Greenhouse gas emissions by the United States of Energy's Energy Information Administration (EIA). Electricity generation increased by 2.5%, and carbon dioxide emissions from the power sector increased even more, at 3%, indicating that U.S. utilities shifted towards energy sources that emitted more carbon. That shift was partially caused by a 40 billion kilowatt-hour decrease in hydropower production causing a greater reliance on fossil fuels like natural gas and coal. Carbon dioxide emissions from power plants fueled with natural gas increased by 10.5%, while coal-burning power plants increased their emissions by 1.8%. Paper is the fourth largest contributor to greenhouse gas emissions in the United States and one
Underground coal gasification Underground coal gasification Underground coal gasification (UCG) is an industrial process which converts coal into product gas. UCG is an "in-situ" gasification process carried out in non-mined coal seams using injection of oxidants, and bringing the product gas to surface through production wells drilled from the surface. The predominant product gases are methane, hydrogen, carbon monoxide and carbon dioxide. Ratios vary depending upon formation pressure, depth of coal and oxidant balance. Gas output may be combusted for electricity production. Alternatively gas can be used to produce synthetic natural gas or hydrogen and carbon monoxide can be used as a chemical