Natural gas compressors are able to compress natural gas (methane) up to 200 bar. America, Canada, Italy and Argentina are the main owners of technology to manufacture these compressors. Major consumer countries of this technology are Iran, Russia, Italy, Argentina and parts of Eastern Europe. Currently, there are about 17 million personal cars in Iran, and about 20% of them use natural gas that the major problem for the owners of such vehicles is accessing to CNG fuel. According to the fuel quota in Iran, Iran’s international sanctions about charging fuels, and lack of subsidies on gasoline, a great need for natural gas refueling stations have created. According to the National Iranian Gas Company, at this time there isn’t enough fuel stations around the country due to increasing demand of clean and low price fuel for the national transportation industry. The strategic importance of national producing of this product is because of the following reasons:

  • Good Alternative for gasoline
  • Complete cessation of imports from foreign countries like Italy and Argentina
  • Long-term natural gas resources for use in the transportation industry (at least 170 years)
  • Make the fuel sanctinos ineffective
  • The use of natural gas as a clean fuel alternative to gasoline and diesel fuel
  • The use of natural gas as a low cost fuel in comparison with gasoline

Medium stations are classified as class L of compressors and are divided into the two group of first and second type by ISIRI 12141 standard. The first type of medium natural gas fueling station compresses the natural gas in 2 or 3 stages with the following specifications:

  • Inlet pressure of 17.2 mbarg
  • Outlet pressure of 200 bar
  • Nominal flow rate of 10 to 40 normal cubic meter per hour
  • there is no need to pressure vessels

The second type of medium natural gas fueling station compresses the natural gas in 3 or 4 stages with the following specifications:

  • Inlet relative pressure of 2.5 to 4 barg
  • Outlet pressure of 200 bar
  • Nominal flow rate of 40 to 250 normal cubic meter per hour
  • Maximum pressure vessels volume of 500 normal cubic meter

The technology used in these compressors is hydraulic drive and the seals process is static. Also the compressors compress the natural gas in a isothermal thermodynamic process, so that the efficiency is increased.