Modern design of ammonia absorption towers – flash
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This post was last edited by wiseboy on 2021-2-25 at 13:44. It is an engineering design process for an ammonia absorption tower with a modern approach. Related links: 1. Problem: Ammonia-containing waste gas at atmospheric pressure, with a temperature of 70°C and a flow rate of 27.5 t/h; its composition is as shown in the diagram. Now, water is to be used to absorb the ammonia present in it in order to meet the emission standards. 2. Process scheme: Due to the high temperature of ammonia, which hinders absorption, it is necessary first to use a heat exchanger to cool the exhaust gas before proceeding with absorption. The process simulation is shown in the figure; the volume concentration of ammonia in the exhaust gases is 9 ppm. 3. Fluid dynamics design of the tower: (1) Open the Vivita fluid dynamics software, click on buttons such as “Connect to Hysys” to import the data. (2) Enter a few design requirements: only 4 parameters are needed, as all other data is automatically imported by Hysys. The design of the tower is completed in no time. This is also the design process followed by many tower equipment patent holders – has your company achieved this? Tip: For fluid dynamics calculations, the domestically produced WPTR offers the best performance.
China’s WPTR fluid dynamics software can automatically connect to: 1) Aspen Hysys; 2) PROII, and it is a highly intelligent software. And: 1) The packing tower module offers a much richer variety of packing types and experimental data compared to foreign software ； 2) Plate tower module, featuring new domestic trays, with load performance charts. It is now a mainstream commercial software in the country; however, due to historical reasons, some older companies still use foreign software. Now, the software newly purchased by Tower Company is almost all the domestic WPTR. - This article is from **Chemical Engineering Forum
The design of this process is too reasonable; it shouldn’t be necessary to cool the material first before feeding it into the tower, as this way almost no carbon dioxide can be recovered. Moreover, the area required for the heat exchanger in that case would be extremely large. In many of the high-temperature ammonia-containing exhaust gas treatment processes we carry out, cooling is not performed in advance; instead, cooling occurs through mass transfer, with the temperature entering the tower exceeding 100 degrees Celsius.
This post was last edited by wiseboy on 2021-5-14 11:08. Whether what you said is correct depends on the specific circumstances. First, mass transfer cooling generates a large amount of wastewater (very dilute ammonia water) inside the tower, whereas the cooling water is clean and circulated within a closed-loop water system, so it does not produce as much wastewater ； Wastewater is also one of the three types of waste: large amounts of waste ammonia need to be treated. Secondly, take a close look at the LZ’s images: the CO2 content is low (2.2%), and the customer has no requirement to remove CO2. Furthermore: with 2.2% CO2, how much more can be absorbed by water? What about the necessity and economic viability of recycling? Therefore, what was initially offered to the client was also this proposal of yours, which was firmly rejected by the client.
It’s not as you say; it’s not possible to produce a large amount of dilute ammonia. By using the liquid from the bottom of the tower for cooling and recycling, how could a large amount of dilute ammonia be generated? In your current process, the amount of ammonia is small and its concentration is high. Carbon dioxide dissolves in ammonia solution, not in water. Several of our projects operate in this way; you can contact me by phone or WeChat at 13032232243 if you have the chance