WO2002012618A2 - Flotation deinking process - Google Patents
Flotation deinking process Download PDFInfo
- Publication number
- WO2002012618A2 WO2002012618A2 PCT/US2001/041584 US0141584W WO0212618A2 WO 2002012618 A2 WO2002012618 A2 WO 2002012618A2 US 0141584 W US0141584 W US 0141584W WO 0212618 A2 WO0212618 A2 WO 0212618A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- deinking
- deinking agent
- cloud point
- flotation
- hydrophobic base
- Prior art date
Links
- 239000002761 deinking Substances 0.000 title claims abstract description 96
- 238000000034 method Methods 0.000 title claims description 70
- 238000005188 flotation Methods 0.000 title claims description 54
- 230000008569 process Effects 0.000 title claims description 31
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 44
- 239000000835 fiber Substances 0.000 claims abstract description 28
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 28
- 229920000728 polyester Polymers 0.000 claims abstract description 27
- 239000000126 substance Substances 0.000 claims abstract description 23
- 125000002947 alkylene group Chemical group 0.000 claims abstract description 21
- 239000002253 acid Substances 0.000 claims abstract description 19
- 150000008064 anhydrides Chemical class 0.000 claims abstract description 15
- 239000007844 bleaching agent Substances 0.000 claims abstract description 15
- 150000003839 salts Chemical class 0.000 claims abstract description 15
- 238000006243 chemical reaction Methods 0.000 claims abstract description 14
- 230000003287 optical effect Effects 0.000 claims abstract description 11
- 150000001412 amines Chemical class 0.000 claims abstract description 7
- 239000000539 dimer Substances 0.000 claims abstract description 6
- 150000004665 fatty acids Chemical class 0.000 claims description 30
- 235000014113 dietary fatty acids Nutrition 0.000 claims description 29
- 239000000194 fatty acid Substances 0.000 claims description 29
- 229930195729 fatty acid Natural products 0.000 claims description 29
- 239000010893 paper waste Substances 0.000 claims description 23
- 125000004432 carbon atom Chemical group C* 0.000 claims description 19
- 239000000123 paper Substances 0.000 claims description 18
- 229920001131 Pulp (paper) Polymers 0.000 claims description 17
- 239000013055 pulp slurry Substances 0.000 claims description 16
- 229920000233 poly(alkylene oxides) Polymers 0.000 claims description 9
- 150000007513 acids Chemical class 0.000 claims description 8
- 125000001142 dicarboxylic acid group Chemical group 0.000 claims description 7
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 5
- 125000004122 cyclic group Chemical group 0.000 claims description 5
- 125000001931 aliphatic group Chemical group 0.000 claims description 4
- 238000011068 loading method Methods 0.000 claims description 4
- 150000001298 alcohols Chemical class 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 229920000642 polymer Polymers 0.000 claims description 3
- 125000003342 alkenyl group Chemical group 0.000 claims description 2
- 125000000217 alkyl group Chemical group 0.000 claims description 2
- 125000006165 cyclic alkyl group Chemical group 0.000 claims description 2
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 2
- 229910052700 potassium Inorganic materials 0.000 claims description 2
- 229910052708 sodium Inorganic materials 0.000 claims description 2
- -1 sulphate anion Chemical class 0.000 claims description 2
- 229910021653 sulphate ion Inorganic materials 0.000 claims description 2
- 150000003627 tricarboxylic acid derivatives Chemical class 0.000 claims 7
- 239000000976 ink Substances 0.000 abstract description 61
- 239000006260 foam Substances 0.000 abstract description 34
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 abstract description 9
- 150000003628 tricarboxylic acids Chemical class 0.000 abstract description 7
- 230000009467 reduction Effects 0.000 abstract description 6
- 239000002002 slurry Substances 0.000 abstract description 5
- 229920001515 polyalkylene glycol Polymers 0.000 abstract description 3
- 150000001991 dicarboxylic acids Chemical class 0.000 abstract description 2
- 239000000306 component Substances 0.000 abstract 1
- 239000000203 mixture Substances 0.000 description 25
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 18
- 239000002245 particle Substances 0.000 description 18
- 241000196324 Embryophyta Species 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 14
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 12
- 150000001875 compounds Chemical class 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 238000004537 pulping Methods 0.000 description 8
- 230000008901 benefit Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 229960002163 hydrogen peroxide Drugs 0.000 description 6
- 239000000706 filtrate Substances 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 4
- 239000004115 Sodium Silicate Substances 0.000 description 4
- 239000000654 additive Substances 0.000 description 4
- 229910052791 calcium Inorganic materials 0.000 description 4
- 239000011575 calcium Substances 0.000 description 4
