Thread Content
During the wet desulfurization regeneration of coke oven gas, foam forms in the regeneration tank, making overflow difficult to control, which severely affects the normal operation of desulfurization. 1. Incomplete or abnormal oxidation reactions result in small sulfur particles and a loose foam structure. The core framework of the foam in the regeneration tank is composed of elemental sulfur particles; if these particles are small and highly dispersed, the foam becomes weak due to the lack of a solid framework. Moreover, because the adhesion between the particles is weak, large amounts of foam are produced, but it is difficult for them to aggregate into a dense floating layer that overflows. The ejector draws in insufficient air, resulting in small particles of elemental sulfur, which makes the foam loose and prone to breaking. If the air distribution is uneven (such as due to a malfunctioning injector), oxidation will be insufficient in certain areas, sulfur particles will not be evenly dispersed, and the overall foam will become weak. II. An imbalance in the components of the desulfurization solution affects the stability and flowability of the foam. The alkalinity of the desulfurization solution has a direct impact on the aggregation of sulfur particles and the properties of the foam; an imbalance in its components can lead to a loose foam structure and abnormal viscosity. Excessively high or low alkalinity (pH value): When the pH is too high (e.g., >9.5), the OH⁻ concentration in the desulfurization solution is high, leading to side reactions that result in the formation of thiosulfates. The accumulation of thiosulfates reduces the ability of sulfur particles to aggregate, thereby decreasing the sulfur content in the foam and causing it to become less dense ； At the same time, high alkalinity increases the viscosity of the solution, resulting in poor foam flowability. Too low a pH (e.g., <8.0): The oxidation reaction rate slows down, fewer and smaller sulfur particles are formed, and the foam has poor stability. III. Excessive accumulation of suspended sulfur or impurities: A high concentration of suspended sulfur in the desulfurization solution (>2 g/L), or excessive levels of impurities such as tar, naphthalene, and dust, can adhere to the surface of sulfur particles, preventing aggregation between these particles. Additionally, these impurities increase the viscosity of the solution, reducing the fluidity of the foam and making it difficult to control. IV. Improper control of the level in the regeneration tank exacerbates the deterioration of foam properties. When the liquid level is too high, the thickness of the foam layer is insufficient (<300 mm); the foam does not have enough time to aggregate into a dense floating layer before being washed away by the solution, resulting in excessive liquid being carried over during overflow and weak foam formation ； When the liquid level is too low, the liquid stream ejected by the ejector hits the bottom of the tank directly, breaking up the foam that has already formed. As a result of being sheared, the foam loses its stability and becomes weak.