HRP921109A2 - Process for bleaching chemical paper pulp and the application of the same - Google Patents
Process for bleaching chemical paper pulp and the application of the same Download PDFInfo
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- HRP921109A2 HRP921109A2 HRP921109A HRP921109A2 HR P921109 A2 HRP921109 A2 HR P921109A2 HR P921109 A HRP921109 A HR P921109A HR P921109 A2 HRP921109 A2 HR P921109A2
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- pulp
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- hydrogen peroxide
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- 238000000034 method Methods 0.000 title claims description 32
- 238000004061 bleaching Methods 0.000 title claims description 17
- 229920001131 Pulp (paper) Polymers 0.000 title claims description 13
- 239000000126 substance Substances 0.000 title description 14
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 34
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 claims description 28
- FHHJDRFHHWUPDG-UHFFFAOYSA-N peroxysulfuric acid Chemical compound OOS(O)(=O)=O FHHJDRFHHWUPDG-UHFFFAOYSA-N 0.000 claims description 17
- 235000019398 chlorine dioxide Nutrition 0.000 claims description 16
- 239000002002 slurry Substances 0.000 claims description 16
- 239000000460 chlorine Substances 0.000 claims description 15
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 13
- 239000004155 Chlorine dioxide Substances 0.000 claims description 12
- 239000001301 oxygen Substances 0.000 claims description 11
- 229910052760 oxygen Inorganic materials 0.000 claims description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 10
- 229910052801 chlorine Inorganic materials 0.000 claims description 10
- 230000002378 acidificating effect Effects 0.000 claims description 9
- 239000002655 kraft paper Substances 0.000 claims description 7
- 239000003381 stabilizer Substances 0.000 claims description 7
- 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 claims description 6
- 229960003330 pentetic acid Drugs 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 159000000003 magnesium salts Chemical class 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 239000000123 paper Substances 0.000 claims 1
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 24
- 229920002678 cellulose Polymers 0.000 description 10
- 239000001913 cellulose Substances 0.000 description 10
- 150000003839 salts Chemical class 0.000 description 10
- 239000007864 aqueous solution Substances 0.000 description 9
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 8
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- 235000011121 sodium hydroxide Nutrition 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 238000010411 cooking Methods 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000003513 alkali Substances 0.000 description 5
- 229920005610 lignin Polymers 0.000 description 5
- 230000015556 catabolic process Effects 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- QBWCMBCROVPCKQ-UHFFFAOYSA-N chlorous acid Chemical compound OCl=O QBWCMBCROVPCKQ-UHFFFAOYSA-N 0.000 description 4
- 238000006731 degradation reaction Methods 0.000 description 4
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 4
- 235000019341 magnesium sulphate Nutrition 0.000 description 4
- 238000006116 polymerization reaction Methods 0.000 description 4
- -1 soluble Inorganic materials 0.000 description 4
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 3
- 235000011613 Pinus brutia Nutrition 0.000 description 3
- 241000018646 Pinus brutia Species 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910001902 chlorine oxide Inorganic materials 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 229920000573 polyethylene Polymers 0.000 description 3
- 239000002023 wood Substances 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229920005646 polycarboxylate Polymers 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 235000011149 sulphuric acid Nutrition 0.000 description 2
- 241000726768 Carpinus Species 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 229940120146 EDTMP Drugs 0.000 description 1
- 240000000731 Fagus sylvatica Species 0.000 description 1
- 235000010099 Fagus sylvatica Nutrition 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical class [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229920000388 Polyphosphate Polymers 0.000 description 1
- 241000219492 Quercus Species 0.000 description 1
- 239000005708 Sodium hypochlorite Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000008139 complexing agent Substances 0.000 description 1
- XPPKVPWEQAFLFU-UHFFFAOYSA-J diphosphate(4-) Chemical compound [O-]P([O-])(=O)OP([O-])([O-])=O XPPKVPWEQAFLFU-UHFFFAOYSA-J 0.000 description 1
- 235000011180 diphosphates Nutrition 0.000 description 1
- NFDRPXJGHKJRLJ-UHFFFAOYSA-N edtmp Chemical compound OP(O)(=O)CN(CP(O)(O)=O)CCN(CP(O)(O)=O)CP(O)(O)=O NFDRPXJGHKJRLJ-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 229910052816 inorganic phosphate Inorganic materials 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000012978 lignocellulosic material Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 125000005341 metaphosphate group Chemical group 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 239000001205 polyphosphate Substances 0.000 description 1
- 235000011176 polyphosphates Nutrition 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000004076 pulp bleaching Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
- AKEJUJNQAAGONA-UHFFFAOYSA-N sulfur trioxide Inorganic materials O=S(=O)=O AKEJUJNQAAGONA-UHFFFAOYSA-N 0.000 description 1
- 230000002087 whitening effect Effects 0.000 description 1
Landscapes
- Silver Salt Photography Or Processing Solution Therefor (AREA)
Description
Izum se odnosi na postupak za bijeljenje kaša celuloznog papira koje spadaju u kategoriju kemijskih kaša. The invention relates to a process for bleaching cellulose paper pulps that belong to the category of chemical pulps.
