A Novel Integrated Hydrothermal Liquefaction and Solar Catalytic Reforming Method for Enhanced Hydrogen Generation from Biomass

Abstract

Short energy intensive hydrothermal liquefaction (HTL) of biomass in the presence of Ni salt catalyst selectively generates H<SUB>2</SUB> in the product gas and biocrude mainly containing C<SUB>1</SUB>-C<SUB>3</SUB> acids (formic, lactic, propionic, acetic), HMF and furfural. The H<SUB>2</SUB> mass balance indicated that only 3.12 vol% H<SUB>2</SUB> in biomass (cotton) was released as product gas; 48.7 vol% was captured in the C<SUB>1</SUB>-C<SUB>3</SUB> acids while the remainder H<SUB>2</SUB> was trapped in oxygenated compounds and char. Continuing HTL after 120 minutes caused no further increase in gas phase H<SUB>2</SUB> yields. To enhance the H<SUB>2</SUB> yields with minimal energy input, solar photocatalytic reforming (PR) of the biocrude with Pt/TiO<SUB>2</SUB> catalyst was investigated. Photocatalysis of activated carbon (AC) treated biocrude generated an additional H<SUB>2</SUB>, 17.82 wt%. H<SUB>2</SUB> yields from photoreforming of simulated biocrude acid mixture and actual biocrude were compared. Enhanced H<SUB>2</SUB> generation was observed with integrated HTL-PR of biomass.