REDUCTION OF POLYCYCLIC COMPOUNDS FROM GASIFING COAL

摘要

A process for gasifying coal and other carbonacaeous matter is disclosed which produces fuel gas containing low concentrations of polycyclic aromatic hydrocarbons. In this process the polycyclic aromatic hydrocarbons released by the coal during devolatilization and formed during pyrolysis of volatile matter are decomposed thermally in the presence of hydrogen, at a sufficiently high partial pressure (obtained by increasing the total pressure in the gasifier) to prevent polymerization of free radicals formed during pyrolysis. A relationship between the temperature, the gas residence time in the gasification reactor, the hydrogen partial pressure (i.e., total pressure in the gasifier), and the coal feed conditions are specified to achieve "clean" coal gasification.