Preparation of mesophase pitch by aromatics-rich distillate of naphthenic vacuum gas oil.

Ming Li,Xulian Hou,Qinyin Li,Jiashun Ye,Dong Liu,Hui Du

doi:10.1007/s13203-015-0123-0

Abstract

Two aromatics-rich distillates R1 and R2 with different properties from naphthenic base vacuum gas oil were used for preparing mesophase pitch through high-pressure thermal treatment. 1H-NMR, FT-IR and VPO were employed to characterize the structural parameters of the raw materials. The products’ optical texture and molecular structure were analyzed by polarized light optical microscopy, 1H-NMR, FT-IR and XRD. The effect of raw materials’ structure on the formation of mesophase pitch was discussed. The results showed that the structure of the raw material had an important effect on the formation of mesophase pitch. The raw material R2 with higher aromaticity, more naphthenic structure and less alkyl side chains was easy to form mesophase pitch with large-domains optical texture, lower softening point and more ordered crystal structure.

Highlights

Two aromatics-rich distillates R1 and R2 with different properties from naphthenic base vacuum gas oil were used for preparing mesophase pitch through highpressure thermal treatment. 1H-NMR, FT-IR and VPO were employed to characterize the structural parameters of the raw materials
The results showed that the structure of the raw material had an important effect on the formation of mesophase pitch
Mesophase pitch prepared by bitumen, heavy oil, coal tar and other raw materials through thermal condensation reaction is recognized as the precursor of carbon fiber, needle coke, carbon electrode material, foam materials and other raw materials with excellent advanced features [1,2,3,4]

Summary

Introduction

Mesophase pitch prepared by bitumen, heavy oil, coal tar and other raw materials through thermal condensation reaction is recognized as the precursor of carbon fiber, needle coke, carbon electrode material, foam materials and other raw materials with excellent advanced features [1,2,3,4]. It has been well established that the molecular weight and alkyl groups of a raw material are primary factors controlling the solubility and anisotropic of resultant carbons [5,6,7]. The influences of the alkyl side chains and naphthenic groups on the optical and molecular structures of mesophase pitch have not been studied systematically so far as we know. Two batches of aromatics-rich distillates R1 and R2 with different properties were derived from naphthenic base vacuum gas oil by furfural extraction, mesophase pitches were prepared by thermal treatment using R1 and R2 as raw materials, respectively, namely R1-MP and R2-MP. The influences of the raw materials on the properties of mesophase pitch were studied, and the carbonization mechanism was discussed preliminarily. It indicates that the condensation degree of R2 was higher than that of R1

Experimental methods

Results and discussion

Conclusion