PYROLYSIS OF COALS IN A MICROWAVE DISCHARGE

Pyrolysis of coals of different ranks in a microwave discharge yields gaseous products containing hydrogen, carbon oxides, and hydrocarbons, with acetylene as the main hydrocarbon. The discharge pyrolysis of coal, except for lignite, occurs in three stages: partial carbonization to produce tar, rapid gasification to produce gaseous products, and slow degassing of residual char. When the gas products are cooled with liquid nitrogen as they form during the discharge pyrolysis, the hydrocarbon yield increases markedly and the extent of volatilization in terms of carbon gasified rises. The initial presence of argon increases the rate of gas evolution and appears to yield greater amounts of smaller fragments as the primary gasification products. © 1969, American Chemical Society. All rights reserved.