Is it necessary to add chemicals to the deaerator of the hydrogen production plant to control the pH value?
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Today I went to a newly installed unit; it doesn’t have an ammonia addition system for the deaerator. The designers believe that a pH level of 7–8, which is slightly alkaline, is sufficient. However, in my own unit, neutralizing amines are used to keep the pH between 8.0 and 9.5, thereby facilitating the removal of CO2. According to the relevant standard GBT 1576-2008 \"Water Quality for Industrial Boilers\", for boiler feed water at pressures of 2.5–3.8 MPa, the pH should be maintained between 8.0 and 9.5 when using desalinated water as the feed water. Yet, the two hydrogen production units nearby, each with a capacity of around 20,000 units, do not use any chemicals of this kind. If there really is no need to add chemicals, then we can stop using ours as well. Is there anyone here who can help answer this question?
Some hydrogen production units add chemicals in the deaerator, while others do so in the steam drum; I’m not sure which type you use. Without adding chemicals, it definitely won’t work
The forum didn’t give any hints; I just saw the reply – neutralizing amine is added to the deaerator (it works in the same way as ammonia), and phosphates are added to the drum.
This post was last edited by Riding a snail sjj on 2016-3-12 08:50. The original poster mentioned deoxygenated water and demineralized water. The function of a deaerator is to remove dissolved oxygen from demineralized water; it also removes other gases, including carbon dioxide. As for demineralized water, if it is sent directly to the boiler to generate steam without passing through a deaerator, then there are certainly specific control parameters applicable to this water, and chemicals need to be added. In my opinion, the deionized water should pass through the deaerator before going to the steam drum ； It is two different methods compared to direct introduction of demineralized water into the steam drum. 25,000 cubic meters of hydrogen are produced; no chemicals are added to the deaerator, while phosphates are added to the drum. Everything has been operating normally over the past few years.
Small boilers with a capacity of 4 tons and a pressure of less than 1.3 MPa can be connected directly to the steam drum. What is the pH level of the water in your deaerator, that is, what is the control value for the boiler feedwater pH?
Our system adds chemicals to the large steam drum. .