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The technology being developed by Celtic Renewables Ltd is an innovation of the ABE Fermentation Process. The process has been long established at industrial scale and the technology can be readily adapted for re-introduction in a modern biotechnology context.
During the early part of the twentieth century, ABE fermentation was a very important biotechnological process, surpassed only by ethanol fermentation, as the most successful fermentation process. Its origins sprung from a high demand for natural rubber, where a shortage and expense had prompted research for a cheaper synthetic substitute.
This work was led by Chaim Weizmann whose work led to the isolation of a strain of Clostridium acetobutylicum, a strain which he referred to as BY. BY had the ability to produce acetone, butanol and ethanol as fermentation end-products. However, the work of Weizmann became invaluable for another reason. The onset of World War I demanded an abundance of munitions, smokeless gunpowder – cordite, was required in vast quantities.
Cordite manufacture required acetone and with the supply from Austria and Germany interrupted, left only a short supply from the US. Because of the capability of Weizmann’s BY strain to produce acetone, Weizmann made his work known and he was later commissioned to produce acetone using the ABE fermentation or Weizmann process, as it was also called.
Over the next twenty years expansion of AB fermentation continued on a global scale. In addition, improvements were made through the use of molasses, a cheap and plentiful substrate; and new strains, boosting the efficiency and solvent yield of the process. Demand for butanol continued and coupled with the requirement for acetone during World War II the ABE industry was at its peak. In the post–war years there was a very rapid decline in ABE fermentation, which eventually led to all but a few plants closing.
The decline of the ABE fermentation industry was due to the process being no longer economically viable and reasons for this were two-fold. Firstly, butanol could be synthesised by a more efficient and cheaper method, from crude oil. Secondly, competition arose for the feedstock used at the time, molasses, which were being used in cattle feed, leading to this once cheap and plentiful carbon source becoming too expensive for the ABE industry to compete with the petrochemical industry.
Research and plant operation continued in very few places post Second World War. Plants in South Africa, China and Russia remained operational for decades afterwards. Eventually research was rekindled in a wider field, including in the west, prompted by the oil crisis of the 1970s. This led to fuel alternatives being sought and in Brazil the Proalcool programme begun, where ethanol produced from the fermentation of sugar cane, replaced the need for the importation of oil as a fuel.
The rare expertise in the ABE process at Celtic Renewables Ltd gives the company a strategic position and competitive advantage in the field of biobutanol development.