Study finds that optimized integrated catalytic processing of biomass could produce renewable jet fuel with selling price as low as $2.88/gallon
|Integrated processing of hardwood to renewable jet and chemicals. Click to enlarge.|
A team from seven US universities and the Korea Institue of Science and Technology, led by George Huber, Professor of Chemical and Biological Engineering at the University of Wisconsin-Madison, has developed an integrated catalytic process for the conversion of whole biomass into drop-in aviation fuels with maximal carbon yields.
The researchers expect that in its current state, the proposed technology could deliver jet fuel-range liquid hydrocarbons for a minimum selling price of $4.75 per gallon—assuming nth commercial plant that produces 38 million gallons liquid fuels per year with a net present value of the 20 year biorefinery set to zero. Future improvements in this technology, including replacing precious metal catalysts by base metal catalysts and improving the recyclability of water streams, could reduce this cost to $2.88 per gallon.
A paper on the experimental studies and techno-economic analysis of the process is published in the RSC journal Energy & Environmental Science.
The combined research areas include biomass pretreatment; carbohydrate hydrolysis and dehydration; and catalytic upgrading of platform chemicals. The technology centers on first producing furfural and levulinic acid from five- and six-carbon sugars present in hardwoods and subsequently upgrading these two platforms into a mixture of branched, linear, and cyclic alkanes of molecular weight ranges appropriate for use in the aviation sector.
Results of the lab studies suggest that, with efficient interstage separations and product recovery, hemicellulose sugars can be incorporated into aviation fuels at roughly 80% carbon yield, while carbon yields to aviation fuels from cellulose-based sugars are on the order of 50%.
The team further reported that the use of lignocellulose-derived feedstocks rather than commercially sourced model compounds in process integration provided important insights into the effects of impurity carryover and additionally highlights the need for stable catalytic materials for aqueous phase processing, efficient interstage separations, and intensified processing strategies.
Lignocellulosic biomass is an abundant natural resource that includes inedible portions of food crops as well as grasses, trees, and other woody biomass. According to the United States Department of Energy, the United States could sustainably produce as much as 1.6 billion tons of lignocellulose per year as an industrial feedstock. Lignocellulose can be processed to yield various transportation fuels and commodity chemicals; however, current strategies are not generally cost-competitive with petroleum.
This effort exemplifies the impact of a well-designed collaboration. As individual researchers, we sometimes focus too narrowly on problems that we can resolve using our own existing skills. Biomass refining is complex, and bio-based aviation fuels are difficult targets. Many of the real roadblocks occur at scarcely-studied research intersections. In our view, the only meaningful way to tackle these challenges is through strategic partnerships, and that is precisely what we've done in this program.—Jesse Bond, Syracuse University, lead author
Jesse Q. Bond, Aniruddha A. Upadhye, Hakan Olcay, Geoffrey A. Tompsett, Jungho Jae, Rong Xing, David Martin Alonso, Dong Wang, Taiying Zhang, Rajeev Kumar, Andrew Foster, S. Murat Sen, Christos T. Maravelias, Robert Malina, Steven R. H. Barrett, Raul Lobo, Charles E. Wyman, James A. Dumesic and George W. Huber (2014) “Production of renewable jet fuel range alkanes and commodity chemicals from integrated catalytic processing of biomass,” Energy Environ. Sci. 7, 1500-1523 doi: 10.1039/C3EE43846E