Initially, 600 ml water were put into the feed glass boiler and heated to 50 °C. Six hundred millilitres of 60% LiBr solution were put into the absorber glass boiler and heated to 80 °C. The system operated for a few minutes under vacuum until the temperatures of the feed and the LiBr solution reached steady state. At this point, the temperature of the feed and the LiBr solution was kept constant by controlling the vapour flow rate with valves V1 and V2, while keeping the energy input constant. Then the vacuum pump was turned off, the aroma compounds were added at the bottom of the feed glass boiler without breaking the vacuum and cooling water was circulated in the condenser. The vapour produced was passing through the absorber where most of water vapour and some quantity of aroma compounds were absorbed, while the non-absorbed amount was passing to the condenser where it was condensed. The condensate (distillate) was collected at the bottom of the condenser. The vacuum pump was not running during operation since there were no air leaks in the system and the vacuum was steady (750 mmHg).