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Coke oven gas contains a large amount of latent sulfur and a high H2S concentration; by employing pre-treatment for desulfurization to recover sulfur, the investment is low, the costs are minimal, and the utilization rate of sulfur-containing waste as a resource is high. Currently, wet oxidation is the dominant method for desulfurization in coking plants, and the HPF process, which uses PDS catalysts or complexed iron desulfurization catalysts as its core, is quite common. This article analyzes the problem of tower blockage that often occurs during the desulfurization process using the wet oxidation method: First, there are defects in the design of the desulfurization tower itself. (1) The structural design of the nozzles in the liquid distributor of the desulfurization tower is unreasonable, which can result in the circulation volume of the desulfurization liquid not meeting the design requirements; as a consequence, the spraying density is too low, leading to the formation of \"dry areas\" on some of the packing. Over time, this can cause sulfur or salt crystals to accumulate and block the tower ； (2) The liquid redistributor between the packing layers is poorly designed, resulting in poor gas-liquid flow and thereby an increase in column pressure drop ； (3) The design capacity of the desulfurization tower is relatively low, resulting in a high space velocity. The closer the space velocity inside the tower is to the flooding velocity at design, the more likely flooding will occur; and the occurrence of flooding leads to an increase in the resistance of the packed tower. II. Inadequate regeneration of desulfurization fluid: The regeneration unit for the desulfurization fluid is crucial for the proper operation of the entire desulfurization system. The amount of recycled air is too low, preventing the formation of a proper sulfur foam layer ； An excessive amount of regenerative air can result in a thin sulfur foam layer and the entrainment of sulfur particles in the lean liquid. Therefore, the volume of recycled air needs to be controlled within an appropriate range. If the regeneration efficiency of the desulfurization liquid is poor, the HS- that has not reacted completely in the lean solution is carried into the desulfurization tower, where it is oxidized to elemental sulfur in the upper packing layers; this sulfur adheres to the surface of the packing, resulting in sulfur blockage in those upper layers ； At the same time, if the desulfurization liquid is not regenerated properly, the sulfur particles become very fine, which can easily clog the filter fabric and reduce the efficiency of plate and frame filtration. III. Inadequate control of process parameters (1) Solution temperature. If the temperature of the desulfurization solution is too high, the rate of increase in by-products also rises. When the temperature exceeds 45 degrees, the concentration of sulfates in the desulfurization solution increases sharply, leading to the crystallization of sodium sulfate which in turn blocks the tower ； (2) A high level of suspended sulfur or a high HS- content in the solution can increase the driving force for side reactions to occur. When these substances are present in large quantities in the solution and are not promptly oxidized to the stable S8 form or removed through flotation, it leads to an ongoing transformation of the reaction equations from reactants to products, resulting in the accumulation of large amounts of by-products in the solution and ultimately causing tower blockage ； (3) Poor washing of the gas before it enters the desulfurization tower, as well as inadequate operation of the electrostatic precipitators, result in a large amount of impurities such as tar and coal ash entering the system. These impurities have strong adhesive properties; once they adhere to the packing inside the desulfurization tower, they can also cause blockages in the tower ； (4) Excessive control of alkalinity in the solution, especially in gas sources with high CO2 content, not only leads to a rapid increase in the levels of traditional by-products but also causes bicarbonates to crystallize at the mist catchers at the top of the desulfurization tower or at the gas outlet pipe of the tower, resulting in blockages. IV. Improper use of complexed iron desulfurization catalysts (1) Inappropriate control of the concentration of the complexed iron catalyst. If the concentration of the complexed iron catalyst is too low, it will cause the potential of the lean solution to become very low, thereby leading to an increase in the concentrations of thiosulfate and thiocyanate ； If the concentration of the complexed iron catalyst is too high, the potential of the rich and lean streams becomes high, causing the sulfate concentration to rise sharply. Therefore, it is necessary to control the catalyst concentration within a suitable range. (2) The complexed iron catalyst has poor quality, resulting in weak catalytic oxidation performance. The market for complex iron catalysts is currently plagued by chaos; a wide variety of such catalysts are available, and it is difficult to ensure their quality. In particular, among the new complex iron catalysts that have appeared on the market in recent years, many manufacturers lack their own proprietary technologies or research and development capabilities. As a result, most of these catalysts are unstable and tend to form iron hydroxide precipitates, leading to waste and losses associated with them. Additionally, these precipitates can accumulate on the fillers and cause blockages in the reactors, a problem that has occurred in many coking plants. (3) Improper selection of the complexed iron catalyst. When the coke oven gas contains high levels of tar or a high sulfur content, single-type complexed iron catalysts easily become inadequate for handling such conditions. The catalytic oxidation capacity of ordinary complexed iron catalysts is not sufficient to meet production requirements, which leads to excessive hydrogen sulfide levels after the tower, as well as the formation of fine sulfur foam particles and weakly structured foam. All these issues ultimately result in blockages in the desulfurization unit and forced shutdown of the system. Therefore, for different operating conditions, it is necessary to select an appropriate complexed iron catalyst that can cope with complex and high-sulfur conditions.