Recycling and Reuse of Organo-sulfur Compounds from Barrels of Natural Gas Contaminated with Mercaptan Odorant

Document Type: Original Article

Authors

1 Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran

2 Deapartmenet of chemistry, University of Mazandaran, Babolsar, Iran

3 Research and Development Center, Mazandaran Gas Company, Sari, Iran

Abstract

Natural gas is odorized by trace amount of mercaptans and organic sulfides to be recognized by individuals, in case of gas leakage. These materials may pollute the environment particularly in injection station at local gas plants. Therefore, removal of sulfur compounds from the remaining odorant in barrels is essential. To remove the residual portion of mercaptans and alkylsulfide mixtures different methods were utilized which among them extraction-distillation procedure was implemented in our project owing to environmentally safe and low cost process. Different solvents such as Methyl Ethyl Ketone (MEK), Ethyl acetate, Dichloromethane (DCM), Toluene and Kerosene were attempted for the efficient extraction which among them kerosene was the most desired and the best in terms of use and environmental friendly solvent. The results showed highly efficient method for the removal of odorants in which the regenerated mercaptan from the mercaptan contaminated barrels could be reused in injection step as well as the original odorant. The GC and 1H NMR analyses confirmed that the recovered organo-sulfur compounds, mainly composed of tertiary butyl mercaptan, which was desired for re-injection into natural gas stream as suitable odorants.

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