Sugar factory: Virdia’s pilot-scale plant in Virginia can produce hundreds of pounds of sugar from wood chips per day.
Despite years of federal mandates, the cellulosic biofuels industry—which aims to make ethanol from wood chips and similar plant matter instead of corn—has yet to start commercial-scale production.
But the fledgling industry got some good news yesterday when Virdia, a company that converts cellulose into sugar, announced that it had raised over $100 million in private and public financing to go toward building its first commercial-scale plant. Converting cellulose to sugar is the most difficult part of making cellulosic biofuels. Once the sugars are produced, they can be converted to ethanol using the conventional process for making ethanol, which uses corn sugar.
Wood chips and other cellulosic materials have several advantages: they’re abundant, they don’t compete with food crops like corn, and they result in far lower carbon-dioxide emissions than corn ethanol.
Philippe Lavielle, Virdia’s CEO, says the company’s technology, when employed at a large scale, could make cellulosic sugars economically competitive with sugar made from corn. “A corn ethanol plant could use sugars from Virdia instead of corn sugar,” he says.
Virdia, which until today was called HCL Cleantech, grinds up wood chips and cleans them to remove contaminants, then dissolves the cellulose and hemicellulose components with hydrochloric acid, in a process called acid hydrolysis. That leaves behind a brown powdery substance called lignin that can be used in wood pellet stoves, or could be used to make other fuels and useful chemicals.
Acid hydrolysis is an old process, but it has been too expensive to be used to produce cheap sugar. Virdia’s key innovation is a proprietary process for inexpensively recycling the acid, which makes acid hydrolysis cheaper and cleaner. “The 70-year-old process never recycled hydrochloric acid, it just neutralized it. That made it uneconomical and difficult to justify environmentally, because it produced mountains of salt,” Lavielle says.
The company says another advantage of its technology is that it produces more sugar per ton of biomass than conventional approaches, which typically rely on breaking cellulose down with enzymes. It produces between 95 and 97 percent of the theoretical maximum, compared to 75 to 80 percent with enzyme-based approaches, Lavielle says. “We get all the sugars out from brute-force engineering,” he says.