Oil from Wood
Startup Kior has developed a process for creating “biocrude” directly from biomass.
Dutch biofuels startup Bioecon and Khosla Ventures have launched a joint venture called Kior, which will commercialize Bioecon’s process for converting agricultural waste directly into “biocrude,” a mixture of small hydrocarbon molecules that can be processed into fuels such as gasoline or diesel in existing oil refineries. The process, Kior claims, boasts numerous advantages over other methods of producing biofuels: it could prove relatively cheap, relies on a nontoxic catalyst, taps into the present fuel-refining and transportation infrastructure, and produces clean-burning fuels that can be used in existing engines.
Biofuels are widely seen as a key stepping-stone on the path from fossil fuels to renewable energy sources, particularly for transportation. Their use could also reduce emissions of carbon dioxide and other greenhouse gases. But ethanol, the most widely produced biofuel, contains little energy compared with gasoline or diesel. And a great deal of energy goes into its production: growing the grain from which it is fermented, distilling it, and transporting it. Many biofuels boosters have pinned their hopes on finding ways to produce ethanol from cellulose, the tough polymer that makes up much of plant stems and wood. In practice, though, cellulose must be broken down into simple sugars before it can be fermented into ethanol or converted into synthetic gas and turned into fuels. Despite three decades of research, these remain difficult, expensive, and energy-intensive processes that are not yet commercially viable. Additionally, recent research shows that ethanol, which is highly volatile, may actually exacerbate smog problems when it evaporates directly into the air instead of burning in vehicle engines.
The way to make cellulosic biofuels viable, says Bioecon’s founder, Paul O’Connor, is to use catalysts to convert biomass into a hydrocarbon biocrude that can be processed into gasoline and diesel in existing petroleum refineries. After decades developing catalysts for the petroleum industry, O’Connor started Bioecon in early 2006 to develop methods for converting biomass directly into biofuels. His first success is a catalytic process that can convert cellulosic biomass into short-chain hydrocarbons about six to thirteen carbon atoms long. Khosla Ventures agreed to provide an undisclosed amount of series A funding to spinoff Kior in order to commercialize the process. Vinod Khosla, founder of the venture fund, believes that converting biomass into liquid transportation fuels is key to decreasing greenhouse-gas emissions and compensating for dwindling petroleum reserves. Khosla is funding a number of biofuels startups with competing technologies and says that Kior’s approach is unique. “They have some very clever proprietary catalytic approaches that are pretty compelling,” he says. “They can produce relatively cheap crude oil–that’s attractive.”
The most effective method of converting biomass into fuel is to subject it to high temperatures and high pressure to produce synthetic gas, or syngas. In the presence of a catalyst, the syngas reacts to produce fuels such as ethanol or methanol (used as an additive in biodiesel). But this is a costly process, and catalysts able to withstand the high temperature of the syngas are expensive and frequently toxic.
Attempts to produce fuel by directly exposing agricultural cellulose to a catalyst have had little success because most of the cellulose is trapped inside plant stems and stalks. O’Connor says that while the Bioecon researchers are developing new catalysts, their “biomass cracking” process is the real breakthrough. Using proprietary methods, they have been able to insert a catalyst inside the structure of the biomass, improving the contact between the materials and increasing the efficiency of the process. While O’Connor won’t go into details, he says that the most basic version of the technique might involve impregnating the biomass with a solution containing the catalyst; the catalyst would then be recrystallized. “What we’re doing now is improving the method to make it easier and cheaper,” O’Connor says.
Such a method would eliminate the need for the superhigh temperatures and toxic catalysts used in other thermochemical methods for cellulosic-biofuel production. While O’Connor says that he is still improving Kior’s catalyst, his first versions are different kinds of modified clays, which are both cheap and environmentally friendly. The product is high quality as well, containing less acid, oxygen, and water. These characteristics make it suitable for burning as heating oil or for use in petroleum refineries, which can use existing processes and equipment to convert it into the longer hydrocarbon chains of gasoline and diesel fuel.
Bioecon has produced lab-scale quantities of its biocrude, a few grams at a time, from materials such as wood shavings, sugarcane waste, and various grasses. While the input material affects the yield somewhat, O’Connor says that the output is “all very similar, so we do not have a real preference.” This means that the process can work around the world, with whatever biomass is locally available, almost year-round.
Kior is already in talks with at least two oil companies to establish partnerships to further develop the technology. It is starting a pilot plant with one company that should produce around 20 kilograms of biocrude a day within six to twelve months, says Kior CEO Rob van der Meij. If all goes well, the process could scale up to production of hundreds of kilos per day by 2009, and refined versions of Kior’s biocrude might be blended into gasoline or diesel by 2010. In addition to being renewable, these fuels would have lower sulfur and nitrogen content, which should decrease smog in cities such as Los Angeles and Houston.
Because of its ability to slide into the existing petroleum refining and delivery infrastructure, the technology has a huge cost advantage, says O’Connor. It could also be adopted much more rapidly, according to Khosla. “If you can do a solution that’s compatible with the oil companies and their current refineries, it becomes much easier for them to get comfortable with it,” he says. “Getting them into the game would be a big addition.”
Steve Deutch, a senior research scientist at the National Renewable Energy Laboratory, says that the little information Kior has released about its process is plausible enough, but that until the details are available, the company’s claims are “not really possible to evaluate.” The main challenge for Kior, or anyone working on cellulosic fuels, Deutch says, is to develop a process simple enough to bring close to the sources of biomass–farms. “Collecting biomass and getting enough of it in one place to make a difference is a problem in the biomass world,” Deutch says. “Trucking costs can become exorbitant. You want to preprocess it at the farm and then ship a high-density, high-energy intermediate to processing plants.”