Ethanol revolution brews in Hawaii?

By Jerry W. Kram | March 10, 2008
Web exclusive posted March 21, 2008 at 11:41 a.m. CST

An Australian living in Hawaii claims that by using a combination of innovations, he has developed a system that will profoundly change the ethanol industry. Stephen Finch said his setup will eliminate the need for distillation columns, the most energy-intensive step in ethanol production.

Finch worked as an engineer for the Manildra Group, the largest ethanol producer in Australia, for 12 years. Then, he spent six years working for a company that produced dimethyl ether. He has moved to Hawaii and now works with Value Added Foods and Fuels LLC, a manufacturer of dried tropical fruit powders and other nutritional products, including animal feed, with an interest in ethanol.

Finch said construction is almost complete on a pilot-scale ethanol plant, which will produce approximately 100 gallons of ethanol every 1.5 days (243,000 gallons annually if it ran continuously). His system uses sugarcane juice, with additional sugar added to bring the sugar content up to 48 percent. "We can make ethanol from just about anything, but we think the best thing to extract ethanol from is sugarcane," he said. "That way, you don't affect the food chain, and if you don't have enough cane, you can switch over to sweet sorghum or food-grade sorghum."

Finch uses a variety of yeast from northern England that can ferment the high-specific-gravity sugary liquid to an extremely high concentration of ethanol26 percent to 28 percent. "That's the most important part of what I am trying to do here," he said. "As long as you can get it up to 25 percent, you can use pervaporation, membrane technology or other methods to separate it. So you won't need a massive distillery built with stainless steel, costing an arm and a leg to build."

Solids and chemicals are separated by Finch's custom-designed filter system, preventing nothing but ethanol and water to enter the beer tank. The ethanol is then concentrated by a three-stage membrane filter system, making distillation unnecessary. The solids separated from the process could be used in breakfast cereal or cattle feed, Finch added.

Finding the yeast strain that could tolerate such high levels of ethanol was the key to developing the process, Finch said, adding that getting the beer up to that concentration made separating the ethanol with membrane technology practical.

Finch said he adapted a Symtec membrane system to remove water from the ethanol. The Symtec system does a double filtration to dehydrate a 40 percent ethanol solution into anhydrous ethanol, but Finch's system does a triple filtration to purify the lower-concentrated ethanol coming directly from the beer tank. He said a commercial-scale ethanol plant in Canada was already using the double-filtration system.

Finch is also researching another low-energy method developed by NASA that uses oil and sulfur to purify ethanol. "They are very inexpensive methods to produce ethanol, but for the moment, we are using membrane technology that can separate the ethanol from just about anything," he said, adding the system can also use E. coli bacteria as a fermenter to produce butanol.

In eight to 10 weeks, Finch said he will publicly demonstrate his pilot system. "I want to finish this one off, buy the filtration system rather than just renting it and then demonstrate the system to the public," he said. "Then I will help design and build a full-scale plant." Finch said two proposed ethanol plants in Hawaii and South Africa may be interested in using his system.