초록 ▼

The disclosed invention is an improved method for treating ethanol distillation still bottoms by recovering, through solids separation and pressurized membrane filtration, potable water from still bottoms for human consumption by bottling or for reuse, and concentrating the solids with beneficial pr

The disclosed invention is an improved method for treating ethanol distillation still bottoms by recovering, through solids separation and pressurized membrane filtration, potable water from still bottoms for human consumption by bottling or for reuse, and concentrating the solids with beneficial properties recovered such as chemicals, nutrients and medicinals before anaerobic digestion. The invention is on improved process because it can reduce the volume of solids to manage, recovers the water from the fermentation still bottoms while pasteurized, maintains the chemical and physical properties of solids for beneficial property recovery, improves ethanol and energy efficiency, and results in clean discharge to the environment including carbon dioxide recovery. A bioreactor produces a gas rich in methane fuel from the concentrate to power the pressurized filtration process and an aqueous ammonia solution to recover or recycle. This invention improves environmental quality, conserves energy, and produces a beverage water for bottling that can be of an organic origin with reliable source and quality.

대표청구항 ▼

We claim: 1. Means for separating by centrifugal decantation before pressurized filtration the solid and liquid portions of the soluble and insoluble organic and inorganic still bottom discharge from ethanol fermentation distillation and separately conveying each said liquid and solid at predetermi

