JP5953909B2 - Method for producing dissolving pulp - Google Patents
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- JP5953909B2 JP5953909B2 JP2012102082A JP2012102082A JP5953909B2 JP 5953909 B2 JP5953909 B2 JP 5953909B2 JP 2012102082 A JP2012102082 A JP 2012102082A JP 2012102082 A JP2012102082 A JP 2012102082A JP 5953909 B2 JP5953909 B2 JP 5953909B2
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- 229920000875 Dissolving pulp Polymers 0.000 title claims description 27
- 238000004519 manufacturing process Methods 0.000 title claims description 19
- 238000000034 method Methods 0.000 claims description 50
- 150000002978 peroxides Chemical class 0.000 claims description 47
- 238000010411 cooking Methods 0.000 claims description 45
- 230000002378 acidificating effect Effects 0.000 claims description 41
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical group OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 30
- 238000004061 bleaching Methods 0.000 claims description 24
- 239000012978 lignocellulosic material Substances 0.000 claims description 20
- 239000002655 kraft paper Substances 0.000 claims description 19
- 239000003513 alkali Substances 0.000 claims description 17
- 238000002419 base digestion Methods 0.000 claims description 14
- 239000002994 raw material Substances 0.000 claims description 11
- LUNBMBVWKORSGN-TYEKWLQESA-N P-factor Chemical compound CC(C)C[C@@H](C(O)=O)NC(=O)[C@H](CC(N)=O)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CCCNC(N)=N)NC(=O)[C@H](CC(O)=O)NC(=O)[C@H]1N(C(=O)[C@H](CC(N)=O)NC(=O)[C@@H](NC(=O)[C@H](CC=2C=CC=CC=2)NC(=O)[C@@H](NC(=O)[C@H](CC(N)=O)NC(=O)[C@H](CC=2C3=CC=CC=C3NC=2)NC(=O)[C@H](CO)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CC=2C=CC(O)=CC=2)NC(=O)[C@H](C)NC(=O)[C@H](CCCNC(N)=N)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC=2C=CC=CC=2)NC(=O)[C@H](CC(O)=O)NC(=O)[C@H](C)NC(=O)[C@H](CC=2C=CC(O)=CC=2)NC(=O)[C@@H](N)[C@@H](C)O)[C@@H](C)O)C(C)C)CCC1 LUNBMBVWKORSGN-TYEKWLQESA-N 0.000 claims description 5
- 101800002502 P-factor Proteins 0.000 claims description 5
- 239000011121 hardwood Substances 0.000 claims description 5
- 239000000155 melt Substances 0.000 claims description 3
- 238000011282 treatment Methods 0.000 description 47
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 27
- 229920002488 Hemicellulose Polymers 0.000 description 18
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 17
- 239000001301 oxygen Substances 0.000 description 17
- 229910052760 oxygen Inorganic materials 0.000 description 17
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 14
- 239000002253 acid Substances 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 12
- 229920002678 cellulose Polymers 0.000 description 11
- 239000001913 cellulose Substances 0.000 description 11
- 238000004140 cleaning Methods 0.000 description 11
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 241000219927 Eucalyptus Species 0.000 description 7
- 230000007062 hydrolysis Effects 0.000 description 7
- 238000006460 hydrolysis reaction Methods 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- 238000005406 washing Methods 0.000 description 7
- 239000002023 wood Substances 0.000 description 7
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 6
- 238000005903 acid hydrolysis reaction Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 229920005610 lignin Polymers 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 5
- 238000011276 addition treatment Methods 0.000 description 5
- 239000004155 Chlorine dioxide Substances 0.000 description 4
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 4
- 235000019398 chlorine dioxide Nutrition 0.000 description 4
- 229910001882 dioxygen Inorganic materials 0.000 description 4
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 4
- 150000007522 mineralic acids Chemical class 0.000 description 4
- 239000002738 chelating agent Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 235000011121 sodium hydroxide Nutrition 0.000 description 3
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 2
- 240000007472 Leucaena leucocephala Species 0.000 description 2
- 235000010643 Leucaena leucocephala Nutrition 0.000 description 2
- 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 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 description 2
- -1 alkalis Chemical class 0.000 description 2
- PYKYMHQGRFAEBM-UHFFFAOYSA-N anthraquinone Natural products CCC(=O)c1c(O)c2C(=O)C3C(C=CC=C3O)C(=O)c2cc1CC(=O)OC PYKYMHQGRFAEBM-UHFFFAOYSA-N 0.000 description 2
- 150000004056 anthraquinones Chemical class 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 150000007524 organic acids Chemical class 0.000 description 2
- 235000005985 organic acids Nutrition 0.000 description 2
- 229960003330 pentetic acid Drugs 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000013055 pulp slurry Substances 0.000 description 2
- 150000004053 quinones Chemical class 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 239000008399 tap water Substances 0.000 description 2
- 235000020679 tap water Nutrition 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- AZQWKYJCGOJGHM-UHFFFAOYSA-N 1,4-benzoquinone Chemical compound O=C1C=CC(=O)C=C1 AZQWKYJCGOJGHM-UHFFFAOYSA-N 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- PCFMUWBCZZUMRX-UHFFFAOYSA-N 9,10-Dihydroxyanthracene Chemical compound C1=CC=C2C(O)=C(C=CC=C3)C3=C(O)C2=C1 PCFMUWBCZZUMRX-UHFFFAOYSA-N 0.000 description 1
- YYVYAPXYZVYDHN-UHFFFAOYSA-N 9,10-phenanthroquinone Chemical compound C1=CC=C2C(=O)C(=O)C3=CC=CC=C3C2=C1 YYVYAPXYZVYDHN-UHFFFAOYSA-N 0.000 description 1
- 239000002028 Biomass Substances 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 241000218631 Coniferophyta Species 0.000 description 1
- 238000005698 Diels-Alder reaction Methods 0.000 description 1
- 241001233195 Eucalyptus grandis Species 0.000 description 1
- 241001442228 Eucalyptus grandis x Eucalyptus urophylla Species 0.000 description 1
- 229930192627 Naphthoquinone Natural products 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- KDYFGRWQOYBRFD-UHFFFAOYSA-N Succinic acid Natural products OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 1
- 125000002777 acetyl group Chemical group [H]C([H])([H])C(*)=O 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- RJGDLRCDCYRQOQ-UHFFFAOYSA-N anthrone Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3CC2=C1 RJGDLRCDCYRQOQ-UHFFFAOYSA-N 0.000 description 1
- KDYFGRWQOYBRFD-NUQCWPJISA-N butanedioic acid Chemical compound O[14C](=O)CC[14C](O)=O KDYFGRWQOYBRFD-NUQCWPJISA-N 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 239000007857 degradation product Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- 125000000687 hydroquinonyl group Chemical class C1(O)=C(C=C(O)C=C1)* 0.000 description 1
- 150000004966 inorganic peroxy acids Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000002791 naphthoquinones Chemical class 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 150000004967 organic peroxy acids Chemical class 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 150000004968 peroxymonosulfuric acids Chemical class 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 229920001021 polysulfide Polymers 0.000 description 1
- 239000005077 polysulfide Substances 0.000 description 1
- 150000008117 polysulfides Polymers 0.000 description 1
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
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- 238000001308 synthesis method Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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Description
本発明は、リグノセルロース物質から溶解パルプを製造する方法に関する。さらに詳しく述べれば、幅広いパルプ粘度を有する多品種の溶解パルプを効率よく製造する方法に関する。 The present invention relates to a method for producing dissolving pulp from lignocellulosic material. More specifically, the present invention relates to a method for efficiently producing a variety of dissolving pulps having a wide range of pulp viscosities.