Poznato je tretiranje kemijskih sirovih kaša papira dobivenih kuhanjem lignoceluloznih materija pomoću sekvencije etapa tretmana delignifikacije i/ili bijeljenja koje obuhvaća primjenu kemijskih oksidacijskih proizvoda. Prva etapa klasične sekvencije bijeljenja kemijske kaše ima za cilj dovršiti delignifikaciju sirove kaše, takve kao one koja se dobiva poslije operacije kuhanja. Ova prva etapa delignifikacije tradicionalno se realizira tretiranjem sirove kaše sa klorom u kiseloj sredini ili sa klorom i kloridoksidom, u smjesi ili sekvencijski, tako da reagiraju sa preostalim ligninom iz kaše i dovodi do nastajanja klorolignina koji se mogu izdvojiti iz kaše otapanjem u alkalnoj sredini u etapi kasnijeg tretmana. It is known to treat chemical raw paper pulp obtained by cooking lignocellulosic materials using a sequence of delignification and/or bleaching treatment stages that includes the use of chemical oxidation products. The first stage of the classic chemical pulp bleaching sequence aims to complete the delignification of the raw pulp, such as that obtained after the cooking operation. This first stage of delignification is traditionally realized by treating the raw pulp with chlorine in an acidic environment or with chlorine and chloride oxide, in a mixture or sequentially, so that they react with the remaining lignin from the pulp and lead to the formation of chlorolignin that can be separated from the pulp by dissolving in an alkaline medium in stages of later treatment.
Iz različitih razloga, pokazalo se korisnim u određenim situacijama, zamijeniti ovu prvu etapu delignifikacije sa tretmanom koji ne zahtijeva više reaktivni klor. For various reasons, it has proven useful in certain situations to replace this first stage of delignification with a treatment that no longer requires reactive chlorine.
Prije oko deset godina, predložena je zamjena, bar djelomična, prve etape tretmana pomoću klora i klordioksida sa etapom tretmana sa plinovitim kisikom u alkalnoj sredini (Kirk-Othmer Encyclopedia of Chemical Technology Third Edition vol. 19. 19, New-York 1982, str. 415, 3. paragraf i str. 416, 1. i 2. paragrafi). Cijena delignifikacije koja se dobiva ovim postupkom u kisiku nije međutim povoljna, ako se želi proizvodnja kemijskih kaša velike bjeline. About ten years ago, it was proposed to replace, at least partially, the first stage of treatment using chlorine and chlorine dioxide with a stage of treatment with gaseous oxygen in an alkaline medium (Kirk-Othmer Encyclopedia of Chemical Technology Third Edition vol. 19. 19, New-York 1982, p 415, paragraph 3 and page 416, paragraphs 1 and 2). The price of delignification obtained by this process in oxygen is not favorable, however, if the production of chemical slurries of high whiteness is desired.
U međunarodnom zahtjevu za patent WO-7900637 u ime Mo Och Domsjö predloženo je bijeljenje kemijske kaše papira pomoću vodik peroksida u kiseloj sredini u prisustvu kompleksirajućeg agensa. Bjelina dobivena na ovaj način je međutim samo malo uvećana. Dalje, u ovom postupku celuloza podliježe znatnoj degradaciji. In international patent application WO-7900637 in the name of Mo Och Domsjö, bleaching of chemical paper pulp using hydrogen peroxide in an acidic medium in the presence of a complexing agent is proposed. However, the whiteness obtained in this way is only slightly increased. Furthermore, in this process the cellulose is subject to significant degradation.
Ovaj izum uklanja nedostatke poznatih postupaka i osigurava novi postupak delignifikacije i/ili bijeljenja kemijskih kaša papira koji osigurava dobivanje uvećanih nivoa bjeline bez znatnije degradacije celuloze. This invention eliminates the disadvantages of known processes and provides a new process of delignification and/or bleaching of chemical paper pulps that ensures obtaining increased levels of whiteness without significant cellulose degradation.
U ovom cilju, izum se odnosi na postupak za bijeljenje kemijske kaše papira koji ne obuhvaća preliminiranu etapu delignifikacije sa klorom u kiseloj sredini ili sa klorom i klordioksidom u kiseloj sredini, prema kome se kaša podvrgava tretmanu u dvije uzastopne etape koje po redu obuhvaćaju: tretiranje sa peroksimonosumpornom kiselinom i tretiranje sa alkalnim vodik peroksidom, gdje se prva etapa vrši na temperaturi između 75 i 100ºC za vrijeme između 70 i 150 minuta i sa kašom koja sadrži između 12 i 25% suhih materija. To this end, the invention relates to a process for bleaching chemical paper pulp that does not include a preliminary stage of delignification with chlorine in an acidic medium or with chlorine and chlorine dioxide in an acidic medium, according to which the pulp is subjected to treatment in two successive stages, which in turn include: treatment with peroxymonosulfuric acid and treatment with alkaline hydrogen peroxide, where the first stage is carried out at a temperature between 75 and 100ºC for a time between 70 and 150 minutes and with a slurry containing between 12 and 25% dry matter.
