Liquefaction
Thermo-chemical liquefaction is one of the methods to convert biomass to fluid fuel. In this process, biomass is heated to 250–350 °C in water at a pressure of 5–20 MPa in the absence of air. Solvent or catalyst can be added in the process [36]. The disadvantages of biomass liquefaction are that it is very difficult to achieve the operating condition and its production of hydrogen is low. Therefore, liquefaction is not favorable for hydrogen production.