Method and apparatus for desulfurizing coke oven gases

Abstract

A method of desulfurizing coke oven gas comprises directing the coke oven gases upwardly and in a hydrogen sulfide scrubber tower, washing the coke oven gases in a cyclic ammonia washing including admixing sulfur compounds containing waste gases and without cooling with ammonia in a degasifying unit which is supplied with ammonia containing water which is advantageously obtained from a tar separator and using the heat content of the waste gases to expel the ammonia from the water, and directing the waste gases laden with the expelled ammonia into the tower. The waste gases advantageously come from a Claus plant process and they are laden with ammonia and they are advantageously directed into the upper portion of the scrubber tower. Ammonia water is circulated in an ammonia circuit from an outlet which is advantageously located in the upper portion of the tower to an inlet which connects to the tower above the outlet. The apparatus includes in addition to the tower in the ammonia water circuit connected into the tower a degasifying unit which is supplied with Claus plant waste gases and into which an ammonia liquor from a tar separator is advantageously circulated. The heat of the waste gases causes a liberation of the ammonia to the waste gases which are then directed to the tower above or substantially at the level at the outlet of the ammonia water circuit.