Prema ovom izumu, pod kemijskom kašom papira, podrazumijevaju se kaše koje su podvrgnute postupku delignifikacije u prisustvu kemijskih reagenasa takvih kao što je natrijev sulfid u alkalnoj sredini (kuhani kraft ili sulfat), sumporni anhidrid ili metalna sol sumporne kiseline u kiseloj sredini (kuhana u sulfitu). Polukemijske kaše takve kao ove ili kuhane dobivene pomoću soli sumporne kiseline u neutralnoj sredini (kuhanje u sulfitu još nazvano kuhanje NSSC) također se mogu bijeliti postupkom prema izumu. According to this invention, chemical paper pulp means pulps that have undergone a delignification process in the presence of chemical reagents such as sodium sulfide in an alkaline medium (boiled kraft or sulfate), sulfuric anhydride or a metallic salt of sulfuric acid in an acidic medium (boiled in sulfite). Semi-chemical slurries such as these or boiled obtained using sulfuric acid salts in a neutral environment (sulphite cooking also called NSSC cooking) can also be bleached by the process according to the invention.
Ovaj izum se naročito odnosi na kaše koje su podvrgnute kuhanju krafta (sulfatne celuloze) i čiji sadržaj preostalog lignina je u području indeksa kapa između 8 i 35 prema tipu postojećeg drveta odakle se dobivaju i djelotvornosti procesa kuhanja. Svi tipovi drveta korišteni za dobivanje kemijskih kaša pogodni su za korištenje u postupku iz izuma i naročito oni korišteni za kraft kaše, tj. smolaste šume, npr., razne vrste bora i jela i listopadne šume kao npr., bukva, hrast i grab. This invention particularly relates to pulps that are subjected to kraft (sulfate cellulose) cooking and whose remaining lignin content is in the range of the kappa index between 8 and 35 according to the type of existing wood from which they are obtained and the effectiveness of the cooking process. All types of wood used to obtain chemical slurries are suitable for use in the process of the invention, and especially those used for kraft slurries, i.e. resinous woods, e.g., various types of pine and fir and deciduous forests such as, e.g., beech, oak and hornbeam.
S preliminarnom etapom delignifikacije sa klorom u kiseloj sredini, označava se prva etapa sekvencije bijeljenja u kojoj se koristi vodena otopina plinovitog klora sa pH manjim od 4. Također preliminirana etapa delignifikacije sa klorom i klordioksidom u kiseloj sredini se odnosi na postupak delignifikacije sa smjesom vodene otopine plinovitog klora i vodene otopine klordioksida sa pH manjim od 4 ili još i na sekvencijski postupak sa vodenom otopinom klora i zatim sa vodenom otopinom klordioksida ili sa spomenutim reagensima primijenjenim pri obrnutom redoslijedu, gdje je pH u svakom slučaju ispod 4. With the preliminary stage of delignification with chlorine in an acidic environment, the first stage of the bleaching sequence is indicated, in which an aqueous solution of gaseous chlorine with a pH lower than 4 is used. Also, the preliminary stage of delignification with chlorine and chlorine dioxide in an acidic environment refers to the delignification process with an aqueous solution mixture of gaseous chlorine and an aqueous solution of chlorine dioxide with a pH lower than 4 or even to a sequential procedure with an aqueous solution of chlorine and then with an aqueous solution of chlorine dioxide or with the mentioned reagents applied in reverse order, where the pH is in any case below 4.
Prva etapa tretmana kaše od papira odnosi se na tretman sa peroksimonosumpornom kiselinom (nazvanom još Caro kiselina). Pod peroksimonosumpornom kiselinom se podrazumijeva neorganska kiselina koja odgovara formuli H2SO5 ili njene alkalne, zemnoalkalne i amonijeve soli ili smjesu više ovih soli ili peroksimonosumporne kiseline sa ovim solima. Peroksimonosumporna kiselina ili soli koje se mogu koristiti, u jednoj zanimljivoj varijanti postupka prema izumu, pripremaju se neposredno prije svoje primjene reakcijom vodene otopine koncentrirane sumporne kiseline ili njenih soli sa vodenom otopinom koncentriranog peroksigenog spoja, npr., vodik peroksida. Koncentriranom otopinom označavaju se otopine H2SO4 koncentracije veće od 10 mol/litri i H2O2 koncentracije veće od 20 mas.%. The first stage of paper pulp treatment refers to treatment with peroxymonosulfuric acid (also called Caro acid). By peroxymonosulfuric acid is meant an inorganic acid corresponding to the formula H2SO5 or its alkaline, alkaline earth and ammonium salts or a mixture of several of these salts or peroxymonosulfuric acid with these salts. Peroxymonosulfuric acid or salts that can be used, in one interesting variant of the process according to the invention, are prepared immediately before their use by reacting an aqueous solution of concentrated sulfuric acid or its salts with an aqueous solution of a concentrated peroxygen compound, for example, hydrogen peroxide. Concentrated solution refers to solutions of H2SO4 concentration greater than 10 mol/liter and H2O2 concentration greater than 20 wt.%.
