Used skid-mounted ethanol recovery distillation system with a capacity of 5994 lb/h feed (718 gal/h) and 4566 lb/h ethanol product (692 gal/h), designed by Process Plus. Recovers 76% ethanol from wastewater. Major equipment of the system as follows: Steam Stripper Column (S-426-804) with packing, Feed Economizer (HX404-804), Bottoms Cooler (HX408-804), Reboiler (HX-405-804), Overhead Condenser (HX-406-804).
The wastewater feed containing ethanol, water, methanol, and trace solids is fed to the Steam Stripper (CL-108). Hastelloy C-276 stripper column, manufactured by Hebeler. Rated 34FV at 300F, approximately 44ft tall x 2.5ft dia. National Board #110, Serial #A148, built 1994.
The column bottoms are circulated by a pump through the Reboiler to strip ethanol from the feed. Solids in the feed are rejected in a small purge stream from the reboiler loop, which is cooled in the Bottoms Cooler to 115°F using 85°F cooling water before leaving the unit. A vapor overhead containing the ethanol product is condensed in the Column Condenser and cooled to 140°F. The condensate flows by gravity to the Reflux Drum, from where it is pumped, either returning to the column as reflux or exiting as product. When the Heat Recovery Condenser is in service, vapors are partially condensed there before passing to the Column Condenser for final condensation and subcooling. The ethanol product contains less than 0.1% wt water, and the bottoms purge has less than 1% wt ethanol. Equipment may also be used for other solvent recovery applications requiring Hastelloy materials.