リグノセルロース物質から溶解パルプを製造するには、リグノセルロース物質中のヘミセルロースとリグニンを選択的に除去し、セルロース純度を高める必要がある。セルロース純度を表す指標としては、一般にα−セルロース含量が用いられ、値が大きいほど、高品質の溶解パルプであるとされている。溶解パルプの製造方法としては、古くから酸性サルファイト蒸解法および前加水分解−クラフト蒸解法の二法が知られており、酸性サルファイト蒸解法ではリグノセルロース物質中の多くのヘミセルロースとリグニンを蒸解工程で一度に除去するのに対し、前加水分解−クラフト蒸解法は前加水分解工程では大部分のヘミセルロースを酸加水分解して除去し、続くクラフト蒸解で少量のヘミセルロースと大部分のリグニンを除去する。前加水分解工程では、リグノセルロース物質に水を加えて加熱するだけで、ヘミセルロース中のアセチル基が脱離して酢酸を生成し、自動的に酸性状態となり、酸加水分解が進むため、一般には酸を外から添加することなく行なわれる。酸性サルファイト蒸解法と前加水分解−クラフト蒸解法を比較すると、溶解パルプを製造することだけに焦点をあてた場合、酸性サルファイト蒸解の方が一工程でヘミセルロースとリグニンを除去できるため効率的と言えるが、廃棄物のヘミセルロース、リグニンをそれぞれ分離して有効利用することにも焦点をあてた場合には、前加水分解−クラフト蒸解法の方が有利ということになる。近年、バイオマス原料であるリグノセルロース物質中のセルロース、ヘミセルロース、リグニンを分離して、それぞれから価値の高い物質を製造することはバイオリファイナリーと呼ばれ、注目度が高まってきており、前加水分解−クラフト蒸解法の重要性が再認識されてきている。 In order to produce dissolving pulp from a lignocellulosic material, it is necessary to selectively remove hemicellulose and lignin in the lignocellulosic material to increase the purity of the cellulose. As an index representing cellulose purity, α-cellulose content is generally used, and the higher the value, the higher the quality of dissolved pulp. Two methods of dissolving pulp have been known for a long time: acidic sulfite cooking method and prehydrolysis-kraft cooking method. Acid sulfite cooking method digests many hemicelluloses and lignin in lignocellulosic materials. The pre-hydrolysis-kraft cooking method removes most of the hemicellulose by acid hydrolysis in the pre-hydrolysis step, while removing a small amount of hemicellulose and most of the lignin in the subsequent kraft cooking, whereas the pre-hydrolysis-kraft cooking method removes it in one step. To do. In the prehydrolysis step, simply adding water to the lignocellulosic material and heating, the acetyl group in hemicellulose is eliminated to produce acetic acid, which automatically becomes acidic and acid hydrolysis proceeds. Is carried out without external addition. Comparing acid sulfite cooking with prehydrolysis-kraft cooking, acid sulfite cooking is more efficient because it can remove hemicellulose and lignin in one step when focusing solely on producing dissolved pulp However, the prehydrolysis-kraft cooking method is more advantageous when focusing on separating and effectively utilizing the waste hemicellulose and lignin separately. In recent years, it is called biorefinery to separate cellulose, hemicellulose, and lignin in lignocellulosic material, which is a raw material for biomass, and to produce high-value substances from each. The importance of kraft cooking has been reaffirmed.
溶解パルプは、用途により要求されるパルプ粘度や灰分が異なる。これは、溶解パルプは通常、化学的に加工されて利用されるが、その加工条件および加工後の製品の要求品質が用途により異なるためである。これらの要求を満たすためには、比較的高めのパルプ粘度、灰分を有する溶解パルプを製造しておき、要求に応じてパルプ粘度を下げ、灰分を低下させるという二つの処理を行うのが合理的である。パルプ粘度を低下させる方法としては、パルプをアルカリ性下で次亜塩素酸塩処理する方法が良く用いられ、現在も主流となっている。しかしながら、アルカリ性下で次亜塩素酸塩処理を行うとクロロホルムが副生し、環境に悪影響を与えるという問題点がある。一方、溶解パルプ中の灰分を低下させる方法としては、硫酸、硝酸、塩酸などの無機酸で処理し、灰分を遊離させ、除去する方法が一般的である。このように、パルプ粘度を低下させる処理と、灰分を低下させる処理は、ｐＨが大きく異なり、両者の処理を移行する間で無駄な中和反応を経る必要があり、効率的な処理であるとは言えなかった。 Dissolved pulp differs in pulp viscosity and ash content required depending on the application. This is because dissolved pulp is usually used after being chemically processed, but the processing conditions and required quality of the processed product differ depending on the application. In order to satisfy these requirements, it is reasonable to produce dissolved pulp with relatively high pulp viscosity and ash content, and to perform two treatments to lower pulp viscosity and reduce ash content as required. It is. As a method for reducing pulp viscosity, a method of treating hypochlorite under alkaline conditions is often used, and it is still mainstream. However, when hypochlorite treatment is carried out under alkaline conditions, there is a problem that chloroform is produced as a by-product and adversely affects the environment. On the other hand, as a method for reducing the ash content in the dissolving pulp, a method is generally used in which the ash content is liberated and removed by treatment with an inorganic acid such as sulfuric acid, nitric acid or hydrochloric acid. As described above, the treatment for reducing the viscosity of the pulp and the treatment for reducing the ash are greatly different in pH, and need to undergo a useless neutralization reaction between the two treatments, and is an efficient treatment. I could not say.
前記問題を解決するには、酸を用いて灰分を低下させながら、パルプ粘度を同時に低下させる方法が考えられる。酸を用いてパルプ粘度が低下する事例としては、製紙用のヘミセルロースを含有する未晒パルプを対象とし、ヘミセルロース主鎖あるいは側鎖を分解する目的で、無機酸を用いてｐＨ１．０〜１．６、８０℃以上で処理する際に粘度が低下する事例（特許文献１）や、無機、有機酸を用いてｐＨ２〜５、８５〜１５０℃で処理する際に粘度が低下する事例（特許文献２）、等が知られている。しかしながら、いずれも製紙用のヘミセルロースを含有する未晒パルプを対象とした処理であり、ヘミセルロース含有量の少ない、しかも漂白後のパルプに対しての効果については不明であった。 In order to solve the above problem, a method of simultaneously reducing the pulp viscosity while reducing the ash content using an acid can be considered. As an example in which the viscosity of the pulp is lowered by using an acid, an unbleached pulp containing hemicellulose for papermaking is used as a target, and the pH is 1.0 to 1. using an inorganic acid for the purpose of decomposing the hemicellulose main chain or side chain. 6. Examples in which viscosity decreases when processing at 80 ° C or higher (Patent Document 1), and cases in which viscosity decreases when processing at pH 2 to 5 and 85 to 150 ° C using inorganic and organic acids (Patent Document 1) 2), etc. are known. However, all of these treatments were for unbleached pulp containing hemicellulose for papermaking, and the effect on the pulp after bleaching was low and it was unclear.
一方、酸性下で過酸化物を添加してパルプを処理する事例としては、製紙用のヘミセルロースを含有する未晒パルプを対象とし、ヘミセルロース中のヘキセンウロン酸を分解する方法（特許文献３）や漂白パルプを対象とし、ヘミセルロース中のヘキセンウロン酸を分解する方法（特許文献４）等が知られている。しかしながら、いずれも製紙用のヘミセルロースを含有するパルプを対象とした処理であり、ヘミセルロース含有量の少ない溶解パルプに対して、しかもパルプ粘度に対する影響については不明であった。 On the other hand, as an example of processing a pulp by adding a peroxide under acidic conditions, a method of decomposing hexeneuronic acid in hemicellulose (Patent Document 3) or bleaching is intended for unbleached pulp containing hemicellulose for papermaking. A method for decomposing hexeneuronic acid in hemicellulose (Patent Document 4) and the like is known. However, all of these treatments were intended for pulp containing hemicellulose for papermaking, and the effect on pulp viscosity was unclear for dissolved pulp with a low hemicellulose content.
リグノセルロース物質から溶解パルプを製造する方法において、パルプを蒸解、漂白後に、最後の一段の処理で、所望のパルプ粘度および灰分含量に調整することができる溶解パルプの製造方法である。 In the method for producing a dissolving pulp from a lignocellulosic material, the dissolving pulp can be adjusted to a desired pulp viscosity and ash content by a final one-stage treatment after cooking and bleaching the pulp.
