What is the efficiency of refining petroleum?
Your question is about the “process energy balance” of refining crude oil. If you meant to include the amount of energy expended in exploration and recovery the problem becomes much more complicated and many more variables are introduced. The datapoint I can give you is 4.98:1 for diesel fuel refined from petroleum. In comparison to your “refining efficiency” example for hydrogen, that 70-80% value would be expressed as 0.7:1, or the diesel ratio expressed as a percentage would be 498%, compared to 70% commonly given a the maximum efficiency for producing hydrogen from electrolysis (80-95% is the theoretical maximum efficiency and in reality commercial hydrogen processes today only achieve about 0.3:1 or 30%.) For each unit of energy that goes into the processing of crude oil, 4.98 units are available in the fuel product. This is from: Sheehan, J., Camobreco, V., Duffield, J., Graboski, M., & Shapouri, H. (1998). An overview of biodiesel and petroleum diesel life cycles. National Renew
