Supplementing biomass with hydrogen from natural gas also means less land is needed to make biofuels. But it has a downside—it releases carbon dioxide. However, Cortright says, the environmental benefits of using less land offset these emissions.
The company is still years from large-scale commercial production. One remaining technical hurdle is the durability of the catalysts the company uses. Using catalysts with biomass is particularly difficult, because sulfur and other contaminants in biomass poison the catalysts, so they have to be replaced relatively often. “Catalyst life is always important. How long does it last, and how do you maintain it? That has to be addressed,” says Susanne Jones, a senior research engineer at the Pacific Northwest National Laboratory.
Cortright says Virent is developing catalysts that are more tolerant of the impurities in biomass, as well as purification steps. Overall, he says, the process is now “in the ballpark to be competitive with crude oil,” assuming the price of biomass is right.