Allocating the CO2 emissions of an oil refinery with Aumann-Shapley prices: Comment

The allocation of CO2 emissions of petroleum refineries to their oil products is a necessary step in the retrospective Well-to-Tank (WTT) analysis. These allocated emissions are used to evaluate the environmental impacts of automotive fuels' production within the refinery.Oil refining is a complex joint production system and there exists no simple and unique answer to this allocation question. Recently, Pierru proposed adapting the Aumann-Shapley cost sharing method to deal with this issue. Our paper aims at describing the conceptual and technical difficulties of this adaptation to the WTT context. Moreover, we show that this approach, as proposed by Pierru, is not applicable to any real-type refinery model. Different suggestions are provided to improve its applicability (when it is possible) in real situations. A simple numerical example as well as a real-type refinery case study is provided for illustrations. Finally, we discuss an alternative allocation approach which we believe more adapted to the WTT context.