Study of the process of ozone-air oxidation of vacuum residue to bitumen

Abstract

One of the pressing problems of the oil refining industry is to increase the intensity of the process of obtaining petroleum bitumen. For this purpose, methods are proposed to increase the efficiency of air supply used as an oxidizer and to improve the design of the unit. In this work, an ozone-air mixture was proposed as an oxidizer for the production of bitumen from heavy oil residue – vacuum residue, and the process of bitumen production was studied. Vacuum residue from Pavlodar Petrochemical Plant LLP was used as a raw material for bitumen production. The vacuum residue oxidation process was carried out at a temperature of 240-260 ⁰С for 2-4 hours. The ozone content in the ozone-air mixture was 90%, the mixture consumption was 5 l/min per 1 kg of raw material. The needle penetration depth at 25 ⁰С, softening point and loss angle tangent of vacuum residue and its oxidation products were determined, and their dependences on process time and temperature were obtained. The maximum values of the softening point and the minimum values of the depth of penetration of the needle of the vacuum residue oxidation products are observed at 250 ⁰С, which indicates the optimum temperature of the process. The temperature of the transition from the viscoelastic solid to the liquid state of the vacuum residue oxidation product within 4 hours increased by 16.4 ⁰С compared to the original vacuum residue. The characteristics of the oxidation products were compared with the requirements of the ST RK 1373-2013 standard and it was found that they correspond to the BND 70/100 grade. The use of ozone together with air as an oxidizer made it possible to reduce the duration of the oxidation process to 4 hours.