Industrial & Engineering Chemistry Research, Vol.55, No.41, 10968-10977, 2016
Design of a Multitask Reactive Distillation with Intermediate Heat Exchangers for the Production of Silane and Chlorosilane Derivates
Silane and chlorosilanes are essential materials for manufacturing silicon solar cells, glass microscope slides, oxidation masks, and corrosion-resistant films among other products. Monochlorosilane (SiH3Cl) and dichlorosilane (SiH2Cl2) are produced on a large scale as intermediates in the synthesis of silane (SiH4) by disproportionation of trichlorosilane (SiHCl3). However, seldom are they isolated due to the highly integrated nature of silane production, and the high commercial demand for silane relative to monochlorosilane and dichlorosilane. This study proposes a multitask reactive distillation (MTRD) column with intermediate heat exchangers that has the flexibility to switch between the production of SiH4, SiH3Cl, and SiH2Cl2 from the SiHCl3 disproportionation. Because the reactive distillation that separates SiH4 uses an expensive refrigerant, intermediate heat exchangers are installed to reduce the cost and energy consumption of expensive refrigerants in the optimized MTRD. Process simulation and mathematical programming optimization tools are combined to find the best number, location, and heat distribution of intermediate exchangers.