Original oil and gas trade magazine vintage ad for PETROLEUM RECTIFYING COMPANY OF CALIFORNIA, of Los Angeles, CA. Petreco is a Definite Part of Petroleum History and Ranks High Among the Developments of Genuine and Permanent Value. The Electrical Process for Dehydrating Crude Oil Emulsions. This unique 1934 old petroleum refining and process industry magazine advertisement would look sensational matted and framed. Approximate size 10 x 13 inches.