AUSTIN, Texas — Building on the success of 10 years of investigation into the production of renewable fuels from plants, the Great Lakes Bioenergy Research Center (GLBRC), led by the University of Wisconsin–Madison, recently embarked on a new mission: to develop sustainable alternatives to transportation fuels and products currently derived from petroleum.
On Feb. 18 at the Annual Meeting of the American Association for the Advancement of Science in Austin, Texas, Tim Donohue, GLBRC director and UW–Madison professor of bacteriology, highlighted a decade of developing economically viable bioenergy technologies, while looking forward to the next five years of establishing a production pipeline of advanced fuels and bioproducts.
When most people think of biofuel, it's a first-generation version of ethanol that comes to mind. Corn kernels, harvested for their sugar, are broken down and fermented at a refinery. The resulting product, ethanol, becomes 10% of what we put in our gas tanks.
When the U.S. Department of Energy’s Bioenergy Research Centers were conceived just over ten years ago, GLBRC had a goal of turning more of the corn plant — the stalk and leaves that makes up the stover — into ethanol, while developing perennial plants like switchgrass and miscanthus (also called silvergrass) into potential feedstocks.
“The result was almost 1,100 publications, 154 invention disclosures, 168 U.S. and international patents applications 89 licenses and options and five startup companies relating to improved biomass crops, plant deconstruction and the development of next generation catalysts and microbes for conversion,” Donohue says.
Now, GLBRC is taking its mission one step further. Instead of producing ethanol, GLBRC’s goal is centered on designing advanced biofuels, such as isobutanol. These “drop-in” fuels could be used to replace gasoline without engine modification. By engineering bioenergy crops to enhance their environmental and economic value, and conducting research to generate multiple products from plant biomass, these advancements could optimize the bioenergy field-to-product pipeline.
Breaking down the more complex biological components of woody biomass to extract the sugars for fermentation into fuel is one step of the process. James Dumesic, a GLBRC researcher and UW–Madison professor of chemical and biological engineering, found a way to do just that with gamma valerolactone, a chemical derived from plants themselves.
GLBRC scientists and engineers are also improving the yield and processing traits of dedicated bioenergy crops for cultivation on marginal, or non-agricultural, land. With smart management, these crops have the potential to benefit the ecosystem, help mitigate climate change, and provide farmers with an additional source of revenue.
Donohue’s specialty at GLBRC is in studying how microbes can digest these broken-down pieces of the plant to produce valuable products.
“We’re trying to re-task native pathways and engineer next-generation microbial factories that can manufacture valuable fuels and chemicals from renewable wastes,” he says.
The oil industry isn’t profitable merely because of production of fuel that keeps us warm and makes our cars go vroom. It’s sustained by the production of almost 200 chemicals that go in everything from cosmetics to crayons, and from plastics to paper cups.
GLBRC is focused on enabling a new and different biorefinery, one that is both economically viable and environmentally sustainable. Realizing this goal will mean increasing the efficiency of biomass conversion and generating a mix of specialty biofuels and environmentally-friendly bioproducts, from as much of a plant’s biomass as possible. One such discovery, breaks down lignin’s six-carbon rings — the “aromatics” — into individual components. Traditionally sourced from petroleum, aromatics are used in a wide variety of products, including plastic soda bottles, Kevlar, pesticides, and pharmaceuticals, and are essential components of jet fuel.
“We are in a unique position to not only address a major societal challenge,” Donohue says, “but to create new revenue sources and economic opportunities for farmers, rural communities and a new generation of bio-refineries.”