The focus of this paper is on the progresses in membrane gas separation technology applied in the oil refining and petrochemical sector. Industrial applications, research trends on new materials and technical solutions, challenges and possible applications will be discussed. Other membrane operations will be briefly addressed, owing to their increasing number of installed systems in the refinery/petrochemical industry. This paper outlines how implementation of membrane technology in refineries and in the petrochemical industry result in Process Intensification (e.g., reduced footprint, better material utilization, reduced energy, reduced utilities and waste).