Production of Hydrogen With Low Carbon Monoxide Formation Via Catalytic Steam Reforming of Methanol

Abstract

The production of hydrogen was investigated in a fixed bed tubular reactor via steam reforming of methanol (SRM) using CuO∕ZnO∕Al2O3 catalysts prepared by wet impregnation method and characterized by measuring surface area, pore volume, x-ray diffraction patterns, and scanning electron microscopy photographs. The SRM was carried out at atmospheric pressure, temperature 493-573K, steam to methanol molar ratio 1–1.8 and contact-time (W/F) 3–15kg cat./(mol/s of methanol). Effects of reaction temperature, contact-time, steam to methanol molar ratio and zinc content of the catalyst on methanol conversion, selectivity, and product yields was evaluated. The addition of zinc enhanced the methanol conversion and hydrogen production. The excess steam promoted the methanol conversion and suppressed the carbon monoxide formation. Different strategies have been mentioned to minimize the carbon monoxide formation for the steam reforming of methanol to produce polymer electrolyte membrane (PEM) fuel cell grade hydrogen. Optimum operating conditions with appropriate composition of catalyst has been investigated to produce more selective hydrogen with minimum carbon monoxide. The experimental results were fitted well with the kinetic model available in literature.