초록 ▼

A process for the production of purified water from Fischer-Tropsch reaction water wherein the purified water is an aqueous stream having a COD of between 20 and 500 mg/l, a pH of between 6.0 and 9.0, a suspended solids content of less than 250 mg/l and a total dissolved solids content of less than

A process for the production of purified water from Fischer-Tropsch reaction water wherein the purified water is an aqueous stream having a COD of between 20 and 500 mg/l, a pH of between 6.0 and 9.0, a suspended solids content of less than 250 mg/l and a total dissolved solids content of less than 600 mg/l, and wherein the process includes at least the steps of a primary treatment stage comprising an equilibrium staged separation process having at least one stage for removing at least a fraction of non-acid oxygenated hydrocarbons from the Fischer-Tropsch reaction water to produce a primary water enriched stream, a secondary treatment stage comprising liquid-liquid extraction for removing at least a fraction of organic acids from at least a portion of the primary water enriched stream to produce a secondary water enriched stream, a tertiary treatment stage comprising biological treatment for removing at least a fraction of acidic oxygenated hydrocarbons from at least a portion of the secondary water enriched stream to produce a tertiary water enriched stream and a quartic treatment stage comprising solid-liquid separation for removing at least some solids from at least a portion of the tertiary water enriched stream.

대표청구항 ▼

What is claimed is: 1. A process for the production of purified water from Fischer-Tropsch reaction water containing oxygenated hydrocarbons, aliphatic, aromatic and cyclic hydrocarbons and inorganic compounds, wherein the purified water is an aqueous stream having a COD of between 20 and 500 mg/l,

