Cutting Cost Of Making Cellulosic Biofuels With New Process

A patented Michigan State University process to pretreat corn-crop waste before conversion into ethanol means extra nutrients don’t have to be added, cutting the cost of making biofuels from cellulose.

The AFEX (ammonia fiber expansion) pretreatment process, developed by Bruce Dale, University Distinguished Professor of chemical engineering and materials science, uses ammonia to make the breakdown of cellulose and hemicellulose in plants 75 percent more efficient than when conventional enzymes alone are used. Cellulose in plants must be broken down into fermentable sugars before they can be turned into biofuel.

The research is published in the current issue of the Proceedings of the National Academy of Sciences.

Currently, pretreating cellulose with acid is a common way to break the material down into fermentable sugars. But after acid pretreatment, the resulting material must be washed and detoxified. That removes nutrients, leading to the mistaken idea that crop waste lacks the necessary nutrients, Dale said.

Cellulosic material pretreated with the AFEX process doesn’t have to be washed or detoxified, allowing ethanol to be created from cellulose without added nutrients or other steps.

Science Daily