# US 7,745,660 B2 · Process for recovering a crystalline product from solution > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,745,660 B2 - Document ID: US7745660B2 - Status: Granted - Kind: B2 - Application number: 11/674,201 - Filed: 2007-02-13 - Published: 2008-07-31 - Granted: 2010-06-29 - Earliest claimed: 2003-09-17 - Assignees: Monsanto Technology LLC - Inventors: Eric A. Haupfear; Eduardo A. Casanova; Kenneth S. Meyer; Henry H. Chien - Web page: https://patentgrep.com/patent/US7745660B2 ## CPC - C07F 9/025: {Purification; Separation; Stabilisation; Desodorisation of organo-phosphorus compounds (of natural phosphatides C07F9/103; phosphines C07F9/5095)} - C07F 9/3813: {N-Phosphonomethylglycine; Salts or complexes thereof} - C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22) ## Abstract An improved process for recovering a crystalline product (particularly an N-(phosphonomethyl)glycine product) from a solution comprising both a product subject to crystallization and undesired impurities is provided. ## Claims ### Claim 1 A process for recovering an N-(phosphonomethyl)glycine product from a slurry comprising precipitated N-(phosphonomethyl)glycine product crystals and a mother liquor, the process comprising: dividing the slurry into plural fractions comprising a first slurry fraction and a second slurry fraction; separating precipitated N-(phosphonomethyl)glycine product crystals from said first fraction, thereby producing a first wet-cake product; and separating precipitated N-(phosphonomethyl)glycine product crystals from said second fraction, thereby producing a second wet-cake product, the ratio of solids content of the second wet-cake product to the solids content of the first wet-cake product, as measured by weight percent of solids in said first and second wet-cake products, being at least about 1.1. ### Claim 2 (depends on 1) A process as set forth in claim 1, wherein the ratio of solids content of the second wet-cake product to the solids content of the first wet-cake product, as measured by weight percent of solids in said first and second wet-cake products, is at least about 1.2. ### Claim 3 (depends on 2) A process as set forth in claim 2, wherein the ratio of solids content of the second wet-cake product to the solids content of the first wet-cake product, as measured by weight percent of solids in said first and second wet-cake products, is at least about 1.25. ### Claim 4 (depends on 1) A process as set forth in claim 1, wherein precipitated N-(phosphonomethyl)glycine crystals are separated from said first and second slurry fractions in separate liquid/solids separation devices. ### Claim 5 (depends on 4) A process as set forth in claim 4, wherein precipitated N-(phosphonomethyl)glycine crystals are separated from said first and second slurry fractions in parallel in separate centrifuges. ### Claim 6 (depends on 5) A process as set forth in claim 5, wherein precipitated N-(phosphonomethyl)glycine crystals are separated from said first slurry fraction in a solid bowl centrifuge and precipitated N-(phosphonomethyl)glycine crystals are separated from said second slurry fraction in a basket centrifuge. ### Claim 7 (depends on 6) A process as set forth in claim 6, wherein precipitated N-(phosphonomethyl)glycine crystals are separated from said second slurry fraction in multiple basket centrifuges. ### Claim 8 (depends on 1) A process as set forth in claim 1, wherein the second wet-cake product has a solids content of at least about 85% by weight solids. ### Claim 9 (depends on 8) A process as set forth in claim 8, wherein the second wet-cake product has a solids content of from about 90% by weight solids to about 99% by weight solids. ### Claim 10 (depends on 9) A process as set forth in claim 9, wherein the second wet-cake product has a solids content of from about 95% by weight solids to about 99% by weight solids. ### Claim 11 (depends on 1) A process as set forth in claim 1, wherein the first wet-cake product has a solids content of less than about 85% by weight solids. ### Claim 12 (depends on 11) A process as set forth in claim 11, wherein the first wet-cake product has a solids content of less than about 75% by weight solids. ### Claim 13 (depends on 1) A process as set forth in claim 1, wherein the first wet-cake product has a solids content of from about 70% by weight solids to about 85% by weight solids. ### Claim 14 (depends on 1) A process as set forth in claim 1, wherein the first fraction divided from said slurry constitutes from about 40% to about 60% of the slurry. ### Claim 15 (depends on 14) A process as set forth in claim 14, wherein the first fraction divided from said slurry constitutes about 50% of the slurry. ### Claim 16 A process for recovering an N-(phosphonomethyl) glycine product from a slurry comprising precipitated N-(phosphonomethyl)glycine product crystals and a mother liquor, the