What is claimed is: 1. A process for the production of purified water from Fischer-Tropsch reaction water containing oxygenated hydrocarbons, aliphatic, aromatic and cyclic hydrocarbons and inorganic compounds, wherein the purified water is an aqueous stream having a COD of between 20 and 500 mg/l, a pH of between 6.0 and 9.0, a suspended solids content of less than 250 mg/l and a total dissolved solids content of less than 600 mg/l, and wherein the process includes at least the steps of: a) a primary treatment stage comprising distillation for removing at least a fraction of non-acid oxygenated hydrocarbons from the Fischer-Tropsch reaction water to produce a primary water enriched stream; b) a secondary treatment stage comprising liquid-liquid extraction for removing at least a fraction of organic acids from at least a portion of the primary water enriched stream to produce a secondary water enriched stream; c) a tertiary treatment stage comprising biological treatment for removing at least a fraction of acidic oxygenated hydrocarbons from at least a portion of the secondary water enriched stream to produce a tertiary water enriched stream; and d) a quartic treatment stage comprising solid-liquid separation for removing at least some solids from at least a portion of the tertiary water enriched stream. 2. The process of claim 1, wherein the non-acid oxygenated hydrocarbons are selected from the group including: alcohols, aldehydes, and ketones and wherein the acidic oxygenated hydrocarbons are selected from the group including: formic acid, acetic acid, propionic aid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, and octanoic acid. 3. The process of claim 1, wherein the primary treatment stage includes degassing of the Fischer-Tropsch reaction water before further processing in the primary treatment stage to remove compounds having a very low boiling point and dissolved gases from the Fischer-Tropsch reaction water. 4. The process of claim 1, wherein the liquid-liquid extraction technique used during the secondary treatment stage is either or both of: differential contacting including using equipment selected from the group including: spray columns, packed columns, rotating disc contactors, and Da Laval contactors or equivalent; and stagewise contacting including using equipment selected from the group including: mixer settlers, perforated plate columns, and controlled cycling columns. 5. The process of claim 1, wherein the solvent used during step b) is selected from a group of water insoluble solvents having an affinity for acids, said group including ethers, acetates, amides, and phosphene oxides. 6. The process of claim 1, wherein the biological treatment includes one or both of: anaerobic treatment selected from the group including: Up-flow Anaerobic Sludge Blanket (UASB) processes, Fixed Bed systems, Fluidized Bed reactors, Stirred Tank reactors, Membrane Bioreactors and Baffled reactors; and aerobic treatment selected from group including: Activated Sludge processes, Biological Aerated Filters, Trickling filters, Rotating Biological Contacters, High-rate Compact Reactors, Membrane Bioreactors, and Fluidized Bed reactors. 7. The process of claim 1, wherein the quartic treatment stage removes suspended solids from the tertiary water-enriched stream produced during biological treatment. 8. The process of claim 7, wherein the suspended solid removal is achieved by one or more method selected from the group including: sand filtration, membrane separation, sedimentation with the use of flocculants, sedimentation without the use of flocculants, dissolved air flotation with the use of flocculants, dissolved air flotation without the use of flocculants, and centrifugation. 9. The process of claim 8, wherein the membrane separation method includes one or both of microfiltration and ultrafiltration. 10. A process for the production of highly purified water from Fischer-Tropsch reaction water containing oxygenated hydrocarbons, aliphatic, aromatic and cyclic hydrocarbons and inorganic compounds, wherein the highly purified water is an aqueous stream having a COD of less than 50 mg/l, a pH of between 6.0 and 9.0, a suspended solids content of less than 50 mg/l and a total dissolved solids content of less than 100 mg/l, and wherein the process includes at least the steps of: a) a primary treatment stage comprising distillation for removing at least a fraction of non-acid oxygenated hydrocarbons from the Fischer-Tropsch reaction water to produce a primary water enriched stream; b) a secondary treatment stage comprising liquid-liquid extraction for removing at least a fraction of acidic oxygenated hydrocarbons from at least a portion of the primary water enriched stream to produce a secondary water enriched stream; c) a tertiary treatment stage comprising biological treatment for removing at least a fraction of acidic oxygenated hydrocarbons from at least a portion of the secondary water enriched stream to produce a tertiary treated water enriched stream; and d) a final treatment stage comprising a dissolved salt and organic removal stage for removing at least some dissolved salts and organic constituents from at least a portion of the tertiary water enriched stream. 11. The process of claim 10, wherein the process includes a quartic treatment stage comprising solid-liquid separation for removing at least some solids from at least a portion of the tertiary water enriched stream to produce a quartic water enriched stream which is then be subjected to final treatment. 12. The process of claim 10, wherein the non-acid oxygenated hydrocarbons are selected from the group including: alcohols, aldehydes, and ketones and wherein the acidic oxygenated hydrocarbons are selected from the group including: formic acid, acetic acid, propionic aid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, and octanoic acid. 13. The process of claim 10, wherein the primary treatment stage includes degassing of the Fischer-Tropsch reaction water before further processing in the primary treatment stage to remove compounds having a very low boiling point and dissolved gases from the Fischer-Tropsch reaction water. 14. The process of claim 10, wherein the liquid-liquid extraction technique used during the secondary treatment stage is either or both of: differential contacting including using equipment selected from the group including: spray columns, packed columns, rotating disc contactors, and Da Laval contactors or equivalent; and stagewise contacting including using equipment selected from the group including: mixer settlers, perforated plate columns, and controlled cycling columns. 15. The process of claim 10, wherein the solvent used during step b) is selected from a group of water insoluble solvents having an affinity for acids, said group including ethers, acetates, amides, and phosphene oxides. 16. The process of claim 10, wherein the biological treatment includes one or both of: anaerobic treatment selected from the group including: Up-flow Anaerobic Sludge Blanket (UASB) processes, Fixed Bed systems, Fluidized Bed reactors, Stirred Tank reactors, Membrane Bioreactors, and Baffled reactors; and aerobic treatment selected from group including: Activated Sludge processes, Biological Aerated Filters, Trickling filters, Rotating Biological Contactors, High-rate Compact Reactors, Membrane Bioreactors and Fluidized Bed reactors. 17. The process of claim 10, having a quartic treatment stage that removes suspended solids from the tertiary water-enriched stream produced during biological treatment by one or more method selected from the group including: sand filtration, membrane separation, sedimentation with the use of flocculants, sedimentation without the use of flocculants, dissolved air flotation with the use of flocculants, dissolved air flotation without the use of flocculants, and centrifugation. 18. The process of claim 17, wherein the membrane separation method includes one or both of microfiltration and ultrafiltration. 19. The process of claim 10, wherein residual organic species are removed in the final treatment stage by one or more method selected from the group including: chemical oxidation, ultraviolet light generated free radicals, adsorption and/or absorption processes. 20. The process of claim 10, wherein dissolved salts originating from secondary treatment and/or from the co-treatment of other process effluents, are reduced in the final treatment stage by one or more method selected from the group including: ion exchange, reverse osmosis, nano-filtration, and chemical precipitation processes.