# US 8,147,651 B2 · Use of cyclodextrins for odor control in papermaking sludges, and deodorized sludge and products > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,147,651 B2 - Document ID: US8147651B2 - Status: Granted - Kind: B2 - Application number: 12/147,688 - Filed: 2008-06-27 - Published: 2009-01-01 - Granted: 2012-04-03 - Earliest claimed: 2007-06-28 - Assignees: Buckman Laboratories International, Inc. - Inventors: Gerald M. Dykstra; James N. Graham; Scott D. Branum - Web page: https://patentgrep.com/patent/US8147651B2 ## CPC - D21C 5/00: Other processes for obtaining cellulose, e.g. cooking cotton linters (obtaining fibres for spinning D01C); {Processes characterised by the choice of cellulose-containing starting materials} - C02F 11/147: using organic substances (C02F11/148 takes precedence) - C02F 11/004: {Sludge detoxification} - C02F 2103/28: from the paper or cellulose industry - C02F 2303/02: Odour removal or prevention of malodour - D21C 11/08: Deodorisation {; Elimination of malodorous compounds, e.g. sulfur compounds such as hydrogen sulfide or mercaptans, from gas streams (oxidation of liquors D21C11/0057; post-combustion of gases D21C11/127)} - D21C: PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract Methods to control and suppress odor in papermaking sludge are described. One method involves admixing sludge from a papermaking process and cyclodextrin to provide treated sludge with the cyclodextrin present in an effective amount to control odors in the treated sludge. The deodorized sludge may be used as a component of resin-wood composite products, such as composite decking materials, walls, flooring, casting forms, and the like. ## Claims ### Claim 1 A method for controlling odor in sludge from a papermaking process, comprising flocculating sludge from a papermaking process, at least partly dewatering the sludge after said flocculating on at least one dewatering device, and admixing the sludge and cyclodextrin after the flocculating and the dewatering to provide treated sludge with the cyclodextrin present in an effective amount to control odors in the treated sludge. ### Claim 2 (depends on 1) The method of claim 1, wherein at least a major portion of said cyclodextrin is alpha-cyclodextrin, beta-cyclodextrin, hydroxypropylated beta-cyclodextrin, gamma-cyclodextrin, or mixtures thereof. ### Claim 3 (depends on 1) The method of claim 1, wherein said treated sludge contains at least about 0.01 weight % cyclodextrin. ### Claim 4 (depends on 1) The method of claim 1, wherein said treated sludge is formed into particle form and dried. ### Claim 5 (depends on 1) The method of claim 1, wherein said sludge comprises paper sludge obtained from the making of paper from virgin pulp. ### Claim 6 (depends on 1) The method of claim 1, wherein said sludge comprises paper sludge obtained from the making of virgin pulp from cellulosic materials. ### Claim 7 (depends on 1) The method of claim 1, wherein said sludge comprises paper sludge obtained from the making of paper from recycled waste paper. ### Claim 8 (depends on 1) The method of claim 1, wherein the treated sludge comprising no more than 75 wt. % moisture based on total weight of the treated sludge. ### Claim 9 (depends on 1) The method of claim 1, wherein the treated sludge comprising no more than 50 wt. % moisture based on total weight of the treated sludge. ### Claim 10 A method for controlling odor in sludge from a papermaking process, comprising: a) providing a mixed sludge from a papermaking process; b) admixing the mixed sludge and a flocculant, providing flocculated sludge; c) dewatering the flocculated sludge, providing thickened sludge; d) conducting the thickened sludge into a screw press and discharging dry sludge as extrudate from the screw press, wherein introducing of cyclodextrin is done in conjunction with step d) in an effective amount to control odors in the dry sludge. ### Claim 11 (depends on 10) The method of claim 10, wherein the dry sludge comprising no more than 75 wt. % moisture based on total weight of the thickened sludge. ### Claim 12 (depends on 10) The method of claim 10, wherein the dry sludge comprising no more than 50 wt. % moisture based on total weight of the thickened sludge. ### Claim 13 (depends on 10) The method of claim 10, wherein said dewatering comprises dewatering the sludge on a dewatering device with a gravity table, belt press, rotary screen thickener, or a combination thereof. ### Claim 14 (depends on 1) The method of claim 1, further comprising: forming a mixture by mixing said treated sludge with cellulosic pieces and a binder material; compressing said mixture by applying heat and pressure effective to form a unitary shaped article. ### Claim 15 (depends on 14) The method of claim 14, wherein said compressing step is performed with opposing pressure plates supporting and pressing the mixture from opposite sides thereof. ### Claim 16 (depends on 14) The method of claim 14, wherein said compressing step is performed in a mold comprising at least one die having a surface imparting a three-dimensional non-planar shape to at least a part of the unitary article. ### Claim 17 (depends on 14) The method of claim 14, further comprising the step of drying said sludge to obtain a solids content of from about 90 percent to about 100 percent prior to mixing said sludge with said cellulosic pieces and said binder material. ### Claim 18 (depends on 14) The method of claim 14, wherein at least a major portion of said cyclodextrin is alpha-cyclodextrin, beta-cyclodextrin, hydroxypropylated beta-cyclodextrin, gamma-cyclodextrin, or mixtures thereof. ### Claim 19 (depends on 14) The method of claim 14, further comprising the steps of drying and comminuting said sludge to produce sludge in a form of dry flowable particulate material, prior to mixing said sludge with said cellulosic pieces and said binder material. ### Claim 20 (depends on 14) A unitary-shaped article formed from the method of claim 14, said unitary-shaped article comprising a unitary mixture containing about 25 to about 75 weight % of a comminuted dried papermaking sludge containing about 20 weight % or less moisture and at least about 0.01 weight % cyclodextrin; about 25 to about 75 weight % of a fibrous cellulosic pieces; and a resinous particle board binder in an amount effective to consolidate the sludge and cellulosic material, said weight percentages being based on the total dry weight of the papermaking sludge and the cellulosic material, wherein the cyclodextrin is capable of continuing to control and suppress odor development in the sludge when the article becomes moistened or re-moistened. ### Claim 21 (depends on 20) The article of claim 20, wherein said mixture contains from about 2 to about 50 weight % of said binder, as solids based on the total dry weight of the papermaking sludge and cellulosic pieces. ### Claim 22 (depends on 20) The article of claim 20, wherein said cellulosic pieces are wood strands, wood particles, wood chips, wood flakes, wood fibers, or combinations thereof. ### Claim 23 (depends on 20) The article of claim 20, wherein at least a major portion of said cyclodextrin is alpha-cyclodextrin, beta-cyclodextrin, hydroxypropylated beta-cyclodextrin, or gamma-cyclodextrin, or mixtures thereof. ### Claim 24 (depends on 20) The article of claim 20, wherein said article comprises at least one planar portion. ### Claim 25 (depends on 20) The article of claim 20, wherein said article comprises at least one integral non-planar portion. ### Claim 26 (depends on 20) The article of claim 20, wherein said article is decking material.