- 239000000344 soap Substances 0.000 description 4
- 229910052911 sodium silicate Inorganic materials 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- 230000002411 adverse Effects 0.000 description 3
- 239000007900 aqueous suspension Substances 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000004061 bleaching Methods 0.000 description 3
- 125000002091 cationic group Chemical group 0.000 description 3
- 239000000084 colloidal system Substances 0.000 description 3
- 239000000356 contaminant Substances 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- 238000009472 formulation Methods 0.000 description 3
- 239000010899 old newspaper Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 229940037003 alum Drugs 0.000 description 2
- 125000003118 aryl group Chemical group 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 238000009300 dissolved air flotation Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000011256 inorganic filler Substances 0.000 description 2
- 229910003475 inorganic filler Inorganic materials 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229920001223 polyethylene glycol Polymers 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 159000000000 sodium salts Chemical class 0.000 description 2
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000032258 transport Effects 0.000 description 2
- QOVUSIZUVWPIAP-UHFFFAOYSA-N 2,6-bis(methoxycarbonyl)benzenesulfonic acid Chemical compound COC(=O)C1=CC=CC(C(=O)OC)=C1S(O)(=O)=O QOVUSIZUVWPIAP-UHFFFAOYSA-N 0.000 description 1
- 240000002791 Brassica napus Species 0.000 description 1
- 235000004977 Brassica sinapistrum Nutrition 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- 102000016938 Catalase Human genes 0.000 description 1
- 108010053835 Catalase Proteins 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- 244000060011 Cocos nucifera Species 0.000 description 1
- 235000013162 Cocos nucifera Nutrition 0.000 description 1
- 102000004190 Enzymes Human genes 0.000 description 1
- 108090000790 Enzymes Proteins 0.000 description 1
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 1
- 235000010469 Glycine max Nutrition 0.000 description 1
- 239000004831 Hot glue Substances 0.000 description 1
- QPCDCPDFJACHGM-UHFFFAOYSA-N N,N-bis{2-[bis(carboxymethyl)amino]ethyl}glycine Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(=O)O)CCN(CC(O)=O)CC(O)=O QPCDCPDFJACHGM-UHFFFAOYSA-N 0.000 description 1
- 229910003202 NH4 Inorganic materials 0.000 description 1
- 102000003992 Peroxidases Human genes 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- LEHOTFFKMJEONL-UHFFFAOYSA-N Uric Acid Chemical compound N1C(=O)NC(=O)C2=C1NC(=O)N2 LEHOTFFKMJEONL-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229920006223 adhesive resin Polymers 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 229920006318 anionic polymer Polymers 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000003139 biocide Substances 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 230000009920 chelation Effects 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 235000012343 cottonseed oil Nutrition 0.000 description 1
- 239000013530 defoamer Substances 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- GRWZHXKQBITJKP-UHFFFAOYSA-L dithionite(2-) Chemical compound [O-]S(=O)S([O-])=O GRWZHXKQBITJKP-UHFFFAOYSA-L 0.000 description 1
- HQQADJVZYDDRJT-UHFFFAOYSA-N ethene;prop-1-ene Chemical group C=C.CC=C HQQADJVZYDDRJT-UHFFFAOYSA-N 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000008394 flocculating agent Substances 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 239000008233 hard water Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 125000001165 hydrophobic group Chemical group 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 235000019198 oils Nutrition 0.000 description 1
- 229960003330 pentetic acid Drugs 0.000 description 1
- 238000001935 peptisation Methods 0.000 description 1
- 108040007629 peroxidase activity proteins Proteins 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 125000001453 quaternary ammonium group Chemical group 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 238000007127 saponification reaction Methods 0.000 description 1
- 150000004671 saturated fatty acids Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- 239000012453 solvate Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 150000001629 stilbenes Chemical class 0.000 description 1
- 230000002311 subsequent effect Effects 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L sulfate group Chemical group S(=O)(=O)([O-])[O-] QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000003784 tall oil Substances 0.000 description 1
- 239000003760 tallow Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 238000004383 yellowing Methods 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
- D21C5/02—Working-up waste paper
- D21C5/025—De-inking
- D21C5/027—Chemicals therefor
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/64—Paper recycling
Definitions
- the present invention is directed to the removal of inks from recycled paper products, i.e. de-inking.
