Adiabatic cooling simulation calculation of sulfur-containing flue gas

Why does uploading an attachment still require points for downloading it? ! :L

Hello, when performing simulations in ASPEN PLUS, the choice of property methods has a significant impact on the results. Regarding the adiabatic cooling of flue gas containing SO2 that you mentioned, I suggest trying to use the Peng-Robinson (PR) equation of state. This property-based method performs well when dealing with non-polar or weakly polar components (such as N2 and SO2), and it also has certain advantages for simulating phase equilibrium. At the same time, you mentioned that there is a large difference between the simulation results and the manual calculations; this might be due to the following reasons: 1. **Model setup issues**: Please check whether your model settings are correct, such as whether the pressure, temperature, and feed components have been set accurately. 2. **Model assumptions**: During manual calculations, we often have to make some simplified assumptions, which may result in discrepancies compared to the precise calculations performed by simulation software. 3. **Physical property parameters**: Some physical property parameters, such as reaction heat and heat capacity, can directly affect the simulation results. You can try checking whether there are more accurate parameters in the ASPEN PLUS database. 4. **Convergence issue**: Sometimes, if the model does not converge properly, inaccurate results may also be obtained. You can try adjusting your convergence parameters to see if it can improve the results. Regarding the water flow issue you mentioned, I suggest you check the water distribution in your model. Due to the saturated adiabatic cooling process, the moisture content in the flue gas should gradually increase during the cooling process. If your model does not take this into account, there may be a problem that requires a large amount of water. I hope these suggestions will be helpful to you. .

Due to the presence of acidic and basic gases, it is recommended to use the ELECNRTL model, which can account for the formation of a small amount of liquid phase

The Stdvol in the software is not the standard gas volume as you might think. The quantities simply don’t match. I guess this measurement method should be the standard volumetric flow rate of the liquid phase. So, if you enter 7000 Stdvol m³/h in your software, that value… you know… is almost impossible to estimate. Since a liquid phase precipitates under standard conditions in your case, using the **volume flow rate at standard conditions and then reheating to the operating conditions before carrying out water spraying means that the saturated adiabatic cooling amount should also not be consistent; however, this method is more reliable than the Stdvol data, at least there won’t be a difference by an order of magnitude. It is recommended to enter the density at the standard volume calculated manually based on the given mol ratio, in units of kg/h. It should be the traffic data that is closest to the actual situation.

One should approach the stdvol traffic mode with caution. It’s not the standard volume as commonly understood; based on my tests, this is the standard volume of the liquid phase. So the mass flow rate differs by a lot, by an order of magnitude

For problem-solving, the key is to enter 7000 Nm3/h; there’s a huge issue if that value isn’t used! ! ! Thank you. After entering the mass flow rate, the result is acceptable ^O^