The problem of water in the carbon scrubber tower

When the carbon scrubber tower is severely contaminated with water, it can cause the shift catalyst to be flooded by water; when there is water in the carbon scrubber tower, attention should be paid to the drainage process from the separator before the shift reaction takes place

Increase the amount of condensed liquid, reduce the volume of high-pressure ash water, and increase the thermal load

This post was last edited by pyp222 on 2017-8-12 21:29. Water is carried in the scrubber tower because the gas flow passes through the trays, carrying the water on those trays with it as it moves upward. We know that in trays like these, there is a phenomenon known as flooding (you can search for it on Baidu); flooding occurs when the amount of water on the tray is too large. When flooding occurs, the gas will carry a large amount of liquid water; in addition, a high gas space velocity in the scrubber tower can also lead to the presence of water. Generally, a demister is installed at the top of a washing tower; some demisters are in the form of folded plates while others resemble circular fan blades. Their function is to separate the liquid water carried within the gas. If it is felt that there is too much water in the gas entering the shift reactor, apart from the fact that the scrubber is leaking water, another reason is that the gas pipelines transporting the coal gas from the gasification unit to the shift reactor lack insulation, and due to the long transmission distance, the temperature of these pipelines drops significantly, causing the saturated water vapor in the gas to condense.

Increasing the amount of condensed liquid, reducing the volume of high-pressure ash water, and raising the heat load – won’t this lead to more severe water carryover?

Syngas contains water; some systems now allow the water-to-gas ratio calculated as a result of background processing to be viewed directly on the operation interface. The main reasons for this issue are as follows: the quality of the water in the system is poor, with a high content of ash. In such cases, it is possible to increase the water circulation within the system to facilitate replacement. Additionally, increasing the amount of high-pressure ashwater fed into the carbon scrubber leads to an increase in the amount of wastewater discharged, which in turn reduces the system’s thermal load and helps to reduce the amount of water contained in the syngas

Take a look at this post; the explanation for such issues should be perfect there. http://bbs.hcbbs.com/thread-114398-1-1.html

Generally, the wash water that enters the carbon scrubber is graywater and condensate. There should be no issues with the condensate; it depends on the quality of the water discharged from the graywater tank. I have only seen cases where poor quality of graywater caused serious water contamination in the vaporizer, which in turn led to water contamination in the carbon scrubber as well.

Could considering the addition of a high-temperature resistant anti-entrainment agent be an option to solve the water entrainment problem?

First, it is necessary to explain your process details and the structure of the carbon scrubber in order to facilitate the analysis and resolution of problems. Here are the summarized solutions: 1. Optimize the water quality in the carbon scrubbing tower; 2. Optimize the ash content in the syngas; 3. Replace the type of tray used in the tower; 4. Modify the syngas pipeline in the carbon scrubbing tower, and avoid using a water bath for the syngas. See if the above methods can address the existing issue.