Coke oven gas is a by-product of coke production. Cleaned coke oven gas can be a valuable energy source, ideal as a substitute for natural gas. However, to meet increasingly stringent environmental regulations and to protect combustion equipment, the high efficiency of the coke oven gas purification process must be ensured continuously, even for existing, less up-to-date plants. Process simulators built to support technologies can be a great help in this task. At the same time, they can be used to assist operations, understand general and specific process behaviour features, and examine development suggestions. The H2S scrubber of an existing coke oven gas purification plant was investigated in this study. Previously, the steady-state model of the purification process was studied, and the impact of operating parameters was investigated. Then the dynamic model of the purification process was created in Aspen Hysys simulator software. Finally, the model was validated against laboratory analyses and daily operational plant data. Subsequently, the control structure of the purification process was studied. It was concluded that the control system used in the coke oven gas purification plant is rather elementary and is primarily designed to ensure the safe operation of the technology. However, a more complex advanced control structure is needed to continuously provide a constant gas composition, in which the dynamic model of the technology is a great support. In this study, two examples for improving the control structure of the process were presented using the dynamic model of the H2S scrubber.