Hydrothermal liquefaction of biomass: A review of subcritical water technologies
Abstract
This article reviews the hydrothermal liquefaction of biomass with the aim of describing the current status of the technology. Hydrothermal liquefaction is a medium-temperature, high-pressure thermochemical process, which produces a liquid product, often called bio-oil or bi-crude. During the hydrothermal liquefaction process, the macromolecules of the biomass are first hydrolyzed and/or degraded into smaller molecules. Many of the produced molecules are unstable and reactive and can recombine into larger ones. During this process, a substantial part of the oxygen in the biomass is removed by dehydration or decarboxylation. The chemical properties of bio-oil are highly dependent of the biomass substrate composition. Biomass constitutes of various components such as protein; carbohydrates, lignin and fat, and each of them produce distinct spectra of compounds during hydrothermal liquefaction. In spite of the potential for hydrothermal production of renewable fuels, only a few hydrothermal technologies have so far gone beyond lab- or bench-scale.
- Publication:
-
Energy
- Pub Date:
- January 2011
- DOI:
- 10.1016/j.energy.2011.03.013
- Bibcode:
- 2011Ene....36.2328T
- Keywords:
-
- Hydrothermal liquefaction;
- Biomass conversion;
- Bio-oil