- Decorating is the process of removing ink and other contaminants from waste paper and there are two main techniques in current use.
- Flotation deinking entails forming an aqueous suspension of waste paper pulp fibers, ink, and other non-cellulosic contaminants and then mixing air into the suspension. In the presence of certain additives, air bubbles selectively attach to ink particles and carry those particles to the surface of the aqueous suspension, thereby forming an ink rich froth. The froth is then removed leaving behind a relatively ink-free fiber slurry.
- a deinking process can be divided in three different steps; 1) disintegration/dissolution of recycled fiber and release of the printing ink from the fibers, 2) dispersing printing ink in the water phase and 3) separation of the printing ink. These three steps are included in both the flotation process and the wash process.
- the method which one uses depends on the requirements and conditions which are found where the activity is located.
- the flotation process generally has been found to remove the greatest amount of printing ink from a recycled fiber suspension and to be the most cost effective.
- the first step of flotation deinking is to solvate/sa urate the fiber and disengage the printing ink.
- the particles must be modified so that they obtain suitable physical and chemical characteristics so that afterwards they can be lifted to the surface and removed with help of air bubbles.
- Some parameters are important to be consider at the flotation, such as the size of the particle, airflow (particularly the air: stock ratio) in the flotation cell, the size of the air-bubbles, temperature, flotation time, pulp consistency (the concentration of the recycled fibers in the flotation cell), pH, the concentration of the chemicals as well as the degree of the hardness of the water.
- the flotation process is carried out in such a manner that the recycled raw material of the fiber is passed through mechanical treatment in combination with associated chemicals.
- mechanical treatment There are different methods depending upon the specific chemicals used, the concentration of those chemicals, and methods to process the raw material.
- the purpose of the mechanical treatment is that the paper be disintegrated into fibers that together with the chemicals result in an efficient removal of print ink.
- a too strong mechanical influence can cause undesirable damage to the fibers as well as ink smearing and/or ink re-attachment due to fibers contacting one another.
- a dispersing step the discharge of printing ink continues through mechanical treatment and chemical enhancement. Printing ink and any remaining small particles are separated subsequently in the flotation step.
- Different flotation techniques exist and in the more contemporary ones, one can float all small particles by pressurizing the flotation cell. Small impurities are separated through washing and to increase the brightness of the pulp, bleaching is performed through use of hydrogen peroxide, hydrosulfite, and the addition of conventional optical bleaches. Optical bleaches enhance the contrast between the ink and the paper background causing the paper to look brighter and to enhance ink colors.
- Flotation deinking processes are especially useful in removing hydrophobic inks with particle sizes larger than about 10 ⁇ m.
- the additives used in such processes are generally specialty surfactants or fatty acids which are intended to agglomerate the relatively finer ink particles to increase removal efficiency in the flotation stage.
- the presence of additives which over-disperse the ink particles rather than agglomerate them is considered detrimental to the effectiveness of the flotation stage.
- fatty acids and fatty acid soaps have a number of problems associated with them, e.g. high dosage rates (typically about 16 pounds/ton of waste paper but as high as 30 pounds/ton), relatively poor foam-ability thus causing the high dosage rates, and the general need for high levels of water hardness to achieve acceptable performance.
- high dosage rates typically about 16 pounds/ton of waste paper but as high as 30 pounds/ton
- foam-ability thus causing the high dosage rates
- the hard water often leads to handling problems as well as scale and deposit buildup in mill equipment.
- non-ionic surfactants have been developed for use in deinking systems.
- US 5,736,622 discloses a synthetic collector which consists of a polyester based on a polyalkylene glycol and a di or tricarboxylic acid.
- the patent goes on to improve on such a deinking agent by adding into the polymerization mixture a saturated fatty acid with 12- 18 carbon atoms, and controlling the molecular weight to be between 3,000 and 10,000.
- the present invention is directed to a deinking method which is useful in re-moving inks from recycled printed media in a flotation deinking system or combined flotation/wash deinking system.
- the flotation deinking method generally entails adding to an aqueous waste paper pulp slurry each of (1) a polyester obtained through reaction between di and/or tricarboxylic acids and/or anhydrides thereof and a polyalkylene oxide or an alkylene oxide, (2) a first deinking agent which is an alkoxylated hydrophobic base, e.g.
