Enhanced H2 production in the aqueous-phase reforming of maltose by feedstock pre-hydrogenation

Abstract Coupled hydrogenation and aqueous-phase reforming (APR) was studied as an approach to enhance H2 production from brewery wastewater, where maltose is the main component. Hydrogenation of maltose-bearing wastewater produced essentially maltitol. APR stage was performed over PtPd/C catalysts. Faster catalyst deactivation was observed in the APR of maltose than in the APR of maltitol, especially at high feedstock concentration. Higher H2 selectivity and yield were achieved in the APR of maltitol. The increase of temperature from 175 to 225 °C changed the reaction pathways, favouring the production of C1-C2 alkanes for both feedstocks. Higher selectivity to liquid-phase products was obtained in the APR of maltose, evidencing also reaction routes favouring the formation of solid carbonaceous deposits that lead to higher catalyst deactivation. The coupled process can be considered as efficient since H2 production compensated for H2 consumption in the hydrogenation stage and catalyst durability was increased.