Researchers in Brazil have found that solketal, a derivative of glycerin when reacted with acetone, has a potential for blending with regular gasoline, and may indicate an alternative use for the glycerin by-product from biodiesel production. A paper on their study was published online 22 March in the ACS journal Energy & Fuels.
In their study, they reacted glycerin with acetone and formaldehyde to produce the correspondent ketal (solketal) and acetal, respectively. These compounds were blended in 1, 3, and 5 vol % with gasoline containing 0 and 25 vol % ethanol.
They found that the addition of the glycerin derivatives did not significantly change the distillation curve of the gasolines.
The solketal reduced the gum formation in both gasolines (with and without ethanol) and increased the octane number up to 2.5 points in the gasoline without ethanol. However, the glycerin/formaldehyde acetal was only soluble in the gasoline containing ethanol and led to an increase in gum formation and a slight reduction (up to -0.75 points) in the octane number.
The results indicated the potential of solketal as a gasoline additive, to improve octane and reduce gum formation, especially in gasolines produced from catalytic cracking.
—Mota et al.
Claudio J. A. Mota, Carolina X. A. da Silva, Nilton Rosenbach, Jr., Jair Costa and Flávia da Silva (2010) Glycerin Derivatives as Fuel Additives: The Addition of Glycerol/Acetone Ketal (Solketal) in Gasolines. Energy Fuels, Article ASAP doi: 10.1021/ef9015735