How to choose the decarbonization process and what is the basis?
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Yesterday a friend of mine asked me that they use flue gas (C02 is 7~9%, O2 is 13%, N2) to concentrate carbon dioxide and then make bicarbonate amine without desulfurization. My friend asked me which process to choose. At first I said I could use PSA, but later I found out that I was wrong and should use MEA wet process. I think the reason is that the adsorption capacity of PSA suits in descending order is CO2, N2, and O2. Therefore, if I choose PSA, I cannot remove N and O first, and finally add a CO2 treatment device. I am a newbie, and the above questions may be naive. I would like your advice on how to choose a decarbonization plan. If there is relevant information * That would be better, thank you
Low-concentration CO2 generally uses chemical absorption. The flue gas is a gas under normal pressure, and amine solution is generally used. Therefore, it is reasonable to choose mea.
I encountered this kind of problem recently. MEA has not been studied specifically, but pressure swing adsorption can be realized.
Recovering carbon dioxide from flue gas is an old problem. In fact, Wings knows that it is better to use MEA at present. One of the more troublesome things about using PSA is the increase in the partial pressure of carbon dioxide. If the partial pressure is to be high, relatively large compression work must be achieved. Because the nitrogen concentration is high, the nitrogen will compete to adsorb the carbon dioxide adsorbed on the adsorbent, just like the purge process of Tianli Company. If the adsorbent is silica gel or activated carbon, both are not ideal. I have done experiments. It is still possible to use polar adsorbents, mainly because the desorption scheme is difficult to determine. I recommend using TSA if the waste heat of the flue gas can be used.
The partial pressure of carbon dioxide in the flue gas is too low, and other impurities have a great influence. If pressure swing adsorption is used, the key point is how to effectively remove impurities step by step. 1. In terms of design ideas, how many levels should be considered for the device? 2. The number of pressure equalization times must be increased. ； 3. The necessity of high vacuum degree. 4. The problem of flue gas pressurization. In fact, it is really not complicated and the device can be made.
There is no doubt that the MEA method should be used, but the corrosion and degradation of the amine liquid should be mainly considered, that is, adding corrosion inhibitors and antioxidants!
I have used both MDEA and PSA. Have you ever used HYSYS to write a process?
There is no need to separate and other technologies can be used to use the flue gas as the carbonization raw material.
What media are you targeting for carbonization?
This post was last edited by huwei19890613 on 2016-12-28 14:01 You can use pressure swing adsorption to achieve this, but what you need to recover is the adsorbed CO2, so that N2 and O2 can penetrate and flow out, so the process design is different from the conventional effluent recovery process. There is an introduction in Section 4.3 "Recovery and Production of Carbon Dioxide" in the "Adsorption Gas Separation Technology Manual" that I uploaded. http://bbs.hcbbs.com/thread-1649335-1-1.html In addition, the investment cost and operating cost of MEA are estimated to be higher than that of PSA.