Optimization process of vacuum potassium carbonate method coke oven gas desulfurization and equipment thereof

Abstract

The invention discloses an optimization process of vacuum potassium carbonate method coke oven gas desulfurization. The process comprises the following steps: shunting regenerated potassium carbonate barren liquor, conveying a part of potassium carbonate barren liquor to the lower segment of a desulfurizing tower to come into reverse contact with coke oven gas flow to be recycled; and conveying the other part of the regenerated potassium carbonate barren liquor to the upper segment of the desulfurizing tower to come into reverse contact with coke oven gas to be washed for the second time so as to be recycled. A washing liquid waste outlet at the bottom part of the upper segment of the desulfurizing tower in the equipment is communicated with the liquid return opening of an alkaline tank, and the input end of the alkaline tank is communicated with a barren liquor outlet at the bottom part of a regenerating tower. In the invention, the potassium carbonate barren liquor is used for replacing the alkaline washing segment NaOH to reduce the NaOH consumption to zero on the condition that the H2S content in the coal gas reaches the standard, so that the production cost is greatly reduced; and meanwhile, the dosage of the desulfurization liquid waste generated by the original alkaline washing segment is reduced to zero, and the total yield of the desulfurization liquid waste is reduced by more than 80%, so that the environmental pollution is reduced.

Description

technical field [0001] The invention relates to coke oven gas purification technology, in particular to an optimized process and equipment for coke oven gas desulfurization by vacuum potassium carbonate method. Background technique [0002] Vacuum potassium carbonate desulfurization is a wet desulfurization process, which is widely used in domestic coking plants because of its high desulfurization efficiency. The process uses potassium carbonate solution to directly absorb H in coke oven gas 2 Acid gases such as S and HCN, and then use NaOH solution to wash the gas twice to make the H in the gas 2 The S content meets the requirement. The gas desulfurization tower is divided into two sections, the lower potassium carbonate absorption section and the upper sodium hydroxide alkali washing section. The coal gas first flows through the absorption section from bottom to top and contacts with the potassium carbonate lean liquid countercurrently, so that more than 90% of the H in...

AI Technical Summary

Problems solved by technology

[0003] The operation of the vacuum potassium carbonate desulfurization process in each coking plant is not the same. Although the desulfurization effect of this process is good, it generally faces high alkali consumption in gas purification, and a large amount of NaOH lye is consumed in the alkali washing section, resulting in high chemical costs; and The spent lye after cleaning the gas carries a large amount of salts and organic matter, which is difficult to deal with, and the large amount of sulfur carried by the spent lye leads to the waste of sulfur resources

At present, the domestic research focuses on the treatment technology of desulfurization waste liquid. The conventional treatment is to send the desulfurization waste lye to the biochemical water treatment system. The quality of effluent water is deteriorating, and how to significantly reduce the generation of desulfurization waste liquid through process optimization from the source is still blank in China

Images