Glycerol to renewable fuel oxygenates. Part II: Gasoline-blending characteristics of glycerol and glycol derivatives with C3-C4 alkyl(idene) substituents

The main physico-chemical features, as well as gasoline blending features of eight diol derivatives (1,3-diisopropyl and 1,3-di-tert-butyl glycerol ethers – di-GIPE and di-GTBE; O-isopropyl and O-tert-butyl solketal ethers – SIPE and STBE; isopropylidene ketals of ethylene and propylene glycol – DMD and TMD; cyclic ketals of glycerol with the methyl ethyl ketone and the methyl isobutyl ketone – GBK and GHK) have been estimated in order to reveal the relations between the molecular structures of the compounds and their efficiency as the gasoline oxygenated additives. For the oxygenates, the experimental values of the density, the boiling/melting point, the viscosity and the net heat of the combustion have been obtained. The characteristics of the estimated oxygenate-gasoline blends have involved their density, the calorific value, the fractional composition, the saturated vapor pressure, the research octane number and the motor octane numbers (ON), the oxidation stability, the gum content and the pour point. For di-GTBEs, as the most effective octane booster (among the compounds tested), the effect on the gasoline calorific value has been researched in the combination with the antiknock features improvement, which shows the evident advantages over ethanol and MTBE relatively to ΔAKI/ΔNHOC ratio.