Washing ammonia out of coke oven gas with water - comprises two=stage process without need for distn. of regeneration plant and without environmental and cost drawbacks

摘要

This is a method of washing ammonia out of coke-oven gas. The ammonia is washed out with water in a special circulating washing plant, after which ammonia remaining in the gas is wased out with water in a special final stage. The free ammonia is converted to fixed ammonia by combining with hydrochloric acid, and the resulting ammonium chloride, together with the carbon-rich ammonium chloride, is obtained as a crystalline salt. Several variants are claimed, and include provision for water containing a small amount of free ammonia being mixed with a stoichiometric quantity of hydrochloric acid before the water is used in the final washing stage. USE/ADVANTAGE - The method ensures that ammonia remaining in the coke-oven gas, after the main wash, is washed out without the need for the whole of the washing water to be treated in a still or for a regeneration plant for acid washing media to be employed. Environmental disadvantages and expense of other methods are avoided.