Na poželjan način, prva etapa postupka prema izumu može se vršiti u prisustvu stabilizirajućeg agensa. Poznati stabilizatori peroksigenih proizvoda za ovo dobro odgovaraju. Preferably, the first stage of the process according to the invention can be carried out in the presence of a stabilizing agent. Well-known stabilizers of peroxygen products are suitable for this.
Primjeri takvih stabilizatora su soli zemnoalkalnih metala, naročito topljive soli magnezija, topljivih, neorganskih fosfata i polifosfata, takvih kao pirofosfat i metafosfati alkalnih metala, organski polikarboksilati takvi kao kiseline vinska, limunska, glukonska, dietilentriaminpentaocetena, ciklohesandiamintetraocetena i njihove topljive soli, pli-alfa-hidroksiakrilne kiseline i njihove topljive soli i organski polifosfonati takvi kao kiseline etilendiamintetrametilenfosfonska, dietilentriaminpenta(metilenfosfonska), cikloheksandiamintetrametilfosfonska i njihove topljive soli. Examples of such stabilizers are salts of alkaline earth metals, especially soluble salts of magnesium, soluble, inorganic phosphates and polyphosphates, such as pyrophosphate and metaphosphates of alkaline metals, organic polycarboxylates such as tartaric, citric, gluconic, diethylenetriaminepentaacetene, cyclohexadiaminetetraacetene and their soluble salts, poly-alpha -hydroxyacrylic acids and their soluble salts and organic polyphosphonates such as ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepenta(methylenephosphonic), cyclohexanediaminetetramethylphosphonic acid and their soluble salts.
Također u smjesu je moguće uključiti više ovih stabilizirajućih agenasa. Generalno, polikarboksilati ili organski polisulfonati daju dobre rezultate, naročito kada su udruženi s jednom od topljivih soli magnezija. Udruživanje topljive soli magnezija takve kao što je MgSO4 i dietilentriaminpentaoctene kiseline (DTPA) je poželjno u koncentracijama od 0,02 do 0,2 MgSO4/100 g suhe kaše i 0,05 do 0,3 g DTPA/100 g suhe kaše. It is also possible to include more of these stabilizing agents in the mixture. In general, polycarboxylates or organic polysulfonates give good results, especially when combined with one of the soluble magnesium salts. The combination of a soluble magnesium salt such as MgSO4 and diethylenetriaminepentaacetic acid (DTPA) is preferably in concentrations of 0.02 to 0.2 MgSO4/100 g dry pulp and 0.05 to 0.3 g DTPA/100 g dry pulp.
Etapa tretiranja kaše papira sa peroksimonosumpornom kiselinom obično se vrši u uvjetima atmosferskog pritiska i na temperaturi koja osigurava dobru potrošnju peroksimonosumporne kiseline, i u isto vrijeme ne suviše visokoj koja bi izazvala degradiranje celuloze i povećala znatnije energetski utrošak sredstava za zagrijavanje korištenih u ovoj etapi. Poželjno područje temperatura je 85-95ºC. Najbolji rezultati se dobivaju na 90ºC. The stage of treating paper pulp with peroxymonosulfuric acid is usually carried out under atmospheric pressure conditions and at a temperature that ensures good consumption of peroxymonosulfuric acid, and at the same time not too high which would cause degradation of the cellulose and significantly increase the energy consumption of the heating means used in this stage. The preferred temperature range is 85-95ºC. The best results are obtained at 90ºC.
Trajanje etape tretmana sa peroksimonosumpornom kiselinom mora biti dovoljno da osigura potpunu reakciju. Kako dužina trajanja ne treba utjecati na cijenu delignifikacije kaše kao i na kvalitetu unutarnje otpornosti ne savjetuje se znatno produženje trajanja tretmana u cilju ograničavanja troškova investiranja i energetskih utrošaka zagrijavanja kaše. Praktično, trajanje reakcije vezuje se za izabranu temperaturu koja omogućava najmanje vrijeme trajanja. Trajanja tretmana između 85 i 130 minuta su poželjna i obično su dovoljna. Trajanja od 90 do 120 minuta, međutim, dala su najbolje rezultate. The duration of the treatment step with peroxymonosulfuric acid must be sufficient to ensure a complete reaction. Since the length of time should not affect the price of delignification of the pulp as well as the quality of internal resistance, it is not advisable to significantly extend the duration of the treatment in order to limit investment costs and energy consumption of heating the pulp. Practically, the duration of the reaction is related to the selected temperature that allows the shortest duration. Treatment durations between 85 and 130 minutes are preferred and usually sufficient. Durations of 90 to 120 minutes, however, produced the best results.