本発明者らは、リグノセルロース物質を原料として、前加水分解−アルカリ蒸解法により、幅広い品質の溶解パルプを効率よく製造する方法について種々検討を重ねた結果、前加水分解では所望のセルロース純度に制御するために条件に強弱をつける一方で、その後のアルカリ条件、漂白条件はできるだけ一定に保つようにして溶解パルプを製造し、最後に酸性条件下で過酸化物を添加処理すれば、パルプのセルロース純度、パルプ粘度、灰分を所望の値に制御できることを見出し、本発明に至った。さらに、詳しく説明すると、たとえば広葉樹材を原料とした場合、前加水分解はＰファクターとして２００〜１０００で行ない、次いでアルカリ蒸解は蒸解後のカッパー価が６〜１３になるように行えば、セルロース純度が高く、かつパルプ粘度の高い溶解パルプが得られ、さらに、該溶解パルプを８５〜９２％ＩＳＯまで漂白した後、酸性下で過酸化水素処理すれば、灰分含有量を低減しつつ、所望のパルプ粘度まで下げられることを見出し、本発明に至った。 The present inventors have conducted various studies on a method for efficiently producing a wide variety of dissolving pulp using a lignocellulose material as a raw material by a prehydrolysis-alkali digestion method. As a result, prehydrolysis has achieved a desired cellulose purity. While controlling the conditions to control, while producing the dissolving pulp while keeping the subsequent alkaline and bleaching conditions as constant as possible, and finally adding the peroxide under acidic conditions, It discovered that a cellulose purity, a pulp viscosity, and ash content could be controlled to a desired value, and resulted in this invention. More specifically, for example, when hardwood is used as a raw material, pre-hydrolysis is carried out at a P factor of 200 to 1000, and then alkali digestion is carried out so that the kappa number after cooking is 6 to 13; A dissolved pulp having a high pulp viscosity and a high pulp viscosity is obtained, and further, the bleached pulp is bleached to 85 to 92% ISO, and then treated with hydrogen peroxide under an acidic condition. The inventors have found that the viscosity can be lowered to the pulp viscosity, and have reached the present invention.
本願発明は以下の発明を包含する。
（１）リグノセルロース物質を原料として、前加水分解−アルカリ蒸解法により溶解パルプを製造する方法であって、前加水分解時のＰファクターが２００〜１０００であり、該前加水分解−アルカリ蒸解後のパルプを漂白した後、酸性下で過酸化物を添加して処理する溶解パルプの製造方法。
（２）リグノセルロース物質を原料として、前加水分解−アルカリ蒸解法により溶解パルプを製造する方法であって、前加水分解時のＰファクターが２００〜１０００であり、該前加水分解-アルカリ蒸解後のパルプを漂白した後、得られる溶解パルプ中の灰分含量を低減させるために酸性下で過酸化物を添加して処理することを特徴とする溶解パルプの製造方法。
（３）前記前加水分解−アルカリ蒸解後のパルプを８５〜９２％ＩＳＯまで漂白した後、酸性下で過酸化物を添加して処理する（１）または（２）記載の溶解パルプの製造方法。（４）前記過酸化物が、過酸化水素である（１）〜（３）のいずれかに１項に記載の溶解パルプの製造方法。
（５）前記アルカリ蒸解法がクラフト蒸解法である（１）〜（４）のいずれか１項に記載
の溶解パルプの製造方法。
（６）前記リグノセルロース物質が広葉樹材であり、さらにアルカリ蒸解後のパルプのカッパー価が６〜１３である（１）〜（５）のいずれか１項に記載の溶解パルプの製造方法。
The present invention includes the following inventions.
(1) A method for producing a dissolving pulp by using a lignocellulosic material as a raw material by a prehydrolysis-alkali digestion method, wherein the P-factor at the time of prehydrolysis is 200 to 1000, A method for producing a dissolving pulp, in which a pulp is bleached and then treated by adding a peroxide under acidic conditions.
(2) A method for producing a dissolving pulp using a lignocellulosic material as a raw material by a prehydrolysis-alkali digestion method, wherein the P-factor at the time of prehydrolysis is 200 to 1,000, A method for producing a dissolving pulp, comprising bleaching the pulp and adding a peroxide under acidity to reduce the ash content in the resulting dissolving pulp.
(3) The method for producing a dissolving pulp according to (1) or (2), wherein the pulp after the prehydrolysis-alkali digestion is bleached to 85 to 92% ISO and then treated by adding a peroxide under acidic conditions. . (4) The method for producing a dissolving pulp according to any one of (1) to (3), wherein the peroxide is hydrogen peroxide.
(5) The method for producing a dissolving pulp according to any one of (1) to (4), wherein the alkali cooking method is a kraft cooking method.
(6) In the case of lignocellulosic material hardwood is 6-13 are kappa number of the pulp after the alkali digestion to be al (1) - (5) The method of producing dissolving pulp according to any one of .
本発明者によれば、リグノセルロース物質を原料として、前加水分解−アルカリ蒸解法により、溶解パルプを製造する方法において、予めパルプの白色度を８５〜９２％ＩＳＯまで漂白しておき、最後に酸性下で過酸化物を添加して処理することにより、多品種の溶解パルプを製造することが可能となった。 According to the present inventor, in a method for producing a dissolved pulp by using a lignocellulosic material as a raw material by a prehydrolysis-alkali cooking method, the whiteness of the pulp is previously bleached to 85 to 92% ISO, and finally It became possible to produce various types of dissolving pulp by adding peroxide under acidic conditions.
本発明で使用できるリグノセルロース物質は、木材、非木材のいずれでもよいが、生産効率を考慮すると、容積重が高い木材が好適に用いられる。木材の中では、一般に針葉樹よりも広葉樹材の方が容積重が高く、好適であり、さらに広葉樹の中でも容積重が高い一部のユーカリやアカシアが好適に用いられる。該当する広葉樹としては、ユーカリ・グロブラス、ユーカリ・グランディス、ユーカリ・ユーログランディス、ユーカリ・ペリータ、ユーカリ・ブラシアーナ、アカシア・メランシ等を挙げることができ、特に容積重の高いユーカリ・ペリータがよいが、特に限定されるものではない。容積重の値で表現すると、４５０〜７００ｋｇ／ｍ３のものがよく、さらに好ましくは５００〜６５０ｋｇ／ｍ３のものである。容積重が４５０ｋｇ／ｍ３よりも低い材は、前記のようにパルプの生産効率の面からは不利である。一方、容積重が７００ｋｇ／ｍ３よりも高い材は、前加水分解やアルカリ蒸解時の薬液浸透が不十分と成りやすく、結果としてパルプ品質が低下する可能性があるため、不利である。言うまでもなく、広葉樹、針葉樹、非木材をそれぞれ単独で使用することもできるし、組み合わせて使用することもできるし、その組み合わせは限定されるものではない。 The lignocellulosic material that can be used in the present invention may be wood or non-wood, but considering production efficiency, wood with high bulk weight is preferably used. Among woods, broad-leaved wood materials are generally preferred because they have a higher bulk weight than conifers, and some eucalyptus and acacia with a higher bulk weight among hardwoods are preferably used. Examples of applicable broad-leaved trees include eucalyptus globulas, eucalyptus grandis, eucalyptus eurograndis, eucalyptus perita, eucalyptus brushana, acacia melanci, etc. It is not particularly limited. Expressed in volume weight value, it is preferably 450~700kg / m 3, more preferably those of 500~650kg / m 3. A material having a bulk weight lower than 450 kg / m 3 is disadvantageous from the viewpoint of pulp production efficiency as described above. On the other hand, a material having a bulk weight higher than 700 kg / m 3 is disadvantageous because chemical penetration during pre-hydrolysis or alkali cooking tends to be insufficient, and as a result, pulp quality may be lowered. Needless to say, broad-leaved trees, coniferous trees, and non-woods can be used alone or in combination, and the combination is not limited.
