Towards autothermal hydrogen production by sorption-enhanced water gas shift and methanol reforming: A thermodynamic analysis

Abstract

Hydrogen production by the water gas shift reaction (WGS) is equilibrium limited. In the current study, we demonstrate that the overall efficiency of the WGS can be improved by cofeeding methanol and removing CO 2 in situ. The thermodynamics of the water gas shift and methanol reforming/WGS (methanol-to-shift, MtoS) reactions for H 2 production alone and with simultaneous CO 2 adsorption (sorption-enhanced, SEWGS and SEMtoS) were studied using a non-stoichiometric approach based on the minimisation of the Gibbs free energy. A typical composition of the effluent from a steam methane reformer was used for the shift section. The effects of temperature (450-750 K), pressure (5-30 barg), steam and methanol addition, fraction of CO 2 adsorption (0-95%) and energy efficiency of the shift systems have been investigated. Adding methanol to the feed facilitates autothermal operation of the shift unit, with and without CO 2 removal, and enhances significantly the amount of H 2 produced. For a set methanol and CO input, the MtoS and SEMtoS systems show a maximum productivity of H 2 between 523 and 593 K due to the increasing limitation of the exothermic shift reaction while the endothermic methanol steam reforming is no longer limited above 593 K. The heat of adsorption of CO 2 was found to make only a small difference to the H 2 production or the autothermal conditions.

Hydrogen Produciton Characeristics From Methanol Autothermal Reforming In Sprays

“…The advantages of using Pt is that it can react at normal temperatures, eliminating the preheating part of the experiment, and the Pt content is also lower therefore, cost is saved. In the literature review, most of the ATR uses Cu-based catalysts, but since Cu has poor stability at temperatures above 300 °C, it is commonly used as a substrate to combine different chemicals and produce new varieties of catalysts to improve stability [9,10]. However, this study will use Pt/Al2O3 catalyst to explore its suitability for ATR.…”

Elementary Steps in D2–H2O and H2–D2–H2O Exchange Reactions on Pt Nanoparticles and Consequences of Liquid Water for the Binding and Reactivity of Chemisorbed Hydrogen

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Feasibility and Performance Analysis of a Dual‐Regulation System in the Process of Methanol and Electricity Coproduction by Coal Gasification

“…And the result demonstrated that the overall efficiency of WGS can be improved through simultaneous CO 2 adsorption. [ 15 ] According to the characteristics of WGS–CaL, H/C in syngas can be accurately adjusted and CO 2 emission can be reduced by adjusting the amount of water and CaO. This process can be used as a secondary conditioning tool.…”