"The process could change ethanol production in dry-grind plants so much that energy costs can be reduced by as much as one-third" said Hans van Leeuwenan Iowa State professor of civilconstruction and environmental engineering and the leader of the research project. Van Leeuwen and the other researchers developing the technology – Anthony L PomettoIIIa professor of food science and human nutrition; Mary Rasmussena graduate student in environmental engineering and biorenewable resources and technology; and Samir Khanala former Iowa State research assistant professor who’s now an assistant professor of molecular biosciences and bioengineering at the University of Hawaii at Manoa – recently won the 2008 grand prize for university research from the American Academy of Environmental Engineers for the project (Fig.1). "Those chosen for prizes by an independent panel of distinguished experts address the broad range of modern challenges inherent in providing life-nurturing services for humans and protection of the environment" according to a statement from the academy. "Their innovations and performance illustrate the essential role of environmental engineers in providing a healthy planet." The Iowa State project is focused on using fungi to clean up and improve the dry-grind ethanol production process. That process grinds corn kernels and adds water and enzymes. The enzymes break the starches into sugars. The sugars are fermented with yeasts to produce ethanol. The fuel is recovered by distillationbut there are about six gallons of leftovers for every gallon of fuel that's produced. Those leftoversknown as stillagecontain solids and other organic material. Most of the solids are removed by centrifugation and dried into distillers dried grains that are sold as livestock feedprimarily for cattle. The remaining liquidknown as thin stillagestill contains some solidsa variety of organic compounds from corn and fermentation as well as enzymes. Because the compounds and solids can interfere with ethanol productiononly about 50percent of thin stillage can be recycled back into ethanol production. The rest is evaporated and blended with distillers dried grains to produce distillers dried grains with solubles. The researchers added a fungusRhizopus microsporusto the thin stillage and found it would feed and grow. The fungus removes about 80percent of the organic material and all of the solids in the thin stillageallowing the water and enzymes in the thin stillage to be recycled back into production. The fungus can also be harvested. It’s a food-grade organism that’s rich in proteincertain essential amino acids and other nutrients. It can be dried and sold as a livestock feed supplement. Or it can be blended with distillers dried grains to boost its value as a livestock feed and make it more suitable for feeding pigs and chickens. Van Leeuwen said all of that can save US ethanol producers a lot of energy and money at current production levels: eliminating the need to evaporate thin stillage would save ethanol plants up to US$800million a year in energy costs. Allowing more water recycling would reduce the industry’s water consumption by as much as 10billion gallons/y. And it allows producers to recycle enzymes in the thin stillagesaving about US$60million/y. Adding value and nutrients to the livestock feed produced by ethanol plants would grow the market for that feed by about US$400million per year. In additionthe researchers’ fungal process would improve the energy balance of ethanol production by reducing energy inputs so there is more of an energy gain. Van Leeuwen estimated it would cost US$11 million to start using the process in an ethanol plant that produces 100million gallons/y of fuel. Howeverhe added that the cost savings at such a plant could pay off this investment in about six months. The researchers have filed for a patent on the technology and are looking for investors to commercialise the invention. And while the process needs to be proven at larger scalesthere are high hopes it can do a lot to improve the efficiency of ethanol production. Biomass-to-gas grant Meanwhilethe University of has been awarded US$1million from the US Department of Agriculture and the US Department of Energy to develop rapid solar-thermal chemical reactor systems for the conversion of biomass material such as switchgrass and algae to synthesis gas. The three-year award was made to a team led by Alan Weimerprofessor of the university’s chemical and biological engineering department. The team will use concentrated sunlight to heat biomass like grasssorghumcorn stalks and leaveswood waste and algae to more than 2000°F for just fractions of a second. The process will produce an intermediate syngas – a mixture of carbon oxides and hydrogen – that can be easily converted into hydrogen or liquid fuelshe said. The university will subcontract out to NREL to provide a high-flux solar furnace for the research and to CSU to study switchgrass growth and supply quantities of the tall prairie grass to the researchers for conversion. The CSU collaboration will be led by CSU horticulture professor Yaling Qianwhile the NREL collaboration will be led by Carl Bingham at NREL’s high flux solar furnace. Weimer said he envisions a totally renewable technologyin which a significant fraction of the nation’s fuel supply is provided using solar-thermal processing in marginal lands where the farming of crops such as switchgrass and algae can provide the needed biomass. "Since the process is driven by sunlight and converts biomass to fuelsthe end result is a process that is ‘carbon negative’" Weimer said. "This provides an opportunity to substantially reduce greenhouse gases in the atmosphere without impacting the food supply." The Colorado University grant was part of a new USDA/DOE award package to spend up to US$18.4million to fund 21 biomass R&D demonstration projects over three years. The projects are aimed at addressing barriers to making the production of biomass more efficient and cost-effectiveaccording to the USDA and DOE. "The University of Colorado at Boulder has been working in the area of solar-thermal chemical processing for more than ten years and is the largest academic research team in this area in the world" said chancellor GP ‘Bud’ Peterson. "This award recognises the university's expertise in the field and provides professor Weimer and his team with an opportunity to move this process closer to commercial reality."