本発明では、まずリグノセルロース物質を水の存在下で、加温して前加水分解処理を行う。ここで、リグノセルロース物質に対する水の量（液比）は、１．０〜１０、好ましくは１．５〜５．０である。液比が１．０より少ない場合には、水が不足して加水分解が十分に進まない上に反応が不均一となるので適さない。１０より高い場合には、所望の温度まで加熱するのに要する熱量が多くなり、経済的ではないので適さない。水の添加方法としては、特に限定されるものではなく、外部から水を添加しても良いし、リグノセルロース物質に元々含まれる水を利用しても良いし、加熱時に蒸気を使用する場合には蒸気に含まれる水を利用しても良い。また、水と共にアルカリ、酸、キレート剤等、多糖の加水分解を直接的、間接的に補助する薬品を添加することもできる。本発明の前加水分解の強度はＰファクターとして２００〜１０００であり、温度は１４０〜２００℃、好ましくは１６０〜１７０℃で、処理時間は処理温度に対応して決定される。なお、Ｐファクターは前加水分解時の温度と時間の積であり、化学式１として表される。 In the present invention, the lignocellulosic material is first heated in the presence of water and subjected to a prehydrolysis treatment. Here, the amount (liquid ratio) of water relative to the lignocellulosic material is 1.0 to 10, preferably 1.5 to 5.0. When the liquid ratio is less than 1.0, water is insufficient, hydrolysis does not proceed sufficiently, and the reaction becomes non-uniform, which is not suitable. If it is higher than 10, the amount of heat required for heating to a desired temperature increases, which is not economical, which is not suitable. The method of adding water is not particularly limited, and water may be added from the outside, the water originally contained in the lignocellulosic material may be used, or when steam is used during heating. May use water contained in steam. In addition to water, chemicals that directly or indirectly assist the hydrolysis of polysaccharides, such as alkalis, acids, and chelating agents, can also be added. The strength of the prehydrolysis of the present invention is 200 to 1000 as a P factor, the temperature is 140 to 200 ° C., preferably 160 to 170 ° C., and the treatment time is determined according to the treatment temperature. The P factor is the product of temperature and time at the time of prehydrolysis, and is expressed as Chemical Formula 1.
ＫＨ（Ｔ）／Ｋ１００℃：グリコシド結合の酸加水分解の相対速度
KH (T) / K100 ° C .: Relative rate of acid hydrolysis of glycosidic bond
Ｐファクターが２００より低い場合には、ヘミセルロースの酸加水分解が十分でなく、その後のアルカリ蒸解を行っても、パルプのセルロース純度を十分に高められないので適さない。Ｐファクターが１０００より高い場合には、セルロースの酸加水分解が進んでしまい、パルプのセルロース純度を十分に高められない上に、パルプ粘度が低くなり、さらにはパルプ収率も低くなるので適さない。前加水分解温度が１４０℃よりも低い場合には反応時間を１０時間以上にする必要があり、巨大な反応容器を準備する必要があることから経済的ではないので適さない。逆に２００℃よりも高くすると、場合によっては反応時間を０．１時間以下にする必要があり、反応の制御が困難となる上にそのような熱条件に耐え得る装置の材質は高価になるため、経済的にも適さない。 If the P-factor is lower than 200, the acid hydrolysis of hemicellulose is not sufficient, and the subsequent cellulose digestion is not suitable because the cellulose purity of the pulp cannot be sufficiently increased. When the P factor is higher than 1000, acid hydrolysis of cellulose proceeds, and the cellulose purity of the pulp cannot be sufficiently increased. Further, the pulp viscosity is lowered, and the pulp yield is also lowered, which is not suitable. . When the prehydrolysis temperature is lower than 140 ° C., it is necessary to set the reaction time to 10 hours or more, and it is not economical because it is necessary to prepare a huge reaction vessel. On the other hand, when the temperature is higher than 200 ° C., the reaction time may be required to be 0.1 hour or less in some cases, and it becomes difficult to control the reaction, and the material of the apparatus that can withstand such a thermal condition becomes expensive. Therefore, it is not economically suitable.
前加水分解工程で用いる装置は、リグノセルロース物質を含水状態の加圧状態にて所望の時間の間、保持できるものであればよく、特に限定されるものではないが、好適には汎用の連続蒸解釜、バッチ釜、等が用いられる。本発明の前加水分解工程では、反応終了後、脱水あるいは希釈洗浄、脱水して、次のアルカリ蒸解工程に送られる。なお、前加水分解後の排水は、フラッシュタンクに送り、ガス層と液層に分け、ガス層に多く含まれるフルルラール類を抽出して利用し、液層に多く含まれるヘミセルロースの分解物を抽出して利用することが可能である。 The apparatus used in the prehydrolysis step is not particularly limited as long as it can hold the lignocellulosic material in a pressurized state in a water-containing state for a desired time. A digester, a batch kettle, etc. are used. In the prehydrolysis step of the present invention, after completion of the reaction, it is dehydrated or diluted and washed, dehydrated, and sent to the next alkali cooking step. The waste water after pre-hydrolysis is sent to a flash tank, divided into a gas layer and a liquid layer, and flurrals contained in the gas layer are extracted and used to extract hemicellulose degradation products contained in the liquid layer. It is possible to use it.
本発明のアルカリ蒸解に用いられる装置は、特に限定されるものではないが、好適には汎用の連続蒸解釜、バッチ釜、等が用いられる。アルカリ蒸解法としては、クラフト蒸解、ポリサルファイド蒸解、ソーダ蒸解、アルカリサルファイト蒸解等の公知の蒸解法を用いることができるが、パルプ品質、エネルギー効率等を考慮すると、クラフト蒸解法が好適に用いられる。例えば、木材をクラフト蒸解する場合、クラフト蒸解液の硫化度は５〜７５％、好ましくは２０〜３５％、有効アルカリ添加率は絶乾木材質量当たり５〜３０質量％、好ましくは１０〜２５質量％、蒸解温度は１４０〜１７０℃で、蒸解白液を分割で添加する蒸解法でもよく、その方式は特に問わない。 Although the apparatus used for the alkali cooking of this invention is not specifically limited, A general purpose continuous cooking kettle, a batch kettle, etc. are used suitably. As the alkali cooking method, known cooking methods such as kraft cooking, polysulfide cooking, soda cooking, alkali sulfite cooking and the like can be used, but considering pulp quality, energy efficiency, etc., kraft cooking method is preferably used. . For example, in the case of kraft cooking of wood, the sulfidity of the kraft cooking solution is 5 to 75%, preferably 20 to 35%, and the effective alkali addition rate is 5 to 30% by weight, preferably 10 to 25% by weight of the absolutely dry wood. %, The cooking temperature is 140-170 ° C., and the cooking method in which the cooking white liquor is added in portions may be used, and the method is not particularly limited.
蒸解に際して、使用する蒸解液に蒸解助剤として、公知の環状ケト化合物、例えばベンゾキノン、ナフトキノン、アントラキノン、アントロン、フェナントロキノンおよび前記キノン系化合物のアルキル、アミノ等の核置換体、或いは前記キノン系化合物の還元型であるアントラヒドロキノンのようなヒドロキノン系化合物、さらにはディールスアルダー法によるアントラキノン合成法の中間体として得られる安定な化合物である９，１０−ジケトヒドロアントラセン化合物等から選ばれた１種或いは２種以上が添加されてもよく、その添加率は木材チップの絶乾質量当たり０．００１〜１．０質量％である。 In cooking, as a cooking aid in the cooking solution to be used, known cyclic keto compounds, for example, benzoquinone, naphthoquinone, anthraquinone, anthrone, phenanthroquinone, and nuclear substitutes such as alkyl and amino of the quinone compounds, or the quinone series 1 selected from hydroquinone compounds such as anthrahydroquinone, which is a reduced form of the compound, and a 9,10-diketohydroanthracene compound which is a stable compound obtained as an intermediate of an anthraquinone synthesis method by the Diels-Alder method A seed | species or 2 or more types may be added, and the addition rate is 0.001-1.0 mass% per the absolute dry mass of a wood chip.
