Natural-gas processing at ambient conditions (i.e., pentane and heavier) are called "natural-gas condensate" (sometimes also called "natural gasoline" or simply "condensate"). Natural gas is called "sweet gas" when relatively free of hydrogen sulfide; gas that does contain hydrogen sulfide is called "sour gas". Natural gas, or any other gas mixture, containing significant quantities of hydrogen sulfide, carbon dioxide or similar acidic gases, is called "acid gas." Raw natural gas can also come from methane deposits in the pores of coal seams, and especially in a more concentrated state of adsorption onto the surface of the coal itself. Such gas is referred to
Natural gas reserves in Iran with India and China the main markets for Iran’s gas exports. A recent report (December 11, 2011) from Iran's Petroleum Minister indicates that a large natural gas reserve was discovered inside Iran's side of the Caspian Sea. These reserves are estimated at 50 trillion cubic feet (1.42 trillion cubic meter). Natural gas reserves in Iran According to the Iran Petroleum Ministry, the proved natural gas reserves of Iran are about or about 17.8% of world's total reserves, of which 33% are as associated gas and 67% is in non associated gas fields. It has the world's second largest reserves after