Biomass catalytic gasification performance over unsupported Ni-Ce catalyst for high-yield hydrogen production

Abstract

Catalytic gasification of a residual biomass, obtained from yellow horn (YH) (Xanthoceras sorbifolia Bunge), an energy crop, was conducted to obtain a fuel gas rich in hydrogen. Unsupported nickel-based catalyst modified with cerium was developed, characterized, and used in the advanced catalytic gasification of this residual biomass, using H 2 O + CO 2 as the gasifying agent. Tests were performed in a thermobalance coupled to a mass spectrometer to identify the different steps involved in the gasification process and to correlate them with the estimated kinetic parameters. The sequential processes identified were: dehydration-devolatilization, pyrolysis and gasification. The main pyrolysis step presented a calculated activation energy value of 102 kJ mol −1 . A positive effect was observed for the catalyst in the syngas obtained. A synergistic effect of CO 2 and H 2 O used as gasifying agents was found in the gas yield. Hydrogen production was promoted by several reforming and cracking reactions, aided by CeO 2 -NiO catalyst able to co-activate H 2 O + CO 2 .