LETTER pubs.acs.org/est
Cellulosic Biofuels and the Road to Energy Security n his recent Comment1, Dr. Jerry Schnoor expresses the disappointment many feel with the progress of cellulosic biofuels. I share his frustration and agree with much of his analysis. But there are important factors impeding cellulosic biofuels that Jerry did not mention. We need to understand and deal with these roadblocks if we are to progress toward energy security. The first roadblock is the ethanol “blend wall”. Ethanol is by far the most developed of the cellulosic biofuels and yet federal policy limits ethanol in gasoline to quite low levels. Nearly all of that market is already occupied by ethanol from corn, leaving little room for additional ethanol from cellulosics. Thus we need many more flex fuel vehicles (able to run on any blend of ethanol, methanol, and gasoline) and the infrastructure to deliver ethanol and other petroleum alternatives to consumers. In essence, we must have fuel choice. Without fuel choice, we will be stuck with the status quo of oil and even nastier materials like tar sands “oil”. So-called “drop in” fuels from cellulosic biomass are important and must be pursued, but not at the cost of shelving ethanol. It will be five years or more before these “drop in” biofuels begin to be ready for prime time. The second barrier is the cost of producing cellulosic biofuels. Continued R&D is needed to reduce the capital requirements for cellulosic biofuels even as we pursue commercial scale up. And we badly need some operating commercial scale cellulosic biofuel plants. Experience at scale is crucial for cost reduction. Fortunately, INEOS, Abengoa, POET, DDCE, Mascoma, and BP Biofuels are building or beginning to operate large scale cellulosic ethanol plants. Others will follow if we stay the course. Stable government policy is required to achieve the biofuel volumes that will enable cost reduction. In particular the Renewable Fuel Standard must be maintained so that investors have confidence there will be a market for their fuels. The final roadblock is us. In the words of Pogo: “we have met the enemy and he is us”. We must be patient and persistent. Decades were required to make petroleum fuels cheap and abundant. Likewise,
I
it will take decades to roll out large scale cellulosic biofuels. It took thirty years of hard work and consistent public policies for ethanol from Brazilian sugar cane to become less expensive than gasoline, but it happened. Cellulosic biofuels will likewise be less expensive and much better environmentally than petroleum fuels—if we are persistent. It is unreasonable and selfdefeating to expect that any sustainable replacement for oil can immediately be inexpensive and abundant. The road to sustainable, large scale, low carbon, and low cost transportation fuels runs through fields, farms, and forests of cellulosic biomass. For many reasons that I cannot address in this brief letter, there is no other road. We must deal with and overcome obstacles, disappointments and setbacks as we meet them along the road. There is no other road. Bruce E. Dale* Department of Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, Lansing, Michigan 48910, United States Office
’ AUTHOR INFORMATION Corresponding Author
*Phone: 517-353-6777; fax: 517-3364615; e-mail:
[email protected].
’ REFERENCES (1) Schnoor, J. L. Cellulosic biofuels disappoint. Environ. Sci. Technol. 2011, 45, 7099.
r 2011 American Chemical Society
Received: October 28, 2011 Accepted: October 28, 2011 Published: November 07, 2011 9823
dx.doi.org/10.1021/es203848y | Environ. Sci. Technol. 2011, 45, 9823–9823
