Acetone–butanol–ethanol fermentation

The low pH along with other factors then trigger a metabolic shift to the solventogenesis phase, in which acetate and butyrate are used to produce the solvents.

[5] In 1910 Auguste Fernbach (1860–1939) developed a bacterial fermentation process using potato starch as a feedstock in the production of butanol.

[6] Industrial exploitation of ABE fermentation started in 1916, during World War I, with Chaim Weizmann's isolation of Clostridium acetobutylicum, as described in U.S. patent 1315585.

[7] The Weizmann process was operated by Commercial Solvents Corporation from about 1920 to 1964 with plants in the US (Terre Haute, IN, and Peoria, IL), and Liverpool, England.

[8] After World War II, ABE fermentation became generally non-profitable, compared to the production of the same three solvents (acetone, butanol, ethanol) from petroleum.

Due to different raw material costs, ABE fermentation was viable in South Africa until the early 1980s, with the last plant closing in 1983.

[3] From a compound purification perspective, the main criticalities in the ABE/W product recovery are due to the water–alcohol mixture's non-ideal interactions leading to homogeneous and heterogeneous azeotropic species,[12] as shown by the ternary equilibrium diagram.

Therefore, in order to enhance the ABE fermentation yield, mainly in situ product recovery systems have been developed.

The energy challenge is the key point of the environmental friendly policies adopted by all the most developed and industrialized countries worldwide.

[citation needed] It can be produced from different kinds of cellulosic biomass and can be used for further processing of advanced biofuels such as butyl levulinate as well.