Biofuels Update

Lynne Kiesling

Yesterday the New York Times had an interesting article on new uses for the by-products of biofuels production, particularly glycerol and lignin. Here’s the story of one entrepreneurial venture:

In the foothills of the Rocky Mountains, not far from the Coors brewery in Golden, Colo., PureVision Technology is making lignin. A natural compound that helps provide strength and rigidity in plants, lignin makes up 15 to 25 percent of most plants.

Most plans for cellulosic ethanol processing call for burning the lignin to generate steam and heat to run the process. As a fuel, lignin is worth around $40 a ton.

PureVision has devised a way to make a different form of lignin — one with a molecular composition that could make it an attractive material for a variety of industrial products like glues, sealants and detergents.

Ed Lehrburger, PureVision’s founder and chief executive, said he thought his lignin could sell for $300 a ton or more. Mr. Lehrburger said his company was collaborating with a wood and paper products manufacturer that is interested in using the lignin for a biobased glue for its laminates, plywoods and other products.

“Lignin is going to be one of the big drivers of the switch from oil-based to biobased products,” Mr. Lehrburger predicted.

Meanwhile, researchers at the University of Minnesota are working on using biowaste and new combinations of catalysts to generate syngas.

The key to the new process is a catalyst bed with the right kind of porous structure to maintain the temperatures and movement of materials needed for the chemical reactions. The resulting system breaks down the biomass in just 70 milliseconds. That is ten times faster than other methods for making syngas, says Lanny Schmidt, professor of chemical engineering and materials science at the University of Minnesota. Ideally, that means a reactor with a given volume could make ten times the amount of syngas using the new method compared with conventional methods. Or put another way, it could allow for reactors one-tenth the size, he says.

Hmmmm, that bodes well for scalability … as is typical in such things, the interesting problem to solve is the catalyst.

The overall affordability of such a system will partly depend on whether rhodium, which can cost upwards of $6,000 an ounce, can be used in small enough amounts–and over long enough periods of time. The process also has to be scaled up, even for small distributed systems. Right now, the prototype uses an experimental catalyst bed the size of a person’s thumb. The researchers estimate that a system that can make enough syngas to produce 10 gallons of gasoline a day would require a catalyst bed many times this size, about 15 centimeters across and 3 deep. It could prove difficult, says Theodore Krause, head of basic and applied sciences at Argonne National Laboratory, to make a larger system that remains fast and efficient.

While challenges remain, Schmidt’s system represents a distinct advance in the science of making fuels from biomass, Krause says. In demonstrating the ability to convert solids directly into syngas, he adds, the research has “demonstrated something that most people would have at first guessed was not possible.”

That’s the first thing that research should do, and opens up a range of possibilities.