Efficient distillation of ethanol
Systems and methods in accordance with the present invention provide for the efficient distillation of ethanol in an ethanol plant including a beer column. Heat is captured in the distillation process and utilized to drive operations in the ethanol plant.
1. A heat capture system for an ethanol distillation plant including a beer column driven by energy sources from the plant, which system includes:
a distillers dried grains (DDG) dryer with an exhaust;
a regenerative thermal oxidizer (RTO) receiving DDG dryer exhaust and configured for removing organic impurities therefrom to produce treated gas;
a scrubber vented to the atmosphere and configured for receiving said treated gas;
said scrubber further configured for contacting a warm water return from said plant, heating said warm water return and supplying hot water to said plant;
wherein the DDG dryer is configured for producing the DDG dryer exhaust to said RTO;
said DDG dryer receiving steam from said ethanol plant;
a finish evaporator configured for receiving said warm water stream and feeding same to said scrubber;
said beer column is configured for receiving beer from said ethanol plant;
a reboiler connected to said beer column and configured for providing steam to said ethanol plant;
a centrifuge connected to said beer column and configured for receiving a bottom stream from said beer column and providing said solids cake to said DDG dryer;
a condenser connected to the beer column;
rectifier system connected to a condenser;
said rectifier system configured for splitting ethanol vapors between a molecular sieve system and a vapor condensing system;
said vapor condensing system is configured to condense vapors and boil steam condensate to produce steam vapors;
a first effect main evaporator configured for being driven with said steam vapors;
a reboiler connected to said beer column and configured for being driven with said steam vapors;
the beer column configured for receiving a hot water stream from said plant, and returning warm water to said scrubber;
an evaporator configured for receiving low solids centrate from said centrifuge process; and
said evaporator configured for supplying vapors to said beer column.