Simultaneous gasification of coal and pyrolysis of organic solid waste

Abstract

Gaseous fuels are produced by a process which involves simultaneous gasification of coal and pyrolysis of organic solid waste materials in a pollution-free conversion system. According to this process, a mixture of coal and organic solid waste materials is fed to the top of a reaction vessel such as a vertical shaft furnace or a blast furnace, wherein the feed is dried by heat exchange with the gases rising from the lower section of the reactor. Steam and an oxidant gas containing at least 75 volume percent oxygen are introduced to the bottom of the reactor for partially combusting coke and char in a partial combustion zone thereby providing the thermal driving force for the reactions in the reactor. The organic solid waste materials are pyrolyzed and the volatile components of the coal destructively distilled simultaneously in the presence of hydrogen in a pyrolysis and coking zone of the reactor wherein the organic solid waste materials are converted into char and the coal is converted into coke. The char and coke are reacted with oxygen and steam in the partial combustion zone. The descending inorganic materials are fused and the fused slag and molten metals are tapped from the bottom of the reactor. The gaseous products are removed from the top of the furnace and subjected to a product recovery section to remove the undesirable components. The ratio of hydrogen to carbon monoxide can be varied over a wide, commercially important range, by feeding secondary steam to a high temperature reaction zone intermediate the partial combustion zone and the pyrolysis and coking zone. Depending upon the ratio of hydrogen to carbon monoxide produced, the gaseous products can be used as fuel or as a synthesis gas for the production of methanol or methane. Gaseous product containing larger quantities of methane may be produced by maintaining the reactor at elevated pressures during the process.