Direct rectification of molecular sieve regenerant and method of using the same

A method of continuous production of ethanol comprising:

• (a) introducing a mixture of ethanol and water to a first rectifier to produce an azeotrope comprising first water vapor and first ethanol vapor;
• (b) routing the azeotrope from the first rectifier to a first molecular sieve vessel comprising a first molecular sieve media, in an on-line operational status for dehydration of the azeotrope wherein the first water vapor and the first ethanol vapor are absorbed by the first molecular sieve media, thereby producing a first dry ethanol vapor and a first molecular sieve regenerant comprising water vapor and ethanol vapor absorbed in the first molecular sieve media;
• (c) condensing the first dry ethanol vapor to a first dry ethanol liquid and routing the first dry ethanol liquid to an ethanol storage;
• (d) changing operational status of the first molecular sieve vessel from the on-line operational status to a regeneration operational status, and changing the operational status of a second molecular sieve vessel comprising unsaturated second molecular sieve media to the on-line operational status of step (b);
• (e) releasing the first molecular sieve regenerant from the first molecular sieve vessel in the regeneration operational status and routing the first molecular sieve regenerant to a second rectifier to produce a first rectified vapor, and routing the first rectified vapor to a regen condenser to produce a first condensate;
• (f) routing the first condensate to the second molecular sieve vessel in the on-line operational status for the dehydration, wherein water vapor and ethanol vapor in the first condensate are absorbed by the second molecular sieve media, thereby producing a second dry ethanol vapor and a second molecular sieve regenerant comprising water vapor and ethanol vapor absorbed in the second molecular sieve media;
• and
• (g) condensing the second dry ethanol vapor to a second dry ethanol liquid and routing the second dry ethanol liquid to the ethanol storage.