The Research Of Nature About Liaohe Heavy Oil And Its Heavy Components After Thermal Reaction

Heavier oil has to be processed by refiners currently. Compared with catalytic cracking and hydrocracking, delayed coking technology has great advantages in terms of technology and economic efficiency, which is the best choice of crude oil processing in the future. Heavy oil is a kind of colloidal system.Thermal reactions take place when the oil is heated in the furnace, and then molecular coagulation accurs, eventually coke appears in the furnace pipeline. This is the biggest obstacle which plaguing the technology.In this paper, delayed coking process is similated with Liaohe heavy oil in the high temperature and high pressure reactor. Liaohe heavy oil was heated for2hours in the reactor at350℃,375℃and400℃respectively. Viscosity of the oil sample and its stability was measured. The oil samples are separated into four components, that is saturates, aromantics, resins and asphaltens. IR analysis, elemental analysis, VPO molecular weight determination, H-NMR analysis and XRD analysis for asphaltene and resin were conducted. Critical micelle concentration, zeta potential and particle size of the colloid of the asphaltenes and resins were also measured. This study is expected to provide some theoretical help in industrial coking process. The following conclusions were reached:1. As the rise of the thermal reaction temperature, viscosity and stability of the oil sample is gradually decreased. The content of gasoline increased slightly and then decreased, and the content of diesel fuel decreased slightly and then increased. While the content of distillate oil and heavy oil almost did not change.2. Increasing of the thermal reaction temperature, the content of asphaltenes and saturates increased, while the content of resins and aromatics decreased.3. During the thermal reaction process, the molecular skeleton structure of asphaltenes and resin is not destroyed. But the side chain is broken, which leading to the decreasion of molecular weight. When the temperature of reaction is higher than375℃, the extent of the fracture of side chain reaches its extremes. At this point, as the association of asphaltenes and resinsincreased, the average molecular weight of asphaltenes and resins increased. The quansi-crystal structure of asphaltenes and resin almost did not changed after the thermal reaction, which was indicated by the XRD results.4. As the rise of the thermal reaction temperature, the CMC of asphaltenes and resins decreased, and the absolute value of zeta increased. While the diameter of the colloidal particle decreased at first, after that it increased.