Advanced Biofuels, Done Three Ways
- Primus Green Energy uses gasification of biomass and Exxon's methanol-to-gasoline process, to convert biomass to gasoline.
- Sugars-to-isobutanol producer Gevo has signed an agreement with fuel distributor Mansfield Oil, for the distribution of isobutanol-based fuels to the petroleum market. (Source: GCC) This type of collaboration creates an almost instant distribution infrastructure for advanced biofuels, by piggy-backing onto a pre-existing distribution infrastructure. Gevo uses a proprietary yeast to ferment sugars to isobutanol. The company is in the process of converting corn ethanol plants to produce the higher value, more advanced biofuel isobutanol. Gevo's profit margins are likely to improve as it utilises more economical sources for its sugar feedstocks, derived from cellulosic biomass, over the next few years. This Gevo webcast for investors is available for the next 30 days.
- Finland's Neste Oil, producer of the highly advanced renewable diesel NExBTL, is collaborating with the Finnish Environmental Institute, to research Baltic Sea strains of algae for the purpose of using algal oils in its NExBTL product. (Source: GCC) Neste hydrotreats bio-oils to convert them into a drop-in hydrocarbon replacement for petro-diesel. Neste's NExBTL is a superior fuel compared to both conventional bio-diesel, and compared to traditional petro-diesels. Algal oil production has the potential for the highest yields of any oil crop currently known. The focus of this research is on bringing costs of growing, harvesting, and oil extraction, down to competitive levels with other bio-oils.
Very broadly, the biomass-to-gasoline (BTG) process...gasifies biomass to produce a syngas rich in hydrogen and carbon monoxide. This syngas is cleaned and conditioned and then catalytically converted into methanol for use in the MTG process. In the MTG process, dimethylether (DME), the dehydrated derivative of methanol, is reacted over a ZSM-5 zeolite catalyst, on which the chain growth of molecules is sterically hindered, thus allowing only production of gasoline and lighter material. The gasoline product from the MTG process has more than 51 compounds, similar to straight-run gasoline in a petroleum refinery. This mixture is then separated using a process similar to that used in a gasoline refinery. The design utilized in the NREL model utilizes five distillation columns to separate the remaining gas, LPG, light gasoline, and heavy gasoline. The remaining gas is sent to the fuel combustor. The light gasoline continues without further treatment. The heavy gasoline could proceed through a durene isomerizer in order to eliminate the presence of the 1,2,4,5-tetramethylbenzenes by converting them to 1,2,3,5-tetramethylbenzenes. This stream would then be merged with the light gasoline. The two product streams are LPG and gasoline. _GCCNote that this biomass-to-liquids (BTL) approach does not use the Fischer-Tropsch approach, but the more efficient Exxon methanol-to-gasoline (MTG) approach.
Hydrotreating of bio-oils (Neste etc) is already competitive in particular markets, depending upon government policies, petro-oil prices, and feedstock bio-oil prices.
Algal fuels and advanced bacterial fuels are likely to take a bit longer -- up to ten years to profitability. But one possible shortcut to profitable algal fuels is the IH2 pyrolysis of algal biomass approach. Such an approach could achieve profitability within 5 years.
Scientists and engineers are researching dozens of approaches to advanced biofuels, in the attempt to speed up the conversion of sunlight to fuels faster than the 100,000 years or more that nature requires.