Synthesis of an Odorant Substance for Liquid Petroleum Gas (LPG) as a Substitute for Thiophene (Tetrahydrothiophene)

Tetrahydrothiophene (C4H8S) is used as an odorant for liquid gas (LPG).the Tetrahydrothiophene acts as an alarm when a leak occurs in liquid petroleum gas (LPG) bottles at a gas filling and distribution company. where it is added at a concentration of (20PPM) to the liquefied gas. This research includes the preparation of an alternative substance to (tetrahydrothiophene C4H8S). ethanethiol (C2H5SH), that is used as an odorant for gas leaks. It was prepared in the laboratory at the Petroleum Research and Development Center through the reaction of hydrogen sulfide gas (H2S) with ethanol alcohol (C2H5OH) in the presence of a catalyst (Gama alumina) .at a temperature of (350-400 °C) using the reactor or the system that was manufactured Inside the petroleum research and development center. The prepared substance was identified using various techniques including the (FT-IR) technique to identify the functional groups. In FTIR the thiol group (SH) clearly appeared at a frequency of (2500 cm-1) with the disappearance of the hydroxyl stretching band, which usually appears at a frequency of (3300Cm-1). The density test for the prepared substance was also conducted using a digital density measuring device inside the laboratories of the petroleum Research and Development Center. The result was 0.8452 g/cm3 at the standard temperature (15.6 ○C). The (GC-Mass) assay technique was also used, which is considered one of the most important identification tests and works to give the synthetic formula of the substance. A chart with the highest signal intensity was obtained, which is (62) that represents the molecular weight of the prepared substance ethanethiol (C2H5SH) according to what was extracted from the electronic library of the examination device.