How to choose a vacuum pump for alcohol vacuum distillation recovery?
Thread Content
After preparing to extract a certain substance using anhydrous alcohol, the alcohol is recovered through vacuum distillation while causing the substance to crystallize out. Suppose I have 5 tons of alcohol and I want to recover it within 2 hours; I’m not sure how to choose a vacuum pump What is the pumping speed of the vacuum pump?
The distillation temperature is around 50-60°C
The vacuum level required for alcohol distillation under reduced pressure is not very high; therefore, a water ring pump or a water jet vacuum pump can be considered. The pumping speed depends on the condensation temperature, and generally, a rate of around 200 m3/h is sufficient to meet the requirements. During the vacuum creation process, some alcohol enters the water inside the vacuum pumps, so this water contains alcohol. Discharging it directly could result in losses and environmental pollution; it is therefore recommended to use a closed-loop water system. A cooler can be installed in such a system to prevent the temperature from rising. When the alcohol concentration in the water reaches a certain level, it can be returned to the system for recycling. Although this involves a closed-loop water system, it allows for the recovery of alcohol and reduces emissions.
Thank you very much. I wonder what the optimal vacuum level and temperature are for recovering alcohol through vacuum distillation? What is the percentage loss of alcohol? How is the pumping speed of a vacuum pump calculated?
Reply to 4# hm567: If a liquid ring pump is used for recovery, there is very little waste, with a recovery rate of around 99%
Actually, using a mechanical pump (oil-free pump) is the best option for collecting the discharged gas. If high vacuum levels are required, a dry pump (claw pump or screw pump) can be used
Agree with the person above; definitely, a pump without oil is the best! It has a high recovery rate, and there is no issue with alcohol being drawn into the vacuum tank as in conventional water-jet vacuum systems!