UW-Madison Team Shows Good Yield of Renewable Diesel and Jet Hydrocarbons from Processing of Biomass-Derived GVL
04 May 2010
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| Reaction pathway for conversion of GVL to liquid transportation fuels. Source: Alonso et al. Click to enlarge. |
Researchers at the University of Wisconsin-Madison have demonstrated that it is possible to achieve good yields of renewable hydrocarbons in the molecular weight range suitable for jet and diesel fuel applications through the processing of C9 alkenes produced from biomass-derived γ-valerolactone (GVL).
In February, Dr. James Dumesic and colleagues at the University of Wisconsin-Madison published a paper in the journal Science describing a process to convert aqueous solutions of GVL, an intermediate produced from biomass-derived carbohydrates, to liquid alkenes suitable for transportation by using an integrated catalytic system that does not require an external source of hydrogen or precious metal catalysts. (Earlier post.)
In a new paper, published in the RSC journal Green Chemistry, Dumesic and colleagues focused on the production of alkenes in the range of C18–C27 from the oligomerization of C9 alkenes produced from biomass-derived GVL.
These C18–C27 compounds are in the molecular weight range suitable for jet and diesel fuel applications. The extent of oligomerization can be modified by varying the reaction conditions to yield product distributions tailored to various applications. For example, if a jet fuel range product is desired, a product rich in linear C9 species and branched C18 species can be produced by operating at lower temperatures and elevated space velocities.
We have observed that oxygenated compounds like 5-nonanone (a potential impurity present in streams of C9 alkenes produced from biomass-derived GVL) have no effect on the rate of oligomerization. Alcohols in the feed, such as 5-nonanol, can present a problem for oligomerization, because they undergo dehydration under reaction conditions to produce water, which has a strongly inhibiting effect on the rate of alkene oligomerization. Interestingly, because Amberlyst-70 swells in polar media to produce a higher surface area, the presence of small amounts of nonanol leads to an increase in the rate of oligomerization.
This effect and the fact that nonene separates spontaneously from water, allow the production of diesel and jet fuel range alkenes from 5-nonanone without the need for complicated purification strategies. Overall, we estimate that it is possible to produce approximately 50 kg of C9–C18 alkenes from 100 kg of GVL retaining more than 90% of its energy content.
—Alonso et al.
The basic approach described by Dumesic and his colleagues is to hydrogenate levulinic acid—a product of biomass hydrolysis—to GVL (which is also used as a substitute for blending of ethanol in gasoline). The GVL is upgraded to C9 alkenes, which they then oligomerize over an acid catalyst to produce longer chain alkenes that, after hydrogenation, can be used as drop-in fuels.
Resources
David Martin Alonso, et al. (2010) Production of liquid hydrocarbon transportation fuels by oligomerization of biomass-derived C9 alkenesGreen Chem., 2010, doi: 10.1039/c001899f
Biomass for fuel is always suspect because crops for biomass production change the local ecology and biomass production areas can also always be used for food production. Human food can even be produced from natural gas or gasses from biomass. ..HG..
Posted by: Henry Gibson | 04 May 2010 at 08:58 AM
You must be thinking of Delta-Valerolactone, it has flavor, but Gamma-Valerolactone ?
When is the last time anyone heard of using Gamma-Valerolactone or one of it's non-molecular-analogue derivitives as a food stuff ?
Posted by: ToppaTom | 04 May 2010 at 09:22 PM