蒸解後のカッパー価は特に限定されるものではないが、パルプ品質やその後の漂白性等を考慮すると、例えば広葉樹を原料とした場合にはカッパー価は６〜１３が好ましく、針葉樹を原料とした場合にはカッパー価は２０〜３５が好ましい。 The kappa number after cooking is not particularly limited, but considering the pulp quality and subsequent bleaching properties, for example, when hardwood is used as the raw material, the kappa number is preferably 6 to 13, and coniferous as the raw material. In some cases, the kappa number is preferably 20 to 35.
本発明では、公知のアルカリ蒸解法により得られた未漂パルプは洗浄、粗選および精選工程を経て、公知の漂白法で漂白処理される。好適には、まず酸素脱リグニン法により脱リグニンされる。本発明に使用される酸素脱リグニン法は、中濃度法あるいは高濃度法がそのまま適用できるが、パルプ濃度が８〜１５％で行われる中濃度法が特殊な脱水装置を必要とせず、操業性がよいため好ましい。酸素脱リグニン法に用いるアルカリとしては苛性ソーダあるいは酸化されたクラフト白液を使用することができ、酸素ガスとしては、深冷分離法からの酸素、ＰＳＡ（Ｐｒｅｓｓｕｒｅ Ｓｗｉｎｇ Ａｄｓｏｒｐｔｉｏｎ）からの酸素、ＶＳＡ（Ｖａｃｕｕｍ Ｓｗｉｎｇ Ａｄｓｏｒｐｔｉｏｎ）からの酸素等が使用できる。前記酸素ガスとアルカリは中濃度ミキサーにおいて中濃度のパルプスラリーに添加され混合が十分に行われた後、加圧下でパルプ、酸素およびアルカリの混合物を一定時間保持できる反応塔へ送られ、脱リグニンされる。酸素ガスの添加率は、絶乾パルプ質量当たり０．５〜３質量％、アルカリ添加率は０．５〜４質量％、反応温度は８０〜１２０℃、反応時間は１５〜１００分、パルプ濃度は８〜１５質量％であり、この他の条件は公知のものが適用できる。本発明では、酸素脱リグニン工程において、上記酸素脱リグニンを連続して複数回行い、できる限り脱リグニンを進めるのが好ましい実施形態である。酸素脱リグニンを施されたパルプは洗浄段へ送られる。 In the present invention, unflooded pulp obtained by a known alkali digestion method is subjected to a bleaching process by a known bleaching method after washing, rough selection and selection steps. Preferably, first, delignification is performed by an oxygen delignification method. As the oxygen delignification method used in the present invention, the intermediate concentration method or the high concentration method can be applied as it is, but the intermediate concentration method performed at a pulp concentration of 8 to 15% does not require a special dehydrating apparatus, and the operability is improved. Is preferable. As the alkali used in the oxygen delignification method, caustic soda or oxidized kraft white liquor can be used. As the oxygen gas, oxygen from a cryogenic separation method, oxygen from PSA (Pressure Swing Adsorption), VSA (Vacuum) Oxygen from Swing Adsorption) can be used. The oxygen gas and alkali are added to a medium-concentration pulp slurry in a medium-concentration mixer and mixed sufficiently, and then sent to a reaction tower capable of holding a mixture of pulp, oxygen and alkali for a certain period of time under pressure, and delignified. Is done. The oxygen gas addition rate is 0.5 to 3% by mass per mass of dry pulp, the alkali addition rate is 0.5 to 4% by mass, the reaction temperature is 80 to 120 ° C., the reaction time is 15 to 100 minutes, and the pulp concentration Is 8 to 15% by mass, and other known conditions can be applied. In the present invention, in the oxygen delignification step, it is a preferred embodiment that the oxygen delignification is continuously performed a plurality of times and the delignification proceeds as much as possible. The pulp subjected to oxygen delignification is sent to a washing stage.
本発明では、酸素脱リグニン後の洗浄段に限らず、漂白段毎に洗浄段を設けるのが好ましく、洗浄段で使用される洗浄機としては、プレッシャーディフューザー、ディフュージョンウオッシャー、加圧型ドラムウオッシャー、水平長網型ウオッシャー、プレス洗浄機等を挙げることができ、特に限定されるものではない。各洗浄段では、一機の洗浄機でまかなうこともできるし、複数の洗浄機を使用することもできる。本発明においては、各洗浄段の洗浄水にアルカリ、酸、キレート剤、界面活性剤等の洗浄助剤を添加することもできる。また、洗浄排水を前段の洗浄段の洗浄水として再利用する向流洗浄を行なうこともできる。 In the present invention, it is preferable to provide a washing stage for each bleaching stage, not limited to the washing stage after oxygen delignification, and as a washing machine used in the washing stage, a pressure diffuser, a diffusion washer, a pressure drum washer, a horizontal A long-net type washer, a press washer, etc. can be mentioned, and it is not particularly limited. In each cleaning stage, a single cleaning machine can be used or a plurality of cleaning machines can be used. In the present invention, a cleaning aid such as an alkali, an acid, a chelating agent, and a surfactant can be added to the cleaning water in each cleaning stage. Further, countercurrent cleaning can be performed in which the cleaning wastewater is reused as cleaning water for the preceding cleaning stage.
本発明では、未晒パルプは、好ましくは酸素脱リグニン工程を経て、多段漂白工程へ送られる。本発明の多段漂白工程では、二酸化塩素（Ｄ）、アルカリ（Ｅ）、酸素（Ｏ）、過酸化水素（Ｐ）、オゾン（Ｚ）といった公知のＥＣＦ漂白段を組合せて使用でき、各漂白段後には前述の洗浄段を設けることができる。また、多段漂白工程中に、高温酸処理段（Ａ）や酸洗浄段、高温二酸化塩素漂白段、エチレンジアミンテトラ酢酸（ＥＤＴＡ）やジエチレントリアミンペンタ酢酸（ＤＴＰＡ）等によるキレート剤処理段等を導入することもできる。本発明の多段漂白工程では、パルプの白色度が８５〜９２％ＩＳＯになるように、漂白されるのが好ましい。白色度が８５％ＩＳＯ未満の場合には、その後の酸性下での過酸化物添加処理を行っても白色度が９０％ＩＳＯより低くなる。白色度が９２％ＩＳＯよりも高い場合には、多段漂白工程で使用する漂白薬品量が多くなりすぎて経済的ではない上に、場合によっては溶解パルプに余計な官能基が導入され、溶解パルプの品質が低下するので適さない。 In the present invention, the unbleached pulp is preferably sent to a multi-stage bleaching step via an oxygen delignification step. In the multistage bleaching process of the present invention, known ECF bleaching stages such as chlorine dioxide (D), alkali (E), oxygen (O), hydrogen peroxide (P), and ozone (Z) can be used in combination. Later, the aforementioned cleaning stage can be provided. In addition, a high-temperature acid treatment stage (A), an acid washing stage, a high-temperature chlorine dioxide bleaching stage, a chelating agent treatment stage using ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), etc. are introduced during the multistage bleaching process. You can also. In the multistage bleaching process of the present invention, bleaching is preferably performed so that the whiteness of the pulp is 85 to 92% ISO. When the whiteness is less than 85% ISO, the whiteness becomes lower than 90% ISO even if the subsequent peroxide addition treatment is performed under acidic conditions. When the whiteness is higher than 92% ISO, the amount of bleaching chemicals used in the multi-stage bleaching process is excessive and not economical, and in some cases, additional functional groups are introduced into the dissolved pulp, and the dissolved pulp It is not suitable because the quality of
本発明では、必ず多段漂白工程後、酸性下での過酸化物添加処理が行われる。本発明の酸性下での過酸化物添加処理は、パルプ濃度は１〜４０重量％、好ましくは８〜１５重量％の範囲で、ｐＨは１〜５、好ましくは２〜４、温度は３０〜９５℃、好ましくは５０〜９０℃で行われる。パルプ濃度が１重量％未満の場合には、ｐＨ調整用に添加する酸が多くなりすぎて経済的ではないため適さず、４０重量％より高い場合には、パルプと薬品の混合が不十分となり、反応が不均一になるので適さない。ｐＨは、１より低い場合には反応容器が腐食しやすくなり、５より高い場合には灰分除去効果が不十分になるため適さない。反応温度は、３０℃より低い場合にはパルプの粘度の低下効果が不十分となり、９５℃より高い場合には昇温に多大なエネルギーが必要となり、経済的ではないので適さない。 In the present invention, the peroxide addition treatment under acidic conditions is always performed after the multi-stage bleaching step. The peroxide addition treatment under acidic conditions of the present invention has a pulp concentration in the range of 1 to 40% by weight, preferably 8 to 15% by weight, pH of 1 to 5, preferably 2 to 4, and temperature of 30 to 30. It is carried out at 95 ° C, preferably 50 to 90 ° C. If the pulp concentration is less than 1% by weight, too much acid is added for pH adjustment, which is not economical and not suitable. If it is higher than 40% by weight, mixing of the pulp and chemicals becomes insufficient. This is not suitable because the reaction becomes uneven. When the pH is lower than 1, the reaction vessel tends to corrode. When the pH is higher than 5, the ash removal effect becomes insufficient, which is not suitable. When the reaction temperature is lower than 30 ° C., the effect of reducing the viscosity of the pulp becomes insufficient. When the reaction temperature is higher than 95 ° C., a large amount of energy is required to raise the temperature, which is not economical.
