Study On Regeneration Of Waste Diesel

With the development of economic and society,the shortage of petroleum resources has become more and more serious.On the other hand,the random disposal of waste oil has caused seriously environmental pollution.Therefore,the regeneration of waste diesel is meaningful to research based on environment,resources,and economics.According to the current situation of waste diesel regeneration in China,a new process for the regeneration of waste diesel was studied.Waste diesel was pretreated through thermostatic settlement and extraction flocculation,and filtrated using inorganic ceramic membrane followed by clay refining to get the qualified fuel oil.The thermostatic settlement experiment was carried out to investigate the removal rate of mechanical impurity on the following condition,temperature was set to 60?,the time was set to 20 h by through.In the extraction-flocculation experiment,isopropanol,n-butanol and methyl ethyl ketone were used as solvents.The influence of solvent-to-oil ratio and reaction temperature to the morphology of slag layer,yield of regenerated oil,acidity and sulfur content were investigated by single factor experiment.Experiments show that the best solvent is isopropanol,the optimum process conditions are:the ratio of solvent-to-oil is 4:1,and the reaction temperature is 50°C.Under this condition,the yield of regenerated oil was 73.5%,the acidity was7.65 mg KOH/100 mL,and the sulfur content was 0.205%.Compared with waste diesel,the acidity is reduced by 9.10 mg KOH/100 mL,and the sulfur removal rate is65.20%.In the filtration experiment of inorganic ceramic membrane,the effects of filtration temperature and membrane pore size on membrane filtration flux,mechanical impurities content of regenerated oil,yield,acidity and sulfur content were discussed.Under the vacuum degree of 0.095 MPa the best process conditions were as follows:membrane pore size was 100 nm,operating temperature was 60°C.Under these conditions,the membrane flux of regenerated oil was 156.7 L/(m~2·h),mechanical impurity content reduced to 0.16%,acidity value to 6.57 mg KOH/100 mL,and sulfur content to 0.157%,the transmittance of recycled oil was 43.57%.Compared with waste diesel,the mechanical impurity content was reduced by 5.3%,the acidity was reduced by 10.18 mg KOH/100 mL,the sulfur removal rate was 73.34%,and the light transmittance was increased by 30.92%.In activated clay refining process,the influence of adsorption temperature and time as well as the amount of clay on the recycled oil were investigated by orthogonal experiment.The best process conditions were as follows:dosage of clay to the recycled oil was 15%,adsorption temperature was 75°C,and the adsorption time was40 min.Under these conditions,the yield of the recycled oil was 83.7%and the transmittance was 82.3%.By analysis of the physical and chemical properties of the recycled oil under the conditions above,it is showed that the viscosity,density,residual carbon content,mechanical impurity content,acidity,flash point and moisture content have all reached national standard for marine fuel oil(GB/T17411-2015).