System for recycling water to facilitate the production of ethanol

1. A system for recycling water in an ethanol production process in an ethanol production facility comprising:

a water supply that supplies water from the water supply to the ethanol production process;

a reverse osmosis filter system that produces a permeate stream and a retentate stream, wherein the reverse osmosis filter system supplies the retentate stream from the reverse osmosis filter system to the ethanol production process; and

a cooling tower system that supplies water from the cooling tower system to the ethanol production process, wherein the reverse osmosis filter system supplies the permeate stream to the cooling tower system, and wherein the water supply supplies the water from the water supply to the cooling tower system.

2. The system of claim 1 , wherein the water from the water supply comprises less than 100 percent of water supplied to the ethanol production process.

3. The system of claim 1 , wherein the water from the cooling tower system comprises between 1 and 7 percent of water supplied to the ethanol production process.

4. The system of claim 1 , wherein the retentate stream comprises between 10 and 25 percent of water supplied to the ethanol production process.

5. The system of claim 1 , wherein water supplied to the ethanol production process comprises between 100 and 600 parts per million of Calcium.

6. The system of claim 1 , wherein water supplied to the ethanol production process comprises between 30 and 600 parts per million of Magnesium.

7. The system of claim 1 , wherein water supplied to the ethanol production process comprises between 10 and 500 parts per million of Sulfate.

8. The system of claim 1 , wherein water supplied to the ethanol production process comprises between 0 and 125 parts per million of Silicon Dioxide.

9. The system of claim 1 , wherein water supplied to the ethanol production process comprises between 0 and 250 parts per million of Chloride.

10. The system of claim 1 , wherein water supplied to the ethanol production process comprises between 1000 and 4000 parts per million of total dissolved solids.

11. The system of claim 1 , wherein water supplied to the ethanol production process comprises a Langelier Saturation Index less than 2.

12. A biorefinery comprising:

a water recycling system that supplies water to an ethanol production process, wherein the water recycling system comprises:

a water supply;

a reverse osmosis filter system that produces a permeate stream and a retentate stream, wherein the reverse osmosis filter system supplies the retentate stream from the reverse osmosis filter system to the ethanol production process;

a cooling tower system, wherein the reverse osmosis filter system supplies the permeate stream to the cooling tower system, and wherein the water supply supplies water from the water supply to the cooling tower system; and

wherein the water supply supplies less than 100 percent of the water to the ethanol production process, the cooling tower system supplies less than 10 percent of the water to the ethanol production process, and the reverse osmosis filter system supplies less than 30 percent of the water to the ethanol production process.

13. The biorefinery of claim 12 , wherein water supplied to the ethanol production process comprises between 100 and 600 parts per million of Calcium.

14. The biorefinery of claim 12 , wherein water supplied to the ethanol production process comprises between 30 and 600 parts per million of Magnesium.

15. The biorefinery of claim 12 , wherein water supplied to the ethanol production process comprises between 10 and 500 parts per million of Sulfate.

16. The biorefinery of claim 12 , wherein water supplied to the ethanol production process comprises between 0 and 125 parts per million of Silicon Dioxide.

17. The biorefinery of claim 12 , wherein water supplied to the ethanol production process comprises between 0 and 250 parts per million of Chloride.

18. The biorefinery of claim 12 , wherein water supplied to the ethanol production process comprises between 1000 and 4000 parts per million of total dissolved solids.

19. The biorefinery of claim 12 , wherein water supplied to the ethanol production process comprises a Langelier Saturation Index less than 2.