Fungus Could Save Ethanol Plants $800 M

Written by Jaymi Heimbuch

It’s quite a week for biofuel breakthroughs and news. Iowa State University research has revealed a way to reduce the energy and water use required to produce corn ethanol, saving ethanol plants a possible collective $800 million a year in energy costs and as much as 10 billion gallons of water a year. And it’s all based on a fungus, and recycling.

The new breakthrough is aimed at the dry-grind part of the ethanol production process. Basically, corn kernels are ground up, water and enzymes are added, starches are turned into sugars, and sugars are fermented to produce ethanol. The ethanol is recovered with distillation. At the end of the ethanol distillation process, there is a liquid left over – about 6 gallons for every 1 gallon of ethanol. Only about half of the leftover liquid can be recycled, and the process to remove solids and organic materials in it is expensive. When the fungus Rhizopus microsporus is added to the liquid and allowed to flourish, it makes possible as much as 80% of the organic matter and solids in the sillage to be removed, and the liquid leftover can then be recycled into the production process.

The fungus has another useful element – it can be eaten. Ethanol plants can harvest the protein- and nutrient-rich fungus and sell it as a livestock food supplement.

Implementing the new technology would cost an ethanol plant that produces 100 million gallons a year about $11 million – kind of a lot for ethanol plants right now, but still do-able. And, researchers say that investment could be paid back in as little as six months, thanks to the energy savings. The process is still waiting for a patent, and investors to help the project prove that the process can work on a commercial scale, so all this is still iffy. But iffy it works, then ethanol plants could have a new way to reduce overall costs and environmental impact on production.

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