process comprising: dividing the slurry into plural fractions comprising a first slurry fraction and a second slurry fraction; introducing said first slurry fraction into a first liquid/solids separation device; separating precipitated N-(phosphonomethyl) glycine product crystals from said first slurry fraction, thereby producing a first wet-cake product; introducing said second slurry fraction into a second liquid/solids separation device in parallel with said first liquid/solids separation device; and separating precipitated N-(phosphonomethyl) glycine product crystals from said second slurry fraction, thereby producing a second wet-cake product, the second wet-cake product having a greater solids content than the first wet-cake product as measured by weight percent of solids in said wet-cake products. ### Claim 17 (depends on 16) A process as set forth in claim 16, wherein the ratio of solids content of the second wet-cake product to the solids content of the first wet-cake product, as measured by weight percent of solids in said first and second wet-cake products, is at least about 1.1. ### Claim 18 (depends on 17) A process as set forth in claim 17, wherein the ratio of solids content of the second wet-cake product to the solids content of the first wet-cake product, as measured by weight percent of solids in said first and second wet-cake products, is at least about 1.2. ### Claim 19 (depends on 18) A process as set forth in claim 18, wherein the ratio of solids content of the second wet-cake product to the solids content of the first wet-cake product, as measured by weight percent of solids in said first and second wet-cake products, is at least about 1.25. ### Claim 20 (depends on 16) A process as set forth in claim 16, wherein precipitated N-(phosphonomethyl)glycine product crystals are separated from said first and second slurry fractions in parallel in separate centrifuges. ### Claim 21 (depends on 20) A process as set forth in claim 20, wherein precipitated N-(phosphonomethyl)glycine product crystals are separated from said first slurry fraction in a solid bowl centrifuge and precipitated N-(phosphonomethyl)glycine product crystals are separated from said second slurry fraction in a basket centrifuge. ### Claim 22 (depends on 21) A process as set forth in claim 21, wherein precipitated N-(phosphonomethyl)glycine product crystals are separated from said second slurry fraction in multiple basket centrifuges. ### Claim 23 (depends on 16) A process as set forth in claim 16, wherein the second wet-cake product has a solids content of at least about 85% by weight solids. ### Claim 24 (depends on 23) A process as set forth in claim 23, wherein the second wet-cake product has a solids content of from about 90% by weight solids to about 99% by weight solids. ### Claim 25 (depends on 24) A process as set forth in claim 24, wherein the second wet-cake product has a solids content of from about 95% by weight solids to about 99% by weight solids. ### Claim 26 (depends on 16) A process as set forth in claim 16, wherein the first wet-cake product has a solids content of less than about 85% by weight solids. ### Claim 27 (depends on 26) A process as set forth in claim 26, wherein the first wet-cake product has a solids content of less than about 75% by weight solids. ### Claim 28 (depends on 16) A process as set forth in claim 16, wherein the first wet-cake product has a solids content of from about 70% by weight solids to about 85% by weight solids. ### Claim 29 (depends on 16) A process as set forth in claim 16, wherein the slurry comprising the N-(phosphonomethyl)glycine product crystals and mother liquor is produced by cooling an aqueous oxidation reaction solution comprising N-(phosphonomethyl) glycine product as water is evaporated therefrom under substantially adiabatic conditions. ### Claim 30 A process for recovering an N-(phosphonomethyl) glycine product from an aqueous oxidation reaction solution comprising an N-(phosphonomethyl)glycine product, the process comprising: cooling the aqueous oxidation reaction solution as water is evaporated therefrom under substantially adiabatic conditions to precipitate N-(phosphonomethyl)glycine and produce a slurry comprising precipitated N-(phosphonomethyl) glycine product crystals and a mother liquor; dividing the slurry into plural fractions comprising a first slurry fraction and a second slurry fraction; separating precipitated N-(phosphonomethyl) glycine product crystals from said first fraction, thereby producing a first wet-cake product; and separating precipitated N-(phosphonomethyl) glycine product crystals from said second fraction, thereby producing a second wet-cake product, the ratio of solids content of the second wet-cake product to the solids content of the first wet-cake product, as measured by weight percent of solids in said first and second wet-cake products, being at least about 1.1.