Some issues with solvent regeneration
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My solvent regeneration unit has just started operating, and I’ve encountered some issues; I’d like to ask for everyone’s advice. Currently, the pressure at the top of the tower is 0.7–0.8, while the temperature at the bottom of the tower is 116. The temperature of the gas stream leaving the tower is 120, and the temperature at the top of the tower is 104. 1. There is no liquid level in the reflux tank at the top of the regeneration tower, or the liquid level rises very slowly; as a result, top reflux cannot be established. 2. With the steam supply remaining unchanged, will increasing the tower pressure raise the temperature at the top of the tower?
1. What is the temperature at the top of the tower after cooling? Is it too high? Reducing it appropriately helps to establish a liquid level in the reflux tank； 2. Increasing the tower pressure will certainly raise the bottom temperature of the tower, while the top temperature may decrease
What are the temperatures of the cold water at the top after it has cooled down? If the temperature is too high, the liquid level in the reflux tank will rise slowly; one cannot just increase the steam supply, as this will raise the pressure further. In such cases, it’s necessary to lower the temperature of the rich liquid entering the tower, by adjusting it through the rich-liquid bypass and the heat exchanger between the rich and poor liquids.
Generally, rich-lean liquid heat exchangers do not have bypass lines.
1. Check whether there are any leaks in other processes within the reflux tank, such as the concentration line and the close-packing line. The simplest way is to check the temperatures along each pipeline to make a judgment. Or calculate the flow rate based on the current of the return pump to see if it matches the flow rate returning to the tower. 2. Control the tower pressure and the temperature after cooling at the top of the tower. 3. Determine the hydrogen sulfide level in the rich amine solution; analyze it to see if the amount extracted from the tower top is appropriate.
How do you divert water to the regeneration tower when starting up? Isn’t there a water replenishment line available for the reflux tank?
This post was last edited by hbszjkm on 2019-1-26 at 23:04. The temperatures at the bottom and top of the tower are a bit low; it is recommended that you add some steam
First, is the ethanolamine you are using a lean solution or a rich solution? If it is a lean solution, how can you establish a reflux without H2S being released? If it is rich liquid, it is recommended that you lower the temperature of the acidic gas at the top of the tower after cooling, as well as the pressure at the top of the tower.
There is no backflow; the feed is at the top of the tower. Increasing the tower pressure causes the temperature at the top to rise momentarily, before falling again due to a decrease in the heat transfer temperature difference, which results in a reduction in the heat flow and thus less steam rising