Patent ID: 6942844
Filing Date: 2005-09-13
Classification: B01J,C01B

Abstract:
1. A continuous process for producing silane SiH 4 by catalytically disproportionating trichlorosilane SiHCl 3 to silane SiH 4 and silicon tetrachloride SiCl 4 wherein disproportionation is carried out in at least 2 reaction areas for reaction/distillation containing catalytically active solid under a pressure which ranges between 500 mbar and 50 bar, wherein the lower-boiling product mixture containing SiH 4 produced in a first reaction area for reaction/distillation is intercondensed at a temperature ranging between −40° C. and 50° C. and the product mixture which has not been condensed during the aforesaid step and which is enriched with highly volatile chlorosilanes, particularly with dichlorosilane SiH 2 Cl 2 , monochlorosilane SiH 3 Cl and silane SiH 4 , is passed into at least one further reaction area for reaction/distillation and the mixture which has been condensed in the intercondenser, which mixture is enriched with low-volatility chlorosilanes and contains in particular high amounts of trichlorosilane SiHCl 3 and silicon tetrachloride SiCl 4 , is recycled into the first reaction area.