Druga etapa tretmana iz postupka prema izumu sastoji se od etape tretiranja alkalnim vodik peroksidom. Ova etapa vrši se na sličan način kao i tradicionalna etapa ekstrakcije u kojoj se dodaje vodena otopina vodik peroksida u alkalni reagens. Količine vodik peroksida koje se koriste u ovoj etapi ovisit će o sadržaju preostalog lignina prisutnog u kaši kao i prirode drveta koje se koristi za proizvodnju. Generalno ove količine će biti u području između 0,3 u 3,0 g H2O2/100 g suhe kaše i poželjno između 0,5 i 2,0 g H2O2/100 g suhe kaše. Priroda korištene alkalije mora biti takva da ima dobru djelotvornost i u isto vrijeme dobru topljivost. Jedan primjer takve alkalije je natrijev hidroksid u vodenoj otopini. Sadržaj alkalije mora se prilagoditi tako da osigura potpunu potrošnju peroksida na kraju reakcije. Sadržaji alkalije između 1 i 3 g alkalije izraženo u NaOH na 100 g suhe kaše dobro odgovaraju. Količine H2O2 od 1 g H2O2/100 g suhe kaše i NaOH od 2 g NaOH/100 g suhe kaše daju odlične rezultate. The second stage of treatment from the process according to the invention consists of the stage of treatment with alkaline hydrogen peroxide. This stage is performed in a similar way to the traditional extraction stage, in which an aqueous solution of hydrogen peroxide is added to the alkaline reagent. The amounts of hydrogen peroxide used in this stage will depend on the content of the remaining lignin present in the pulp as well as the nature of the wood used for production. Generally these amounts will be in the range between 0.3 to 3.0 g H 2 O 2 /100 g dry pulp and preferably between 0.5 and 2.0 g H 2 O 2 /100 g dry pulp. The nature of the alkali used must be such that it has good effectiveness and at the same time good solubility. One example of such an alkali is sodium hydroxide in aqueous solution. The alkali content must be adjusted to ensure complete consumption of the peroxide at the end of the reaction. Alkali contents between 1 and 3 g of alkali expressed in NaOH per 100 g of dry pulp are suitable. Amounts of H2O2 of 1 g H2O2/100 g of dry pulp and NaOH of 2 g NaOH/100 g of dry pulp give excellent results.
U jednoj varijanti postupka prema izumu, mogu se ako se želi dobiti visoki nivoi bijeljenja, primjenom druge etape tretmana sa sekvencijom etapa tradicionalnog bijeljenja koje obuhvaćaju ili ne klorirane reagense. Primjeri takvih etapa su sljedeći: tretiranje sa klor dioksidom, natrijevim hipokloritom, ekstrakcija u kaustičnoj sodi u prisustvu vodik peroksida. Može se, npr. primijeniti i treća etapa postupka prema izumu sa nizom od dvije dopunske etape tretmana sa alkalnim klor dioksidom i vodik peroksidom. Dodavanje šeste etape u kojoj se koristi klordioksid omogućava lako postizanje bjeline od 90º ISO. In one variant of the process according to the invention, high levels of bleaching can be obtained, if desired, by applying a second treatment step with a sequence of traditional bleaching steps that may or may not include chlorinated reagents. Examples of such stages are the following: treatment with chlorine dioxide, sodium hypochlorite, extraction in caustic soda in the presence of hydrogen peroxide. It is possible, for example, to apply the third stage of the process according to the invention with a series of two supplementary stages of treatment with alkaline chlorine dioxide and hydrogen peroxide. Adding a sixth stage that uses chlorine dioxide makes it easy to achieve a whiteness of 90º ISO.
