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

Short energy intensive hydrothermal liquefaction (HTL) of biomass in the presence of Ni salt catalyst selectively generates H₂ in the product gas and biocrude mainly containing C₁-C₃ acids (formic, lactic, propionic, acetic), HMF and furfural. The H₂ mass balance indicated that only 3.12 vol% H₂ in biomass (cotton) was released as product gas; 48.7 vol% was captured in the C₁-C₃ acids while the remainder H₂ was trapped in oxygenated compounds and char. Continuing HTL after 120 minutes caused no further increase in gas phase H₂ yields. To enhance the H₂ yields with minimal energy input, solar photocatalytic reforming (PR) of the biocrude with Pt/TiO₂ catalyst was investigated. Photocatalysis of activated carbon (AC) treated biocrude generated an additional H₂, 17.82 wt%. H₂ yields from photoreforming of simulated biocrude acid mixture and actual biocrude were compared. Enhanced H₂ generation was observed with integrated HTL-PR of biomass.