Mechanism of Hydrogen Production by the Catalytic Steam Reforming of Bio-oil

Abstract

Many oxygen compounds were contained in bio-oil, such as acids, alcohols, ketones, aldehydes, phenols, and sugar. Acetic acid, ethylene glycol, butanone, furfural, and m-cresol were selected as bio-oil model compounds in this article. Hydrogen production was carried out via catalytic steam reforming under the conditions of the mole ratio of steam and carbon = 6, liquid hourly space velocity = 5 h−1, and 600°C with catalyst Ni/MgO. Infrared gas analyzer was used to analyze gas concentration via catalytic steam reforming of model compounds on line, while the liquid products from a collection device were analyzed by gas chromatography/mass spectrum. Intermediates were formed under catalytic steam reforming through elimination and recombination reaction, etc. The intermediates reacted with steam to produce H2 and CO2, and then the reactions reached equilibrium in the end. The hydrogen yield of acetic acid, ethylene glycol, and butanone as materials were higher than that of furfural and m-cresol as materials at the same conditions. The lowest hydrogen yield is only 34.0% (m-cresol as feedstock) and the highest hydrogen yield is up to 78.6% (butanone as feedstock).