Average specific heat capacity of gas

So many experts have seen it – why hasn’t anyone reported me? Is it that difficult to figure out?

You haven’t specified what kind of gas it is or what its components are; how do you expect others to answer your question?

Hydrogen 49, Nitrogen 19, Ammonia 11, Methane 18, Argon 3

Pressure 28 MPa, gas flow rate 2420 kmol

Pressure 28 MPa, gas flow rate 2420 kmol

The average heat capacity of a gas is independent of flow rate and depends on pressure and temperature. You can first calculate the ideal gas heat capacities for each pure component using the empirical power-law equations for Cp provided in the textbook, then determine the heat capacity under actual conditions by using the reduced pressure and reduced temperature along with Edmestri’s \"excess heat capacity chart\", and finally compute the heat capacity of the actual mixture based on the composition percentages.

I happened to do a calculation related to specific heat capacity some time ago. Hehe, to calculate specific heat capacity, one first needs to know the temperature and pressure. Then, in textbooks on chemical engineering principles, there is a table showing the specific heat capacities of various gases (it’s necessary to use a scale for that, hehe). After that, the calculation can be carried out. Of course, such tables can be found in many books, such as chemical engineering design manuals and chemical engineering calculation manuals.

　　The friend on the seventh floor is right; for multi-component substances, it’s necessary to multiply the content of each component by the specific heat capacity of a certain gas, and then add up those values. Generally, when the temperature difference isn’t large, this variation is very small!

Yes, that’s right!!!!!!!!!!!!

Hehe. These days I’ve been calculating the heat content of certain process gases used in methanol and synthetic ammonia production, to see if there’s anything that can be utilized. It was calculated using the method mentioned on floor 7, but when calculating for hydrogen–argon–methane–ammonia–nitrogen, it was found that in the chart in \"Isothermal Pressure Correction for Gas Heat Capacity\" (3rd edition of Chemical Process Design Manual), when the reference pressure exceeds 1, no corresponding curve with a reference temperature between 0.6 and 0.95 can be found, making the calculation difficult. I roughly estimated the difference, and the result was that the enthalpy of the gas after being cooled by the water-cooled radiator was actually higher than that of the gas before cooling by it; it’s a bit confusing. I would like to ask: when calculating the constant-pressure molar heat capacities of each component, should the partial pressures of each component be used, or should the total pressure of the gas mixture be used? I searched online these past few days, but still couldn’t find any relevant information. If anyone knows, please give some advice; I would be very grateful! The gas composition is similar to that on the 4th floor; the pressure is 22.5 MPa, the inlet temperature of the water-cooled exhaust is 90 degrees, and the outlet temperature is 20 degrees. Edmist’s “excess heat capacity diagram”?