RESEARCH mass gasification and subsequent FischerTropsch conversion to liquid fuels are just not economic processes, Flynn says. “[The researchers are] getting a higher yield of syngas from the biomass by using methane, so in effect, they have a way of turning biomass and methane into a precursor of liquid fuels,” he explains. “But today, if you just turn biomass into liquid fuel, it’s not as attractive as other things you can do with the biomass and if you turn natural gas into liquid fuel, it’s not as attractive as other things you can do with natural gas, unless you’ve got a stranded field [of natural gas]. So I don’t know if putting these two things together will make favorable economics. But it is something new.” The process might modify the actual yield from the process for the same capital cost, says Doug Bull, thermochemical projects manager for Iowa State University’s Center for Sustainable Environmental Technologies. “That’s how it might help the economics because they might actually get more product for a similar cost of plant equipment,” Bull says. Understanding both the chemistry that’s happening and the reactor that can double the yield of carbon monoxide does change the economic analysis considerably, Dauenhauer says. “If you derive twice as much fuel from an acre of land as before, you’re doubling your return potentially,” he says. Bull agrees with Flynn that gasification is not economic, adding that fast pyrolysis is pulling ahead in popularity with its cheaper cost and simplicity. Even the U.S. DOE is shifting more toward pyrolysis, Bull says, as investment is risky for costly gasification processes. At the end of May, the DOE allocated up to $11 million over the next three years for research and development of biomass pyrolysis for advanced biofuels. Both Bull and Flynn are skeptical of some of the details of the team’s process, having not experimented with the reactions themselves. “They’re sort of just modifying the reaction chemistry to get more of the gasses they desire,” Bull says, adding that complete conversion of all the biomass carbon is a difficult feat. “They might be able
to increase it dramatically, but I don’t think entirely all of it would be [converted]. I’m pretty sure they’d still have a little bit of carbon dioxide, even if it’s only like 5 percent.” The reaction can only be forced to a certain point, he explains. Dauenhauer says the amount of carbon dioxide that is converted to carbon monoxide depends on where inside the teardrop shape the reactor is operating. “The closer the reaction conditions are to the center, the higher the conversion of CO2,” he says. Even some of the carbon dioxide added to the process is converted, he adds. Since char production has been a problem in biomass gasification, a system that eliminates it would be a significant development, Flynn says, although there are other proposed solutions. “They are saying they have found a spot they can operate where they don’t produce any char, and if that’s
true, it’s a big deal.” It’s one of two reasons the process is intriguing, he adds, along with methane that in effect can be converted to liquid transportation fuels. “It sounds reasonable. I know enough to say to it sounds reasonable.” Dauenhauer says the ultimate goal of the research is to answer the scientific questions that will lead to a wide array of new biomass processes and reactions. “In terms of the university, we’re focused on generating the intellectual property that American companies and start-up companies can use to get these new types of processes and reactors into the field as quickly as possible.” BIO
Lisa Gibson is a Biomass Magazine associate editor. Reach her at lgibson@ bbiinternational.com or (701) 738-4952.
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