Research On Vacuum Calcination Of Petroleum Coke And Analysis Of Flue Gas Components - Emission Reduction Of VOCs In Petroleum Coke Processing

At present,the demand of carbon anode in electrolytic aluminum industry is facing the problem of raw material quality decline and the local environmental problems caused by it.The high volatile content in petroleum coke is one of the sources of environmental problems.The process equipment and application of petroleum coke calcination treatment have become a hot spot.It is of practical significance to explore a simple and efficient calcination process for petroleum coke.Therefore,based on the current rich theory of petroleum coke calcination process,this paper studies the high-temperature calcination analysis of petroleum coke under the condition of vacuum strengthening in the traditional high-temperature calcination device,explores the calcination law of petroleum coke in this experimental state and analyzes the flue gas generated by calcination,so as to provide reliable theoretical and experimental data for environmental protection.The core of this research strategy is to explore the influence of temperature,vacuum conditions,calcination time and physical form volatile matter removal of petroleum coke.This paper mainly carried out the comparative experiments of petroleum coke calcination under constant pressure and vacuum conditions,and the comparative experiments of different calcination times under vacuum conditions,supplemented by flue gas collection and analysis experiments,analyzed the calcination of petroleum coke under vacuum conditions The main research results are as follows:(1)Petroleum coke was calcined at high temperature for 30 min under atmospheric pressure.The experimental results showed that the highest removal rate of volatile matter was 85.95% when the calcination temperature was 1100? under atmospheric pressure,while the volatile matter removal rate was 85.95% under vacuum condition When the calcination temperature is 1300?,the volatile content of calcined coke is 0.92%,and the removal rate is 90.05%.The best effect is obtained.When the calcination temperature is 1500?,the volatile content of calcined coke is0.96,and the removal rate is 89.62%.Compared with atmospheric pressurecalcination,1100 ? is no longer the best calcination temperature,and continuous heating under vacuum will continue to remove volatile matter.(2)Under vacuum condition,bulk petroleum coke was calcined at high temperature for 30 min.the high temperature and low temperature were beneficial to the removal of volatile matter from petroleum coke.However,the increase of temperature means the increase of energy consumption and cost.When the calcination temperature is 900 ? ?1300 ?,the volatile matter removal rate of petroleum coke rises suddenly,indicating that graphitization begins to appear at high temperature,and the amount of flue gas increases At 1500 ?,the rising trend of volatile matter removal rate of petroleum coke is slow,which indicates that the graphitization of petroleum coke has reached the peak,and it is of little significance to calcine the petroleum coke at higher temperature.The volatile matter has been largely removed in the previous calcination stage,and there is little room for the removal rate to increase.(3)Under the vacuum condition,Block petroleum coke was calcined at high temperature for 60 min and 90 min respectively,and the effect of powdered petroleum coke on calcination was considered.The results showed that calcination time and particle size of petroleum coke were favorable for volatile matter removal,and the effect was significant at low temperature.With the increase of temperature,the effect of particle size was weak,which was consistent with the results of lump petroleum coke.Although the particle size is beneficial to the devolatilization,some of the powder raw materials will be lost along with the flue gas emission during the calcination process.(4)Considering the effect of powdered petroleum coke on calcination under vacuum condition The effects of calcination temperature,holding time and morphology of petroleum coke on the removal rate of volatile matter of petroleum coke were investigated.The results showed that the calcination temperature required to achieve the same removal rate of volatile matter of petroleum coke was lower than that of atmospheric environment to create a vacuum environment and appropriatelyincrease the calcination time.Through GC-MS analysis of flue gas collected liquid,the results showed that the main components of flue gas were volatile organic compounds(VOCs).(5)On the basis of the experiment,the calcined coke and the typical calcined coke were analyzed by thermogravimetry,XRD and scanning electron microscope,respectively.The comparison and analysis were made on the surface appearance,phase composition and thermal stability of petroleum coke.The results show that after high temperature vacuum calcination,the structure of Petroleum Coke tends to loose state,the cracks and layered structure are obvious,the thermal stability tends to be stable,and the graphitization degree is enhanced,which shows the changes of morphology and thermal stability of petroleum coke after calcination.The good effect of vacuum calcination is confirmed.