【Process Consultation】Isopropyl alcohol exhaust gas absorption unit. . . . . .

Everyone, why are you all so low-key today? Let’s share our opinions; waiting online

Isopropyl alcohol can be absorbed by water. It is likely that the emission standards required for environmental protection in this case are not very strict, making it easy to meet them. To design an absorption tower, it is necessary to conduct some calculations using relevant data. Even qualified environmental protection companies may not be able to provide accurate results; the best approach is to research available information to make an assessment, and then conduct experiments to gain a better understanding of the situation. Then, make a slight enlargement during the design process. Because systems like spray towers, which are used to treat exhaust gases, are not very large. When it gets small enough, the price doesn’t decrease in proportion either, so roughly okay is fine.

Waste gas containing isopropanol is generally treated using an adsorption-vacuum desorption-condensation recovery process. Although isopropyl alcohol is soluble in water and water scrubbers can be used to absorb exhaust gases containing it, isopropyl alcohol forms an azeotrope with water; at atmospheric pressure, the azeotrope point is 80.4°C, with the azeotrophic composition containing about 87.8% alcohol by weight. If isopropyl alcohol is to be recovered from wastewater using water for absorption, other azeotrope-forming agents must be added to carry out azeotropic distillation for dehydration, making the process rather complex. However, if it is a plant that produces isopropanol, water absorption can be used; the aqueous azeotrope vaporized at the top of the recovery tower is sent to the azeotropic dehydration tower in the isopropanol production facility for treatment.

Well, I found the phase equilibrium curve for isopropanol and water, as shown in the figure below: How can we tell that it is soluble in water? ?

Hello, I have found the phase equilibrium curve for isopropyl alcohol and water, as shown above. It’s fine to have an azeotrope form, but my absorption tower simply can’t handle such high concentrations. The content of isopropanol in the exhaust gas is estimated to be less than 1%, and the concentration in the recirculated spray is also very low; it’s impossible to reach the azeotrope temperature.

http://www.doc88.com/p-7018333850622.html According to this information, the vapor pressure at 40 degrees is 14 Kpa (A). Assuming exhaust occurs at 50 Kpa (G) with a concentration of about 10%, the equilibrium coefficient as indicated in your graph is 5, meaning the concentration in the gas phase is one-fifth of that in the liquid phase; thus absorption is easy to occur

Check the property data sheet or the MSDS for isopropyl alcohol; it states there that isopropyl alcohol is readily soluble in water or even completely dissolves in it. The problem of azeotropy formation between isopropanol and water that I mentioned earlier refers to the issue encountered when distilling isopropanol back from the isopropanol-containing wastewater generated during absorption; only an aqueous isopropanol mixture with a composition close to that of the azeotrope can be obtained at the tower top. If the amount of isopropanol absorbed is small, and recycling is not considered, as long as the wastewater containing isopropanol can be treated, it poses no problem.

On this graph, at low concentrations, the concentration in the gas phase is 5 times that of the liquid phase, right? It’s not 1/5, is it? Did you get it backwards?

Can isopropanol be adsorbed using activated carbon?