I am designing a packed bed reactor and in order to perform my heat balance I need to calculate the heat capacities. Given the reactor is adiabatic and I aim to also calculate the pressure drop, the temperature and pressure will vary along the length. Therefore, I need to be able to calculate the heat capacities depending on temperature and pressure, are there any equations to do this?

My other line of thinking is, if I assume ideal gas and use the heat capacity at constant volume (my reactor volume is obviously not expanding) then if my I am correct, the heat capacity is only dependent on temperature and I could then use Shomate equations etc to determine Cp at differing temperatures.

Ideally, I'd like to not make that assumption because I am operating at a moderate pressure (around 30 bar) and ideal gas is not a safe assumption in this scenario.

Any guidance would be much appreciated.

Thanks,