Reinventing Cellulosic Ethanol Production

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Baniel says that the company's goal is to team up with fermentation plants to complete the last stage of ethanol production. "When we started, we thought we might need to go all the way to biofuel," he says. "However, we discovered that there are technologies for fermentation of sugars that are way ahead of anything that we possess."

The company anticipates that its pilot plant will be ready in the latter part of 2010. In the meantime, Baniel says that the company will test multiple steps of its process at various industrial plants in Israel to see whether the technology can run efficiently at large scales.

James McMillan, manager of biochemical refining process research and development at the National Renewable Energy Laboratory, in Golden, CO, says that scaling up the technology to run robustly is the key to its long-term success. "The proof in the pudding is demonstrating it performs under robust conditions and can handle upsets that happen in the real world, all at a cost that's attractive in the marketplace," says McMillan. "That's what has to be shown." He adds that when it comes time to build a plant, the company may have to invest in expensive materials to contain HCL, which is extremely corrosive and potentially volatile, especially in its gaseous phase.

Another company that is using concentrated acid hydrolysis to produce ethanol is BlueFire Ethanol, based in Irvine, CA. The company is using sulfuric acid, which is slightly cheaper than HCL, to break down sugars from cellulosic sources like municipal solid waste and wood residues. John Cuzens, chief technology officer at BlueFire Ethanol, says that recycling HCL in a gaseous form may help improve sugar yields. However, he cautions that HCL-Cleantech will have to account for the increased risk associated with potential hydrochloric gas emissions.

"Their process may have chlorine gas escaping, and the chlorine gas will corrode everything outside and inside the reactor," says Cuzens. "So the carbon steel walkways--virtually everything in the plant they have to watch for."