- the deinking method of the present invention effectively and efficiently removes ink in a flotation process or in the flotation stage of a combined flotation/wash process.
- the present invention entails adding to an aqueous waste paper pulp slurry each of (1) a polyester obtained through reaction between a di- and/or tri-carboxylic acid and/or anhydride thereof with an alkylene oxide or a poly-alkylene oxide, (2) a first deinking agent which is an alkoxylated hydrophobic base, e.g. an alcohol, amine, acid, dimer acid, salts thereof, or the like, and (3) a second deinking agent which is an alkoxylated hydrophobic base and which has a cloud point about 2 to 20°, preferably 4 to 18°, lower than the cloud point of the first deinking agent.
- the combination may further contain a fatty acid or salt thereof.
- the polyesters for use herein may be obtained through reaction of (a) a hydro-phobe, i.e. a dicarboxylic acid, a tricarboxylic acid, an anhydride of a dicarboxylic acid, an anhydride of a tricarboxylic acid, and combinations thereof with (b) a hydrophile, i.e. polyalkylene glycol or an alkylene oxide in an alkoxylation reaction.
- a hydrophobic acids/anhydrides may be either aliphatic or aromatic. Preferably for better foam control ring structures are used. Such acids and anhydrides are well known and commercially available from numerous sources.
- a particularly preferred class )of cyclic aliphatic di-acids are of the formula:
- A is a cyclic aliphatic group having 6 to 10 carbon atoms and x is an integer from 0 to about 15. While the acid groups may be ortho, meta or para, they are pre-ferably ortho or para.
- the ring is further substituted with one or more hydrophobic groups, such as a straight or branched chain alkyl group having about 3 to 18, preferably about 4 to 12, carbon atoms.
- cyclic di- and/or tri-carboxylic acid and/or anhydride is substituted by sulphate or other anions. Increased anionicity has been found to enhance the removal of stickies.
- Suitable alkylene oxides have 2 to 4 carbon atoms, preferably 2 to 3, and most preferably 2. While mixtures of alkylene oxides may be used, no benefit from so doing has been observed. If a hydrophilic polyalkylene oxide polymer is used, it is prepared from the same alkylene oxides.
- the polyester generally has a hydrophobe loading of about 35 to 55 wt %, a hydrophile loading of about 35 to 55 wt %, and a terminal carboxyl content of about 5 to 15 wt %.
- the polyester has a molecular weight in the range of about 2,500 to 5,000 daltons, though higher or lower molecular weight polymers may be used in specific circumstances depending upon the specific composition of the materials being deinked.
- the first deinking agent is an alkoxylated hydrophobic base.
- Suitable hydro-phobic bases include any compounds which are hydrophobic and which can be alkox-ylated by reaction with an alkylene oxide. Examples of such compounds include alcohols, amines, acids, dimer acids, and salts thereof. Most commonly an alcohol or an acid will be used.
- the hydrophobe compound will contain about 12 to 60 carbon atoms, preferably about 12 to 30 carbon atoms, and most preferably about 14 to 20 carbon atoms.
- Suitable alkylene oxides have 2 to 4 carbon atoms, preferably 2 or 3. Generally a mixture of two alkylene oxides will be used, either jointly or sequentially to form a block or a random configuration.
- the second deinking agent is an alkoxylated hydrophobic base, but it has a cloud point of about 2 to 20°C below the cloud point of the first deinking agent. Preferably the cloud point is about 4 to 18° below that of the first deinking agent.
- Suitable hydrophobic bases include any compounds which are hydrophobic and which can be alkoxylated by reaction with an alkylene oxide. Examples of such compounds include alcohols, amines, acids, dimer acids, and salts thereof. Most commonly an alcohol or an acid will be used.
- the hydrophobe compound will contain about 12 to 60 carbon atoms, preferably about 12 to 30 carbon atoms, and most preferably about 14 to 20 carbon atoms.
- Suitable alkylene oxides have 2 to 4 carbon atoms, preferably 2 or 3. Generally a mixture of two alkylene oxides will be used, either jointly or sequentially to form a block or a random configuration.
- Table 1 identifies some alkoxylated hydrophobic bases suitable for use as either the first or second deinking agent, depending upon the specific cloud point of the alkoxylated base.
- the cloud point is determined in a water solution between 0 and 100°C by heating a solution of the sample being analyzed until the solution clouds, then cooling until the solution clears. The temperature at which the solution clears is the cloud point.
