부산대학교 도서관

Coal has played an important role in the energy picture in the United States for many years, although significant changes have occurred in the end use. For example, coal production was more than 600 million tons in 1920. Direct burning was the largest use, but conversion to other fuels and products was substantial. In that year, steam locomotives used more than 25% of the total consumed and only 8% was burned by electric utilities. Only a few trains serving tourists use coal today. A significant amount of coal was used in producing water gas early in this century, when it was common for cities to distribute gas produced this way through city mains. This was displaced as natural gas transmission lines were constructed, particularly after World War II. Germany, of course, produced much of the fuel for its war machine through liquefaction of coal. However, except for the major facilities at Sasol, South Africa, Beulah, ND, and Johnson City, TN., the production of coal-derived liquid and gaseous fuels has largely disappeared. Coke production was another major use and although declining, this market still continues to be important for coal. Coal production climbed to 683 million tons in 1944, when railways used more than 136 million tons. Coke production was more than 105 million tons while electric utilities used only about 77 million tons. According to the National Coal Association, 1991 production grew to an estimated 998 million tons and domestic consumption was 892 million tons.