Molecular sieve depressurization recovery system
A system for depressurizing a molecular sieve used in ethanol production is provided. The ethanol production system includes a plurality of on-line molecular sieve bottles for removing water from ethanol production. When the molecular sieve bottle becomes saturated with water it is taken off-line to depressurize it. The depressurization and removal of water is done from the product discharge end resulting in an approximately 5% to 10% reduction in external energy required to run the ethanol production line.
1. A system for depressurizing a molecular sieve used in ethanol production comprising:
a rectifier for producing 190-proof ethanol vapor;
a condenser for condensing the 190-proof ethanol to a liquid product stream;
an economizer for heating the 190-proof ethanol;
a vaporizer for vaporizing the 190-proof ethanol into a vapor product stream;
at least one on-line molecular sieve columns for removing water from said 190-proof ethanol vapor stream to produce 200-proof anhydrous ethanol, said at least one molecular sieve column having a product input end and a product discharge end and including a media therewithin, wherein said off-line molecular sieve columns are configured to contain said 200-proof anhydrous ethanol at the product discharge end, wherein said at least one on-line molecular sieve column is configured to be depressurized from the product discharge end without reversing flow through the molecular sieve media to the input end;
an extraction mechanism for extracting at least a portion of said 200-proof anhydrous ethanol from said product discharge end;
a condenser for turning at least a portion of said anhydrous ethanol to 200-proof liquid ethanol;
a flash vessel for removing carbon dioxide from the 200-proof liquid ethanol; and
a storage tank for storing said 200-proof liquid ethanol.
2. The system of claim 1 further comprising an automatic valve that opens to a 190-proof condenser in the system to lower pressure in said off-line molecular sieve column.