Effects of ethanol and mtbe additives on properties of blends with base gasoline

Abstract

In this study, specific emphasis is given to the comparison of the effects of two gasoline additives, methyl tert-butyl ether (MTBE) and ethanol, on several physicochemical properties of the blends with base gasoline. The following characteristics were considered: relative density at 20° C., distillation curves, Reid vapor pressure, research (RON) and motor octane (MON) numbers and oxygen content. An unleaded gasoline (RON: 94.4) without any additive was used as a base gasoline for the preparation of gasoline/ethanol blends and gasoline/MTBE blends with additions in the following volumetric proportions of 3, 5, 7, and 10% (v/v). The obtained results are discussed in relation to the European Norm 228 for gasoline and also to the recently introduced Directive 2009/30/EC regarding the environmental specification of fuels. The results implied that special care must be taken to control the oxygen content and vapor pressure of the ethanol blends to be in compliance to the maximum allowed values. © by PSP.