- the polyester, the first deinking agent, and the second deinking agent are used in as low amounts as will produce the desired deinking effect.
- the polyester is generally used in an amount of about 0.05 to about 0.5 wt % based on the total weight of fiber present, preferably about 0.075 to about 0.25 wt %.
- the two deinking agents are used in a ratio of about 1 : 10 to about 10: 1 and in a total amount of about 0.001 to 0.3 wt % based on the total weight of fiber present.
- the specific amounts to be used for optimum performance will vary depending upon many factors including the equipment being used and the specific recycle composition. Thus they must be determined by routine trial and error testing.
- a fatty acid or salt thereof of the formula RCOO-M wherein R is a linear, branched, or cyclic alkyl or alkenyl group having about 7 to about 48 carbon atoms and M is hydrogen or a counterion such as Na, K, Ca, NH4, or NH ⁇ (CH2CH 2 OH) y wherein x and y are each integers from 0 to 4 and total 4, may be added along with the polyester and the two alkoxylated deinking agents, so doing is not preferred due to the problems caused by use/compatibility of such compounds.
- the fatty acid or salt thereof are most commonly used in the form of mixtures of such materials having about 12 to 48 carbon atoms and derived from natural oils such as marine, rapeseed, tallow, tall oil, soy, cottonseed, coconut, and the like.
- the fatty acid functions primarily to agglom-erate ink particles.
- the fatty acid or the salt thereof may be present in an amount from about 0.05 to 1.5 wt % based upon the weight of the waste paper, more preferably from about 0.1 to 0.5 wt %, and most preferably from about 0.2 to 0.5 wt %.
- the fatty acid or salt may be added either to an aqueous pulp slurry at the pulping stage or to the pulp slurry prior to its introduction to the flotation stage.
- the deinking procedure of the present invention entails the use of a flotation stage to remove inks, including very fine hydrophilic inks (flexographic inks) from printed media, particularly some waste newspapers wherein up to 100% of the ink may be flexographic.
- inks including very fine hydrophilic inks (flexographic inks) from printed media, particularly some waste newspapers wherein up to 100% of the ink may be flexographic.
- the process comprises a pulping step wherein printed waste paper, sometimes in combination with virgin wood pulp, is treated in an alkaline medium with water in a reactor having an agitation system.
- the aqueous suspension so form-ed contains pulp fiber, inks, coatings, inorganic fillers, and the like, in an amount of from about 3 to 18 wt % and is maintained at a pH of about 7.5 to 1 1.
- Typical chemicals used in the pulper have conventionally included such as NaOH and hydro-gen peroxide.
- Sodium silicate, a metal chelating agent such as diethylenetriamine-pentaacetic acid (DTP A), and calcium chloride have also been added to the pulper and/or flotation to maintain water hardness to ensure calcium soap formation. It is a particular benefit of the present invention that the total chemical demand of the pulping process can be reduced by the more efficient removal of the ink which permits use of less severe conditions and/or less chemicals.
- the sodium hydroxide adjusts the pH to be alkaline to aid ink release, swell cellulose fibers, wet the fibers, and disperse the released ink, fillers, etc. It also neutralizes chemical components such as fatty acids and provides the desired pH for subsequent bleaching and the flotation steps.
- the downside is increased fiber yellowing (a pronounced effect at pH > 9.5 which requires correction by the addition of bleaching agents), saponification of organics (the binders and adhesives in the recycled paper products) which results in stickies and machine deposits and release/formation of colloidal material via alkaline peptization which can adversely effect the efficiency of the foam to effectively transport the released ink during the flotation.
- the released organics and colloids contami-nate the water circuits which in turn increases the BOD/COD (biological oxygen demand/chemical oxygen demand) and the demand for water treatment chemical clean-up before discharge or reuse.
- Hydrogen peroxide is typically used as a bleaching agent and in the pulper to offset the adverse effects of excessive sodium hydroxide.
- Other conventional bleach-ing agents e.g. sodium hyposulfite, and optical bleaches such as sulfonated stilbenes, may be used.
- Sodium silicate is used to provide system buffering and metal chelation. It is used to avoid pH shocks which could result in deposits, and as a wetting or anti-corrosion agent, bleaching agent stabilizer and a source of alkalinity for pH control.
- the downside of using the silicate include its strong dispersive action and colloid generation which result in variable foam flotation profiles which can negatively impact ink removal.
