Generating Ethanol from Lignocellulose Possible, But Large Cost Reductions Still Needed

November 08, 2011

Generating Ethanol from Lignocellulose Possible, But Large Cost Reductions Still Needed

The production of ethanol from lignocellulose-rich materials such as wood residues, waste paper, used cardboard and straw cannot yet be achieved at the same efficiency and cost as from corn starch. A cost comparison has concluded that using lignocellulose materials is unlikely to be competitive with starch until 2020 at the earliest. The study, published in the international journal Biofuels, Bioproducts & Biorefining, did identify many opportunities for reducing costs and improving income within the lignocellulose-to-ethanol process, and provides insight into the priority areas that must be addressed in coming years.

Ethanol can be blended with gasoline to reduce our dependency on fossil fuels. The last 15 years has seen a massive growth of so-called first-generation processes that use enzymes and bacteria to turn the starch and sugars in corn and sugarcane into ethanol. But corn and sugarcane are also important components of the human food web, so using them for ethanol production has the potential to affect the price and availability of these basic commodities.

On the other hand, lignocellulose materials are often hard to dispose of, but they are rich in sugars that can be fermented into ethanol following appropriate processing. “Not only is cellulose the most abundant polymer on Earth, it cannot be digested by humans, so using it for fuel production does not compete directly with food supplies,” says the study’s lead author Jamie Stephen, who works in the Department of Wood Science at the University of British Columbia in Vancouver, Canada. The race is on to commercialize this second generation ethanol.

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Overall Stephen believes we have a considerable way to go before second-generation ethanol production will be ready for commercialisation. “Production requires significant cost reductions and at least the same level of financial support that was given to the first-generation systems if second-generation ethanol is going to be fully competitive by 2020,” says Stephen.