Research On Waste Oil Resource Utilization Technology

Lubricating oil is composed of base oil supplemented with various additives.Under high temperature,heavy pressure,high-speed shearing and oxygen-enriched conditions,modified components such as polycyclic short side chain aromatic hydrocarbons,colloids,asphaltenes,additive consumables which are come from the oxidation,decomposition,polymerization of polar additives containing S,N,O in lubricating oil and unsaturated hydrocarbon components in base oil cause damage to the properties of oil products,it is difficult to play a role of long-term use and oil replacement is necessary.The total amount of waste lubricating oil replaced in China is about 8 million tons annually,of which about 60%of the waste lubricating oil can be recovered,but the waste oil is often directly poured into the soil,rivers or used as fuel without any treatment.With the increasing tension of oil resources and the enhancement of environmental awareness,the recycling of waste lubricating oil attractting widespread attention from all sectors of society.Studying the regeneration process in line with objective reality and determining the appropriate operating conditions have become the key to dealing with HW08hazardous solid waste-waste lubricating oil,improving the utilization rate of petroleum resources and reducing environmental pollution.By comparing the advantages and disadvantages of various regeneration processes of waste lubricating oil,it is pointed out that the molecular distillation process has absolute advantages in terms of technical background,processing form,and product yield.On the strength of physical and chemical performance data of waste lubricating oil,the distillate yield and viscosity index are regarded as evaluation indicators,and based on the preliminary determination of process parameters such as pressure,heating temperature,preheating temperature,feed volume,scraping film speed in a single factor experiment,orthogonal experiments is carried out.Combined the analysis of range and variance,this study points out the primary and secondary relationships of the factors that affect the yield:system pressure>heating temperature>feed rate>preheating temperature,optimizes the process parameters of waste oil regeneration,and determine the optimal process conditions for the three-stage molecular distillation:first-stage pressure 90 Pa,heating temperature 170℃,pre-heating temperature 150℃,feed rate 2.0 kg/h,rotational speed80 r/min,second-stage pressure 50 Pa,heating temperature 220℃,pre-heating temperature190℃,feed rate 1.0 kg/h,rotational speed 100 r/min,three-stage pressure 10 Pa,heating temperature 270℃,pre-heating temperature 250℃,feed rate 0.4 kg/h,rotational speed 130r/min.Based on the best process conditions,a three-stage molecular distillation experiment was performed,the distillate yield rate was 83.64%,which reached the ideal level.Compared with the relevant performance indicators of neutral oil and bright oil,the effectiveness of the distillation operation is analyzed and evaluated.The results show that the physical and chemical performance parameters of the first and second distillate oils meet the technical requirements of HVIⅡ~+4 and HVIⅡ6 base oils in the Lubricant Base Oil Protocol Standard,the third distillate oils meet the performance of HVIⅡ8 base oil except chroma.In order to improve its chromaticity,research on clay adsorption process is carried out.The effects of dosage of clay,adsorption mode,temperature,time,and stirring rate on oil chroma is investigated by means of a single factor experiment and orthogonal experiments.It is concluded that the optimum process conditions for clay adsorption process:refining temperature of 230℃,refining time of 45 min,stirring rate of 120 r/min,the dosage accounts for 25%of the mass of the lubricant and batch feeding.Through the test,the color of distillate oil after replenishment of white clay reached the standard.The experimental results show that the combination of molecular distillation and clay adsorption process is feasible for the regeneration of waste lubricating oil,and can be used as the mainstream technology for the future recycling of waste lubricating oil.In order to provide technical support for the industrialization and promotion of molecular distillation regeneration of waste lubricating oil,a set of pilot equipment for molecular distillation with a feed volume of 80 kg/h was designed and analyzed,on the basis of mastering the experimental data of molecular distillation laboratory.According to the calculation,the liquid film thickness of the feed liquid in the molecular still is 0.28 mm,the average residence time is 9s,the outer diameter and height of the molecular still are 245 mm and 1000 mm,the heating surface area is 0.77 m~2,and the condensation surface area 0.48m~2.