Jedna druga, varijanta postupka prema izumu obuhvaća primjenu prve etape tretmana kemijske kaše papira s kisikom. Ovaj tretman s kisikom vrši se kontaktiranjem sirove kaše s plinovitim kisikom pod pritiskom između 20 i 1000 kPa u prisustvu alkalnog spoja u takvoj količini da se masa alkalnog spoja u odnosu na masu suhe kaše nalazi u području između 0,5 i 4,0%. Temperatura prve etape mora se prilagoditi u obujmu između 70 i 130ºC i poželjno između 80 i 120ºC. Trajanje tretmana sa kisikom mora biti dovoljno dugo da reakcija kisika sa sadržajem lignina u kaši bude potpuna. Ne može suviše preći vrijeme reagiranja zbog opasnosti od degradacije u strukturi celuloznih lanaca kaše. U praksi se ono fiksira na vrijednost između 30 i 120 minuta i, poželjno, između 40 i 80 minuta. Kombinacija uvjeta temperature i trajanja od 90ºC i 60 minuta daje dobre rezultate. Another variant of the process according to the invention includes the application of the first stage of treatment of chemical paper pulp with oxygen. This oxygen treatment is carried out by contacting the raw pulp with gaseous oxygen under a pressure between 20 and 1000 kPa in the presence of an alkaline compound in such an amount that the mass of the alkaline compound in relation to the mass of the dry pulp is in the range between 0.5 and 4.0%. The temperature of the first stage must be adjusted between 70 and 130ºC and preferably between 80 and 120ºC. The duration of the treatment with oxygen must be long enough for the reaction of oxygen with the lignin content in the pulp to be complete. The reaction time cannot be exceeded too much because of the danger of degradation in the structure of the pulp's cellulose chains. In practice, it is fixed at a value between 30 and 120 minutes and, preferably, between 40 and 80 minutes. The combination of temperature and duration conditions of 90ºC and 60 minutes gives good results.
Također je moguće kombinirati predtretman u kisiku sa dvije etape tretmana prema izumu i s naknadnim etapama klasičnog bijeljenja. It is also possible to combine pre-treatment in oxygen with two treatment stages according to the invention and with subsequent stages of classic whitening.
Postupak prema izumu nalazi primjenu za bijeljenje kemijskih kaša tipa kraft ili sulfitnih ili polikemijskih kaša visoke kvalitete, naročito onih koje su namijenjene za prehrambenu ambalažu. Ovo je pogodno bez razlike i za kaše koje potječu od zimzelenih ili listopadnih šuma. The process according to the invention is used for bleaching chemical slurries of the kraft type or sulfite or polychemical slurries of high quality, especially those intended for food packaging. This is equally suitable for pulps originating from evergreen or deciduous forests.
Sljedeći primjeri su dani radi ilustracije izuma bez ograničavanja predmeta. Primjeri 1R i 2R nisu primjeri izuma i dani su radi usporedbe. Primjeri 3-5 su primjeri izuma. The following examples are provided to illustrate the invention without limiting the subject matter. Examples 1R and 2R are not examples of the invention and are provided for comparison. Examples 3-5 are examples of the invention.
Primjer 1R (nije prema izumu) Example 1R (not according to the invention)
Uzorak kemijske kaše od bora koji je podvrgnut kraft kuhanju (početne bjeline 29,3º ISO mjerena prema normi ISO 2470, indeksa kapa 27,6 mjerenog prema normi SCAN Cl:59 i stupnja polimerizacije celuloze 1350 mjerenog prema normi SCAN 15:62) pomiješa se sa 1,4 mas.% H2SO4 u odnosu na suhu kašu i stavi se u vrećicu od polietilena. U vrećicu se zatim uvodi demineralizirana voda radi prilagođavanja sadržaja suhe materije na 15 %, sadržaj se izmijesi i vrećica se pažljivo zatvara. Vrećica se zatim unosi u kadu vodenog termostata na 90ºC i pusti da se reakcija odvija tijekom 90 minuta. Na kraju ovog prvog testiranja kaše, pH kaše je 2,2. A sample of chemical pine pulp subjected to kraft cooking (initial whiteness 29.3º ISO measured according to ISO 2470, kappa index 27.6 measured according to SCAN Cl:59 and cellulose polymerization degree 1350 measured according to SCAN 15:62) is mixed with 1.4 wt.% H2SO4 compared to the dry mash and placed in a polyethylene bag. Demineralized water is then introduced into the bag to adjust the dry matter content to 15%, the contents are mixed and the bag is carefully closed. The bag is then placed in a water thermostat bath at 90ºC and the reaction is allowed to take place for 90 minutes. At the end of this first slurry testing, the pH of the slurry is 2.2.
Vrećica se izvuće iz termostata, otvori i kaša se ispere u volumenu demineralizirane vode koja odgovara 40-strukoj masi suhe kaše. Kaša se zatim filtrira na buchner filteru, stavi se u polietilensku vrećicu i izmiješa sa 1,0 mas.% vodik peroksida i 2,7 mas.% NaOH u odnosu na suhu kašu i demineraliziranu vodu u količini koja održava suhi sadržaj na 15 %. Polietilenska vrećica koja sadrži uzorak reaktanata poslije pažljivog gnječenja se uvodi u kadu vodenog termostata na 90ºC. Poslije 120 minuta reagiranja, kaša se ispere u volumenu demineralizirane vode koja odgovara 40-strukom sadržaju suhe mase i filtrira na buchner filteru. Zatim se postupak nastavlja određivanjem bjeline tretirane kaše sukladno radnom načinu opisanom u normi ISO 2470 i indeksa kapa (sadržaj preostalog lignina) prema normi SCAN Cl:59. The bag is pulled out of the thermostat, opened and the pulp is washed in a volume of demineralized water corresponding to 40 times the mass of dry pulp. The slurry is then filtered on a buchner filter, placed in a polyethylene bag and mixed with 1.0 wt.% hydrogen peroxide and 2.7 wt.% NaOH relative to the dry slurry and demineralized water in an amount that maintains the dry content at 15%. After careful kneading, the polyethylene bag containing the reactant sample is introduced into the bath of the water thermostat at 90ºC. After 120 minutes of reaction, the slurry is washed in a volume of demineralized water corresponding to 40 times the content of dry mass and filtered on a Buchner filter. The procedure then continues with the determination of the whiteness of the treated pulp in accordance with the working method described in the ISO 2470 standard and the cap index (remaining lignin content) according to the SCAN Cl:59 standard.
