Process for separating liquid compositions in a film evaporator

摘要

A method for separating a liquid mixture containing readily-volatile and sparingly-volatile components involves using a film evaporator with a heat-exchange surface which is coated with material which catalyses the formation of readily-volatile component(s) in the liquid film. A method for separating a liquid mixture containing (A) readily-volatile and (B) sparingly-volatile components in a film evaporator by (i) producing a continuous stream of a liquid starting mixture, (ii) producing a liquid film from the mixture and bringing it into contact with a heat-exchange surface of the evaporator, and (iii) partly evaporating the film to give two gas streams rich in (A) and (B) respectively. In this method, (iv) the heat-exchange surface is coated with a catalytic material and (v) a chemical reaction in which (A) is/are formed is catalysed in the liquid film. An independent claim is also included for a film evaporator with a heat-exchanger wall which is coated with catalytic material.