A molecular-sieve-based unit, which consists of 2-3 adsorbers, is applied for complete dehydration of ethyl alcohol. The adsorbers are operated by turns. Silica gel is used as an adsorbent.
Rectified ethyl alcohol is pumped out of the tank through a heat exchanger, where it is heated by hot vapour from adsorbers and is further taken to the tank of heated rectified ethyl alcohol. The level in the tank is maintained in automatic mode by means of an automatic regulator.
The heated rectified ethyl alcohol is pumped by a circulating pump through a steam heater, where it is heated up to the temperature set by the process, and where vapour and liquid phases are formed. The heating is performed by live steam and is regulated by an automatic regulator.
In order to feed the adsorbers only by a vapour phase and have a stable temperature, there is a steam superheater installed which is fed by live steam through the automatic regulator. The live steam condensate is taken from the heaters to a condensate tank.
Superheated steam of ethyl alcohol goes through the adsorber operated in dehydration mode. Molecules of water which are present in the steam are rejected in the pores of molecular sieve. Dehydrated steam at the outlet of the adsorber is taken to heat exchangers, where it heats the rectified ethyl alcohol taken to dehydration, then it is fully condensed and goes to the tank. Dehydrated ethyl alcohol is taken from the tank to the heat exchanger to be cooled. The cooled dehydrated ethyl alcohol is pumped through a metering unit to the storage facility.
After the molecular sieve in the adsorber No1 is saturated with water, the adsorber No2 is launched, and the adsorber No1 is taken to regeneration. For performing regeneration in the adsorber No1, vacuum is created by a vacuum pump in order to decrease water boiling temperature and its evaporation. The regeneration cycle of the following adsorbers is similar to that described above.
Circulation water supply system is applied to condensate the steam of dehydrated ethyl alcohol in the heat exchangers. Water cooled in a cooling machine is used for cooling the dehydrated ethyl alcohol.