The issue of water consumption in caustic soda production
Thread Content
This post was last edited by sunjl1981 on 2013-1-6 at 19:59. I have a question: in ion-exchange membrane caustic production, if 30% caustic enters the cathode cell, the output product contains 32% caustic. If 200 tons of caustic are produced per day (calculated as 100%), how much water is required in the cathode cell? This includes the water vapor present in the hydrogen gas exiting the cathode, the water that is consumed in the cathodic reaction, and the water contained in the 32% caustic. The person who trained me said that to account for the water content in the hydrogen gas, the concept of saturated vapor pressure needs to be used; I’m not quite sure how this works... This post was last edited by wksyy on 2009-3-28 at 00:02. ] # ， ， &
For this issue, it is necessary to establish a balance, as well as take into account the amount of water that penetrates from the anode. It’s recommended to take a look at the following post; it will be helpful. http://bbs.hcbbs.com/viewthread.php?tid=230526
Amount of pure water added = Amount of pure water required to produce alkali + Amount of pure water used for diluting 32% alkali in the tank + Amount of water carried away by hydrogen gas – Amount of water that permeates through the anode solution
It seems there is a problem in establishing balance in this way; it should be as follows: The amount of water entering the system = amount of pure water added + amount of water carried in by the catholyte leaving the tank + amount of water permeating from the anode. The amount of water leaving the system = amount of water carried out by the catholyte leaving the tank + amount of water carried away by hydrogen. By using these two equations, the amount of water can be calculated. Of course, this is theoretical; there was a paper on this topic in the chlor-alkali industry in 2008. Written by Wang Li of Jiangshan; it’s quite comprehensive.
3/20 【Title】Discussion on the Relationship between Water Migration Amount and Ion Exchange Membrane Performance 【Author】Wang Li 【Institution】Nantong Jiangshan Pesticide and Chemical Co., Ltd., Nantong, Jiangsu 226006 【Journal Name】China Chlor-Alkali. 2008(3).-9-10 【Abstract】The water migration amount was calculated based on the operation data of ion exchange membrane cells, and the operating condition of the ion exchange membranes was analyzed through the trends in this amount. http://bbs.hcbbs.com/thread-378548-1-2.html