Research Of Chlorosilane Redistribution Reactive Distillation And Its DWC Process Construction

Enrichment of low boiling chlorosilane has become increasingly prominent indomestic polysilicon industry. This work would deal with low boiling chlorosilane byredistribution reactive distillation, based on a large number of literature and collectioninformation, to improve the original process. Ideal results have been achieved byprocess simulation, design and industrial applications.This study begins from the comparison, selection and pretreatment of catalyst. Akind of catalyst is selected from five because of its high reliability, excellentperformance and affordable. In order to meet the need of some domestic corporation,the process is designed and industrialized successfully based on simulation,modifying the old equipments. Stable operation and more than98.5%DCSconversion indicate desired effect.On the basis of the existing simulation and industrial data, the effect of designand operating parameters on the process is discussed, including liquid holdup per tray,number of theoretical trays in reaction, rectifying and stripping section, STC and DCSfeeding location, the STC circulation rate and temperature. By analyzing, when thetreatment capacity of DCS is300kg/h, optimal operating conditions are determinedas that liquid holdup per tray is100L, theoretical trays of reaction section is8, whichis both12for rectifying and stripping section, STC is fed in the upper part of thereaction bed, and DCS lower part, STC circulation rate is controlled in4000-8000kg/h, and temperature30℃. Energy saving and efficient production can be achievedunder these conditions.Chlorosilane redistribution reactive distillation process still has some defects. Inthis study, reactive distillation and dividing wall column are considered to combinefor further optimizing. The idea of dividing wall column design is initially studied byanalysing the case of thionyl chloride purification by dividing wall column. Thensome simulations of chlorosilane redistribution reactive dividing wall column aredone on this basis, and the good results can guide the subsequent improvement work.