Japanese researchers develop economically viable model for on-farm cellulosic ethanol

In Japan, researchers from the National Institute for Agro-Environmental Sciences have determined a way to make second generation ethanol production economically viable on-farm. The process, known as ‘solid-state fermentation’, involves packing harvested whole rice plants with yeast and enzymes into a round bale wrapped in impermeable film. During incubation, sugars and starch in the rice plant are converted by yeast to ethanol, which accumulates and is then drained and distilled for fuel, leaving a bale of high quality animal feed in the form of silage.

In the tests, the process yielded up to 12.4 kg of pure ethanol per bale, after six months of incubation – ten times more ethanol than would result from natural silage production. A steady amount of ethanol also continuously drained out in the effluent from the bale during the test, resulting in an additional 1.7 kg of ethanol that could be easily collected without extraction.