Hydrogenation, intercooling, high-pressure separation
Thread Content
In the hydrogenation process, the intermediate cooling stage has a high pressure of 11–12 MPa and a temperature of 50 degrees. What is the purpose of this? What is meant to be prevented from separating?
The purpose of cold high-pressure separation is to achieve three-phase separation of gas, water, and oil, to prevent circulating hydrogen from carrying liquid (oil) that could contaminate the desulfurization system, and to avoid such liquid from reaching the hydrogen circulation pump.
Generally, separation of the gas, liquid, and water phases is carried out. The gas phase mainly consists of sulfur- and nitrogen-containing gases produced by the reaction, along with hydrogen present in the system (along with some hydrocarbon components as well) ； The water is the deionized water that was injected earlier to prevent ammonium salt crystallization ； The liquid phase is naturally the oil product formed as a result of the reaction. As for the high temperature of 50 degrees you mentioned, I personally think it’s a bit high; it can easily lead to the presence of liquid in the system (and if there is a circulating hydrogen desulfurization system, it can cause the amine solution to foam, affecting the desulfurization efficiency). The recommended value for such temperatures is usually between 40-50°C, but in actual operation, the temperature rarely exceeds 45°C. As a side note, the difference between hot high pressure and cold high pressure lies mainly in the solubility of hydrogen: it is not easily soluble at high temperatures, which also leads to waste.
Separate hydrogen so that hydrocarbons are not separated, prevent the compressor from operating with liquid present, and avoid foaming of the amine solution in the recycle hydrogen desulfurization tower.
Separation of gas, liquid, and water; recycled hydrogen, oil, water