Process for the catalytic gasification of coal

Abstract

A process for the production of synthetic natural gas from a carbon-alkali metal catalyst or alkali-metal impregnated carbonaceous feed, particularly coal, by reaction of said feed with water (steam) in the presence of a mixture of hydrogen and carbon monoxide, in a series of staged fluidized bed gasification reactors (or gasification zones). The first reactor, or main reactor, of the series is operated as an entrainment reactor and entrained solids are carried over to the second reactor, or reactors, of the series. A carbonaceous feed, or coal, is thus partially gasified in a fluidized bed in the main reactor to form a product gas and a char, and char is entrained within the effluent gases, separated therefrom and then fed into the secondary gasification reactor, or reactors, of the series, the entrained char constituting feed to a secondary reactor, or reactors. Some char is also passed via dense phase transfer from the main reactor to the secondary reactor to maintain catalyst balance. More effective ultilization of the feed carbon is possible by use of the reactor system operated in such a manner than is possible by the sole use of the main reactor, even when the latter is operated at the same or at more optimum conversion conditions.