Evaluation of glycerol tert-butyl ethers as renewable fuel additive

Abstract

The aim of this research is the investigation of using glycerol tert-butyl ethers as a bio-renewable fuel additive to diesel-biodiesel blend in a diesel engine. In this context, an experimental study was carried out to synthesize glycerol tert-butyl ethers and investigate the effect of glycerol ethers on diesel engine performance and emissions. Glycerol tert-butyl ethers were synthesized by the etherification reaction of glycerol with tert-butyl alcohol (TBA) in a high-pressure stainless steel batch reactor using Amberlyst-15 as solid acidic catalyst. Produced glycerol ethers were mixed by 2 vol.% with a biodiesel-diesel blend to investigate the glycerol ethers usage as a fuel additive in a diesel engine. Three test fuels were considered for the experiments: (i) diesel fuel, (ii) B20 (80 vol.% diesel + 20 vol.% corn oil biodiesel); (iii) BD+GTBEs (80 vol.% diesel + 18 vol.% corn oil biodiesel + 2 vol.% glycerol tert-butyl ethers). Some basic fuel properties of test fuels were determined prior to engine tests. Engine performance and emissions tests were performed on a single-cylinder research diesel engine at four brake power output. The results revealed that the addition of glycerol tert-butyl ethers in the fuel showed no significant effect on determined fuel properties and caused a decrease in engine performance and exhaust emissions except for CO emissions when compared to base diesel fuel. However, BD+GTBEs presented similar performance and emissions characteristics with B20, as a consequence, glycerol tert-butyl ethers have the possibility of being utilized as a bio-renewable fuel additive to diesel-biodiesel blends.