METHOD OF RECOVERING ENERGY AND CHEMICALS FROM BLACK LIQUOR

摘要

A method and apparatus for treating black liquor generated in a sulfate pulping process to recover energy and chemicals therefrom includes heating (4) the black liquor (2) at a temperature and for a time period to produce substantial volumes of off gases (7) containing organic sulfur compounds; generating hydrogen sulfide (9) and preferably methane from the off gases; and utilizing the generated hydrogen sulfide in the sulfate pulping process. The hydrogen sulfide can be absorbed (13) into white liquor (15) to selectively control the sulfur content of the white liquor. The methane (31) is used as fuel in a lime reburning kiln (16).