Study On The Colloidal Stability Of Residue/Coal Tar Blend System

With blend system of Merey atmospheric residue(MRAR)and Yulin middle/low temperature coal tar(CT)as material,colloid stability change characteristics of the blending system were investigated in the autoclave under different blending ratio,blending temperature and blending time,the asphaltenes were analyzed by means of TG,~1H-NMR,FT-IR and SAXS,and the influence of the composition structure of asphaltenes on the stability of the system is studied.The coal tar fraction at<470°C was cut into six narrow fractions,and the stability of the coal tar and residue blends of the six narrow fractions was examined to determine the narrow fraction coal tar suitable for blending with the residue oil.The effects of additives and coal tar primary solid particles on the colloidal stability of MRAR/CT system were studied in order to select the proper way to improve the colloidal stability of MRAR/CT system.The results showed that MRAR has good colloidal stability and high viscosity.With the increase of coal tar addition,the viscosity of the system showed a downward trend,and the colloidal stability index of the system decreased,and the colloidal stability of the system became worse.The aromatic carbon content of the asphaltenes in the blending system gradually increase,and the degree of condensation increases,the asphaltene of the MRAR and the CT asphaltene have a synergistic effect.The asphaltene association size of the system increases.When the mass fraction of CT in the blending system is 30 wt%,the colloidal stability of the blended system gradually decreases with the increase of the blending temperature or the blending time.In the coal tar fraction of<470°C,the stability of the blending system increased with the increase of the temperature of the narrow distillate fraction of coal tar blended.It was found that with the same amount of CTAB and SDBS added,the addition of CTAB could increase the colloidal stability of the system.the aromaticity is smaller,and the degree of condensation is smaller,which is beneficial to the peptization of asphaltenes in the system.The addition of SDBS can not improve the colloidal stability of the system.Different amount coal tar primary solid particles have different effects on the colloidal stability of the residue/coal tar system.The addition of 1 wt%coal tar primary solid particles can reduce the asphaltene content and the hydrogen bonding between asphaltenes,weaken the asphaltene inter-association.The heavy components of the system are well dispersed,and the system colloidal stability is improved;With the increase of the amount of coal tar primary solid particles added,the asphaltene inter-association effect is enhanced,the dispersion of the heavy components of the system is poor,the heavy-component inter-linkage phenomenon is heavy,and the stability of the system is deteriorated.