The experimental setup used, is schematically depicted in Fig. 1. It consists of a 1000 ml glass boiler that contains the feed and is heated with an electric mantle. The boiler is connected to a falling film glass absorber with an outer jacket in which cooling water could be circulated. A peristaltic pump is used to re-circulate the LiBr solution in the absorber. The solution is fed at the top of the absorber where a liquid distributor is used to form a liquid film on the inside wall of the absorber. A glass condenser, cooled with ice water circulated with a peristaltic pump, is connected to the absorber. An oil-sealed vacuum pump is used to remove non-condensables from the system