VATIS UPDATE Article

Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL), the United States, have a new process developed that recycles wastewater from biofuel production to generate hydro-gen. The hydrogen can then be used to convert bio-oil into higher grade liquid fuels such as gasoline or die-sel. “We are solving multiple problems at the same time,” said Abhijeet Borole, at ORNL. The team’s lab-scale demonstration can produce 11.7 liters of hydrogen per day at rates that are required for industrial applications.

Borole noted that although more work is required to bring the technology to the commercial scale, their pro-gress demonstrates the potential of microbial electrolysis to make bio-refineries more efficient and economically viable. Much like a conventional petroleum refinery, the bio-refinery concept is focused on the conversion of plant materials into higher value products, including hydrocarbon fuels and chemicals. Microbial electrolysis is powered by electrogens – bacteria that digest organic compounds and generate an electric current.

Borole put these bacteria to work in breaking down organic acids in liquid bio-oil that is produced from plant feedstocks such as switchgrass. Normally, about a quarter of the liquid bio-oil is contaminated water that contains corrosive acids. The hydrogen generated from the microbes could displace the need for natural gas, which is used later in the production process to upgrade bio-oil into more desirable drop-in liquid fuels. “You can recycle the water, produce clean hydrogen and eliminate the natural gas,” said Borole.