Researchers at the Université de Sherbrooke, Canada, with colleagues at the Université de Toulouse, France, have developed a process for the direct production of levulinates from cheap residual lignocellulosic biomass using an affordable homogeneous catalyst. A paper on their work is published in Fuel.

In Canada, the lumbering industry produces large volumes of residues (such as bark, tree tops, and sawdust) and while some of it used to be integrated in the forest value-chain, the decline of the pulp and paper industry in the country has led to an accumulation of unused residues. The price of lignocellulosic residues generated from the forest sector is currently very low (often reaching as low as $5 per tonne for bark and $50 per tonne for white wood chips) and the fact that the pulping industry is not using as much biomass as it used to certainly represents an opportunity for the energy sector. Therefore, now more than ever, conversion of lignocellulosic residues (forest or agricultural) could represent a low Carbon Intensity source for different fuels and chemicals.

Methyl levulinate is a short-chain ester that possesses properties that could, to a certain extent, be compared to fatty acid methyl esters (FAME). It has the potential to be used as biodiesel (as an additive) due to some of its properties (high lubricity, non-toxicity, and better flow properties under cold conditions). In addition, levulinate esters have shown many potential applications in the fragrance, flavoring, medicine, and energy sectors.

… This work aims at demonstrating the possibility of producing affordable methyl levulinate using low-cost residual forest and agricultural biomass. The objective here was to determine the effects of the different variables (acid concentration, temperature, α-cellulose content, and reaction time on methyl levulinate and levulinic acid yield as well as residue production) using a central composite design (CCD) under the response surface methodology (RSM).

—Aguilar et al.

The team applied a central composite design (CCD) to analyze the effects of four selected factors (acid concentration, temperature, α-cellulose content, and reaction time) on the production of levulinates (levulinic acid derivatives).

This optimization led to a total production of levulinates of 78 wt%, 72.5 wt%, 83 wt%, and 73 wt% using α-cellulose, poplar, sorghum, and softwood bark, respectively.

Resources

• Maricelly Martínez Aguilar, Xavier Duret, Thierry Ghislain, Doan P. Minh, Ange Nzihou, Jean-Michel Lavoie (2020) “A simple process for the production of fuel additives using residual lignocellulosic biomass,” Fuel, Volume 264 doi: 10.1016/j.fuel.2019.116702