Butanol fuel
[8] Although unproven commercially, combining electrochemical and microbial production methods may offer a way to produce butanol from sustainable sources.
[citation needed] Methods such as elementary mode analysis have been used to improve the metabolic efficiency of E. coli so that larger quantities of isobutanol may be produced.
To minimize the sensitivity of E. coli in high concentrations, mutants of the enzymes involved in synthesis can be generated by random mutagenesis.
The feedstocks for biobutanol are the same as those for ethanol: energy crops such as sugar beets, sugar cane, corn grain, wheat and cassava, prospective non-food energy crops such as switchgrass and even guayule in North America, as well as agricultural byproducts such as bagasse, straw and corn stalks.
[18] A combination of succinate and ethanol can be fermented to produce butyrate (a precursor to butanol fuel) by utilizing the metabolic pathways present in Clostridium kluyveri.
Bacillus subtilis offers many of the same advantages and disadvantages of E. coli, but it is less prominently used and does not produce isobutanol in quantities as large as E.
[10] Similar to E. coli, B. subtilis is capable of producing isobutanol from lignocellulose, and is easily manipulated by common genetic techniques.
[10] Elementary mode analysis has also been used to improve the isobutanol-synthesis metabolic pathway used by B. subtilis, leading to higher yields of isobutanol being produced.
[28][29][30] S. cerevisiae, however, has proved difficult to work with because of its inherent biology: Cupriavidus necator (=Ralstonia eutropha) is a Gram-negative soil bacterium of the class Betaproteobacteria.
This conversion is completed in several steps:[31] High cost of raw material is considered as one of the main obstacles to commercial production of butanols.
Butanol production from glycerol is economically viable using metabolic pathways that exist in the bacterium Clostridium pasteurianum.
[34] DuPont and BP plan to make biobutanol the first product of their joint effort to develop, produce, and market next-generation biofuels.
[35] In Europe the Swiss company Butalco[36] is developing genetically modified yeasts for the production of biobutanol from cellulosic materials.
Gourmet Butanol, a United States–based company, is developing a process that utilizes fungi to convert organic waste into biobutanol.
[10] Isobutanol's properties make it an attractive biofuel: Butanol better tolerates water contamination and is less corrosive than ethanol and more suitable for distribution through existing pipelines for gasoline.
[45] t-Butanol is used as an additive in gasoline but cannot be used as a fuel in its pure form because its relatively high melting point of 25.5 °C (79 °F) causes it to gel and solidify near room temperature.
[46] A fuel with a higher octane rating is less prone to knocking (extremely rapid and spontaneous combustion by compression) and the control system of any modern car engine can take advantage of this by adjusting the ignition timing.
Alcohol fuels, including butanol and ethanol, are partially oxidized and therefore need to run at richer mixtures than gasoline.
Standard gasoline engines in cars can adjust the air-fuel ratio to accommodate variations in the fuel, but only within certain limits depending on model.
The kinematic viscosity of butanol is several times higher than that of gasoline and about as viscous as high quality diesel fuel.
16 Lola B09/86 - Mazda MZR-R of Dyson Racing ran on a mixture of biobutanol and ethanol developed by team technology partner BP.
