What are the disadvantages of high temperatures in a dry gas desulfurization tower?
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The dry gas in our plant is produced by the reaction of ethanolamine with stabilized gas in a desulfurization tower, after which it exits the facility. I have noticed that the temperature in the desulfurization tower is increasing, rising from 41 degrees initially to 48 degrees now. What impact does this have on the desulfurization process and the desulfurizing agents? Stable dry gas 44, ethanolamine 36?
At high temperatures, the desulfurization efficiency decreases; pay attention to the sulfur content in the dry gas. It has no effect on the amine solution.
Theoretically, dry gas desulfurization is an absorption process; an increase in temperature is detrimental to absorption and affects its efficiency. The temperature of the dry gas must be higher than that of ethanolamine, to prevent ethanolamine from condensing the hydrocarbons in the dry gas.
High temperatures in the desulfurization tower can reduce the efficiency of desulfurization, and this is due to the properties of the desulfurizing agent (ethanolamine)! The principle of desulfurization is that the desulfurizing agent (currently, a grade A diethanolamine solution is most commonly used) combines with hydrogen sulfide at low temperatures and separates from it at high temperatures. Therefore, the higher the temperature, the less favorable it is for desulfurization. Additionally, when the temperature is high, the dry gas after separation contains a certain amount of moisture. Especially in winter, ice can form on the inner walls of the dry gas lines at points such as the exit from the equipment, which can lead to pressure buildup in the system!
Thank you for your excellent answer. Currently, the temperature of the dry gas is 44 degrees, and that of ethanolamine is 36 degrees. The temperature in the dry gas desulfurization tower is 47 degrees. Is this higher temperature due to the heat of reaction? How can I lower this temperature?
The liquefied gas in our plant is processed through a reaction with alkaline solution, after which the alkaline solution is regenerated. It has been found that the temperature of the regenerated alkaline solution is around 48 degrees. What’s wrong with this for desulfurization? Won’t it be good for the operation? Could you answer this?
In the desulfurization process using ethanolamine, the reaction between ethanolamine and hydrogen sulfide is a reversible chemical reaction. At 40 degrees Celsius, ethanolamine and hydrogen sulfide combine to form a compound; around 120 degrees Celsius, this compound decomposes back into ethanolamine and hydrogen sulfide.
The dry gas temperature should be lower than that of the amine solution, right?
When dry gas comes into contact with ethanolamine, some heat is released; it is necessary to analyze and compare whether the hydrogen sulfide content in the dry gas before separation increases, as well as to examine the hydrogen sulfide content in the rich liquid.
Now that the weather is warming up, higher temperatures are normal; in winter, temperatures are usually lower. If the temperature of the dry gas is too high, liquid may form, which in turn reduces the efficiency of desulfurization
Generally, the tower top temperature is kept below 50 degrees, which yields a good desulfurization effect