Method for detecting hydrogen sulfide (H2S), carbon dioxide (CO2) and hydrogen cyanide (HCN) in acid gas

Abstract

The invention provides a method for detecting hydrogen sulfide (H2S), carbon dioxide (CO2) and hydrogen cyanide (HCN) in acid gas. The method comprises the following steps: combining a mixing solution of potassium hydroxide and a phenolphthalein indicator which are contained in different flasks in a volumetric flask; and adding pure water until reaching the scale, wherein potassium carbonate is generated by the CO2 adsorbed by the potassium hydroxide and reacts with calcium chloride to generate a calcium carbonate precipitation; the calcium carbonate precipitation is dissolved and titrated by using hydrochloric acid and a sodium hydroxide solution respectively, so that the content of the CO2 is obtained. The H2S adsorbed by the potassium hydroxide can generate potassium sulphide which reacts with a zinc acetate solution, so that a flocculent yellow precipitation is generated; an excess amount of standard iodine solution is added under the acid condition; the back titration is performed by using sodium thiosulfate; the content of the H2S is computed after blanking. After the HCN is adsorbed by potassium hydroxide, lead carbonate solid powder and a rhodanine indicator are added; the content of the HCN is computed after blanking. The method is rapid in detection speed and strong in operability; the precision and accuracy of the method can completely meet the requirement of a coking desulfurization and dehydrogenation process. Thus, the accurate detection data for the coking desulfurization and dehydrogenation process is provided.

Description

technical field [0001] The invention belongs to the technical field of inspection and testing, and in particular relates to a method for detecting hydrogen sulfide, carbon dioxide and hydrogen cyanide in acid gas in a desulfurization and dehydrogenation process. Background technique [0002] At present, the desulfurization and dehydrogenation process used in the domestic coking production process generally adopts the ZL old-fashioned potassium thiocyanate method, which has the problem that the desulfurization effect is not obvious and often exceeds the standard, so it cannot meet the technical requirements of the desulfurization and dehydrogenation process. For this reason, some enterprises have established a new vacuum potassium carbonate desulfurization and dehydrogenation process, and added an acid production process, but it is necessary to re-establish the detection methods for hydrogen sulfide, carbon dioxide, and hydrogen cyanide in the acid gas of the desulfurization a...

AI Technical Summary

Problems solved by technology

[0003] However, so far, there are no domestic standards for the detection of hydrogen sulfide, carbon dioxide, and hydrogen cyanide in the acid gas of the desulfurization and dehydrogenation process, and there are no relevant detection methods for hydrogen sulfide, carbon dioxide, and hydrogen cyanide in the acid gas of the desulfurization and dehydrogenation process. Therefore, there is an urgent need to establish a detection method for the analysis of hydrogen sulfide, carbon dioxide, and hydrogen cyanide in the acid gas of the desulfurization and dehydrogenation process to fill this gap