Study On Removal Of Ash From Pyrolytic Carbon

With the rapid development of the transportation industry,the demand for vehicle in various countries has increased year by year.In particular,the number of motor vehicles has increased by a large margin.The growing number of cars has led to the accumulation of tires,which has not only caused a waste of resources but also caused environmental pollution.Some research institutes and companies use pyrolysis to recycle rubber,but ash content of pyrolytic carbon black is too high to be used.So we needs to remove redundant ash content.In this thesis,the ash content of the sample carbon black was firstly measured.The problem of mixing the acid solution and the carbon black was solved by adding ethanol.The acid washing experiments were performed using sulfuric acid,hydrochloric acid,and nitric acid,respectively.Then,the experimental conditions were optimized in six aspects: the particle size of carbon black,the stirring rate,reaction time,acid concentration,reaction temperature,and number of picklings.In the pickling process,sulfuric acid and ethanol are consumed in large amounts.To save costs,repeated use of sulfuric acid was performed.The Aspen software was used to simulate the ethanol recovery tower.Finally,the process flow was designed and the process was cost-accounted.Draw the following conclusions:1.Sulfuric acid is used as pickling solution.The optimal experimental conditions are: carbon black particle size is 2400 mesh;sulfuric acid concentration is 3.5 mol/L,stirring rate is 1100 r/min,reaction time is 35 minutes,constant temperature is 30°C,residual ash content is 8.44% after pickling;2.Sulfuric acid can be circulated 7 times,and recycling has little effect on the removal of ash;3,Aspen simulation results show that the ethanol recovery tower plate number is 34,can make the recovery rate of 99%,according to the actual situation,the design of reflux ratio of 3.75;4.Conduct economic calculations and the results show that under the condition of an annual output of 5000 tons,the process is profitable and the scheme is feasible.