Rezultat ovih mjerenja je 42,9º ISO za bjelinu i 14,4 za indeks kapa. The result of these measurements is 42.9º ISO for whiteness and 14.4 for the cap index.
Prema istom postupku zatim se vrše tri etape klasičnog bijeljenja u klordioksidu, vodik peroksidu i klordioksidu, tako da se realizira sekvencija globalnog bijeljenja A P1 D1 P2 D2 u sljedećim uvjetima: According to the same procedure, three stages of classic bleaching in chlorine dioxide, hydrogen peroxide and chlorine dioxide are then carried out, so that the global bleaching sequence A P1 D1 P2 D2 is realized in the following conditions:
a) etapa D1: a) stage D1:
količina ClO2: 4 mas.% u odnosu na sadržaj u suhoj kaši: 12 % suhe materije amount of ClO2: 4 wt.% in relation to the content in dry pulp: 12 % of dry matter
trajanje: 150 minuta duration: 150 minutes
temperatura: 70ºC temperature: 70ºC
b) etapa P2: b) stage P2:
količina H2O2: 0,15 mas.% u odnosu na količinu NaOH u suhoj kaši: 0,5 mas.% u odnosu na sadržaj u suhoj kaši: 12 mas.% suhe materije amount of H2O2: 0.15 wt.% in relation to the amount of NaOH in the dry pulp: 0.5 wt.% in relation to the content in the dry pulp: 12 wt.% of dry matter
trajanje: 120 minuta duration: 120 minutes
temperatura: 70ºC temperature: 70ºC
c) etapa D2: c) stage D2:
količina ClO2: 1 mas.% u odnosu na sadržaj u suhoj kaši: 12 mas.% suhe materije amount of ClO2: 1 wt.% in relation to the content in dry pulp: 12 wt.% of dry matter
trajanje: 120 minuta duration: 120 minutes
temperatura: 70ºC temperature: 70ºC
Izmjereni su sljedeći rezultati: The following results were measured:
a) poslije etape D1: a) after stage D1:
bjelina: 52,9º ISO whiteness: 52.9º ISO
b) poslije etape P2: b) after stage P2:
bjelina: 64,1º ISO whiteness: 64.1º ISO
c) poslije etape D2: c) after stage D2:
bjelina: 79,8º ISO whiteness: 79.8º ISO
indeks kapa: 1,6 cap index: 1.6
stupanj polimerizacije celuloze: 1020 cellulose polymerization degree: 1020
Primjer 2R (nije prema izumu) Example 2R (not according to the invention)
Ponovi se primjer 1R uz dodatak vodik peroksida prvoj etapi sa kisikom u količini 0,75 % u odnosu na suhu kašu dok svi drugi uvjeti ostaju isti. Dobivaju se sljedeći rezultati: Example 1R is repeated with the addition of hydrogen peroxide to the first stage with oxygen in the amount of 0.75% compared to the dry pulp, while all other conditions remain the same. The following results are obtained:
a) poslije etape P1: a) after stage P1:
bjelina: 44,2º ISO whiteness: 44.2º ISO
b) poslije etape P1: b) after stage P1:
bjelina: 59,6º ISO whiteness: 59.6º ISO
c) poslije etape P2: c) after stage P2:
bjelina: 66,4º ISO whiteness: 66.4º ISO
d) poslije etape D2: d) after stage D2:
bjelina: 82,0º ISO whiteness: 82.0º ISO
indeks kapa: 1,4 cap index: 1.4
stupanj polimerizacije celuloze: 860 cellulose polymerization degree: 860
Primjeri 3 i 4 (prema izumu) Examples 3 and 4 (according to the invention)
Ponovi se primjer 1R uz zamjenu prve etape tretiranja sa sumpornom kiselinom tretmanom sa tretiranjem sa peroksimonosumpornom kiselinom u količini 0,5 mas.% kiseline Caro na suhu kašu pri čemu svi drugi uvjeti ostaju isti. U primjeru 4 osim ove kiseline u prvoj etapi se koriste i sljedeći proizvodi: u svojstvu stabilizatora 0,2 mas.% dietilentriaminpentaoctene kiseline (DTPA) i 0,1 mas.% MgSO4 u odnosu na suhu kašu. Example 1R is repeated, replacing the first stage of treatment with sulfuric acid with treatment with peroxymonosulfuric acid in the amount of 0.5% by weight of Caro acid on dry pulp, while all other conditions remain the same. In example 4, in addition to this acid, the following products are used in the first stage: as a stabilizer, 0.2 wt.% diethylenetriaminepentaacetic acid (DTPA) and 0.1 wt.% MgSO4 in relation to the dry slurry.
