Biofuels and Bioenergy

Hydrothermal Liquefaction (HTL)

Hydrothermal Liquefaction (HTL) is an advanced thermochemical process that converts wet biomass into bio-crude oil, syngas, and valuable biochemicals by using high temperatures (250°C–400°C) and moderate-to-high pressures (10–25 MPa) in a water-based environment. Unlike traditional biofuel production methods that require extensive drying of biomass, HTL effectively processes wet feedstocks such as algae, sewage sludge, food waste, and agricultural residues, making it an efficient and sustainable technology for biofuel generation. The process mimics the natural geological conditions responsible for crude oil formation but accelerates it to a matter of hours rather than millions of years, providing a promising alternative to fossil fuels.The HTL process involves the decomposition of complex organic molecules under subcritical or supercritical water conditions. At these high temperatures and pressures, water acts as both a solvent and a reactant, facilitating the breakdown of biomass into simpler organic compounds. The process occurs in four key stages: hydrolysis, depolymerization, repolymerization, and phase separation. During hydrolysis, macromolecules such as carbohydrates, proteins, and lipids are broken down into smaller molecules.