-side of the MS, as shown in Figure S11, that is, 1.2 × 10 −5 mol s −1 for two membranes versus 5.4 × 10 −6 mol s −1 for one membrane at feed total flow rate of 40 mL min −1 . Consequently, under the conditions used (Figure 6b and Figure S10b), the integrated system with two membrane units (in the MS) promoted the CH 4 formation in the NTPR (i.e., 5.3 × 10 −6 to 9.2 × 10 −6 mol s −1 versus 2.7 × 10 −6 to 3.4 × 10 −6 mol s −1 for the integrated system with one membrane unit).…”

“…Specifically, zeolite membranes in the MS subsystem can be replaced by other state-of-the-art membranes for different industrial CO 2 sources, such as polymeric membranes for biogas separation, 16 metal−organic frameworks (MOFs) membranes for CO 2 capture from natural gas, 48 or carbon molecular sieve membranes (CMSM) for CO 2 capture in coal/biomassderived gasification gases in the integrated gasification gas combined cycle (IGCC) power generation plant. 3,49,50 Figure 8 shows a generic schematic of the integrated MS-NTPR process for CCU toward various CO 2 sources. Specifically, in this process, CO 2 separation from the relevant sources can be achieved effectively via the MS for the subsequent conversion.…”

“…Carbon dioxide (CO 2 ) emissions originate from many sources such as decomposition of organic wastes and combustion of fossil fuels . CO 2 is the primary greenhouse gas (∼82%) that contributes to the global warming and climate change significantly, as emphasized by the 21st Conference of the Parties (COP21, 2015 in Paris). − CO 2 capture and storage (CCS) is the current technology to allow the control of CO 2 emission and geological sequestration of CO 2 on a large scale, and hence mitigating the relevant environmental impact of CO 2 . , In addition, CO 2 capture and utilization (CCU) was also proposed as an alternative to CCS, being able to convert CO 2 emission to value-added chemicals (e.g., formic acid), fuels (e.g., methanol), and polymeric/construction materials (e.g., poly­(urethane)­s), − and hence enabling the circular economy.…”

Integrative Technical, Economic, and Environmental Feasibility Analysis for Ethane Steam Reforming in a Membrane Reactor for H2 Production

“…It is reasonable data because an MR has a fairly high H 2 yield in comparison with a CR according to previous research studies. 34,51,52 Moreover, the PSA and compressor costs were dramatically decreased more than the increase in the membrane module cost.…”

Process intensification connects scales and disciplines towards sustainability

“…They obtained a reduction of 8.17% and 6.59% in the total investment and operations and maintenance (O&M) costs, respectively, compared to the base case design. Recently, in the effort to make IGCC plants with a CO 2 capture unit sustainable, Chen et al [ 113 ] propose an integrated IGCC power plant with a membrane reactor and adsorptive reactor (MR‐AR) combined. In this system, syngas flows through a membrane reactor (MR) filled with a WGS catalyst (Co/Mo/Al 2 O 3 ).…”