method for removing the waste water in the desulfurization of coke oven gas with a washing solution containing oxygen carriers

摘要

A process is disclosed for the elimination of waste water falling out with the desulfurization of coking oven gas by means of an organic oxygen carrier-containing washing solution with simultaneous recovery of elemental sulfur. The waste water is decomposed in a combustion chamber in a reducing atmosphere at temperatures between about 1000 DEG and 1100 DEG C. under such conditions that the mole ratio of H2S:SO2 in the exhaust gas of the combustion chamber amounts to at least 2:1. Sulfur falling out is separated and the sensible heat of the exhaust gas is utilized for steam generation. The cooled and desulfurized exhaust gas is added to the coking oven gas before the pre-cooling. Sulfur falling out from the washing solution in the oxidizer is separated out and lead into the combustion chamber together with the part of the washing solution discharged as waste water from the washing solution circulation. Preferred embodiments include that the sulfur loading of the waste water can amount to up to about 370 kg sulfur per m3 waste water; having the cooling of sulfur-containing exhaust gas leaving the combustion chamber follow in a waste heat boiler and a sulfur condenser heated by pre-heated boiler feed water, from which condenser sulfur is discharged in liquid state.