Until it closed in July 2007, Indianapolis Coke, the Manufacturing Division of Citizens Gas, produced coke, manufactured gas and various chemical by-products for industrial use.
Coke is a solid carbon material that is used as a fuel primarily by steel mills and foundries. The plant, located at 2950 Prospect Street on the southeast side of Indianapolis, produced about 577,000 tons of coke in 2006.
Indianapolis Coke had been in operation since 1909 and once produced all of the gas used for heating and other purposes in Marion County. Coke oven gas started to be phased out of the gas distribution operation during the 1950s with the introduction of natural gas transported to Indianapolis via interstate pipelines. By 1998 coke oven gas was completely phased out of the gas distribution system.