Patent ID: 6905576

Claim:
A continuous process for the preparation of silane of formula SiH 4 by catalytic disproportionation of trichlorosilane of formula SiHCl 3 to form SiH 4 and silicon tetrachloride of formula SiCl 4 in a reactive/distillative reaction zone comprising (a) introducing SiHCl 3 into a reactive/distillative reaction zone comprising a catalyst bed of a catalytically active solid at a pressure of 1 to 50 bar to form a lower-boiling SiH 4 -containing product and a higher-boiling SiCl 4 -containing bottom product; (b) removing the lower-boiling SiH 4 -containing product from the reactive/distillative reaction zone and condensing the SiH 4 -containing product in an intermediate condensation at a temperature in the range from −5° C. to 40° C.; (c) introducing the lower-boiling SiH 4 -containing product which is not condensed in the intermediate condensation into a rectifying section and increasing the SiH 4 -concentration in the SiH 1 -containing product which is not condensed in the intermediate condensation; (d) further condensing any SiH 4 -containing product that is not condensed in the intermediate condensation and concentrated in the rectifying section in an overhead condenser from which the SiH 4 -containing product is discharged as final product.