Hydrothermal gasification of biomass: consecutive reactions to long-living intermediates

Abstract

The reaction of intermediates formed during hydrothermal biomass gasification (HBG) with each other or with hydrogen produced by the water-gas shift reaction has a significant influence on the process. To understand these reactions, the conversion of different C4 compounds (1-butanol, 1-butanal, cis-butendiol) was investigated in a batch reactor. These compounds carry different functional groups also found in intermediates of HBG. All compounds react to make products with aromatic ring systems, which shows that the intermediates can react with each other and aromatic rings are formed independently of the functional groups. The HBG intermediates can also react with hydrogen formed via the water-gas shift reaction (CO + H₂O ⇔ CO₂ + H₂). This is shown by the reaction of deuterated glucose in H₂O. The reaction of hydrogen originating from water leads to the formation of C–H bonds not present in the feedstock.