Calculation of H2S gas partial pressure
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Title: It is known that at normal temperature and pressure, i.e., 0.1 MPa and 20°C, the concentration of H2S in the mixed gas is ≤ 20 mg/m3. Requirement: It is necessary to calculate the partial pressure of H2S in the mixed gas at an operating temperature of 20°C and an operating pressure of 3.6 MPa Universal Haiyou: May I ask if such conditions can be used to calculate the partial pressure of H2S? How is it calculated, and is there any basis for this? Thank you.
I used the ideal gas equation to determine the total number of moles per cubic foot of gas, then calculated the number of moles of hydrogen sulfide to find the mole fraction.
Good question, but I can’t do it. Please advise me
The reason for your question is simple: the equation of state for real gases. It’s not practical to show the calculation process, as it involves solving complex nonlinear equations; it’s impossible to do it by hand, so I can only give you the result.
This post was last edited by wiseboy on 2020-8-3 11:29. It is no longer an ideal gas; it is a mixture that requires mixing rules. What I mean is: if you want the result, I’ll calculate it for you; but if you want to learn the *manual calculation process, it’s almost like asking for trouble.
It would be great if the senior could help with the calculations; I trust you!
What materials are used for equipment and pipelines?
This post was last edited by wiseboy on 2020-8-5 at 15:43. The H2S partial pressure is 0.0000504 MPa, which equals 50.4 Pa. In fact, for high-pressure gases, the Dalton’s law of partial pressures does not apply; this concept of partial pressure no longer exists and is meaningless. In other words, for high-pressure gases, the total pressure is not equal to the simple sum of the partial pressures of each component. However, you can roughly use the concept of Dalton’s partial pressure. What exactly do you want to calculate? It’s best to state the ultimate goal, and try to avoid using the concept of Daltonic partial pressures.
Material selection is determined based on the hydrogen sulfide partial pressure
The purpose is to determine the work pressure and the partial pressure of H2S gas at the operating temperature, in order to select appropriate materials for the equipment.
Severe H2S corrosion should involve the emergence of liquid, as H2S is an acid when dissolved in water. In this situation, no liquid comes out, so there is no acid corrosion. I’m not very familiar with other types of corrosion.