- the three components can be added directly to the pulper during the pulping stage, preferably near the beginning thereof, or to the flotation cell prior to flotation.
- the components can be added individually or they may be pre-mixed. Mill conditions will determine the most suitable condi-tions.
- the slurry exits the pulper After the slurry exits the pulper, it is diluted to about 1 wt % solids. If a fatty acid or salt thereof is used, it may be added. Alternatively, the fatty acid component may be added partially during the pulping operation and partially upon entry to flotation. Thereafter, air is introduced into the flotation equipment to cause vigor-ous mixing of the diluted pulp slurry and to ensure foam generation for ink trans-port/removal from the system.
- a fatty acid or salt thereof it may be added. Alternatively, the fatty acid component may be added partially during the pulping operation and partially upon entry to flotation. Thereafter, air is introduced into the flotation equipment to cause vigor-ous mixing of the diluted pulp slurry and to ensure foam generation for ink trans-port/removal from the system.
- the ink particles are released from the recycled printed media and agglomerated into larger particles.
- the air bubbles then attach to the agglomerated ink particles and carry the agglomerated particles to the surface of the flotation equipment and form a foam thereon.
- This ink-rich foam is removed from the surface in any of the conventional manners well known in the art of deinking.
- a particular benefit of the present invention is the character of the foam which is produced.
- the foam has high ink carrying capability that upon leaving the flotation cell collapses in a regular and controlled manner so that the resulting inky liquid can be easily removed and sent to waste treatment for final disposal.
- the pulp slurry is thickened to about 6 to 12 wt % solids and washed using conventional equipment readily available and in widespread commercial use.
- the filtrate from the washing is typically treated in a dissolved air flotation (DAF) clarifier to remove inks, fillers, fiber fines, and other suspended solids so that the filtrate water can be recycled for use in a sub-sequent deinking procedure.
- DAF dissolved air flotation
- cationic, nonionic and/or anionic polymers are added to the filtrate prior to or in the dissolved air flotation clarifier so that the suspended solids will be agglomerated and/or flocculated and removed.
- the pulping process may be carried out either in a continuous way or batchwise, with excellent results with any type of printed media including newspaper, magazines, printed cardboard and colored printed media.
- the recycled paper is fed to the process so that it is present in an amount of about 10 to 100 wt % of the fiber undergoing pulping.
- the equipment used in this process is conventional equipment which is readily available and in widespread use.
- the use of the deinking components of the present invention has several advantages when compared to the conventional prior art. Compared to conventional deinking methods, a significant reduction in total chemical demand is realized when using this method. The ink removal rate is often also increased over conventional flotation methods, resulting in either increased production rates without sacrifice of product quality. Most importantly, the foam profile is such that extended continuous operations result.
- the dosage rate of the fatty acid component of the composition can be substantially reduced from the 1 to 2 wt % for a conventional process to below about 0.2 wt %, preferably below about 0.1 wt %, based on the total weight of fiber for the present invention.
- the none or lower amount significantly reduces the potential for scale and deposit problems normally associated with fatty acid components of deinking formulations both in the deinking equipment itself and at the subsequent paper machine. Expensive downtime for equipment clean-up is minimized and a higher quality final paper product can be produced.
- the brightness data represents the percent of light at wavelength 452 nanometers which is reflected off the filter pad and recorded by the spectrophotometer.
- Example 1 A mixture of 35% MAG (old magazines), 65% ONP (old newspapers) were shredded dry and combined. The mixture was added to a plant pulper along with water (120°F) and the each of the four different deinking/flotation deinking chemical systems specified in Table 2. The pulps had a consistency of about 12- 14 %.
- the polyester was the 1 : 1 molar reaction product of 5(6)-carboxy-4-hexyl- 2-cyclohexene-l-octanoic acid with polyethylene glycol (mw 1450).
- “Deink agent 1” was a block ethoxylated and propoxylated C- 18 alcohol having a cloud point of 48-50°C.
- “Deink agent 2” was a random ethoxylated and propoxylated C-18 alcohol having a cloud point of 42-44°C.
- the fatty acid was predominantly C-18.
- A is a prior art conventional fatty acid only foaming system used in the plant.
- B is a prior conventional fatty acid/alkoxylated hydrophobe blend deinking system used in the plant.
- C is a blend of an aromatic polyester and a single alkoxylated hydrophobe deinking system.
