Research On The Dust Removal Technology Of The Acrylonitirle Catalyst Calcinator Exhaust Gas

In the process of acrylonitrile catalyst production, high temperature exhaust gas containing dust and nitrogen oxides was discharged from the calcinatory, and the exhaust gas must be treated to meet the emission standard. In the original exhaust gas treatment process, the dusts are removed by the cyclone separator, and the nitrogen oxides are processed by the SCR (Selective Catalytic Reduction) system. Due to the low efficiency of dust removal equipment, some fine catalyst particles entered the SCR system and made the SCR catalyst blocked, thereby debased the treatment effect of nitrogen oxides. The improvement of the dust removal equipment has great significance to the normal operation of the exhaust gas treatment system and the stable production of the acrylonitrile catalyst. In this research, the CFD (Computed Fluid Dynamics) technology and RS (Response Surface) analysis method were used to optimize the dust removal equipment and the process of exhaust gas treatment. The main contents of the research are:(1) Analyzed the treatment results of the acrylonitrile catalyst calcinatory exhaust gas and the problems in the treatment process, confirmed that the key to improve the exhaust treatment effects is to increase the dust removal efficiency. The properties of the exhaust gas and the particles in the gas are analyzed, and the performance of the previous dust removal equipment is studied, which provided the basis for the selection of dust removal equipment and the structure optimization.(2) Using CFD technology to simulate the original dust removal equipment, the factors that affect the efficiency of the dust removal equipment and the calculation method of the performance index of the dust removal equipment in the CFD process are studied. According to the requirement of the exhaust gas treatment and the actual status of the catalyst production plant, it is determined that cyclone separator being used as the dust removal equipment, and its structure should be optimized to increase the dust removal efficiency.(3) The response surface method was used in the design of the experiments, and different models of the dust removal equipment were established using CFD technology. Analyzed the influence of structure parameters on the separation efficiency and pressure drop, established an empirical regression equation of the structural parameters and the separation efficiency, and accordingly designed a new cyclone separator for the exhaust gas treatment.(4) The new dust removal equipment and exhaust treatment process were used in the production of acrylonitrile catalyst. The dust removal efficiency is increased from 91.5% to 96.1%, and the stable operation period of the SCR system is increased from 3 months to 6 months. The exhaust gas after treatment meets the emissions standards, and the acrylonitrile catalyst production plant achieved a long period of stable operation, which results in a good economic and social benefits.