Auburn University researchers have succeeded in using hydrothermal liquifaction to liquify switchgrass into biocrude at 235 degrees C. The image above (from Green Car Congress) illustrates the various means of converting biomass to fuels, at different temperatures. The lower the temperature utilised, the less process energy required, causing the process to be more efficient and economical.
More than 50 wt% of the organic carbon available in switchgrass was converted to biocrude after 20 minutes of steady operation at 235 °C in the presence of 0.15 wt % of K2CO3. At 260 °C, dehydration of biomass was favored over hydrolysis reactions.The more tools in the toolkit, the better we can adapt biomass to human uses. Hydrothermal liquefaction should prove useful, along with pyrolysis and gasification, for breaking down biomass into its more fuel-like components.
The resulting biocrude consists of an aqueous phase and solid precipitates. The aqueous phase contains oligomers and monomers of five and six carbon sugars, degradation products (5-HMF and furfural), organic acids (lactic, formic, and acetic acid), 2-furancarboxaldehyde, and other phenolic products containing five to nine carbon atoms. The residual solid (i.e., biochar) contained mainly lignin fractions and a small amount of cellulose.
Using infrared spectroscopy and electron microscopy, they confirmed that subcritical water treatment leads to a breakdown of lignocellulosic structure. _GCC
Update: Speaking of pyrolysis,
In Massachusetts, the University of Massachusetts at Amherst recently granted a biofuels startup company, Anellotech, exclusive global rights to the university’s catalytic fast pyrolysis technology developed by chemical engineer and UMass Amherst faculty member George Huber for producing clean, green “grassoline.” Huber will serve as chairman of Anellotech’s scientific advisory board.The company predicts that its biofuels will achieve price parity with gasoline by 2019.
Anellotech will offer a low-cost, single-step process for turning forest residues and waste biomass into gasoline, diesel fuel, heating oil and renewable chemicals including benzene, toluene and xylenes. _BiofuelsDigest
Various biofuels companies have predicted achieving price parity with gasoline anywhere from 2010 through 2020. As these products are incorporated into the overall fuel economy, they will influence the price of hydrocarbon fuels.
Sometime around 2020, biofuels should create a solid ceiling for the price of liquid fuels. From that point on, the race will be to the bottom -- to the most economical means of producing liquid fuels from microbes and/or biomass. Petroleum and other fossil fuels will find themselves increasingly sidelined as the economics of energy and chemicals pushes progress away from fossils.
Meanwhile, deep underground, oil fields will regenerate once again. Only by then, no one will care.
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