New capabilities to predict, design and control the chemistries of carbon could answer a global imperative to transition from fossil-based to sustainable transportation fuels. While the use of inexpensive hydrocarbons has been an unparalleled achievement and enabler of economic prosperity for many nations, singular dependence upon crude oil has given rise to systemic vulnerabilities in climate, energy, economic, and national security. Lignocellulosic biomass, a renewable and carbon-neutral resource, has the potential to displace an estimated annual equivalent of three billion barrels of oil in the U.S. alone (1,2). However, biomass has only one-third the energy density of crude oil (3,4) and lacks petroleum’s versatility as a feedstock for fuels and chemicals. These limitations keep biomass conversion below the efficiency level needed for strategic impact while the scientific challenge of routing carbon from one molecular context to another remains unmet.
In 2009, the Center for Direct Catalytic Conversion of Biomass to Biofuels(C3Bio) recognized the potential of chemical catalysis and fast pyrolysis to overcome such limitations by transforming the main components of biomass (cellulose, xylan, and lignin) from grasses and trees directly to liquid hydrocarbons and aromatic co-products. Enabled by the EFRC high-risk, high-reward approach to grand challenge science, C3Bio researchers have been key national players in disrupting the conventional paradigm of the cellulosic biorefinery into a new future of “no carbon left behind”—the full utilization of carbon from plant cell walls in energy-dense fuels. We identified catalytic and fast-pyrolytic pathways that utilize xylan, cellulose, and, most significantly, lignin. We developed catalytic processes that deoxygenate and transform monomers and isolated polymers into useful products and tested their use with intact biomass. We gained control of lignin synthesis within plants and initiated tailoring biomass to its end-use through the tools of plant molecular biology and genetic engineering. C3Bio breakthroughs have increased the energy density of biomass-derived substrates via catalytic and pyrolytic conversions into reaction products such as furfural and levoglucosan.
- National Research Council (2009) Liquid transportation fuels from coal and biomass: Technological status, costs, and environmental impacts. Washington, DC: The National Academies Press.
- U. S. Department of Energy (2011) U.S. billion-ton update. Biomass supply for a bioenergy and bioproducts industry. Energy Efficiency and Renewable Energy, Office of the Biomass Program.
- Agrawal R, Singh NR (2009) Synergistic routes to liquid fuel for a petroleum-deprived future. AIChE J. 55:1898-1905.
- Richard TL (2010) Challenges in scaling up biofuels infrastructure. Science 329:793-796.