Hydrothernal Liquification

Hydrothermal Liquefaction:

This process is first of its kind which is developed in Denmark by 2 Danish universities Aalborg University and Aarhus University according to this process HTL all the crude bio-oil produced is sufficiently similar to the fossil crude oil. The HTL process only consumes approximately 10-15 percent of the energy in the feedstock biomass, yielding an energy efficiency of 85-90 percent.

To emphasize, the HTL process accepts all biomasses from modern society – sewage sludge, manure, wood, compost and plant material along with waste from households, meat factories, dairy production and similar industries. It is by far the most feedstock flexible of any liquid fuel producing process, including pyrolysis, bio-ethanol, gasification with Fischer-Tropsch or catalytic upgrading of different vegetable or agro-industrial residual oils, and does not carry higher costs than these.

Hydrothermal liquefaction is basically pressure cooking, but instead of cooking the biomass in batches, one pot-full at a time, this new generation of HTL is based on flow production, where the biomass is injected into a 400 °C pre-heated reactor, "cooked" under high pressure for ~15 minutes and then quickly cooled down to 70°C.

At 400°C and high pressure the water is in a supercritical state, neither liquid nor gas, at which it easily decomposes the biomass. The process is environmentally friendly, since no harmful solvents are involved, and the energy efficiency is very high: The HTL process only consumes approximately 10-15% of the energy in the feedstock biomass, because the heat energy is recycled between the heating and cooling of the process medium.

The wet medium means that HTL readily accepts moist or wet biomasses, such as those mentioned above. Wet biomasses are in vast majority on Earth. All other known processes for liquid bio-fuel production either require expensive drying or only make use of a limited proportion of the biomass, e.g. the carbohydrate...