Study On The Composition,Structure And Characteristic Of Liaohe Heavy Oil Residue

There are rich heavy oil resources in Liaohe Oilfied,but the utilization of Liaohe heavy oil residue is single.In order to explore a new residue processing plan for Liaohe Petrochemical Company,so it is necessary to obtain the structural information of Liaohe heavy oil residue more systematically and comprehensively.Low Freezing Point?LFP?and Mix AR were used as raw materials in this paper.SFEF was adopted to separate raw materials into a set of narrow fractions at first,Then,raw materials and the narrow fractions were separated into saturate,aromatic,resin and asphaltene respectively.The structural,compositional characteristics of aromatic,resin and asphaltene of the two raw materials were investigated by RICO reaction.RICO reaction results showed that the carbon number distribution of n-alkyl chain in LFP and Mix AR are C₁?C₃₁ and C₁?C₃₂,respectively.The carbon number distribution of polymethylene bridge chain for the two raw materials was the same between C₂?C₂₆.Taking peroxidation effect into considered,the carbon number distribution of polymethylene bridge chains should be between C₁?C₂₆.Besides,the content of n-alkyl chain and polymethylene chain decreased with the increase of carbon number.At the same time,the content of n-alkyl and polymethylene chain increased with the component becoming heavier.The carbon number variation of n-alkyl and bridge chains in narrow fractions was similar to the raw materials.The maximum carbon number of the n-alkyl chain and the bridge chain gradually increased as the fractions became heavier.The distribution of benzenecarboxylic acid of two raw materials was similar with their narrow fractions in the RICO reaction product.Besides,the content of ternary or heavier benzene carboxylic acid rose if the fractions became heavier.However,the content of Benzoic acid and Phthalic acid gradually reduced.Furthermore,the content of benzoic acid was abnormal in the RICO reaction product of LFP AR asphaltene.Then,LFP AR was separated into a fraction with boiling point above 420°C and a VR with boiling point above 500°C.RICO reaction results of the two asphaltenes were similar to LFP AR.The above results showed that biphenyl structure dominated in LFP heavy oil asphaltene,which was a signal of low maturity.Furthermore,it could be inferred that LFP asphaltenes was of archaeological structure and its structure was mainly composed of some smaller aromatic units connected by polymethylene and biphenyl structure bridges.The FT-ICR MS results of all components of the RICO reaction illustrated that there were many naphthenic fatty acids,high carbon fatty acids and carboxylic acids containing heteroatoms other than O₂ and O₄ fatty acids in RICO reaction product.These chemical compounds could not be detected by gas chromatography,leading to a low carbon recovery rate of this study.