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 In turn, many studies from MIT, Black & Veatch and the DOE predict that natural gas will account for a larger portion of electricity generation and heat in the future. The world's largest gas field is the offshore South Pars / North Dome Gas-Condensate field, shared between Iran and Qatar. It is estimated to have of natural gas and of natural gas condensates. Because natural gas is not a pure product, as the reservoir pressure drops when non-associated gas is extracted from a field under supercritical (pressure/temperature) conditions, the higher molecular weight components may partially condense upon isothermic depressurizing—an effect