Natural gas gas is often described as the cleanest fossil fuel. It produces 25–30% and 40–45% less carbon dioxide per joule delivered than oil and coal respectively, and potentially fewer pollutants than other hydrocarbon fuels. However, in absolute terms, it comprises a substantial percentage of human carbon emissions, and this contribution is projected to grow. According to the IPCC Fourth Assessment Report, in 2004, natural gas produced about 5.3 billion tons a year of emissions, while coal and oil produced 10.6 and 10.2 billion tons respectively. According to an updated version of the Special Report on Emissions Scenario by 2030, natural gas
Coal gasification commercialization resulting from the gasification of feed coal is shifted, and a Rectisol process is utilized for sulfur removal and CO removal. Recovered CO is sold for use in making carbonated beverages. "Lignite gasification to produce synthetic natural gas or ammonia" The Great Plains Synfuels Plant (GPSP) in Beulah, North Dakota has been in operation since 1984 producing synthetic natural gas (SNG) from lignite coal, and remains the only coal-to-SNG facility in the United States. GSPS is operated by the Dakota Gasification Company. In addition to the production of SNG, the plant also produces high purity carbon dioxide, which is distributed