- Example 1 is a composition of the present invention utilizing the 3 component deinking system applied under plant conditions.
- the bleach demand for samples "A” and “B” was 0.4 wt % in each of the pulper and the tower.
- the bleach demand for samples "C” and Example 1 was 0 in the pulper and 0.6 wt % in the tower Table 2 Chemical Regimes - % on Dry Fiber
- the deinking performance of the 4 deinking compositions was evaluated and the results are shown in Table 3.
- water and waste paper was pulped for 15-20 minutes, test samples were taken. The samples were diluted to 1% using additional water and deinking performance deter-mined. Filter pads were made for measuring the brightness of the deinked pulp at this point. The balance of the pulp slurry was then passed into the plant's normal flotation cell. The foam that collected on the surface was allowed to flow over a weir and the foam characteristics determined. Another filter pad was made for measuring the brightness of the deinked pulp after flotation.
- Samples A and B (conventional fatty acid deinking with sodium salt of stearic acid) exhibited a typical wide operating band of foam life ranging from about 1.5 to 3.5 minutes.
- Sample A had a foam density p of 0.15-0.2 g/cc and a low foam half life of 1.5 minutes.
- Sample B had a foam density p of 0.2-0.3 g/cc, which indicates a higher ink content than Sample A, and a foam half life of 2.5-3.5 minutes.
- Sample C produced a foam which continued to increase and did not collapse on a regular basis.
- Sample C had a higher foam density p of 0.25-0.35 g/cc which indicates a still higher ink carrying capability than Samples A and B, but in view of the foam not collapsing, the system is not useful in the absence of a defoamer, the use of which causes the aforementioned problems.
- Sample 1 (invention) exhibited a quite narrow operating band with foam life ranging from 2.5 to 3.5 minutes.
- Sample 1 had a high foam density p of 0.2- 0.3 g/cc, which indicates good a high ink content.
- the half life of the foam was less than 2 minutes.
- the three component deinking composition produced an excellent foam profile while simultaneously allowing a reduction in the sodium hydroxide/silicate requirement from 2.25 wt % to 0.2 wt %.
- Example 2 The procedure of Example 1 was repeated at a plant processing mixed office waste paper at a rate of 265 tons per day (TPD). This actual mill data resulted from on-line 24-hr processing at this low yield plant (about 50%). With mixed office waste feed, the focus is on quality. The trial covered three of the 10 grades of paper produced at the plant.
- TPD tons per day
- DIA-3 was a block ethoxylated and propoxylated C-18 alcohol having a cloud point of 62°C.
- DIA-4" was a random ethoxylated and propoxylated C-18 alcohol having a cloud point of 44°C.
- the polyester was the 1 : 1 molar reaction product of 5(6)-carboxy-4-hexyl-2-cyclohexene-l-octanoic acid with polyethylene glycol (mw 1450). The fatty acid was predominantly C-18.
- Example 3 The procedure of Example 1 was repeated on a mixed office waste furnish while varying the composition of the polyester resin. The first was as disclosed in Example 1 , the second contained 1.9 wt % of the sodium salt of dimethylsulfo- isophthalate, and the third contained 5 wt % of the same salt. When the polyesters were used in a three component deinking system, the level of stickies found in the deinked product was reduced as the amount of the anionic salt increases.
- Example 4 The procedure of Example 1 was repeated at a deinked market pulp operation processing a 70:30 ratio of old newspaper:magazines. The plant was typically operating with 0.44 % fatty acid and 0.06 % of DIA-3 to produce paper having a brightness of 60-62 with an ERIC spread of 130- 180, of which the majority was 130- 160.
