Methanol reformation for hydrogen production from a single channel with cavities

Abstract

This paper proposes a novel design concept to enhance the methanol conversion rate in a single channel plate type microreformer with cavities. Detailed numerical studies have been carried out to understand the steam reforming of methanol for hydrogen production. The effects of operating parameters such as steam-to-methanol molar ratio, reforming temperature, reformer gas hourly space velocity (GHSV), channel wall conductivity, wall thickness and catalyst layer thickness on reforming characteristics are investigated. The effect of cavities on microreformer performance is discussed in terms of cavity aspect ratio and its spacing. For a reforming temperature of 250 °C, steam–methanol molar ratio of 1.1, average inlet fluid temperature of 120 °C and catalyst thickness of 30 μm, a methanol conversion of ∼98% with product gases consisting of 75% H2, 23% CO2 and 928 ppm CO have been obtained at the outlet of the channel. Present studies show that higher methanol conversion rates can be achieved within a shorter channel length with cavities. The proposed design can overcome the issue of shape and size of manifolds and flow equi-distribution for multiple microchannels type design and also suitable from fabrication viewpoint and practical applications.