Euro-4 gasoline indexes are regularly checked to ensure they do not violate international standard levels, director of the Comprehensive Monitoring Office at the Department of Environment said.
"The critical factors, namely octane number, aromatic compounds, olefin, sulfur and benzene, should stand at 91, 35%, 18%, less than 50 parts per million and less than 1% respectively, most of which show improvement in domestically produced gasoline," Shina Ansari was also quoted as saying by Shana.
An octane rating, or octane number, is a standard measure of the performance of an engine or aviation fuel. The higher the octane number, the better the quality of fuel.
Pointing to recent improvements in meeting standard criteria, she said, "As of October 2017, gas stations have been monitored randomly in Tehran Province and compared to previous years, the level of aromatic compounds as well as benzene has decreased notably."
"In line with efforts to protect the environment, so far, some 50 random samples from different filling stations have been scrutinized, which will reach 100 by the end of the current fiscal [March 20]," she added.
Asked about adding benzene to gasoline, Ansari noted that processing complexes do not add the material to the fuel, yet it is produced as a result of reactions in gasoline production reactors.
According to the official, refining plants are equipped with isomerization units, which minimize the amount of benzene as much as possible. On the other hand, they add MTBE to the fuel not only to facilitate the ignition process in vehicles, but also to curb greenhouse gas emissions.
MTBE is antiknock additive and a fuel oxygenate used in gasoline and diesel at high levels to replace lead as an octane enhancer.
"MTBE consumption to produce gasoline in the country is very low," Ansari said, noting that 22.4 tons of MTBE were used in the world in 2016, of which the Middle East, Europe and North America accounted for 5.4 tons, 4.5 tons and 1.3 tons respectively.
Projections show that MTBE consumption will reach 26.5 tons in 2021.
Some refining plants, including Arak, Isfahan, Tabriz and the Persian Gulf Star Refinery in the city of Bandar Abbas in southern Hormozgan Province, are manufacturing Euro-4 gasoline that is distributed in megacities such as Tehran, Karaj, Arak, Tabriz, Isfahan and Mashhad.
According to Shana, as soon as incomplete ventures are launched, the strategic commodity will be widely distributed throughout the country.
Average Consumption
Iranians have burnt 80.2 million liters of gasoline per day on average so far this year (March 21, 2017-March 3, 2018), indicating an 8% hike year-on-year (74.3 million liters per day).
The average daily consumption during the past 19 days stands at 80.2 million liters, too. However, the figure shows a 7.5% growth compared with that of the last year's corresponding period, ISNA reported.
The decrease seems to be temporary since the Iranian year is coming to an end (March 20) and gasoline consumption is expected to hit a hike during the two-week Iranian holidays.