本発明の、酸性下での過酸化物添加処理では、酸性状態にするために酸を添加することができる。酸としては、蟻酸、蓚酸、酢酸等の有機酸、硫酸、塩酸、硝酸等の無機酸のいずれでもよく、特に限定されるものではないが、好適には比較的安価な硫酸、塩酸等が使用される。本発明の酸性下での過酸化物添加処理で使用される過酸化物としては、有機過酸、無機過酸のいずれでもよく、特に限定されるものではないが、好適には比較的安価で、分解後も環境負荷のない過酸化水素が使用される。例えば、過酸化水素の場合、添加率は対パルプ絶乾重量あたり０．０１〜２％、好ましくは０．１〜１．０％である。添加率が０．０１％未満の場合には添加効果がほとんど見られず、２％以上になると反応しきらなくなるので適さない。処理時間は、１０分以上、好ましくは３０分〜１８０分であるが、時間については特に限定されない。なお、過酸化物添加によるパルプ粘度の低減効果は、処理対象のセルロース純度が高いために過酸化物とセルロースの反応頻度が高くなり、解重合され易いためであり、灰分低減効果は、例えば鉄のような元素が酸化され、水に溶解し、除去され易くなるためであると考えられる。 In the peroxide addition treatment under acidic conditions of the present invention, an acid can be added in order to obtain an acidic state. The acid may be any of organic acids such as formic acid, succinic acid, and acetic acid, and inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid, and is not particularly limited. However, relatively inexpensive sulfuric acid, hydrochloric acid, etc. are preferably used. Is done. The peroxide used in the peroxide addition treatment under the acidity of the present invention may be either an organic peracid or an inorganic peracid, and is not particularly limited, but is preferably relatively inexpensive. Hydrogen peroxide, which has no environmental impact even after decomposition, is used. For example, in the case of hydrogen peroxide, the addition rate is 0.01 to 2%, preferably 0.1 to 1.0%, based on the absolute dry weight of pulp. When the addition rate is less than 0.01%, the effect of addition is hardly observed, and when the addition rate is 2% or more, the reaction cannot be completed. The treatment time is 10 minutes or more, preferably 30 minutes to 180 minutes, but the time is not particularly limited. The pulp viscosity reduction effect due to the addition of peroxide is due to the fact that the cellulose purity of the treatment target is high, so that the reaction frequency of the peroxide and cellulose is high, and the depolymerization is easy. This is considered to be due to the fact that such elements are oxidized, dissolved in water, and easily removed.
以下に、実施例及び比較例を挙げて本発明をより具体的に説明するが、もちろん本発明はこれらの実施例に限定されるものではない。特に示さない限り、チップの容積重、パルプのカッパー価、白色度、粘度、α−セルロースの測定は以下の方法で行なった。また、前加水分解後のろ液中のピッチ数は目視で評価した。なお、実施例及び比較例における薬品の添加率は絶乾パルプ質量当たりの質量％示す。 Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples. Unless otherwise indicated, the measurement of the bulk weight of the chip, the pulp kappa number, the whiteness, the viscosity, and the α-cellulose was carried out by the following methods. Moreover, the pitch number in the filtrate after prehydrolysis was evaluated visually. In addition, the addition rate of the chemical | medical agent in an Example and a comparative example shows the mass% per absolute dry pulp mass.
１．パルプのカッパー価測定
ＪＩＳ Ｐ ８２１１に準じて測定した。
1. Pulp kappa number measurement Measured according to JIS P 8211.
２．パルプの白色度測定
漂白パルプを離解後、パルプスラリーに硫酸バンドを対パルプ３．０％加え、Ｔａｐｐｉ試験法Ｔ２０５ｏｓ−７１（ＪＩＳ Ｐ ８２０９）に従って作成した坪量６０ｇ／ｍ２のシートを用い、ＪＩＳ Ｐ ８１２３に従ってパルプの白色度を測定した。
2. Measurement of the whiteness of the pulp After the bleached pulp was disaggregated, a sulfuric acid band was added to the pulp slurry at a ratio of 3.0% to the pulp, and a basis weight of 60 g / m 2 prepared according to the Tappi test method T205os-71 (JIS P 8209). Using the sheet, the whiteness of the pulp was measured in accordance with JIS P 8123.
３．パルプの粘度測定
Ｊ ＴＡＰＰＩ Ｎｏ．４４に準じて測定した。
3. Viscosity measurement of pulp J TAPPI No. It measured according to 44.
４．パルプのα−セルロース含量測定
ＪＩＳ Ｐ ８１０１に準じて測定した。
4). Measurement of α-cellulose content of pulp Measured according to JIS P8101.
５．パルプの灰分測定
ＪＩＳ Ｐ ８２５１に準じて測定した。
5. Pulp ash measurement Measured according to JIS P 8251.
実施例１
ユーカリ・ペリータ材チップを絶乾質量で３００ｇ採取し、水道水１０リットルに一晩浸漬した。その後、チップを取り出して４００メッシュの篩に空け、濾別した後、この脱水後のチップを２．５リットル容量のオートクレーブに入れ、液比が３になるように水道水を加えた後、１７０℃で６０分間、前加水分解処理した。この時のＰファクターは５９７であった。前加水分解後、オートクレーブの脱気コックから廃ガスを抜き出し、オートクレーブ内の圧力が０になったことを確認した後、処理後のチップを４００メッシュの篩に空け、濾別した。濾別後のチップを絶乾質量で２００ｇ採取し、再度２．５リットル容量のオートクレーブに入れ、液比５、絶乾チップ質量当たり活性アルカリ２０％、蒸解液の硫化度２８％、蒸解温度１６５℃、蒸解時間５０分の条件下でクラフト蒸解を行なった。蒸解後、黒液とパルプを分離し、パルプを８カットのスクリーンプレートを備えたフラットスクリーンで精選して、カッパー価１０．８の未晒パルプを絶乾８４．０ｇを得た。
Example 1
Eucalyptus / perita material chips (300 g) were collected in an absolutely dry mass and immersed in 10 liters of tap water overnight. Thereafter, the chips are taken out, emptied through a 400 mesh sieve, and filtered. Then, the dehydrated chips are put into a 2.5 liter autoclave, tap water is added so that the liquid ratio becomes 3, and 170 Prehydrolysis treatment was performed at 60 ° C. for 60 minutes. The P factor at this time was 597. After pre-hydrolysis, waste gas was extracted from the deaeration cock of the autoclave, and after confirming that the pressure in the autoclave was zero, the treated chips were evacuated through a 400-mesh sieve and filtered. 200 g of the chips after filtration were collected at an absolute dry mass, and again put into a 2.5 liter autoclave. The liquid ratio was 5, the active alkali was 20% per absolute dry chip mass, the sulfidity of the cooking liquid was 28%, and the cooking temperature was 165 Kraft cooking was performed under the conditions of ℃ and cooking time of 50 minutes. After cooking, the black liquor and the pulp were separated, and the pulp was carefully selected with a flat screen equipped with an 8-cut screen plate to obtain 84.0 g of unbleached pulp having a kappa number of 10.8.
