Biomass conversion to renewable hydrogen by aqueous phase reforming based process

Valorisation of three residual biomasses to H 2 , produced in large scale in Brazil (Pequi, Baru and Cupuaçu husk), was performed by both one-step and two-step APR approaches. One-step (direct) APR of solid biomasses yielded up to 18 mmolH 2 /gC o at 46 % in gas. The two-step approach involved solubilisation of biomass by pretreatment at different water-to-biomass ratio (W:B, 1000:1 and 10:1) and temperature followed by APR. After pretreatment optimisation, the best APR results were observed for the hydrolysates obtained at W:B of 10:1, resulting in C conversion of 72 %, and H 2 production and concentration of ca. 53 mmol/gTOC o and 54 %, respectively. Characterisation of used catalysts showed that deactivation is mainly related to formation of deposits. Although the APR of hydrolysates obtained at low W:B (10:1) leads to higher formation of deposits, they are less evolved solids than in the case of high W:B (1000:1) hydrolysates and seem to affect less catalytic activity. • Three lignocellulosic biomasses were valorised to H 2 by APR and hydrolysis plus APR. • Up to 18 mmolH 2 /gC o at 46 mol% in gas was obtained by direct APR of Cupuaçu husk. • Lower water-to-biomass ratio in pretreatment yielded higher H 2 production in APR. • 72 % TOC conversion and 52 mmolH 2 /gTOC o by APR of Pequi shells hydrolysate at 160 °C. • Higher H 2 yield and less deactivation for carbohydrate-rich biomasses.