Study On The Recovery Of Xylene From Abolished Industrial Solvent Oil

Because of shortage of resources and wasting of energy, the energy crisishas become an important factor that restricts the mankind survival and socialdevelopment. Besides wasting resources, the irrational treatment has broughteven enormous environmental pollution and caused deterioration of the globalenvironment. Therefore, how to recycle the available resources in waste andachieving reuse are key to reduce the wastage of resources and achievingsustainable development. In response to treating xylene as the main componentof industrial waste solvents oil, no good treatment could solve the environmentalpollution. By studying the chemical separation methods, author found thatthrough increase efficiency-quality, enhance performance and returning goodtemperature control range, traditional batch distillation industrial waste solventsoil can achieve separation and purification, and recycle the main elements whichxylene. Therefore this study used the methods of distillation and batchdistillation to separate the xylene in industrial waste solvents oil.Based on batch distillation theory, in batch distillation tower design for theseparation of solvent oil needed number of tower plates, and appropriate refluxratio, and thus rectify the design of batch distillation tower. The features of batchdistillation tower designed in this study was add a digital reflux device on thetop of batch distillation tower, by adapt the reflux ratio to achieve betterseparation effect;At the same time, the use of fill to replace plate design, so asto further enhance the mass transfer performance efficiency of batch distillationcolumn;the hole batch distillation tower components are used throughout thedigital heating, warming and temperature monitoring equipment, the computercontrolled temperature throughout the batch distillation process.After six small test experiments, that through integration methods ofdistilling and batch distilling can make good recycle xylene.The study concluded that In the batch distillation with reflux section, theunstable control was transferred into controlling the temperature and flow rate ofoutside cooling agent from thermostat which had large buffer capacity and thestabilization was strongly raised;the batch distillation with reflux section hasbig operation elasticity, the temperature of cooling water on reflux section andheating ability could impact the top temperature and the operation reflux ratioobviously, but on the process the vaporization capacity and cooling watertemperature could change obviously, the tower has strong adapter andantijamming capabilities, it made the operation of the batch distillation towersimpler;through the distillation of industrial waste solvents oil it was found thatthe main ingredients in distillate are C8,C9 and C10 aromatic hydrocarbons,and the C8 aromatic hydrocarbon is one of the most components. Thedistillation could remove the heavy components and light components in wasteoil effect and simplified the oil, it is good for further separation in batchdistillation process;by simulation Calculated, the theory plate of batchdistillation tower is 9, and the theory minimum reflux ratio is 2, designed thebatch distillation tower based on the calculations above;through the batchdistillation experiments found that if raise the minimum reflux ratio from 2 to 3will lead xylene concentrations increased 3-6%. Experimental results show thatthe effect of separation and reflux ratio are not proportional, and therefore usedreflux ratio 3 as the best reflux ratio;the vapor could rise up the RelativeVolatility of xylene in oil. From the experimental results shows that if thesolvent oil contained water, the distillate temperature of batch distillation woulddecrease obviously, the separation effects of xylene was good. After added water,the temperature of distillate decreased almost 20 degrees, and at the beginningof distillation the distillate contained more xylene;by second batch distillation,the average concentration of xylene in distillate would reach nearly 60% ormore, if ethyl benzene calculated in, the average concentration over 90%.