Coal gas sampling method for determining content of hydrogen cyanide in coal gas

Abstract

The invention provides a coal gas sampling method for determining the content of hydrogen cyanide in coal gas. The coal gas sampling method includes steps of leading coal gas to pass through cadmium acetate liquor so as to absorb hydrogen sulfide in the coal gas; then leading the coal gas to pass through potassium hydroxide liquor twice respectively to absorb the hydrogen cyanide in the coal gas so as to obtain sample absorption liquid absorbed with the hydrogen cyanide; leading the coal gas to pass through sulfuric acid liquor to absorb ammonia in the coal gas so as to protect a flow meter; and finally, leading the coal gas to pass through saturated picric acid liquor to absorb naphthalene in the coal gas and leading the coal gas to pass through the flow meter to obtain coal gas sampling quantity. After the sample absorption liquid absorbed with the hydrogen cyanide is inspected, the content of the hydrogen cyanide in the coal gas is obtained by means of conventional calculation. The coal gas sampling method effectively resolves the problem that as the content of sulfion in absorption liquid for determining the content of the hydrogen cyanide in the prior art is high, the content of the hydrogen cyanide in coal gas cannot be determined by a silver nitrate titration method. In addition, the coal gas sampling method is simple and practicable, and is easy in implementation.

Description

technical field [0001] The invention relates to a sampling method, in particular to a coke oven gas sampling method for measuring the hydrogen cyanide content in the gas, and belongs to the technical field of chemical analysis. Background technique [0002] Both hydrogen sulfide and hydrogen cyanide are harmful components in coke oven gas. In the process of gas purification, not only the hydrogen sulfide in the gas must be removed, but also the hydrogen cyanide in the gas must be removed. The gas before the desulfurization tower and the gas coming out of the desulfurization tower are measured to determine the removal of hydrogen cyanide in the gas. In order to measure, it is necessary to sample the gas before and after the desulfurization tower. Conventional sampling is to let the gas pass into the bottle with potassium hydroxide absorption solution to the set volume before and after the desulfurization tower, and then send it to the laboratory for measurement. Due to the h...

AI Technical Summary

Problems solved by technology

Due to the high content of hydrogen sulfide in the coal gas before the desulfurization tower, the content of sulfide in the potassium hydroxide absorption liquid increases. And consume too much cadmium acetate solution, resulting in test solution PH < 11, can not meet the titration conditions, thus can not be measured down

Therefore, conventional sampling methods can only measure the hydrogen cyanide content of the gas after the desulfurization tower, but cannot measure the hydrogen cyanide content of the gas before the desulfurization tower.