Wet desulfurization does not produce sulfur foam problem

Is it because the air blowing effect is not good, the air pressure is insufficient, or the catalyst is not added enough, or the catalyst components are insufficient.

Problems and modifications in the application of bubbling desulfurization towers in synthetic ammonia production. Although the new tower has achieved the predetermined desulfurization efficiency, some problems have also been exposed. The most prominent problem is foam entrainment, which in severe cases carries a large amount of liquid, causing the H2S content in the decarbonization regeneration gas to reach as high as 1000mg/m3, seriously affecting the service life of the urea synthesis tower. At that time, the following reasons were analyzed:: (1) After being put into operation, the pressure of the entire ammonia synthesis system is unstable, fluctuates greatly, and the gas flow rate is large (instantaneously). At the same time, due to the low technical level of workers, the suspended sulfur content in the desulfurization liquid is high (2-3g/t), causing the desulfurization liquid to foam. (2) The liquid inlet pipe of the desulfurization tower is too close (5000mm) to the gas outlet at the top of the tower, and the fine foam is taken out by the gas before it has time to fall. The five hand holes designed on the original cylinder are reserved for installing solution nozzles. Due to the excellent desulfurization efficiency, solution nozzles are not used at all. When the H2S content of the cracked gas is 350 to 450 mg/m3, two-layer bubbling can also meet the requirements. Therefore, during the overhaul in 1991, we made the following modifications to the new desulfurization tower. (1) Cancel the first layer of bubble section and retain the second and third layer of bubble section. (2) Move the solution inlet pipe down to the middle hand hole. After modification, the distance between the solution inlet pipe and the gas outlet pipe is 12500mm, which prolongs the droplet landing time. At the same time, the original groove-shaped incision liquid distributor was changed to a tubular liquid distributor. (3) Change the overflow weir plate type downcomer to downcomer type downcomer type. After the transformation, when the system pressure is stable, the suspended sulfur in the solution is less than 3g/t, there is no liquid entrainment, and the desulfurization efficiency is above 99%. In 1991, we changed the old system porcelain Raschig ring packed tower into a bubble tower. After it was put into operation, the desulfurization effect was also very good.

I agree with Wang Junqing on the second floor. It may also be that the hydrogen sulfide content before desulfurization is low, and it is a new start-up stage, and secondary salt is being generated at a high speed.