The technology being developed by Celtic Renewables is an innovation of the ABE Fermentation Process which was invented in the run-up to the First World War. The technology was then used for decades to produce solvents, and was one of the largest biological industries in the world until the 1960s when it declined significantly due to the inability to compete with the Petrochemical industry. Hence the process has been long established at industrial scale, and in instances of closed economies such as South Africa, Russia and China where sufficient supplies of crude oil were not available or subject to economic embargoes, the production of biofuel has continued as a viable industry up until recent times. The technology can be readily adapted for re-introduction in a modern biotechnology context and the rare expertise in the ABE process at Celtic Renewables gives the company a strategic position and competitive advantage in the field of biobutanol development.

The innovative process was researched over two years at the Biofuel Research Centre, which was established at Edinburgh Napier University in 2007 by Professor Martin Tangney, who is a world-authority in biobutanol production. Professor Tangney has being researching the ABE fermentation process for many years, but it only now that due to the environmental pressures around carbon emissions, the economic pressures of high oil prices, and the desire of countries for security of energy supply, that there is huge interest with the potential production of biofuels.

At present most biofuel, especially bioethanol, is made from fermenting food crops which are grown specifically for the purpose. However the economic viability and environmental advantages of this are questionable. Consequently the research at the Biofuel Research Centre concentrated specifically on organic residues or by-products which have little or no value, but have sufficient quantity of unused sugars, which can be fermented to produce biofuel. The Celtic Renewables technology uses ‘bugs’ which can convert both the complex sugars, such as xylose and arabinose, and simple glucose into biofuels. The initial primary source of the by-products is from the Scotch Whisky Industry.

This diagram shows the process by which the two  by-products: draff and pot ale are mixed and then fermented to produce a  “broth”. During fermentation a number of gases, particularly Hydrogen is  produced. The broth is then distilled to produce Butanol, Acetone and Ethanol,  and the remainder is separated into solid material, which can be dried to  produce a high-grade animal feed; and an effluent. It is anticipated that the latter can be further treated to produce other gases and water, which will provide additional value or energy for the enterprise.

The outputs from the fermentation of Draff and Pot Ale are:

                                    BUTANOL                             ETHANOL

                                    ACETONE                             ANIMAL FEED

                                    GASES  (H2, CO2)