Glycerol to renewable fuel oxygenates. Part I: Comparison between solketal and its methyl ether

Solketal methyl ether (SME) was synthesized from glycerol by conversion with methanol followed by ketalization with acetone. The values for the equilibrium constant of the ketalization of glycerol and glycerol 1-monomethyl ether in the temperature range of 298-323 K were determined experimentally, and its thermodynamic parameters (Delta H-0, Delta S-0, Delta G(0)) have been calculated, which appear to be very close for these two reactions. The gasoline blending properties of SME have been studied in comparison with solketal by examining the effects of solketal and SME additives on the fractional composition, saturated vapor pressure, oxidation induction period, existent gum content, density, and antiknock value of gasoline components and a model fuel blend. It has been shown that SME has better volatility, but a much lower antiknock value than solketal. The influence of the solketal additive on the antiknock value of components of compounded gasoline (alkylate, reformate, FCC gasoline) and the performance of composite additives based on solketal with ethanol, MTBE, and TAME are described.