Patent ID: 8617359

Claim:
A method for distilling a starting material, which consists of a liquid to be distilled Fd, using a gas-tight container system that is resistant to excess and/or negative pressure, said container system comprising an evaporator with the liquid starting material the temperature of which can be adjusted, a condenser for condensing the liquid Fd which has turned to vapor and the temperature of which can be adjusted to give the condensate, as well as a vapor chamber connecting the evaporator and the condenser, the condenser having a condensation pathway with an end thereof, the temperature in the vapor chamber being the mixed temperature (Tm) and the pressure in the vapor chamber being the mixed pressure (pm) wherein the vapor chamber is provided with a pressure sensor for measuring the mixed pressure pm established therein, wherein the vapor chamber is provided with a temperature sensor for measuring the mixed temperature Tm established therein and a pressure regulator, the method comprising the following process steps: a) the evaporator with the liquid starting material is brought to a first temperature T 1 , and the condenser to a second lower temperature T 2 ; b) the mixed pressure pm and the mixed temperature Tm are measured; c) the saturation vapor pressure ps of the liquid starting material at the measured mixed temperature Tm is determined; d) a set-pressure range is determined, which is limited by a lower pressure limit p 1 , which is at least 0.1% above the saturation vapor pressure ps and an upper pressure limit p 2 , which is at the most 6% above the saturation vapor pressure ps; e) the mixed pressure pm is compared with the set-pressure range; f) the mixed pressure pm is reduced by the pressure regulator exactly until it has reached the lower pressure limit p 1 by sucking off gases at the end of the condensation pathway in the condenser to remove foreign gas from the container system; g) the steps a) to e) are repeated, until the mixed pressure pm has reached the upper pressure limit p 2 ; h) the steps f) and g) are repeated until the distillation is to be stopped.