Regulation Of Deep-cut Vacuum Distillation Technology In Atmospheric And Vacuum Distillation Unit

With the further excess of domestic crude oil processing capacity,quality and efficiency of the existing device will become one of the important direction in the technical improvement during the 13 th Five-Year Plan.The atmospheric and vacuum distillation unit as the fundamentals of crude oil deep processing,the fractionation efficiency of the atmospheric and vacuum distillation unit is related to the yield and quality of the target product,the production of the downstream unit and the economic benefit of the whole plant.Vacuum deep cut technology can increase the extraction rate of the distillate oil by increasing the cutting temperature.On the one hand,the key condition is temperature.In general,the method of improving vacuum furnace outlet temperature is used to carry out the deep drawing,but at the same time coking will be caused by the increase of temperature,and the coking properties of different kinds of oil are also different.On the other hand,the distribution of impurities in oil and the application of heavy oil fractions also have an effect on the vacuum deep cut.Therefore,the study on the change rule of the different oil in the coking process and the properties of the vacuum wax at different temperatures have a theoretical guidance in improving the furnace temperature and cutting temperature.By the study of impact of oil products of different properties on coke formation(toluene insoluhles)under different temperatures and different residence time,according to the nature of the raw material come to the conclusion that when the temperature reaches 415?,the stay time of naphthenic oil sample should be before 8min,and the temperature should be strictly controlled below 420?.The reaction temperature of the intermediate-base oil and paraffin-base oil samples has little influence on the coke formation,which can control the coking capacity by controlling the 10 min or prolonging the residence time according to the working condition.The eight components of the oil samples with different reaction temperature were separated and correlated with the coke yield,and get the formula Y=0.6929K+0.0988,the correlation coefficient is 0.9643.The elemental composition of oil samples at different reaction temperatures of three kinds of residues were determined,by means of the modified Brown-Ladner's method,the average structural parameters of the naphthenic oil samples were calculated based on proton magnetic resonance spectroscopy combined with infrared spectroscopy,and average molecular weight determination.The results show that the H/C of naphthenic oil is close to 1.5,so the quality of this oil is poor,and it is not easy to light.The other two kinds of residues are better in quality and easy to be lighter.With the increase of reaction temperature,the H/C of the three kinds of oil samples reduced in turn.And the aromaticty fA and the average molecular weight of naphthenic oil samples increased gradually,and the paraffinic carbon fP decreased gradually.The three kinds of oil samples were distilled and the contents of heavy metals in different temperature vacuum fraction were determined.The results showed that the paraffin base oil can continue deep drawing at 540? to improve oil yield.Although the heavy metal(Ni+V)content of the intermediate-base,naphthenic-base oils is less,but the vacuum residuum of viscosity is large.It is advisable to consider deep drawing temperature at around 540?.