To collect toxic emissions, the first and second stages of a plan to recover gasoline vapor have been implemented at 450 filling stations across the country, the head of Engineering Department at the National Iranian Oil Products Distribution Company (NIOPDC) said.
“Stage I gasoline vapor recovery systems, which capture vapors expelled from underground storage tanks at gas stations, have been completed in all [3,400] filling stations, but the second stage has been delayed in most pumps for the last two years due to financial constraints,” Kavous Samani was also quoted as saying by the Oil Ministry’s news portal.
Stage II includes the installation of special fuel dispensing nozzles at the pumps to capture gasoline vapor that would otherwise be vented during individual vehicle refueling.
“The development of Phase II of the project requires an investment of at least $100 million that filling stations’ owners cannot afford,” he said.
To help pump owners with the expenses, negotiations are being held with some banks.
While refueling, vapor is pushed out of the vehicle's gas tank by the inflowing fuel. The vapor is then captured by the special nozzle and directed into the underground storage tanks where they are recycled with the help of vapor recovery units (VRU), a kind of high-tech, energy saving and environmentally advanced technology.
According to the official, NIOPDC's gasoline storage facilities covering a wide geographical area, namely Neka in Mazandaran, Malayer in Hamedan, Rey in Tehran and Kharg Island, Asalouyeh, Mahshahr and Genaveh in Bushehr Province, are all equipped with vapor recovery systems.
VRUs in Tehran, Karaj and Esfahan help recover 16,000 cubic meters of vapor, which are converted to 24,000 liters of gasoline.
In Bandar Abbas, Tabriz, Mashhad, Arak and Ahvaz, 17,000 cubic meters of vapor are collected daily, which are then used to produce 25,000 liters of gas.
Tanker Trucks
Referring to tanker trucks, Samani noted that of the total 6,200 tankers, about 5,000 are equipped with VRUs and the rest is awaiting funds.
Close to 105 million liters of gasoline are sold in Iran per day and 260,000 cubic meters of (gasoline) vapor are emitted into the atmosphere.
Collecting the vapor (260,000 cubic meters) can help produce as much as 400,000 cubic meters of fuel per day.
“Vapor recovery units can reduce air pollution, save money by conserving gasoline that would be lost into the air and protect public health by reducing inhalation of toxic gasoline vapors,” he said.
Gasoline vapors accumulate in automobile and truck tanks, above the liquid level. When the tanks are filled, the rising liquid forces the vapors to seek an escape route. When a conventional nozzle is used, the displaced vapors flow around the nozzle spout into the air. When thousands of vehicles are refueled, the escaping vapors add significantly to air pollution.
According to Mohammad Semanbouye, a member of the Board of Directors of Kahab Gostaran Ayrik Company, the knowledge-based company has developed a vapor recovery unit for fuel reservoirs and gas stations, which costs a quarter of foreign counterparts.
“The product is, in fact, an absorption refrigeration system that condenses at very low temperatures and turns vapors into gasoline. Its absence could cause diseases,” he said.
