NREL looks to expand biofuels partnerships

The scenario for your business dream plays out like this. You have an idea to make a fuel from biomass using a biochemical conversion processes. You and your investors have completed bench-scale tests of your process, but now it is time to take it to the next level and process up to one ton of dry biomass a day. However, in a tough economy you don't want to build your own demonstration facility, but still need somewhere to test it. It turns out that "somewhere" is located at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL).

This past year, NREL completed construction on phase one of its Integrated Biorefinery Research Facility (IBRF) and phase two is currently underway. The idea for the IBRF is deliberate - a place for NREL and industry to test demonstration-scale projects and speed the commercialization of biofuels.

"The IBRF is designed specifically to help industry scale up their technology," NREL Team Leader for Partnership Development John Ashworth said. "We have created an empty bay in the facility so someone can bring in their own pretreatment reactor or other equipment required for biochemical biomass conversion. Companies can use part of our system or they can use their own technology and we can run it in parallel with ours. That way, they can see if their system is better than ours."

NREL's creation is a $33.5 million pilot plant and facility upgrade capable of supporting a variety of advanced biofuels projects. The IBRF boasts a 27,000 square foot high bay with one area where industry partners can bring in and test equipment, as well as upgraded laboratories, additional office space, and access to NREL expertise. The IBRF also features enhancements to NREL's existing biochemical pilot plant which now includes:

  • Three parallel front-end process trains for pretreatment through enzymatic hydrolysis
  • The ability to do research on pretreatment using a range of pH conditions
  • The capability to handle high solids concentrations through enzymatic hydrolysis.

"Industry partners can come in and try whatever they might have in mind from a very mild pretreatment to a very strong pretreatment and the system is set up for that," Ashworth said. "The high solid enzymatic hydrolysis reactors sit directly beneath the pretreatment reactors. All of this allows us to really push the limits of how you can use the system and still get to sugars."

NREL's pilot plant has been serving the lab for more than a decade and researchers have made significant discoveries along the way. But, putting that new-found knowledge to the test was becoming a challenge. "Our existing pilot plant was at capacity, we no longer had room to add equipment," NREL Manager for Bioprocess Integration R&D Dan Schell said. "We've learned a lot over the years but didn't have the capacity to expand the pilot plant and add more equipment or newer cost-effective technology."

Flexible Facility Welcomes Many Treatments

Taking that as a lesson learned, flexibility has become a key word when NREL staff discuss the capabilities of the IBRF.

"We looked at how could we upgrade the pretreatment systems to meet current and future needs and test a wider range of or reaction conditions?" Schell added. "The new system can operate at residence times as low as several minutes up to two hours. This gives us the ability to support a wide range of pretreatment catalyst options, including dilute acid and alkaline treatments."

Researchers also can use the IBRF to conduct high solid enzymatic hydrolysis. The ability to test biochemical processes using high solids is a key metric for increasing biofuel concentrations and decreasing production costs.

"In the IBRF, we have two large batch mixers that perform high solid enzymatic hydrolysis," Schell said. "Once we liquefy the biomass in the high solids reactors, we can pump it into a conventional stirred tank reactor and finish converting biomass to sugars. This gives us the capability to perform enzymatic hydrolysis at commercially relevant solids levels."

Although research in cellulosic ethanol derived from corn stover - the stalks, leaves and cobs - is a focus for research at NREL, the new capabilities of the IBRF open the doors to all types of fuels research. "The IBRF is not restricted to one end fuel," Ashworth said. "The technology here will work just fine if someone wants to make butanol or take lignocellulose and go to jet fuel or diesel. All of these technologies on the biochemical side use pretty much the same front-end pretreatment and enzymatic hydrolysis equipment."

Learn more about the Integrated Biorefinery Research Facility or NREL's work in biomass research.

By Heather Lammers, NREL