What’s the difference between a “rate model” and a “mass and heat transfer rate model”?
A so-called rate model is roughly equivalent to a kinetic model and is not to be confused with a mass and heat transfer rate model. “Rate model” is the name given by some to an empirical correction for the CO2-amine reaction rate on the separation achieved by a given number of ideal stages. This use of the term really has nothing to do with rates at all—the term “rate-based model” should properly be reserved as shorthand for a mass and heat transfer rate model, not for an empirical correction to ideal stages. A mass and heat transfer rate model doesn’t even use the concept of ideal or equilibrium stages. It applies the same kind of fundamental rate principles to mass (and heat) transfer on contact trays and packing, that you take for granted in the context of heat exchanger design. It uses the mass transfer characteristics of the tower internals to calculate the actual rate of transfer of the acid gases and water between the vapor and liquid phases. The degree to which the phases are n
