Membrane separation project receives DOE grant

By Susanne Retka Schill
Web exclusive posted August 29, 2008 at 10:42 a.m. CST

With water removal an energy intensive stage in ethanol production, an industry partnership has been awarded $5.6 million by the U.S. DOE to develop a membrane solvent-extraction technology for water removal. The partnership includes 3M Co. in collaboration with Archer Daniels Midland Co., the National Renewable Energy Laboratory and Karges-Faulconbridge Inc.

The project is being led by 3M to test their proprietary technology. "You take the fermentation broth and pass it through the membrane system along with a solvent," explains John Ashworth, team leader for partnership development at the National Bioenergy Center at the National Renewable Energy Laboratory. "The system operates at low temperatures and when you get done, you have ethanol concentrations at about 70 percent," he said, adding that distillation of the higher concentrations should result in large energy savings in the ethanol process.

ADM will be testing the technology at commercial scale in a conventional corn ethanol facility, Ashworth said, while NREL's role will be to test the technology in its pilot-scale cellulosic ethanol facility using corn stover as the raw material. "[3M is] looking at the conventional ethanol industry as the first market," he said. "And running in parallel, we'll se if there are any unique problems with cellulosic ethanol they'll have to contend with."

Once the data is accumulated, NREL will also do an economic analysis of the technology. "A lot have tried membranes in the past," he said. "But the problem with membranes is that if you have to keep replacing the membranes because they foul, it's not cost effective."

The grant is one of eight projects awarded funds totaling $26 million that were announced Aug. 22 by U.S. DOE Principal Deputy Assistant Secretary of Energy Efficiency and Renewable Energy John Mizroch. The projects support the Energy Policy Act of 2005's goals to reduce the energy intensity of U.S. manufacturing industries by 25 percent in 10 years and contribute significant reductions in greenhouse gas (GHG) emissions.

The industrial sector consumes nearly one-third of the energy used in the United States and accounts for 28 percent of domestic GHG emissions, according to the DOE. Much of this energy is used in processes that are common across numerous industries.