A Milestone for Cellulosic Ethanol

The past few months have been an exciting time for renewable energy proponents in the US.  The first three commercial cellulosic ethanol facilities began operating in August and September, a major milestone for a technology jokingly thought to be “five years away” for almost three decades. Rather than converting corn grain to ethanol, these convert inedible corn stover – the stalk, husk, and cob. Biorefineries in Emmetsburg and Nevada, Iowa and Hugoton Kansas will have a combined capacity of 75 million gallons of cellulosic ethanol per year – more than a 300-fold increase from the total US production of 213,000 gallons in 2013. Although the US still lags behind the targets set by the 2007 Renewable Fuels Standard, which called for 100 million gallons in 2010 and 1.75 billion gallons in 2014, the Congressional Research Service reports that the EPA expects to meet this year’s proposed revised target of 17 million gallons of cellulosic biofuels.

Major news outlets have taken note of this new commercial technology, which allows biofuel production without competing with food crops.  The New York Times reports that most of the ethanol produced by Abengoa’s facility in Hugoton, KS may be destined for California, where more stringent fuel standards may generate demand.  Reporting on POET-DSM facility in Emmetsburg, IA, The Seattle Times emphasizes that the current production cost of cellulosic ethanol from these facilities ($3/gallon) is substantially higher than corn ethanol ($2/gal). The current production cost is also higher than predicted by a widely-cited report by the National Renewable Energy Laboratory (NREL) of Colorado, which anticipated a selling point of just over $2/gal based on a sophisticated process and economic model.

Though the cost of ethanol from these second-generation plants is expected to drop, the high price and saturated ethanol market in the US (nearly all gasoline already contains 10% ethanol – primarily produced domestically from corn grain – the maximum amount legally permitted to be blended for car fuel) have driven cellulosic ethanol manufacturers to seek additional markets. Abengoa is targeting beverage companies, who could use ethanol to produce a “green” alternative to plastic and reduce their carbon footprint. According to Bloomberg, DuPont’s 30 million gallon/yr facility in Nevada, IA may sell ethanol to Proctor & Gamble for blending into Tide detergent.  Both Abengoa and DuPont expect to license process design, enzymes, and other technologies for these facilities to other prospective cellulosic ethanol producers.

Abengoa’s biorefinery in Hugoton is the most capital-intensive of the new plants at $500 million.  Though it’s maximum capacity (25 million gal/yr) is not greater than POET-DSM ($275 million, 20 million gal/yr) or DuPont ($225 million, 30 million gal/yr), it features an on-site power plant to convert waste biomass to heat and power.  In addition to powering the biorefinery, the power plant is expected to generate a 10 megawatt surplus for sale to the regional electric grid.  The Hugoton facility will also incorporate new feedstocks as it becomes fully operational, including wheat straw and switchgrass.

Finally, I am pleased to note that concerns over biomass storage featured prominently in Abengoa’s decision to site their cellulosic biorefinery in Hugoton, where the climate is expected to be dry enough to store feedstock outdoors without cover, thereby reducing costs.