Comparison Of Properties And Composition Of Oil Slurry And Its Supercritical Extraction Components And Comparison Of Their Mesophase Pitch Textures

In China,catalytic cracking units produce a large amount of heavy residual oil every year.After separation and upgrading,it can be used as a raw material for the preparation of high value-added carbon materials.This subject analyzes the properties,composition,and boiling point distribution of three types of slurry,and selects one of the raw materials for the preparation of mesophase.Supercritical fluid extraction(SFE)was used to separate Daqing slurry oil(DQ SLO)to obtain extraction oil(SFEO).DQ SLO and SFEO were used as raw materials for thermal poly-condensation experiments.Explore the formation law of mesophase,and make qualitative and quantitative analysis of mesophase products.The properties and composition of the oil slurry and its supercritical extraction components and mesophase pitch texture were compared and analyzed.The effects of process conditions and raw material composition on the mesophase morphology and yield were studied.Chromatography,mass spectrometry,nuclear magnetic resonance proton spectroscopy,and simulated distillation were used to study the properties,composition,structure,and boiling point distribution of the three types of slurry.The results showed that the three types of slurry were two different types of oil.No.1 oil slurry has a higher alkane content and less aromatics;No.2 and No.3 oil slurry have a low alkane content and a high aromatic content,and the fraction is concentrated at 350?500?,which is more suitable as a raw material for preparing mesophase.However,No.3 oil slurry has a high content of colloidal asphaltenes,which can be separated by SFE technology.Therefore,No.3 oil slurry(ie DQ SLO)was selected as the raw material for the thermal polycondensation reaction experiment.DQ SLO was used as the raw material to conduct thermal poly-condensation reaction under different temperature and time conditions,and the morphology and yield of the thermal polycondensation product were analyzed.The results show that with increasing temperature and reaction time,the optical texture of the mesophase becomes better,and the low temperature is more favorable for the formation of the mesophase watershed type texture for a long time.The mesophase content increased gradually with the increase of temperature and time.After reaching a certain value,the mesophase content no longer increased and the mesophase developed completely.Taking into account the effects of temperature and time,440?/8 h/0.7 MPa was selected as the optimal reaction conditions for DQ SLO to prepare mesophase.Through the modification of the raw materials,it was found that under the conditions of 390?/2 h/0.1 MPa?440?/8 h/0.7 MPa,the mesophase domain structure is better,the mesophase content is high,and the product yield is high.SFE technology achieves a certain degree of optimization of raw material properties,removes heavy components,and obtains SFEO with better properties.SFEO has a moderate alkane content,high aromatics content,and low colloidal asphaltene content.SFEO thermal polycondensation reaction,the development of the mesophase is consistent with DQ SLO.Under the same conditions,compared with DQ SLO,the mesophase prepared by SFEO has better optical texture and higher mesophase content.