Thanks thelastone, Enthalpy.
I guess I wasn't too clear as it might have seem like I was asking for a complete and exact answer. I apologize for that. I understand that there are different variables and different outcomes even if we just take a single unit to test. But what I was asking for really is to understand, for each of the main chem product produced, how much of propane or butane is typically required as feedstock.
For example, a typical olefins steam cracker's purpose is to produce ethylene and propylene. It can be max'd ethylene or propylene but typically ethylene. Even then, there are other streams like butadiene that produced. I have learned that in such a case, I would expect a typical cracker to need approximately 2.4 units of propane feedstock for every 1 unit of ethylene. Likewise, approximately 2.6 units of butane feedstock for every 1 unit of ethylene produced. 3.5 units of Naphtha for every 1 unit of ethylene produced. So, although the cracker will be producing more than just ethylene, it is the main stream produced so using it as a marker or benchmark.
Alternatively, we could also look at it from the other angle: what would be a typical product yield for steam cracker IF it was run with propane feedstock. And then IF it was run with butane...so on.
Typical or general feedstock to product ratios will be more than good enough for me. I do not need specific details on exact yields and how these yields may change with different variables, conditions, etc.
I understand that maybe not one person can answer every part of my demanding question but i do hope to get some guidance overall.
Sorry if I am asking for too much. I just don't know if this is something possible so I have to try. If this post dies a quick death, I will understand that my request is not a realistic one.
Thanks for even replying and trying to help. I really appreciate it.