New clean one-pot process for high-yield production of biofuel GVL from biomass-derived levulinic acid
08 September 2014
A team from Brown University and Lakehead University (Ontario, Canada) has devised a one-pot process for the clean and highly selective production of γ-valerolactone (GVL) from biomass-derived levulinic acid (LA) at up to 96.3% yield using a series of robust, stable and reusable Pd nanoparticles in water solvent. A paper on the work is published in the Journal of Cleaner Production.
GVL (C5H8O2) is a feedstock of interest in the production of both fuels and fine chemicals from biomass. With more energy than ethanol, GVL can be used on its own, used as an additive, or used as a precursor to other fuels. (Earlier post.) GVL could also be useful as a “green” solvent or a building block for creating renewable polymers from sustainable materials.
GVL can be produced by the continuous catalytic hydrogenation of biomass-derived levulinic acid (LA); however, production has been challenged by a number of factors, including the separation and recycling of the catalysts from reaction residues and the generation of organic waste from the organic solvents used.
To more efficient and clean production of GVL, we want to report a series of robust, stable and reusable Pd nanoparticles confined in the mesoporous channel of the support, are highly selective for one-pot production of biofuel GVL from LA in water solvent. It indicated that Pd metal nanoparticles confined in the mesoporous channel, could prevent the potential metal leach or aggregation. Besides, the stable metal nanoparticles were easy to recycle. Without any reduction or treatment, the spent metal nanoparticles maintained high stability over several runs, which may be a cleaner route to process biomass.
—Yan et al.
The researchers synthesized the Pd nanoparticle catalysts in the mesoporous channel of various supports. In their experiments, LA (~3.0 g) and 5 mL water were added into the reactor, with 0.1 g catalyst was added into the solution, followed by the slow vacuum of reaction system. After this, 60 bar H2 was slowly introduced. After reactions, the vessel was cooled down to room temperature. The reaction products were centrifuged for 0.5 h and then filtrated to obtain a clear solution for gas chromatography (GC) analysis.
They found that the highest activity was obtained on the 5 wt% Pd/MCM-41 catalyst, which displayed 57.3% yield and 57.8% conversion at low temperature. Increasing the reaction temperature resulted in higher performance. The conversion was increased to 78.5% at 200 ˚C and 92.7% at 240 ˚C, where the yield of GVL was obtained with 77.6% and 91.9%, respectively. Prolonging the reaction time to 10 hours resulted in close to complete conversion with 96.3% yield.
The Pd nanoparticles catalysts also exhibited stable catalytic performance over several runs.
Resources
Kai Yan, Todd Lafleur, Cody Jarvis, Guosheng Wu (2014) “Clean and selective production of γ-valerolactone from biomass-derived levulinic acid catalyzed by recyclable Pd nanoparticle catalyst,” Journal of Cleaner Production doi: 10.1016/j.jclepro.2014.02.056
In my mind, the long-term energy solution would be one that takes a renewable source of energy and stores it in a very clean, easy to store and transport medium, with minimal conversion losses. My impression is that biofuels and synfuels all have relatively poor "round trip" conversion losses. This fairly reasonable analysis suggests almost 70% of energy content is lost with synfuels today. http://theenergycollective.com/schalk-cloete/459401/seeking-consensus-internalized-costs-synfuels
As a result, I keep thinking that cheaper solar power and better, cheaper batteries are the long term answer.
Posted by: HealthyBreeze | 17 September 2014 at 04:09 PM