Method and equipment for improving desulfurization efficiency of coke oven gas by vacuum potassium carbonate method

Abstract

The invention discloses a method for improving desulfurization efficiency of coke oven gas by a vacuum potassium carbonate method. The method comprises the steps of adding KOH solution into regenerated potassium carbonate barren liquor to fully mix, conveying the mixing solution to the lower segment of a desulfurizing tower, reversely contacting airflow of coke oven gas to absorb acid gas, so as to reuse in circulation, wherein the barren liquor outlet at the bottom part of a regeneration tower in the equipment is connected with the input end of a barren liquor tank; a sylvite supply opening is arranged in the barren liquor tank; and the output end of the barren liquor tank is communicated with the barren liquor inlet at the top part of the lower section of the desulfurizing tower. The KOH solution is supplied to the regenerated potassium carbonate barren liquor; the pH value of the potassium carbonate barren liquor is increased because of adding of KOH; adsorption of the acid gas inside the desulfurizing tower is facilitated, so as to improve the desulfurization efficiency; and the pH value of pregnant solution is constant due to the supplement of KOH, so as to optimize the acid gas analysis condition. Therefore, the desulfurization efficiency is further improved.

Description

technical field [0001] The invention relates to coke oven gas purification technology, in particular to a method and equipment for improving the desulfurization efficiency of coke oven gas by vacuum potassium carbonate method. Background technique [0002] The vacuum potassium carbonate gas desulfurization process has been adopted by many domestic coal chemical enterprises in recent years. The process mainly includes desulfurization and regeneration. Potassium carbonate solution is used in the desulfurization tower to directly absorb H in coke oven gas. 2 Acid gases such as S and HCN, potassium carbonate solution absorb a lot of H 2 After S, it becomes desulfurization-rich liquid; the rich liquid that has absorbed acid gas from the lower part of the desulfurization tower is stored and buffered in the rich liquid tank, and then enters the regeneration tower for regeneration. The acid gas is analyzed in the regeneration tower, and the acid gas is released to become the regene...

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Problems solved by technology

At present, the replenishment method of mixing KOH with the rich liquid in front of the regeneration tower after the desulfurization tower is adopted. This replenishment method is simple to operate, but since KOH is replenished in front of the regeneration tower, the alkalinity and pH of the rich liquid in the regeneration tower are increased after supplementing KOH value, according to the analysis principle of the analysis tower, the increase of alkalinity and pH value will have an adverse effect on the analysis of acid gas in the rich liquid, which will lead to the occurrence of H in the lean liquid after regeneration. 2 The concentration of S is high, which leads to the decrease of desulfurization efficiency after the lean liquid returns to the desulfurization tower

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