We claim: 1. Means for separating by centrifugal decantation before pressurized filtration the solid and liquid portions of the soluble and insoluble organic and inorganic still bottom discharge from ethanol fermentation distillation and separately conveying each said liquid and solid at predetermined volumes to a concentrate line for anaerobic digestion and remainder of said liquid portion to a pressure filtration line to further separate solids and liquids. 2. A potable water product from ethanol fermentation still bottoms through a process to separate still bottom liquid from solid organic and inorganic components while pasteurized by a sequence of steps that continuously subjects the still bottom liquid to steps that further separate organic and inorganic concentrate fractions of solids of lesser molecular weight from the liquid, wherein the separated solid concentrate fractions are anaerobically digested, the sequence of steps consisting of centrifugal decantation, pressurized ultrafiltration and nanofiltration to produce a filtration permeate through semi-permeable membranes with predetermined molecular weight pore sizes no more than 10,000 Dalton and no less than 700 Dalton, adjustment of pH of the filtration permeate to a predetermined level, pressurized reverse osmosis through a semi-permeable membrane of a molecular weight pore size between 50-100 Dalton producing a clear potable liquid that is finished to render the potable water product of low molecular weight solids of still bottoms used fur recycling, discharge, or human consumption by bulk handling or bottling. 3. The process in claim 2 wherein pressurized ultrafiltration, nanofiltration and reverse osmosis occurs at inlet pressures of 20-50 bar in spiral-wound filtration assemblies. 4. The process in claim 2 wherein the still bottoms are pasteurized and pressure filtered at temperatures between 25-80 C and said semi-permeable membrane filters for pressure filtration and reverse osmosis are of a polyamide type when temperatures of filtration are greater than 65 C. 5. The process in claim 2 wherein the filtration permeate from nanofiltration is adjusted with an alkali to neutralize organic acids at a predetermined pH between 4.0 and 7.5 before pressurized reverse osmosis. 6. The process in claim 2 wherein the filtration permeate from ultrafiltration-nanofiltration is anaerobically treated in an upflow anaerobic sludge blanket reactor. 7. The process in claim 2 wherein a permeate from reverse osmosis is finished by either activated carbon, aeration, or vacuum degasification and cooled in a heat exchanger. 8. The process in claim 2 wherein a permeate from reverse osmosis is finished by adjustment to a neutral pH. 9. The process of claim 2 wherein a permeate from reverse osmosis is reused or discharged. 10. The process of claim 2 wherein the potable water product is handled in bulk or bottled for human consumption, as a distillers water. 11. The organic and inorganic concentrate fractions of claim 2 wherein total or separate fractions of solid organic concentrate is anaerobically digested including under thermophilic conditions above 50 C to liquefy insoluble organics to improve acidogenisis, hydrogen production efficiency and methanogenisis. 12. The anaerobic digestion of claim 2 wherein a methane gas of fuel value is produced and used to recover its energy and the methane is separated from gas of no fuel value and the enriched gas separately used for its energy value. 13. The organic and inorganic concentrate fractions of claim 2 wherein the total or separate fractions of organic solids is anaerobically digested to produce by a predetermined process a ammonia solution for use as a fertilizer, for recycling to the ethanol fermentation process as a nutrient for yeast culturing, as a buffering agent to neutralize acids following nanofiltration wherein the ammonia salts are recovered from the concentrate of reverse osmosis filtration. 14. The organic and inorganic concentrate fractions of claim 2 wherein clean water is separated from the concentrate following anaerobic digestion by a sequence of steps that continuously subjects the concentrate to steps that further separate fractions of solids of lesser molecular weight from the concentrate, the steps consisting of anaerobic digestion, centrifugation, and nanofiltration through a semi-permeable membrane with a molecular weight pore size no less than 700 Dalton, recovery of ammonia by a predetermined process from the permeate, the resulting product being clean water for reclamation, discharge, or reuse. 15. The organic and inorganic concentrate fractions of claim 2 wherein solids are separated from the concentrate following anaerobic digestion by a sequence of steps that continuously subjects the solid phase to steps that further separate fractions of solids of lesser molecular weight from the concentrate, the steps consisting of anaerobic digestion, centrifugation and nanofiltration through a semi-permeable membrane with a predetermined molecular weight pore size no less than 700 Dalton, with a predetermined fraction of the solid phase from centrifugation returned to the anaerobic digester and the remaining solid, with the concentrate from nanofiltration, conveyed to an outside receiver. 16. A potable water product from ethanol fermentation still bottoms through a process to separate still bottom liquid from solid organic and inorganic components while pasteurized by a sequence of steps that continuously subjects the still bottom liquid phase to steps that further separate organic and inorganic concentrate fractions of solids of lesser molecular weight from the liquid, wherein the separated solid concentrate fractions are anaerobically digested after beneficial properties recovered, the sequence of steps consisting of centrifugal decantation, pressurized ultrafiltration and nanofiltration to produce a filtration permeate through semi-permeable membranes with predetermined molecular weight pore sizes no more than 10,000 Dalton and no less than 700 Dalton, adjustment of pH of the filtration permeate to a predetermined level, pressurized reverse osmosis through a semi-permeable membrane of a molecular weight pore size between 50-100 Dalton producing a clear potable liquid that is finished to render the potable water product of low molecular weight solids of still bottoms used for recycling, discharge, or human consumption by bulk handling or bottling. 17. The process in claim 16 wherein pressurized ultrafiltration, nanofiltration and reverse osmosis occurs at inlet pressures of 20-50 bar in spiral-wound filtration assemblies. 18. The process in claim 16 wherein the still bottoms are pasteurized and pressure filtered at temperatures between 25-80 C and said semi-permeable membrane filters for pressure filtration and reverse osmosis are of a polyamide type when temperatures of filtration are greater than 65 C. 19. The process in claim 16 wherein the filtration permeate from nanofiltration is adjusted with an alkali to neutralize organic acids at a predetermined pH between 4.0 and 7.5 before pressurized reverse osmosis. 20. The process in claim 16 wherein the filtration permeate from ultrafiltration-nanofiltration is anaerobically treated in an upflow anaerobic sludge blanket reactor and the separated solid concentrate used to recover the beneficial properties and the resulting solids and liquids returned to anaerobic digestion or the process in claim 16. 21. The process in claim 16 wherein a permeate from reverse osmosis is finished by either activated carbon, aeration, or vacuum degasification and cooled in a heat exchanger. 22. The process in claim 16 wherein a permeate from reverse osmosis is finished by adjustment to a neutral pH. 23. The process of claim 16 wherein a permeate from reverse osmosis is reused or discharged. 24. The process of claim 16 wherein the potable water product is handled in bulk or bottled for human consumption, as a distillers water. 25. The organic and inorganic concentrate fractions of claim 16 wherein the beneficial properties of concentrates are recovered before anaerobic digestion and the separated non-beneficial concentrate returned to anaerobic digestion, beneficial properties of the fractions including distillers dried grain, distillers dried grain solubles, medicinals, chemicals, and nutrients. 26. The organic and inorganic concentrate fractions of claim 16 wherein total or separate fractions of solid organic concentrate is anaerobically digested including under thermophilic conditions above 50 C to liquefy insoluble organics to improve acidogenisis, hydrogen production efficiency and methanogenisis. 27. The anaerobic digestion of claim 16 wherein a methane gas of fuel value is produced and used to recover its energy value and methane is separated from gas of no fuel value and the enriched gas separately used for its energy value. 28. The organic and inorganic concentrate fractions of claim 16 wherein the total or separate fractions of organic solids is anaerobically digested to produce by a predetermined process a ammonia solution for use as a fertilizer, for recycling to the ethanol fermentation process as a nutrient for yeast culturing, as a buffering agent to neutralize acids following nanofiltration wherein the ammonia salts are recovered from the concentrate of reverse osmosis filtration. 29. The organic and inorganic concentrate fractions of claim 16 wherein nutrients, chemicals and medicinals of beneficial value are recovered from the concentrate before anaerobic digestion and non-beneficial separated solids returned to an anaerobic digester and beneficial solids returned to the potable water. 30. The organic and inorganic concentrate fractions of claim 16 wherein clean water is separated from the concentrate following anaerobic digestion by a sequence of steps that continuously subjects the concentrate to steps that further separate fractions of solids of lesser molecular weight from the concentrate, the steps consisting of anaerobic digestion, centrifugation, and nanofiltration through a semi-permeable membrane with a molecular weight pore size no less than 700 Dalton, recovery of ammonia by a predetermined process from the permeate, the resulting product being clean water for reclamation, discharge, or reuse.