Abstract:

Gas chromatography-mass spectrometry (GC-MS) qualitative characterization of C₅-C₇ alkenes in gasoline from methanol to olefins (MTO) was investigated in detail. It showed that the retention indices of 49 alkenes, 11 alkadienes and 9 cycloalkenes, a total of 69 C₅-C₇ isomeric alkenes were determined and qualitatively confirmed. The retention indices of all C₅-C₇ alkenes in MTO gasoline were measured on polydimethylsiloxane as the stationary phase. According to the library of retention indices by GC-MS characterization, the contents of C₅-C₇ alkenes in MTO gasoline were analyzed by GC and characterized by its composition of hydrocarbon categories. The results of quantitative analysis showed that the composition of MTO gasoline mainly consisted of C₅-C₇ alkenes, and a small amount of alkadienes and cycloalkenes. The contents of alkanes and cycloalkanes existed in MTO gasoline were very low. The study of the composition is helpful for the comprehensive application of MTO gasoline.

Key words: alkenes, gas chromatography (GC), gasoline, mass spectrometry (MS), methanol to olefins (MTO)