Steam reforming and water–gas shift of ethanol on Rh and Rh–Ce catalysts in a catalytic wall reactor

Abstract

Ethanol is a renewable, portable, and non-toxic liquid that is a possible source of hydrogen for PEM fuel cells. This work describes an auto-thermal flat plate catalytic wall reactor for steam reforming of ethanol into H 2 and CO 2. Catalytic methane combustion on Pt is coupled to ethanol steam reforming on Rh and Rh–Ce across an auto-thermal wall. At a steam/carbon ratio of 3/1 the reactor gave >99% conversion of ethanol. An H 2/CO ratio of 3/1 was obtained at a residence time of ∼100 ms and an upstream temperature of ∼800 °C. Methane selectivities of less than 1% were obtained with Rh–Ce. Water–gas shift was also considered in order to increase the H 2/CO ratio. The reactor was lengthened to include a cooler water–gas shift section using a Pt–Ce catalyst. The extended reactor produced >99% conversion of ethanol and an H 2/CO ratio of 30/1 at a steam/carbon ratio of 4/1. The residence time was ∼400 ms, and the upstream temperature was ∼900 °C in the extended reactor. The reactor was stable for at least 100 h with no detectable degradation in performance.