In the regeneration of amine solution, is the water added to the amine solution preparation and recovery tank deionized water or deoxygenated water?

Theoretically, the amine solution needs to be isolated from air; otherwise, decomposition of the amine solution will occur. However, catalytic dry gas inevitably contains air as well. We originally used deoxygenated water, but our amine solution circulation tank was open to the atmosphere and did not isolate oxygen; using deoxygenated water was somewhat wasteful, so we switched to demineralized water instead. It is also possible to directly supply the steam condensate from the reboiler to the regeneration tower.

Isn’t this amine solution preparation tank located in a pit? It also receives waste amine solution from other places, right? Isn’t it not very good to have an open design?

The last edit to this post was made by ylb913 on 2015-6-16 at 10:07. 1. The amine solution preparation tank we originally designed was an underground tank, with a funnel on the surface (which remains the case to this day), to facilitate manual pouring of the amine solution (in 200 kg buckets). However, there are now many ways to add the amine solution; it can be added directly to the amine solution circulation tank using an air pump (such tanks were not available before; they should be available now—we started using them after our first renovation in 1994). 2. The key is that the method of adding water has changed; we have been adding water to the amine liquid circulation tank for a long time, probably since the plant was modified in 1994. 3. The main current use of the underground tank is as a transfer tank during shutdowns for amine removal; when removing amine under pressure, it can be connected to the amine circulation tank or the amine storage tank (the larger amine storage tank located on the surface). But without pressure, when it relies on gravity flow, it can only retreat to the underground tank, and then be pumped up to the circulation tank or storage tank.

Dude, the amine liquid circulation tank you’re talking about must refer to that tank with a capacity of four or five hundred cubic meters or more, used for storing lean amine liquid, right? It should be a dome-shaped tank equipped with a vent valve or something like that; how could it be an open-tank design?

Due to historical reasons, the situations vary from one place to another. Our tanks were originally designed to be sealed with gas; when exhaling, gas was released into the atmosphere, as nitrogen from the factory was not allowed to be used at that time. But this pressurization system and water seal were probably never used; they were removed before 1994, and since then the opening has been left open to the atmosphere, with the top opening also being sealed. Add some kerosene to the amine solution to isolate it from air. Currently, designs generally include nitrogen sealing and step control. I haven’t paid attention to those with breather valves; when drawing air in, it’s probably the atmospheric air being drawn in.

Is using split control for a pressure vessel at atmospheric pressure a bit of a waste? What we’re doing now is adding a self-acting control valve

A self-acting type should work fine too; is there also a vent valve?

The projects that were referenced at the beginning are still there now; whether they will be removed in the future will depend on what it says above

The last edit to this post was made by ylb913 on 2015-6-16 at 12:20. Two sets of devices designed in the past two years: 1. The amine liquid buffer tank (circulation tank) designed by the Beijing Institute for the natural gas desulfurization project in Yuanba is a pressure vessel that is controlled in stages; it is filled with nitrogen and low-wattage gas, and it also has safety valves. The amine liquid storage tank could not be found in the PID setup (but it must be there)； The design provided by the Beijing Institute for Hainan in 2006 was similar; there were also amine liquid storage tanks with vaults, which used self-regulating valves along with nitrogen filling and a water seal to isolate them from the atmosphere – desalinated water was used for replenishing the water level ； 2. The Luoyang Institute designed a dome tank for Dongying United Petrochemical; nitrogen is introduced into this tank using flow-limiting orifice plates, and the gas that emerges from the top of the tank is released into the atmosphere after passing through a water seal. ——Deoxygenated water for hydration.

What is the operating pressure of the first circulation tank?