Miscanthus is a promising energy crop

Miscanthus is a promising energy crop

By John Addison (5/13/09).

Scientists know how to make fuel from prairie grasses growing on marginal land. They know how to make fuel from fast growing trees with root systems that extend 25 feet into the ground, sequestering carbon emissions and enriching the soil. They even know how to make fuel from algae. They do all this in their labs every day. The problem is making cellulosic and algal fuel in large quantities at costs that compete with fuels from petroleum such as gasoline, diesel, and jet fuel.

This is my second article (previous article) from the 31st Symposium on Biotechnology for Fuels and Chemicals sponsored by NREL. 800 global bioscientists gathered in San Francisco to share their research and showcase their progress.

Their progress with biofuels from cellulosic sources is important. Some corn ethanol plants have closed. Once promising corporations, such as VeraSun, are now bankrupt. Lifecycle greenhouse gas emissions for fuel-from-food are being scrutinized. Industry would benefit from biomass that can be grown at much higher yields per acre than corn. Industries such as agriculture, wood, and paper would benefit from making money from waste and from having added revenue sources.

At the conference, Verenium shared their progress. In Jennings, Louisiana, they are producing 1.4 million gallons per year of cellulosic ethanol. The fuel can be mixed up to 10 percent with our current gasoline, saving us from needing almost 1.4 million gallons of foreign oil each year. Some might be delivered as E85. Instead of using corn, which requires high inputs of energy, nitrogen, fertilizer, and water to produce, Verenium is using a crop that produces eight times the energy required to process it – energy cane, a hybrid of sugar cane optimized as a fuel source not a food source.

Sugarcane and energy cane are part of Brazil’s energy independence, being the source of over 40 percent of their fuel. Now energy cane is being grown in some of the more tropical places in the United States. At a time when project financing is difficult, major partners are critical to financing larger commercial plants. In a joint-venture with BP, Verenium plans to build a 36 million gallon per year plant in Florida.

Dr. Stuart Thomas with DuPont Danisco Cellulosic Ethanol outlined their plans to bring a 20 million gallon per year plant on line in 2012. They are evaluating non-food feedstocks with much higher yields per acre than corn, including switchgrass and sorghum. DuPont Danisco anticipates reaching parity with $60 to $100/barrel oil by 2015. The pilot plant will be in Tennessee which is providing $70 million of funding for ethanol from switchgrass.

The long-term potential for biofuels may not be in ethanol, but in renewable gasoline, biodiesel, bio-jet fuel, and biocrude. All contain more energy than ethanol, which only delivers 84,000 BTU/gallon. Gasoline delivers 114,000; biodiesel 120,000.

With better microbes and fewer process steps, Chief scientist Dr. Steve del Cardayre with LS9, presented plans to produce industry standard biodiesel from energy cane. The plant should be able to compete with oil at today’s prices by also producing other valuable outputs, such as chemicals which can be used to make detergents. Synthetic biology competitor, Amyris, is moving even faster in building process plants to convert energy cane into renewable hydrocarbons and bio-jet fuel.

Indeed, creating multiple products from a process plant is likely to be critical to having a profitable industry. Oil refining is profitable because fractional distillation creates many valuable products at one refiner:

·    Naphtha which can be processed into chemicals and plastics
·    Gasoline
·    Jet fuel
·    Diesel
·    Heavy oils which can be processed into lubricants and asphalt

Gevo will build plants with mass efficiency of over 40 percent that can produce multiple products including:
·    Bio-jet fuel
·    Bio-diesel
·    Isobutanol for other products

Gevo sees opportunities to buy existing moth-balled ethanol plants and retrofit for $30 million per plant, a fraction of building a cellulosic plant from scratch. Gevo’s yeast fermentation process produces heat and steam which would be valuable if co-located with industrial processes that benefit from combined heat and power.

By converting wood waste to next generation fuel, Mascoma has a significant potential to co-locate with existing paper mills and wood processing operations. The same is true for Range Fuels.

Enerkem is being paid to covert municipal solid waste into fuel as it targets 2011 to bring live a 9.6 million gallon per year plant in Edmonton, Canada, and a 20 million gallon per year plant in Pontotoc, Mississippi.

Beyond the cellulosic sources for fuel, covered in this article, is the potential for fuel from algae. A future article will examine the near-term challenges and long-term potential of algal fuel.

As this Symposium took place in California, in Copenhagen, Greenpeace protesters stopped all buses because they use biofuel from food sources. In the future, they may welcome biofuel from wood and waste sources as an alternative to gasoline from tar sands and jet fuel from coal.

This December, the leaders of the world will gather in Copenhagen, Denmark, to develop a framework for a more promising sustainable future. In Denmark they will be able to visit a new cellulosic ethanol plant developed by Inbicon. The feedstock will be an agricultural waste product – wheat straw. The plant will process 24 metric tons per day of wheat straw, ten times more than a demonstration plant that Inbicon only a few years ago. The plant will be more efficient and come closer to competing with refined oil because the operation will have three products creating three revenue streams:

1.    5.4 million liters ethanol year
2.    8,250 MT biofuel which will displace some coal used by a power plant
3.    11,250 MT of molasses which will be used to feed cattle

Can such operations displace all our need for petroleum? No, but in five years we will see commercial scale next generation biofuel operations. If oil is selling for $100 dollar per barrel, then cellulosic biofuels may lower our cost of fuel. In ten years, all such operations could displace 20 percent of our petroleum use and represent an important step towards energy independence.

Cellulosic ethanol is not the only sustainable solution that world leaders will see in Copenhagen. They will see at least 40 percent of the population commuting on bicycles, demonstrating an immediate and very cost-effective way to reduce our need for oil. Many delegates will ride on electric light-rail from the airport and notice the wind farms that deliver the electricity. Some will ride in electric cars that further demonstrate transportation that uses renewable energy.

Next generation biofuels promise to be part of a portfolio of solutions to our current climate and energy problems.