Process for the manufacture of silane from trichlorosilane.

摘要

1. Process the manufacture of silane from trichlorosilane, characterized in that : a) in a first step, the disproportionation of trichlorosilane is carried out in the presence of a compound containing at least one alpha oxo-amine group ; according to this first step trichlorosilane (1) is introduced into the disproportionation reactor R1 which, furthermore, constitutes the bottom of the column A ; the compound containing at least one alpha oxo-amine group, optionally dissolved in a diluent, is also introduced into this reactor R1 ; the reactor is maintained at a pressure equal to or above atmospheric pressure and at a temperature such that the mixture boils ; b) in a second step, the dichlorosilane formed during the first step is separated from the reaction mixture by distillation ; according to this second step the column A is operated under reflux so that the dichlorosilane (2) formed is taken off at the top of the column ; c) in a third step, the disproportionation of the dichlorosilane originating from the second step is carried out in the presence of a compound containing at least one alpha oxo-amine group ; according to this third step the dichlorosilane (2) is introduced into the reactor R2 constituting, furthermore, the bottom of the column B, in liquid or gaseous form ; the compound T containing at least one alpha oxo-amine group, optionally dissolved in a diluent and which has been chosen also as a compound effecting the selective solvation of the chlorosilanes is fed in (3) at the top of column B ; d) in a fourth step, separation of the silane formed from the other gaseous products is carried out by bringing the gaseous mixture originating from the third step into contact with a compound which effects the selective solvation of the chlorosilanes present in the gaseous mixture ; according to this fourth step, a temperature gradient is maintained in column B such that the disproportionation products other than SiH4 remain dissolved in the liquid phase, silane (4) being recovered pure at the top of B, trichlorosilane, residual chlorosilanes, and the compound containing at least one alpha oxo-amine group, optionally dissolved in a diluent, are collected in the reactor R2 of the column B ; this mixture may be recycled to the reactor R1 .