For a Cracked Gas Compressor in an Ethylene Plant, I am doing a simulation for determining optimum wash oil rate for the CGC. As a rule of thumb, 0.01 to 0.25 percent of cracked gas rate is taken as wash oil rate in plant. But I want to know how to calculate it using simulation now. I do not have compressor curves, so to start with I am doing it like this : three phase separator I have taken . I am flashing cracked gas outlet from compressor and wash oil and wash water in this three phase separator here. Now I want to know what is the point where I can say that it is an optimum flow of wash oil ? Do I need to run more wash oil to get dienes from the cracked gas outlet into the wash oil ?