The mercaptan unit of South Pars Phase 1 Refinery has produced 1,400 tons of the odorant and plans are underway to increase the yearly output, the manager of the refinery said.
“The unit is the only one of its kind in the Middle East and one of the few production units of this substance in the world,” Mehrdad Abdi was also quoted as saying by IRNA.
The unit was designed with innovative and up-to-date knowhow, and constructed by local experts. It started operation in July 2018 and helped decrease the need for mercaptan import, he added.
Abdi noted that the indigenization of the chemical by domestic engineers has made Iran one of the few countries with the technical knowhow to produce it and helped save foreign currency needed to import it.
Mercaptan, also known as methanethiol, is a foul-smelling gas that is added to natural gas. Since natural gas is colorless and odorless, the odorant makes it easier to detect. It is added as a safety measure to ensure that natural gas leaks do not go undetected.
“The production unit has a design capacity of 800 tons per year, but its current production has fallen to 550 tons a year,” he said.
“Currently, about 1.8 tons per day of mercaptan are produced at the unit. However, due to the increasing domestic demand and future plans to meet the needs of gas supply and export this strategic product, several projects are underway to increase output.”
The construction of a pipeline has been planned to supply the unit’s feed from the third refinery and increase production to about 850 tons per year.
Another project that can raise output to 2,000 tons per year is the construction of a gas condensate concentration unit at the third refinery as the provider of feed for the mercaptan unit. When completed, it will fully meet domestic demand and pave the way for export, he added.
Mercaptan is an organic gas composed of carbon, hydrogen and sulfur. Mercaptans bond strongly with mercury compounds, and most release strong odors that resemble those of garlic or rotting cabbage.
These compounds are detectable at concentrations as small as only 10 parts per billion, making them an effective odorant.
Natural gas distributors began adding these mercaptans to natural gas after a deadly school explosion in 1937 at the New London School in New London, Texas. Currently, most gas odorants are mixtures of mercaptans and sulfides.
