OXIDATIVE METHANOL STEAM REFORMING IN MICROCHANNEL REACTOR

doi: 10.25712/ASTU.2072-8921.2021.04.021

Abstract

A microchannel reactor for hydrogen production has been developed, characterized by high values of heat and mass transfer for solving problems of creating an autonomous fuel processor. The microchannel reactor consists of metal microchannel plates with submillimeter-sized channels coated with an oxide catalyst of the Zn/TiO₂ composition. The microchannel reactor was tested in the process of oxidative steam reforming of methanol. The initial reaction mixture consisted of an aqueous solution of methanol (molar ratio 1:1) and oxygen gas. The thermal characteristics of the operation of the microchannel reactor in the reaction of oxidative steam reforming of methanol at a temperature of 400 ºC and at different molar ratios of oxygen to a water-methanol mixture have been investigated. It is shown that the addition of gaseous oxygen to the initial reaction mixture significantly reduces the power of the external heat source required to maintain the operating temperature of the microchannel reactor, the maximum decrease is from 58 to 70%, depending on the input flow of the water-methanol mixture and oxygen. Analysis of the composition of the hydrogen-containing gas at the outlet of the microchannel reactor showed that as the ratio of oxygen to the water-methanol mixture increases, the concentration of carbon monoxide at the outlet increases, not exceeding values of 5-8 vol. %. At the same time, the value of the hydrogen output is stable in a wide range of the input oxygen flow and is 5.7-5.9 ml/sec, starting to decrease only at maximum flows. Calculation of the thermal efficiency of the microchannel reactor showed that this value increases with an increase in the input oxygen flow, reaching 47% at its maximum value.