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In the wet hydrogen sulfide removal process for coke oven gas, packed towers are commonly used in absorption towers, with parallel or multiple stages in series to achieve the desired level of hydrogen sulfide removal after the tower. In actual operation, due to the characteristics of coke oven gas, its gas composition is complex, containing tar and dust; these impurities inevitably adhere to the surface of the packing. Furthermore, hydrogen sulfide is continuously absorbed on the surface of the packing inside the desulfurization tower, along with the desulfurization reaction; as a result, fine sulfur particles accumulate on that surface. Over time, the gaps between the packing elements become gradually blocked by tar, dust, salts, and sulfur, leading to an increase in the resistance within the desulfurization tower. To reduce the risk of blockage in the desulfurization tower and extend the operational life of the desulfurization system, most coking plants in China have switched to regularly structured packing with large pores instead of bulk packing, which has proven to be very effective in actual operation. However, some coking plants still use plastic wreath fillers, which leads to periodic increases in the resistance of the desulfurization tower and a shorter operating cycle for the desulfurization system. The Guolitong GLT chelated iron series catalysts have been successfully used in wet desulfurization units for coke oven gas for over 6 years, and can be installed in existing HPF-based coke oven gas treatment systems without requiring major modifications. The principle of the complexed iron desulfurization reaction is as follows: within the packing layer of the desulfurization tower, the desulfurization solution first absorbs hydrogen sulfide from the gas. The gaseous hydrogen sulfide molecules ionize in the solution to form HS-, and then the trivalent complexed iron catalyzes a reaction that converts this HS- into a sulfur sol. Thus, absorption and desulfurization reactions occur almost simultaneously within the desulfurization tower. To prevent the packing from being adhered to by sulfur, the best approach is to use regularly structured packing with large pores, and to arrange the packing height in each layer of the desulfurization tower in a rational manner. Inside the desulfurization tower, gas and liquid come into contact in a counter-current manner. The solution in the tower is sprayed from the upper part of the tower and passes through three layers of packing sequentially, while the gas flows from the bottom of the tower upward, also passing through these three layers of packing. In most cases, the filler at the bottom of the desulfurization tower is exposed to the greatest amount of sulfur and tar dust, and this area is also the most prone to accumulation and blockage. Therefore, under normal circumstances, the impurities accumulated in the filler layers increase gradually from top to bottom; when blockage occurs, the bottom layer is the most severely affected, the middle layer to a lesser extent, and the top layer the least. Therefore, when designing the packing filling or refilling the packing in the desulfurization tower after maintenance, it is necessary to take into account the operating process and catalysts, as well as past experiences with blockages, and conduct a comprehensive analysis to develop a specific packing layout plan. Under normal circumstances, a complexed iron catalyst is used; when filling the packing from top to bottom, it is possible to gradually reduce the height of each layer, while the total height of the packing should be determined based on the solution circulation rate (spray density) in the desulfurization tower. Of course, the most basic requirement is to ensure that the total area for mass transfer meets the demands of desulfurization.