What are the typical amounts of purified water added to the reflux tank at the top of the amine liquid regeneration tower, and of acidic water discharged from it?

This post was last edited by ylb913 on 2016-1-8 at 07:14. Whether acidic water is discharged continuously or intermittently depends mainly on the pressure drop in the acidic gas pipeline; this is because salt accumulation can cause blockages in such pipelines, and discharging the water helps to reduce the circulation and buildup of salts. Continuous or intermittent water replenishment is determined by the changes in the liquid level of the visamine solution circulation tank. Since there has been no significant improvement in the situation of acidic gas-induced salt formation over the past two years, we basically carry out continuous discharge and continuous water addition; the amount of discharge also depends on the results, and of course it should be kept as low as possible. I forgot one thing: when operating in the deheat steady-state salt mode, it is necessary to discharge acidic water externally.

In the ammonia solution regeneration process, isn’t there basically no ammonia left? Then how can salt formation occur?

This depends on the washing effect of the upstream device. The issue arose after the major maintenance campaign started in April 2013; what changes were made to the upstream units? We don’t know about this; they can’t get in touch with them either. Then there were two successive upgrades to diesel, with sulfur content being the focus of control; however, the increase in nitrogen removal should be greater than the increase in sulfur removal. Our main suspect is the diesel hydrogenation unit.

If there is ammonia present, it should be converted into acidic water. The amount of ammonia in that recycled hydrogen and exhaust gases is likely to be quite low

What’s the relationship between the deheating steady-state salt and the acidic water that is discharged? Isn’t it simply about sending a stream of lean amine solution through those ion resins? The saturated ion resins are then washed with alkali inside that unit as well. How could it be related to the tower top reflux tank?

The last edit to this post was made by ylb913 on 2016-1-11 at 20:44. Before regenerating with an alkaline solution, it is necessary to use deionized water to flush the amine solution in the resin bed back into the amine circulation system, thereby increasing the capacity of the system. Below are my previous topics, along with the diagrams I created myself: Self-drawn flow diagrams and process control charts for adiabatic steady-state salts http://bbs.hcbbs.com/thread-1286312-1-1.html

I understand that the amine solution in the resin bed is flushed back into the amine circulation system. But once the amine solution in the resin bed is forced out by the deionized water, it goes directly into the lean amine tank, right? The amount of liquid in that tank should be quite small. In that PDF you mentioned, the manufacturer’s instructions state that one cycle takes 15 to 25 minutes； Use nearly 200 L of demineralized water ； 7L of 30% concentrated alkali (to prepare a solution with about 2.5% alkali concentration) ； Approximately 90 L of alkaline slag was discharged (containing about 0.82% NaOH), with most of the alkali solution converting into NaOH and ending up in the alkaline slag ； 80 tons of wastewater (pH=8～10) were discharged into the sewer. . Using 200 L of deionized water means that 200 L of such water is required to completely flush out the amine solution in the resin bed; in other words, all of this 200 L of deionized water ends up in the lean amine solution tank? Is it necessary to discard 200 L of acidic water through the top reflux tank in order to maintain a constant MDEA concentration?

Using 200 L of demineralized water is to completely flush out the amine solution in the resin bed. Then, all of these 200 L of deionized water end up in the lean amine tank; 200 L of acidic water must be removed through the overhead reflux tank in order to maintain a constant concentration of MDEA and thus a constant amount of amine solution in the system.

This post was last edited by longkui1990 on 2016-1-17 at 15:25. I understand what this 200L refers to; by the way, what are your normal water addition and drainage amounts?