Science News Online has a great article reviewing the emerging technologies in the biofuels area which inspired me to write a similar post adding some of the technologies from The Energy Blog. Many of them have been subjects of previous posts in The Energy Blog, but putting them all together puts a fresh perspective on the future of biofuels. Despite the excesses that make up much of the Energy Act of 2005, advocates of biofuels should be fairly happy with provisions of the act that directly promote their agenda. With the rising prices of oil products biofuels are about the only answer to augmenting our liquid fuels supplies, not to diminish the importance of the conservation benefits of more fuel efficient vehicles, plug in hybrids, electric vehicles and mass transportation. Neither conservation efforts or biofuels alone can totally mitigate increasing prices, but without extreme efforts on both fronts supply and demand can do nothing but increase the price of fossil fuels.
The Energy Act of 2005:
- Requires gasoline to contain 7.5 billion gallons/yr of renewable fuel by 2012, this is almost double the 4 billion gallons produced in 2004.
- Provides incentives for the production of renewable fuels from non-traditional sources; plants, grasses, agricultural residues and waste products with greater credits for ethanol produced from cellulosic biomass or waste.
- Establishes loan guarantees and grants for the construction of facilities to convert municipal solid waste and cellulosic biomass to fuel ethanol and other commercial byproducts.
- Allows tax credits for alternative fuel vehicles
- A grant program is established for rural and remote communities to use biomass, landfill gas, and livestock methane,
- Provides for grants to those owning/operating a facility using forest biomass as raw material to produce electric energy, transportation fuels, or other petroleum-based substitutes.
- Calls for projects which address the production of hydrogen from biomass and biofuels.
ORNL published a report early this year that projected that we could get 30% of our liquid fuels from biomass without displacing any land used for crop production or grazing. Government funding as provided in the Energy Act will be of great assistance in assuring that some of the technologies outlined below get developed and brought to the commercial market to allow attaining this goal.
Ethanol Developments - By far the most emphasis has and is being placed on ethanol production in a biorefinery. The first group of technologies are related to improving this process.
Bruce Dale of Michigan State University is working on a liquid ammonia pretreatment process to prepare wastes for enzymatic treatment. The Ammonia Fiber Explosion System (AFEX) "blows apart" plants reducing the pretreatment cost in half.
The development of low cost enzymes that enables converting cellulose into its constituent sugars is a breakthrough that will enable making ethanol from corn stover, bagass, grasses and perhaps waste wood products. Novozymes, Genencore and Iogen are producing such enzymes. Novozymes in particular has reduced the price from $5.40/gallon to $0.20/gallon.
Instead of the two steps of first breaking down the cellulose into sugars and then fermenting the sugars into alcohol, Lee Lynd and Yi-Heng Percival Zhang of Dartmouth College have discovered an anaerobic microbe that will do both tasks. These microbes still need some bioengineering tweaking before they can produce ethanol.
Enhancements of ethanol production to produce byproducts such as the Panda process which makes biodiesel from waste corn oil in dry mill processes. They intend to build a 30 MMgpy biodiesel production facility and will process the crude corn oil in a new facility that is expected to be completed in 2007. The University of Missouri has developed a process for converting glycerin, a byproduct of biodiesel production, to propylene glycol, a nontoxic antifreeze. This technology can reduce the cost of biodiesel production by as much as $0.40 per gallon of biodiesel. The process has been licensed to three biodiesel plants.
Biodiesel - Biodiesel at present is produced in much smaller quantities, but larger quantities will be required as our oil supplies deplete. These technologies need much more development that the ethanol process. The use of algae or the alkane process are both very promising but little work is being done on algae and the alkane process is in early stages of research.
Production of biodiesel from algae has long been proposed, Greenfuels Corporation has developed a process that it is being demonstrated on pilot scale that uses algae and smokestack emissions to produce biodiesel. The biodiesel is a byproduct resulting from using the algae to clean up the smokestack emissions.
Distillation of the impure alcohol from the digestive process is the most energy intensive step in the production of ethanol. George Huber and his colleagues at the University of Wisconsin are developing a process to produce alkanes from cellulosic sugars. Alkanes are oil-like hydrocarbons that can be blended with diesel fuel just like biodiesel.
Thermochemical processes can be used to produce either a synthetic gasoline or synthetic diesel by modifying the synthesis step. These processes consist of two steps, gasification and Fischer-Tropsch synthesis. One process has stepped to the forefront of this technology.
Choren Industries is well on its way to develop a gasification process which, used in conjunction with a Fischer-Tropsch synthesis process, is being used to produce SunDiesel. Their Carbo-V’s three step biomass gasification process produces syngas without the tars and other impurities usually associated with biomass gasification. By partnering with Shell and using the Shell Middle Distillate Synthesis (SMDS) technology, a low-temperature, cobalt catalyst based FT process, they are able to produce SunDiesel, a synthetic oil liquid that is very clean, sulfur free and aromatic free; that meets the most stringent environmental standards.
Other biofuel processes - Biogas and bio-oil are low volume process that can contribute a meaningful quantity of fuel to our energy resources. They are especially suited for agricultural setting or distributed energy systems.
Biogas by anaerobic digestion of animal waste is becoming popular as indicated by the plants being built by Microgy. Their largest facility produces pipeline grade methane (650 BTU/cubic ft) equivalent to 12,700 gallons per day of heating oil. That isn't very much in the total picture of energy, but there is potential to build 1,200 such plants in the U.S. The Canadian IMUS process is similar using the methane to generate between 1 MW and 3 MW of power.
Biomass liquefaction via pyrolysis is the least complicated thermochemical route to producing liquid fuels from biomass. It is a thermal decomposition process operating at moderate temperatures (450-600 C) with high heat transfer rates to the biomass particles and a short residence time. Under these conditions, organic vapors, pyrolysis gases and charcoal are produced. The vapors are condensed to produce bio-oil. The resulting liquid is a low energy fuel that can be burned in diesel engines or gas turbines. Dyanamotive (Canada), BTG (the Netherlands) and Fortum (Finland) are among the companies with this process. Dynamotive, who claims to be the leader in the technology, has a 2.5 MWe plant in operation and is developing more plants.
A continuing debate is underway as to whether ethanol is an energy efficient fuel; is their more energy used in the production of ethanol than is contained in the product ethanol. Both sided of the argument keep refining their arguments with rebuttals to the other sides latest calculations. The pro-ethanol side seems to be winning in my opinion. There are also discussions as to whether their are better uses for the feedstocks, such as burning the feedstock to provide heat or electricity. I think this argument is mute, we need to supplement our liquid fuel supplies, other uses do not answer that need. No amount of conservation can totally make up for declining oil production.
Production of ethanol from corn and biodiesel from oil seeds is will not enable us to meet our production goals. There is not enough land to produce the corn and oil seeds. Development of process that use cellulosic feedstock is a necessity and should be a national priority. Biorefineries should meet this requirement, but either the alkane process or thermochemical processes are needed to supplement our diesel supplies. Use of these processes should end the energy debate once and for all.
Implementation of the technologies described above could cut the energy consumption considerably. Some of them are ready for large scale demonstration that is badly needed. Development and implementation of these technologies will go a long way towards supplanting the worlds energy needs.