Productivity of transport Biofuel

Transport fuel can be produced from biomass by any of the following processes:

Fermentation

Ethanol is currently produced from starch and sugar based products which are fermented to form a dilute alcohol. Various grades of industrial, beverage and fuel grade ethanol are then distilled from the initial dilute solution.

Transesterification

Biodiesel can be produced from any non mineral oil or fat through transesterification, a reaction with alcohol and a catalyst. The products of the reaction are and ester (biodiesel) and glycerol. A variation of the transesterification reaction has been used for centuries to produce soap but modern biodiesel production plants use a very fast, high pressure and temperature continuous process.

Gasification

Interest is currently growing in the use of biomass gasification products to produce Fischer-Tropsch liquids (FTLs).  These liquids may eventually be produced at similar prices to petroleum-based diesel.  FTL formulations tend to be cleaner burning than petroleum-based diesel.

Pyrolysis

Pyrolysis processes provide greater flexibility and higher conversion efficiencies compared to combustion, but capital costs are also currently excessive and technology is in the early stages of development.  The product, pyrolysis oil, which can be used in turbines and other heat plant, can be easily transported and thus allows separation of the resource location from the site of use.

Hydrolysis/Fermentation

Advances in the hydrolysis/fermentation of ligno-cellulose to produce ethanol/methanol and lignin are promising, with future cost reductions claimed.  The alcohol fuels can be used in present designs of internal combustion engines, new micro-turbines, or as a source of hydrogen for fuel cells.