Natural gas is a fossil fuel formed when layers of buried plants and animals are exposed to intense heat and pressure over thousands of years. These animals and plants originally produced energy from the sun, and it is stored as carbon in natural gas. NG is burned to produce electricity, allowing this energy to be transformed into electricity. Natural gas is a non-renewable resource. However, it is clean, convenient to use and easy to transport, which is why it is considered an ideal fossil fuel. Industrial users use nearly half of the gas produced in the United States. Thanks to increased shale gas development and new technologies in recent years, the United States now has enough natural gas to power its country for generations. Source: http://anga. us/why-natural-gas/abundant/shale-plays#.UyDnA_l_vC8Burning natural gas produces carbon dioxide and nitrogen oxides in the power plant, but in smaller amounts than burning coal or oil. In the United States, the average emission rates from natural gas generation are: 1,135 lb/MWh of carbon dioxide, 0.1 lb/MWh of sulfur dioxide, and 1.7 lb/MWh of oxides nitrogen [1]. Compared to average air emissions from coal-fired power plants, natural gas produces 1 percent more sulfur oxides in the power plant, less than a third more nitrogen oxides and half as much carbon dioxide. . However, the extraction, processing and transportation of natural gas produces additional emissions. Given the higher carbon efficiency of the production process and all the advantages of using natural gas over other fossil fuels, the United States is radically changing its primary fuel. The United States has shifted to reduce coal production and increase natural gas production... middle of paper ...... likely to cause supply disruptions, price fluctuations, and trade deficits. Therefore, biodiesel helps the United States reduce its oil imports, thereby increasing job opportunities and improving the environment. The physical properties of this fuel are very similar to those of petroleum diesel. One of the main advantages of using biodiesel is that it can be used in any pre-existing diesel engine. Additionally, it reduces GHG emissions by at least 57 percent, compared to petroleum diesel, because the CO2 released from burning biodiesel is offset by the CO2 sequestered when growing soybeans or other feedstocks. [3]. Biodiesel also helps reduce tailpipe emissions of unburned hydrocarbons (HC), carbon monoxide (CO), sulfates, polycyclic aromatic hydrocarbons, nitrated polycyclic aromatic hydrocarbons and particulate matter (PM), l one of the most dangerous in the United States.