There has been growing interest in the potential for converting glycerol—a relatively large (about 10 wt %) byproduct of the conventional production of biodiesel (fatty acid methyl esters)—into solketal (2,2-dimethyl 1,3-dioxalane-4-methanol) for use as an oxygenated fuel additive or diesel combustion promoter.
A number of approaches to solketal production have been explored. One of the latest comes from a team from the Topchiev Institute of Petrochemical Synthesis and Gubkin State University of Oil and Gas in Russia.
In a paper in the journal Fuel, they report a continuous, one-step process for the quantitative conversion of glycerol into a mixture of ethers under mild conditions (atmospheric pressure and temperatures of 40–70 °C) over a zeolite BEA catalyst.
Zeolite-BEA converts glycerol completely into a mixture of solketal and solketal tert-butyl ether (STBE).
They also reported that the introduction of solketal into hydrocarbon oil improves its antiwear properties; solketal was the most effective antiwear agent from all the ethers formed.
Vadim O. Samoilov, Dzhamalutdin N. Ramazanov, Andrey I. Nekhaev, Anton L. Maximov, Leonid N. Bagdasarov (2016) “Heterogeneous catalytic conversion of glycerol to oxygenated fuel additives” Fuel, Volume 172, Pages 310-319, doi: 10.1016/j.fuel.2016.01.024