A partnership to develop and market advanced biofuels was formed in late June by BP, London, U.K., and DuPont, Wilmington, Del. The companies have been working together since 2003 in this area and are now poised to commercialize their first jointly developed product. “Biobutanol” will be introduced as a gasoline blendstock in the U.K. in 2007. Current European regulations allow up to 10% by volume of the alcohol in gasoline.
The biobutanol will be produced from sugar beets by British Sugar, a subsidiary of Associated British Foods (ABF), at a 30,000-metric-ton/yr plant currently under construction at Wissington, Norfolk, U.K. That plant, originally designed to make ethanol, will require some tweaking of fermentation and distillation to produce biobutanol.
Biobutanol is an attractive component for gasoline, say the firms. It has a low vapor pressure and so can easily be added to gasoline. In addition, it can be used at higher concentrations than bioethanol in conventional engines — potentially up to 16% by volume. Moreover, its energy content is closer to that of gasoline; so it poses less of a compromise in fuel economy. Initial indications are that, on the same feedstock basis, biobutanol provides emissions reductions at least equal to those of ethanol.
The companies also say that biobutanol is less susceptible to separation in the presence of water than ethanol/gasoline blends. So, it can be handled by the existing distribution infrastructure without having to modify blending facilities, storage tanks or gas-station pumps. In addition, unlike existing biofuels, it may suit pipeline transport.
Biobutanol also can potentially extend the use of ethanol/gasoline blends, by reducing ethanol’s impact on vapor pressure — one of the issues, note the firms, that hampers wider use of ethanol in existing distribution channels.
Production and economics
ABF, BP and DuPont are evaluating the feasibility of constructing much larger facilities in the U.K. for biofuels production from cereals. Meanwhile, BP and DuPont are seeking other partnership opportunities worldwide with biofuels producers and expect biobutanol output of at least 80 million to 100 million gal/yr by 2010. These plants would use locally grown crops such as corn and wheat and, eventually, fast-growing energy crops such as grasses or agricultural wastes. John Ranieri, vice president and general manager of DuPont Biofuels, hopes biobutanol production in the U.S. could start by 2010.
The Wissington plant will rely on existing technology, to speed the introduction of biobutanol to market. However, the companies already are working on a new process to produce the material at a cost competitive with that of bioethanol and hope to commercialize it by 2010.
The new process’ better economics will stem from improvements in yield, rate and concentration, not from the use of lower-cost feedstocks, such as agricultural wastes, says DuPont. However, the company is working on a research program, funded by the U.S. Dept. of Energy, that next year should deliver technology to economically convert corn stover into ethanol. And, adds DuPont, that process should be adaptable to biobutanol production, but probably won’t see use in that service until after 2010.
DuPont is active in other bioprocessing areas. For instance, in partnership with Tate & Lyle, London, it building a plant to make 1,3 propanediol from corn (CP, Oct., p. 11); that 45,000-mt/yr plant should be in operation later this year. Meanwhile, BP recently embarked on an ambitious program to boost its role in alternative energy (CP, Jan., p. 19). It also just announced plans to establish an Energy Biosciences Institute at an as-yet-unnamed university, and give it $500 million in funding over the next 10 years.