前記未漂白クラフトパルプの絶乾質量で７０．０ｇを採取し、絶乾パルプ質量当たり苛性ソーダを２．０％添加し、次いでイオン交換水で希釈してパルプ濃度を１０％に調整し、間接加熱式オートクレーブに入れ、９９．９％の市販の圧縮酸素ガスを注入してゲージ圧力を０．５ＭＰａとし、１００℃で６０分間、酸素脱リグニンを行った。酸素漂白終了後、ゲージ圧力が０．０５ＭＰａ以下になるまで減圧し、パルプをオートクレーブから取り出し、イオン交換水７リットルを用いて洗浄、脱水した。 70.0 g was collected from the unbleached kraft pulp by dry weight, 2.0% caustic soda was added to the dry pulp weight, diluted with ion-exchanged water to adjust the pulp concentration to 10%, and heated indirectly. It put into the type | mold autoclave, 99.9% of commercially available compressed oxygen gas was inject | poured, the gauge pressure was 0.5 Mpa, and oxygen delignification was performed for 60 minutes at 100 degreeC. After the oxygen bleaching was completed, the pressure was reduced until the gauge pressure became 0.05 MPa or less, and the pulp was taken out from the autoclave, washed and dehydrated with 7 liters of ion-exchanged water.
前記アルカリ酸素脱リグニン後のクラフトパルプを絶乾質量で６０ｇ採取し、プラスチック袋に入れ、イオン交換水を用いてパルプ濃度を１０％に調整した後、絶乾パルプ質量当たり１．０％の二酸化塩素を添加し、温度が７０℃の恒温水槽に６０分間浸漬してＤ０段処理を行った。得られたパルプをイオン交換水で３％に希釈した後、ブフナーロートで脱水、洗浄した。前記Ｄ０段後のパルプをプラスチック袋に入れ、イオン交換水を加えてパルプ濃度を１０％に調整した後、絶乾パルプ質量当たり苛性ソーダを１．０％、過酸化水素０．２％を添加してよく混合した後、温度が７０℃の恒温水槽に９０分間浸漬してＥ／Ｐ段処理を行った。得られたパルプをイオン交換水で３％に希釈した後、ブフナーロートで脱水、洗浄した。 60 g of kraft pulp after alkaline oxygen delignification was collected at an absolute dry mass, put in a plastic bag, adjusted to a pulp concentration of 10% using ion-exchanged water, and then 1.0% of dioxide dioxide per mass of the absolute dry pulp. Chlorine was added and D0 stage treatment was performed by immersing in a constant temperature water bath having a temperature of 70 ° C. for 60 minutes. The obtained pulp was diluted to 3% with ion-exchanged water, then dehydrated and washed with a Buchner funnel. The pulp after the D0 stage is put in a plastic bag, ion-exchanged water is added to adjust the pulp concentration to 10%, 1.0% caustic soda and 0.2% hydrogen peroxide are added per mass of dry pulp. After mixing well, it was immersed for 90 minutes in a constant temperature water bath having a temperature of 70 ° C. to perform E / P stage treatment. The obtained pulp was diluted to 3% with ion-exchanged water, then dehydrated and washed with a Buchner funnel.
前記Ｅ／Ｐ段後のパルプをプラスチック袋に入れ、イオン交換水を用いてパルプ濃度１０％に調整した後、絶乾パルプ質量当たり二酸化塩素を０．３％添加し、温度が７０℃の恒温水槽に６０分間浸漬し、Ｄ１段の漂白を行った。得られたパルプをイオン交換水で３％に希釈した後、ブフナーロートで脱水、洗浄した。白色度９０．５％、粘度１４．４ｃＰ、α−セルロース９７．６％、灰分０．２２％のパルプを得た。 The pulp after the E / P stage is put in a plastic bag, adjusted to a pulp concentration of 10% using ion-exchanged water, 0.3% of chlorine dioxide is added per mass of dry pulp, and the temperature is kept at 70 ° C. It was immersed in a water tank for 60 minutes to perform D1 stage bleaching. The obtained pulp was diluted to 3% with ion-exchanged water, then dehydrated and washed with a Buchner funnel. A pulp having a whiteness of 90.5%, a viscosity of 14.4 cP, α-cellulose of 97.6%, and an ash content of 0.22% was obtained.
前記Ｄ１段後のパルプをプラスチック袋に入れ、イオン交換水を用いてパルプ濃度１０％に調整した後、絶乾パルプ質量当たり硫酸を０．５％、過酸化水素を０．３％添加し、温度が９０℃の恒温水槽に６０分間浸漬し、処理ｐHを２．５で酸性過酸化物処理を行った。得られたパルプをイオン交換水で３％に希釈した後、ブフナーロートで脱水、洗浄した。白色度９１．５％ＩＳＯ、粘度８．０ｃＰ、α−セルロース９７．７％、灰分０．０８％の完成パルプを得た。以上の結果を表１、２に示す。 The pulp after stage D1 is put in a plastic bag, adjusted to a pulp concentration of 10% using ion-exchanged water, and then 0.5% sulfuric acid and 0.3% hydrogen peroxide are added per mass of dry pulp, It was immersed in a constant temperature water bath at a temperature of 90 ° C. for 60 minutes, and an acidic peroxide treatment was performed at a treatment pH of 2.5. The obtained pulp was diluted to 3% with ion-exchanged water, then dehydrated and washed with a Buchner funnel. A finished pulp having a whiteness of 91.5% ISO, a viscosity of 8.0 cP, α-cellulose of 97.7%, and an ash content of 0.08% was obtained. The above results are shown in Tables 1 and 2.
実施例２
実施例１において、前加水分解時の温度を１５７℃、６０分（Ｐファクターは２１４）に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。酸性過酸化物処理ｐＨは２．５で行った。
Example 2
In Example 1, the same operation as in Example 1 was performed except that the temperature at the prehydrolysis was changed to 157 ° C. and 60 minutes (P factor was 214). Tables 1 and 2 show the results. The acidic peroxide treatment pH was 2.5.
実施例３
実施例１において、前加水分解時の温度を１６５℃、６０分（Ｐファクターは４０６）に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処はｐＨ２．５で行った。
Example 3
In Example 1, the same operation as in Example 1 was performed except that the temperature at the prehydrolysis was changed to 165 ° C. and 60 minutes (P factor was 406). Tables 1 and 2 show the results. The acidic peroxide treatment was performed at pH 2.5.
実施例４
実施例１において、前加水分解時の温度を１７０℃、１００分（Ｐファクターは９９５）に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理はｐＨ２．５で行った。
Example 4
In Example 1, the same operation as in Example 1 was performed except that the temperature at the prehydrolysis was changed to 170 ° C. and 100 minutes (P factor was 995). Tables 1 and 2 show the results. The acidic peroxide treatment was performed at pH 2.5.
実施例５
実施例１において、前加水分解時の温度を１７０℃、４０分（Ｐファクターは３９８）に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理はｐＨ２．５で行った。
Example 5
In Example 1, the same operation as in Example 1 was performed, except that the temperature at the prehydrolysis was changed to 170 ° C. and 40 minutes (P factor was 398). Tables 1 and 2 show the results. The acidic peroxide treatment was performed at pH 2.5.
実施例６
実施例１において、酸性過酸化物処理時の過酸化水素添加率を０．１％に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理はｐＨ２．７で行なった。
Example 6
In Example 1, the same operation as in Example 1 was performed, except that the hydrogen peroxide addition rate during the treatment with acidic peroxide was changed to 0.1%. Tables 1 and 2 show the results. The acidic peroxide treatment was performed at pH 2.7.
