A new Purdue University-developed process for creating biofuels has shown
potential to be cost effective for production scale, opening the door for
moving beyond the laboratory setting.
A Purdue economic analysis shows that the cost of the thermochemical H2Bioil
method is competitive when crude oil is about $100 per barrel when using
certain energy methods to create hydrogen needed for the process. If a federal
carbon tax were implemented, the biofuel would become even more economical.
H2Bioil is created when biomass, such as switchgrass or corn stover, is heated
rapidly to about 500 C in the presence of pressurized hydrogen. Resulting gases
are passed over catalysts, causing reactions that separate oxygen from carbon
molecules, making the carbon molecules high in energy content, similar to
gasoline molecules.
The conversion process was created in the lab of Rakesh Agrawal, Purdue’s
Winthrop E. Stone Distinguished Professor of Chemical Engineering. He said
H2Bioil has significant advantages over traditional standalone methods used to
create fuels from biomass.
“The process is quite fast and converts entire biomass to liquid
fuel,” Agrawal said. “As a result, the yields are substantially
higher. Once the process is fully developed, due to the use of external
hydrogen, the yield is expected to be two to three times that of the current
competing technologies.”
The economic analysis, published in Biomass
Conversion and Biorefinery, shows that the energy source used to create
hydrogen for the process makes all the difference when determining whether the
biofuel is cost-effective. Hydrogen processed using natural gas or coal makes
the H2Bioil cost effective when crude oil is just over $100 per barrel. But
hydrogen derived from other, more expensive, energy sources—nuclear, wind, or
solar—drive up the break-even point.
“We’re in the ballpark,” said Wally Tyner, Purdue’s James and Lois
Ackerman Professor of Agricultural Economics. “In the past, I have said
that for biofuels to be competitive, crude prices would need to be at about
$120 per barrel. This process looks like it could be competitive when crude is
even a little cheaper than that.”
Agrawal said he and colleagues Fabio Ribeiro, a Purdue professor of chemical
engineering, and Nick Delgass, Purdue’s Maxine Spencer Nichols Professor of
Chemical Engineering, are working to develop catalysts needed for the H2Bioil
conversion processes. The method’s initial implementation has worked on a
laboratory scale and is being refined so it would become effective on a
commercial scale.
“This economic analysis shows us that the process is viable on a
commercial scale,” Agrawal said. “We can now go back to the lab and
focus on refining and improving the process with confidence.”
The model Tyner used assumed that corn stover, switchgrass, and miscanthus
would be the primary feedstocks. The analysis also found that if a federal
carbon tax were introduced, driving up the cost of coal and natural gas, more
expensive methods for producing hydrogen would become competitive.
“If we had a carbon tax in the future, the break-even prices would be
competitive even for nuclear,” Tyner said. “Wind and solar, not yet,
but maybe down the road.”
Source: Purdue University