Dobivaju se sljedeći rezultati: The following results are obtained:
Primjer 3 Primjer 4 Example 3 Example 4
a) poslije prve etape P1: a) after the first stage P1:
bjelina, º ISO: 42,5 41,7 whiteness, º ISO: 42.5 41.7
indeks kapa: 13,0 13,5 cap index: 13.0 13.5
b) poslije etape D1: b) after stage D1:
bjelina, º ISO: 58,8 57,8 whiteness, º ISO: 58.8 57.8
c) poslije etape P2: c) after stage P2:
bjelina º ISO: 71,2 70,7 whiteness º ISO: 71.2 70.7
d) poslije etape D2: d) after stage D2:
bjelina º ISO: 85,1 85,8 whiteness º ISO: 85.1 85.8
indeks kapa: 1,1 1,1 cap index: 1.1 1.1
stupanj polimerizacije degree of polymerization
celuloze 910 1020 cellulose 910 1020
Primjer 5 (prema izumu) Example 5 (according to the invention)
Isti uzorak kraft kaše bora se pomiješa sa 3,0 mas.% NaOH i 0,1 mas.% MgSO4 u odnosu na suhu kašu i stavi se u autoklav koji je snabdjeven sustavom za mehaničko mućkanje. U autoklav se zatim uvodi demineralizirana voda radi dostizanja sadržaja suhe materije od 15 % i zatim se uvodi kisik pod pritiskom od 600 kPa. Ostavi se zatim da sve reagira na temperaturi od 110ºC tijekom 60 minuta. The same sample of kraft pine pulp is mixed with 3.0 wt.% NaOH and 0.1 wt.% MgSO4 relative to the dry pulp and placed in an autoclave equipped with a mechanical shaking system. Demineralized water is then introduced into the autoclave to reach a dry matter content of 15% and then oxygen is introduced under a pressure of 600 kPa. Then everything is left to react at a temperature of 110ºC for 60 minutes.
Autoklav se otvori i kaša se ispere za volumenu demineralizirane vode koja je 40-struka u odnosu na suhu masu. Kaša se zatim filtrira na buchner filteru i podvrgava bijeljenju prema sekvenciji Ca P1 D1 P2 D2 u uvjetima identičnim sa onima iz primjera 4 osim što se količina ClO2 u etapi D1 smanjuje na 3,0 g ClO2/100 g suhe kaše. The autoclave is opened and the slurry is washed with a volume of demineralized water that is 40 times the dry mass. The pulp is then filtered on a buchner filter and subjected to bleaching according to the sequence Ca P1 D1 P2 D2 under conditions identical to those of example 4 except that the amount of ClO2 in stage D1 is reduced to 3.0 g ClO2/100 g of dry pulp.
Dobivaju se sljedeći rezultati: The following results are obtained:
a) poslije etape O: a) after stage O:
bjelina, ºISO: 35,2 whiteness, ºISO: 35.2
indeks kapa: 14,8 cap index: 14.8
b) poslije etape Ca: b) after stage Ca:
bjelina, º ISO: 37,8 whiteness, º ISO: 37.8
c) poslije etape P1: c) after stage P1:
bjelina, º ISO: 53,7 whiteness, º ISO: 53.7
indeks kapa: 7,5 cap index: 7.5
d) poslije etape D1: d) after stage D1:
bjelina, º ISO: 71,8 whiteness, º ISO: 71.8
e) poslije etape P2: e) after stage P2:
bjelina, º ISO: 81,4 whiteness, º ISO: 81.4
f) poslije etape D2: f) after stage D2:
bjelina, º ISO: 90,8 whiteness, º ISO: 90.8
indeks kapa: 0,5. cap index: 0.5.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| HRP921109 HRP921109A2 (en) | 1992-10-23 | 1992-10-23 | Process for bleaching chemical paper pulp and the application of the same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| HRP921109 HRP921109A2 (en) | 1992-10-23 | 1992-10-23 | Process for bleaching chemical paper pulp and the application of the same |
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| HRP921109A2 true HRP921109A2 (en) | 1994-12-31 |
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| HRP921109 HRP921109A2 (en) | 1992-10-23 | 1992-10-23 | Process for bleaching chemical paper pulp and the application of the same |
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| HR (1) | HRP921109A2 (en) |
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1992
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