実施例７
実施例１において、酸性過酸化物処理時の過酸化水素添加率を１．０％に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理はｐＨ２．２で行なった。
Example 7
In Example 1, the same operation as in Example 1 was performed, except that the hydrogen peroxide addition rate during acidic peroxide treatment was changed to 1.0%. Tables 1 and 2 show the results. The acidic peroxide treatment was performed at pH 2.2.
実施例８
実施例１において、酸性過酸化物処理時の硫酸添加率を０．２％に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理はｐＨ３．９で行なった。
Example 8
In Example 1, the same operation as in Example 1 was performed except that the sulfuric acid addition rate during the treatment with acidic peroxide was changed to 0.2%. Tables 1 and 2 show the results. The acidic peroxide treatment was performed at pH 3.9.
実施例９
実施例１において、酸性過酸化物処理時の硫酸添加率を０．８％に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理ｐＨは１．９で行なった。
Example 9
In Example 1, the same operation as in Example 1 was performed except that the sulfuric acid addition rate during the treatment with acidic peroxide was changed to 0.8%. Tables 1 and 2 show the results. The acidic peroxide treatment pH was 1.9.
実施例１０
実施例１において、クラフト蒸解時の活性アルカリ添加率を１８％に変更し、酸性過酸化物処理時の過酸化水素添加率を１．０％に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、クラフト蒸解後のカッパー価は、１２．８、酸性過酸化物処理はｐＨ２．２で行なった。
Example 10
In Example 1, the same operation as in Example 1 except that the active alkali addition rate during kraft cooking was changed to 18% and the hydrogen peroxide addition rate during acidic peroxide treatment was changed to 1.0%. Was done. Tables 1 and 2 show the results. The kappa number after kraft cooking was 12.8, and the acidic peroxide treatment was performed at pH 2.2.
実施例１１
実施例１において、Ｄ０段での二酸化塩素添加率を０．６％に変更し、酸性過酸化物処理時の過酸化水素添加率を１．０％に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理ｐＨは２．２で行なった。
Example 11
In Example 1, the chlorine dioxide addition rate in the D0 stage was changed to 0.6%, and the hydrogen peroxide addition rate during the acidic peroxide treatment was changed to 1.0%. The operation was performed. Tables 1 and 2 show the results. The acidic peroxide treatment pH was 2.2.
実施例１２
実施例１において、酸性過酸化物処理時の過酸化水素を過酢酸に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理ｐＨは２．４で行なった。
Example 12
In Example 1, the same operation as in Example 1 was performed except that the hydrogen peroxide during the acidic peroxide treatment was changed to peracetic acid. Tables 1 and 2 show the results. The acidic peroxide treatment pH was 2.4.
実施例１３
実施例１において、酸性過酸化物処理時の過酸化水素を過硫酸に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理ｐＨは２．２で行なった。
Example 13
In Example 1, the same operation as in Example 1 was performed except that the hydrogen peroxide during the acidic peroxide treatment was changed to persulfuric acid. Tables 1 and 2 show the results. The acidic peroxide treatment pH was 2.2.
実施例１４
実施例１において、ユーカリ・ペリータ材チップをユーカリ・グロブラス材チップに変えた以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、未晒パルプのカッパー価は６．１、酸性過酸化物処理ｐＨは２．５で行なった。
Example 14
In Example 1, the same operation as in Example 1 was performed except that the eucalyptus / perita material chip was changed to the eucalyptus / globula material chip. Tables 1 and 2 show the results. The unbleached pulp was kappa number 6.1 and acidic peroxide treatment pH 2.5.
比較例１
実施例９において、酸性過酸化物処理を行わなかった以外は、実施例９と同様の操作を行なった。表１、２に結果を示す。
Comparative Example 1
In Example 9, the same operation as in Example 9 was performed except that the acidic peroxide treatment was not performed. Tables 1 and 2 show the results.
比較例２
実施例９において、酸性過酸化物処理時に過酸化水素を添加しなかった以外は、実施例９と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理ｐＨは３．０で行なった。
Comparative Example 2
In Example 9, the same operation as in Example 9 was performed except that hydrogen peroxide was not added during the acidic peroxide treatment. Tables 1 and 2 show the results. The acidic peroxide treatment pH was 3.0.
比較例３
実施例１において、酸性過酸化物処理を酸素脱リグニン直後に変更した以外は、実施例１と同様の操作を行なった。表１、２に結果を示す。なお、酸性過酸化物処理ｐＨは４．１で行なった。
Comparative Example 3
In Example 1, the same operation as in Example 1 was performed except that the acidic peroxide treatment was changed immediately after oxygen delignification. Tables 1 and 2 show the results. The acidic peroxide treatment pH was 4.1.
表１、２の実施例１〜１４と比較例１〜３を比較すると明らかなように、リグノセルロース物質を原料として前加水分解−アルカリ蒸解を行なって未晒パルプを調製した後、漂白し、さらに酸性下で過酸化物を添加して処理することにより、高α−セルロース含量、高白色度、低灰分でかつ所望のパルプ粘度を有する溶解パルプを製造できることがわかる。 As is clear when comparing Examples 1 to 14 and Comparative Examples 1 to 3 in Tables 1 and 2, after preparing an unbleached pulp by pre-hydrolysis-alkali digestion using a lignocellulosic material as a raw material, bleaching, Furthermore, it turns out that the melt | dissolution pulp which has high alpha-cellulose content, high whiteness, low ash content, and desired pulp viscosity can be manufactured by adding and processing a peroxide under acidity.
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| JP6075976B2 (en) * | 2012-06-15 | 2017-02-08 | 日本製紙株式会社 | Method for producing dissolved kraft pulp |
| JP6358771B2 (en) * | 2012-06-15 | 2018-07-18 | 日本製紙株式会社 | Method for producing dissolved kraft pulp |
| JP6221218B2 (en) * | 2012-10-05 | 2017-11-01 | 日本製紙株式会社 | Method for producing dissolved kraft pulp |
| JP6522274B2 (en) * | 2013-08-06 | 2019-05-29 | 日本製紙株式会社 | Method of making dissolved kraft pulp. |
| JP6483021B2 (en) * | 2013-09-11 | 2019-03-13 | 日本製紙株式会社 | Method for producing dissolved kraft pulp |
| JP6197717B2 (en) * | 2014-03-25 | 2017-09-20 | 王子ホールディングス株式会社 | Method for producing dissolving pulp |
| JP2015205972A (en) * | 2014-04-18 | 2015-11-19 | 王子ホールディングス株式会社 | Molten pulp |
| JP2015205966A (en) * | 2014-04-18 | 2015-11-19 | 王子ホールディングス株式会社 | Molten pulp |
| JP6398388B2 (en) * | 2014-07-02 | 2018-10-03 | 王子ホールディングス株式会社 | Dissolving pulp and method for producing the same |
| SG10201503723TA (en) * | 2015-05-12 | 2016-12-29 | Pt Sateri Viscose Internat | Dissolving Pulp |
| SE1650050A1 (en) * | 2016-01-18 | 2017-04-25 | Valmet Oy | Chlorine dioxide stage for controlling viscosity in dissolving pulps |
| JP6423838B2 (en) * | 2016-09-23 | 2018-11-14 | 日本製紙株式会社 | Method for producing dissolved kraft pulp |
| JP6581137B2 (en) * | 2017-03-24 | 2019-09-25 | 日本製紙株式会社 | Method for producing dissolved kraft pulp |
| FI130070B (en) * | 2018-03-07 | 2023-01-31 | Andritz Oy | Method of producing dissolving pulp |
| JP7089959B2 (en) * | 2018-06-25 | 2022-06-23 | 日華化学株式会社 | Method for producing digestion accelerator and pulp for lignocellulosic material |
| JP6820961B2 (en) * | 2019-02-14 | 2021-01-27 | ユニ・チャーム株式会社 | Use of recycled pulp for hygiene products and hygiene products |
| CN113795626B (en) * | 2019-05-10 | 2024-06-07 | 阿尔托大学基金会 | Method for treating cellulosic material, method for producing hydrolyzed cellulosic material, use of chlorite and gaseous pressurized HCl, use of chlorous acid and hydrolyzed cellulosic material |
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