Study On Preparation Of Needle Coke Raw Material And Petroleum Road Asphalt By Solvent Deasphalting Technology

As an efficient heavy oil processing technology,solvent deasphalting has the characteristics of high extraction depth,good refining effect,and flexible process combination,and is widely used in major refineries.In order to improve the processing depth and high-value utilization of heavy oil,this paper first uses FCC slurry as raw material and uses solvent deasphalting process for extraction and refining.The resulting deasphalted oil(DAO)was subjected to high-temperature thermal condensation to prepare needle coke products.Finally,Deoiled Asphalt(DOA)produced by Changqing petrochemical is used as the raw material,and the qualified 50#and 70#A-grade petroleum road asphalt products are prepared by the extraction and blending process.Using S70 as the extractant,the FCC slurry was extracted by atmospheric extraction process,and the effects of extraction temperature,solvent ratio and extraction on the properties of DAO.The study found that when the extraction temperature is 80°C,the solvent ratio is 2and the number of extraction stages is 2.The ash content in the DAO obtained is the least,which can meet the standards of needle coke raw materials.Using n-butane as the extractant,the supercritical extraction process was used to extract and cut the components of the FCC slurry.Using elemental analysis,heavy oil four-component,FTIR and ~1H-NMR methods to analyze FCC slurry and DAO,it can be found that after the slurry is extracted and refined,the content of ash,heteroatoms,and polycyclic aromatic hydrocarbons in DAO is less,and the aromatic ring substitution rate has also been improved.It is more suitable as a raw material for the preparation of needle coke.The FCC slurry and DAO were subjected to coking experiments,and a polarized microscope was used to evaluate the raw coke samples and raw oil.It shows that the raw material composition and process conditions have a significant impact on the properties of the raw coke.Relatively speaking,raw materials with low ash and heteroatom content and higher aromatics are easier to produce coke products with better polarizing properties under a suitable process.Two kinds of mesophase coke by supercritical extraction raw materials were calcined at 1300℃,and the structure of the calcined coke was characterized by XRD and SEM.It shows that the calcination process can promote the further development of the internal structure of the mesophase coke and make the the amorphous carbon is transformed to the crystalline carbon.In the calcined coke,more slices are arranged tightly and layered structure with obvious fibrosis.However,due to the lower calcining temperature,the needle coke products that are currently prepared are still easy to graphitize.Using Changqing DOA and FCC slurry as raw materials,the A-grade petroleum road asphalt product that meets the requirements of“JTG F40-2004 Technical Specification for Highway Asphalt Pavement Construction”standard is prepared by the extraction-blending process.After DOA atmospheric solvent deasphalting process is extracted,the heavy components in the refined asphalt(RDAO)obtained are significantly reduced.When 0.5wt%A101 and 1.5 wt%SBR are added,at the blending temperature of 180℃～200℃,FCC slurry:RDAO=50:50 and the temperature at 170℃～180℃,FCC slurry:Vacuum residue:RDAO=41.03:8.16:50.81 conditions,which can produce qualified 50#and 70#A-grade petroleum road asphalt products.