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP01971357A EP1309754A2 (en) | 2000-08-07 | 2001-08-07 | Flotation deinking process |
JP2002517890A JP4233867B2 (en) | 2000-08-07 | 2001-08-07 | Flotation deinking method |
CA 2418956 CA2418956A1 (en) | 2000-08-07 | 2001-08-07 | Flotation deinking process |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US22341400P | 2000-08-07 | 2000-08-07 | |
US60/223,414 | 2000-08-07 |
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WO2002012618A2 true WO2002012618A2 (en) | 2002-02-14 |
WO2002012618A3 WO2002012618A3 (en) | 2002-06-06 |
Family
ID=22836381
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Application Number | Title | Priority Date | Filing Date |
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PCT/US2001/041584 WO2002012618A2 (en) | 2000-08-07 | 2001-08-07 | Flotation deinking process |
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Country | Link |
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US (1) | US6544383B2 (en) |
EP (1) | EP1309754A2 (en) |
JP (1) | JP4233867B2 (en) |
CA (1) | CA2418956A1 (en) |
WO (1) | WO2002012618A2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010147581A1 (en) * | 2009-06-17 | 2010-12-23 | Kemira Oyj | Deinking process |
EP2386681A1 (en) | 2010-05-14 | 2011-11-16 | Universitat Politècnica de Catalunya | Process for recycling waste paper, product obtained there from and its uses |
CN107119480A (en) * | 2017-06-16 | 2017-09-01 | 江苏金沃机械有限公司 | A kind of waste paper recycles low ink pulping process |
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AU2002953252A0 (en) | 2002-12-09 | 2003-01-02 | Huntsman Corporation Australia Pty Ltd | Compositions, Compounds and Methods for their Preparation |
US7101832B2 (en) * | 2003-06-19 | 2006-09-05 | Johnsondiversey, Inc. | Cleaners containing peroxide bleaching agents for cleaning paper making equipment and method |
US7169257B2 (en) * | 2003-11-12 | 2007-01-30 | Kemira Chemicals, Inc. | Method of deinking waste paper using a reduced alkali system |
US20050115690A1 (en) * | 2003-11-25 | 2005-06-02 | Casella Waste Systems, Inc. | Methods for producing recycled pulp from waste paper |
US20050133172A1 (en) * | 2003-12-01 | 2005-06-23 | Robinson Peter M. | Deinking system for carbonate pulping |
US7862685B2 (en) * | 2006-01-09 | 2011-01-04 | Kemira Chemicals, Inc. | Method for deinking pulp using premixed hydrophobically modified calcium carbonate particles |
US7897010B2 (en) * | 2006-01-09 | 2011-03-01 | Kemira Chemicals, Inc. | Method for deinking pulp using premixed hydrophobically modified calcium carbonate particles |
US8052837B2 (en) * | 2006-06-12 | 2011-11-08 | Thiele Kaolin Company | Deinking of waste paper |
US8815051B2 (en) | 2006-06-12 | 2014-08-26 | Thiele Kaolin Company | Deinking of waste paper |
FI20075638A0 (en) * | 2007-09-13 | 2007-09-13 | Linde Ag | Removal of tack resin from a pulp suspension, reduction of calcium compounds in reject and use of carbon dioxide in papermaking |
US8317973B2 (en) * | 2009-11-11 | 2012-11-27 | Kemira Chemical, Inc. | Polyester surfactants for deinking |
US11447914B2 (en) | 2017-12-07 | 2022-09-20 | Thiele Kaolin Company | Removal of stickies in the recycling of paper and paperboard |
JP7120785B2 (en) | 2018-03-29 | 2022-08-17 | 日本製紙株式会社 | Deinking method for UV printed matter |
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- 2001-08-07 CA CA 2418956 patent/CA2418956A1/en not_active Abandoned
- 2001-08-07 US US09/923,595 patent/US6544383B2/en not_active Expired - Fee Related
- 2001-08-07 EP EP01971357A patent/EP1309754A2/en not_active Withdrawn
- 2001-08-07 JP JP2002517890A patent/JP4233867B2/en not_active Expired - Fee Related
- 2001-08-07 WO PCT/US2001/041584 patent/WO2002012618A2/en active Application Filing
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WO2010147581A1 (en) * | 2009-06-17 | 2010-12-23 | Kemira Oyj | Deinking process |
US8617353B2 (en) | 2009-06-17 | 2013-12-31 | Kemira Oyj | Deinking process |
EP2386681A1 (en) | 2010-05-14 | 2011-11-16 | Universitat Politècnica de Catalunya | Process for recycling waste paper, product obtained there from and its uses |
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CN107119480A (en) * | 2017-06-16 | 2017-09-01 | 江苏金沃机械有限公司 | A kind of waste paper recycles low ink pulping process |
Also Published As
Publication number | Publication date |
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JP2005520057A (en) | 2005-07-07 |
CA2418956A1 (en) | 2002-02-14 |
US6544383B2 (en) | 2003-04-08 |
JP4233867B2 (en) | 2009-03-04 |
EP1309754A2 (en) | 2003-05-14 |
US20020066880A1 (en) | 2002-06-06 |
WO2002012618A3 (en) | 2002-06-06 |
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