Thread Content
Impurities in coke oven gas such as tar, naphthalene, and coke slag (collectively referred to as \"oil dust\" hereafter) have an adverse effect on the absorption, regeneration, and sulfur recovery processes of the desulfurization system: 1. They reduce the absorption efficiency. Oil dust can form a hydrophobic film on the packing in the absorption tower, affecting the absorption efficiency. According to empirical data, an increase of 10% in the oil dust content in coke oven gas results in a decrease of about 10% in desulfurization efficiency. 2. Increase the resistance of the desulfurization tower. Due to the combined presence of oil dust and sulfur, they adhere to the surface of the filler and block the flow channels. At the same time, sulfur is oil-soluble; when the oil dust content is high, it tends to aggregate with sulfur, forming larger particles that are more likely to adhere to the packing, thereby causing the pressure drop in the tower to increase rapidly. 3. Causes the foam to become weak. Due to the presence of tar, naphthalene, etc., sulfur forms large particle agglomerates that sink, making it difficult to float them; as a result, it is hard to form a foam layer during regeneration, or the foam that does form is weak and unstable, while the suspended sulfur levels increase. 4. Sulfur separation is difficult. After sulfur and oil dust accumulate, during the sulfur melting process, sulfur does not heat up effectively. Moreover, large amounts of tar tend to adhere to the inner walls of the sulfur melting vessel, reducing the equipment’s heat transfer efficiency and thus leading to poor sulfur melting results; as a result, the liquid contains many sulfur particles ； During the plate and frame filtration process, tar has strong adhesion properties, which can easily clog the filter fabric and the channels for the clear liquid; therefore, the filter fabric needs to be cleaned and replaced frequently. 5. Consumption of chemical raw materials will increase. Oil dust accumulating in the desulfurization liquid reduces the mass transfer efficiency during desulfurization and regeneration, which in turn lowers the effectiveness of regeneration. A large amount of catalyst must be added to maintain the original performance. To address the issue of high oil dust content in coke oven gas, it is necessary to increase the amount of circulating liquid and raise the liquid-to-gas ratio, depending on the actual conditions. This prevents tar and impurities from accumulating in the packing layer, thereby improving absorption efficiency and reducing the likelihood of an increase in pressure difference; however, it does lead to higher electricity consumption. An increase in the circulation rate leads to a shorter residence time of the desulfurization solution in the regeneration tank, which affects the regeneration of the desulfurization catalyst; therefore, increasing the air volume must be considered as a solution to this problem. At the source, it is necessary to conduct regular inspections of the primary cooler to check whether the spraying pipes are blocked, whether there is excessive resistance, and whether the temperature meets the specified requirements ； Enhance the control of parameters such as current, voltage, steam flushing, and regular slag discharge in electric tar collectors, to ensure that the oil and dust content in the gas at the fan outlet remains within the specified limits; this helps to make full use of the equipment’s capacity and to remove suspended particles and tar droplets from the coke oven gas. Additionally, while adjusting the temperature in the pre-cooling tower, the remaining ammonia water is used to further remove impurities such as tar and naphthalene from the gas, ensuring strict quality control. It is necessary to leverage the advantages of the equipment’s capabilities in order to overcome the impact of tar on the desulfurization system.