Récent 27++ Naphtha Pretreatment Process. Naphtha hydrotreating is an essential step for refiners to produce cleaner gasoline from different feedstocks : The naphtha recovery unit (nru) is an integral part of the processes used in the oil sands industry for the principle role of the nru is to recover naphtha from the tailings for reuse in this process. It can be used as fuel in a compression dynamo, or processed into refined fuel.