Patent ID: 7479567

Claim:
A method of hydrolyzing chlorosilanes comprising: (i) feeding one or more chlorosilanes to a first super-azeotropic hydrochloric acid distillation column, and removing cyclosiloxanes and linear chlorosiloxanes from the first column; (ii) feeding substantially chloride free water to a second sub-azeotropic hydrochloric acid distillation column; (iii) removing HCl gas from the upper portion of the first column; (iv) removing saturated aqueous HCl from the lower portion of the first column and recirculating it to the upper portion of the first column; (v) feeding cyclosiloxanes and linear chlorosiloxanes from the first column to the second column; (vi) removing substantially chloride free cyclosiloxanes from the upper portion of the second column and non-volatile substantially chloride free siloxanes from a lower portion of the second column; and (vii) removing aqueous HCl from the lower portion of the second column and recirculating it to the first column.