Study On Correlation Of Heavy Oil Deep Cut Data

Under the situation of depleting crude oil reservoirs and worsening feedstocks,residue deep processing has become an urgent technical problem to be solved.In this paper,suitable experimental conditions of residue deep-cut by molecular distillation is studied and the correlation between molecular distillation temperature and residue boiling point were researched.By comparing fractions distillated from molecular distillation(MD),high vacuum distillation(HVD)and vacuum deep cut(VDC),which laid a theory foundation for better application of MD in the research of residue processing.Influence of MD operation conditions on atmospheric residue(AR)separation were studied by using three different attribute AR as raw materials.Results show that the best feed rate is 340~370 rpm(paraffin base),220~250 rpm(intermediate base),220~250 rpm(naphthenic base),as greater viscosity leads to smaller feed rate range.All kinds of AR share the same suitable roller rate,which is around 250 rpm.Suitable feed temperature shall ensure that raw materials with good liquidity,as the raw material is more and more heavy,feed temperature should be risen up.Method of fitting true boiling point curve was used to relate MD evaporator temperature and atmospheric pressure boiling point of ARs in three different attribute,and the correlation of paraffin base AR was calibrated.Within the temperature range of 350 ~ 540 ?,distillation curve of MD is similar to true boiling point distillation curve,representing MD has high precision.After deep cut by MD,yield of fractions distillated from paraffin based AR rises to 65.60 wt% and cutting temperature can reaches up to 656.9 ?.Yield of fractions distillated from intermediate based AR rises to 57.75 wt% and cutting temperature can reaches up to 593.8 ?.The research shows that MD has good performance on residue deep cut.The comparison of MD and HVD shows that fractions distillated by MD and HVD have similar basic properties,such as: density,refractive index,average relative molecular weight and elemental composition.change rule of MD fractions properties is reasonable.Research of structure group compositions shows that,molecular structure of MD fractions has more rings and lower percentage of carbon atoms in alkyl side chains in same distillate fractions,which means molecular that has compact structure,high condensation degree and aromatic ring structure,has longer molecular free path and could be distillated by MD more easily.The comparison of MD and VDC shows that,overlapping temperature of nearby wax oil fractions distillated by MD and VDC unit is 27.4 ? and 131.7 ? respectively,so the cutting precision of MD is much higher than VDC unit.Properties of fractions on same temperature range distillated by two different distillate methods is similar.As a result,MD is a good experimental method to solve the practical problem in vacuum deep cut production.