Researchers find “Three Routes Forward for Biofuels”

July 24, 2014 |

3-routes-for-biofuelsFrom California, we heard of a study just released  by the Institute of Transportation Studies at UC Davis — “Three Routes Forward for Biofuels,” that helps chart a new path toward the sustainable use of biofuels as a low-carbon, renewable fuel source.

The study identifies three routes for biofuels produced at biorefineries: (1) an “incremental” route in which small improvements are made at existing plants, (2) a “transitional” route in which cellulosic “bolt-on” production and other innovations leverage existing investments; and (3) a “leapfrog” route that focuses on major technological breakthroughs in cellulosic and algae-based pathways at new, stand-alone biorefineries.

• Incremental Route — progress happens at existing biorefineries, by improving existing production systems: Notable innovations at existing biorefineries that produce corn ethanol and biodiesel are varied: they include new technologies to extract corn oil from the ethanol co-product stream for sale as biodiesel and animal feed (integrated into about 80% of U.S. corn ethanol plants), switching the plant process fuel to lower-carbon sources such as landfill gas, and many others.

• Transitional — firms using existing infrastructure to gain experience with cellulosics: Biofuel technologies are emerging that could facilitate a transition to large-scale cellulosic production. “Bolt-on” systems are equipment added to existing biorefineries or co-located with them (sharing some infrastructure) allowing processing alongside corn or sugarcane sugar streams. Currently, three types of bolt-on feedstocks are being tested: corn kernel fiber that shares most corn ethanol plant facilities; bagasse that is already processed for electricity at sugarcane plants but requires additional processes for ethanol conversion (and could share sugarcane ethanol plant facilities); and corn stover, the leaves and stalks of maize that, unlike bagasse, is not currently collected. Bolt-ons are transitional in that they generate additional demand and larger markets for the enzymes needed to break down cellulosic material. They also help to increase the knowledge base for handling and converting cellulosic biomass.

• Leapfrog — cellulosic and algae investments to produce biofuel, made at new, stand-alone biorefineries. Currently, about 50 firms are pursuing commercial-scale cellulosic and algae plant in the U.S., with six partially or fully completed. Output from completed plants remains far below capacities, due to financial and technical problems. The next Leapfrog biorefineries coming online this year will provide a fuller picture of their viability.

The study also looks at the emerging trade-off between investment risk today and future reduced carbon emissions. Incremental improvements occurring at biorefineries (such as process efficiency) could result in reductions in GHG emissions and in many cases have a payback period of less than two years for the fuel producer. The nation’s small and medium-sized biorefineries are generally willing to take this risk.

You can download the entire 42-page report here.

Busy? Feeling lazy on a summer Friday? OK, you can download and skim the four-page summary here.

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