Kengo Magara's research while affiliated with Forestry and Forest Products Research Institute and other places

Publications (47)

Article
Cellulose nanofibers (CNFs) have many potentials as filler to improve the properties of the other materials. We have developed the novel paints containing CNFs, and which controlled the discoloration of wood products. To clarify the discoloration mechanism of wood panels using an undercoat paint containing CNFs, prepared by an integrated process fr...
Article
We have studied selected applications of cellulose nanofibers (CNFs) prepared via the wet fibrillation of pulp treated with cellulase in a bead mill. We observed that the weatherability of water-based wood paint can be improved when using CNFs as an additive in the undercoat paint (sealer). For the application, however, the low dispersibility of CN...
Article
Full-text available
Cellulose nanofiber (CNF) produced by enzymatic treatment and wet milling was blended with an acrylic resin emulsion, and waterborne varnish for topcoat and undercoat was prepared. Tensile tests of the film prepared from the varnish for topcoat indicated that elastic modulus, strength, and maximum strain depended on the CNF percentage and dispersio...
Article
The process of lignin oxidation by oxygen gas or other oxidative catalysts to produce phenolic monomers, such as vanillin, has become important in the development of new methods for producing polymers from renewable resources. It was found that oxygen-soda anthraquinone(AQ)cooking produces a phenolic monomer yield of over 17%, including vanillin, u...
Article
Since June 2009, we have been operating a pilot plant to evaluate a process for producing bio-ethanol from lignocellulosic biomass, wherein lignin is removed using soda-anthraquinone( soda-AQ) cooking as a pretreatment for enzymatic saccharification. By the end of September 2012, we completed all pilot plant operations and obtained the following re...
Article
We investigated the soda―anthraquinone cooking process of bamboo chips and the recovery of hemicellulose precipitated from the resulting black liquor to study how bamboo hemicellulose may be utilized. The cooking efficiency of bamboo chips improved after hot water extraction, probably because a part of the starch that consumes the active alkali dur...
Article
Soda-anthraquinone (soda-AQ) cooking, focused on obtaining lignin rather than cellulose, was performed under various cooking conditions. The lignin obtained by acidification of the spent liquor to pH 5 was chemically characterized and the correlation between the cooking conditions and the chemical properties of lignin was discussed. The lignin yiel...
Article
In this study, we investigated the proportion of erythro- and threo-forms of β-O-4-ether structures and their enantiomeric compositions in hardwood lignin by applying the ozonation method to birch wood meal. Optical activity was not substantially observed in either the erythronic or threonic acids obtained as the ozonation products of β-O-4-structu...
Article
Bark of desert willow (Salix psammophila, Spsa) grown in Inner Mongolia was successively extracted with n-hexane, diethyl ether, acetone, methanol, and hot water to examine chemical components associated with its environmental adaptability to desert conditions. The yield of n-hexane extract (5.0 % based on dry bark), mainly composed of wax, was hig...
Article
Bamboo is an attractive biomass resource which grows rapidly, reaching their maximum size within a few months. Bamboo pulp, prepared by soda-anthraquinone cooking, was fermented to ethanol with a cocktail enzyme of Aspergillus tubingensis KRCF7OO-33Y and Trichoderma reesei ATCC66587, and thermotolerant yeast (Saccharomyces cerevisiae BA-11) under s...
Article
In this paper, cyclic voltammograms of the film electrodes containing Pb active materials and sodium lignosulfonate formed on Pb plate have been measured in sulfuric acid solution. Discharging capacity decreases and charging capacity increases with longer alkaline hydrothermal treatment of sodium lingosulfonate in the film electrodes. These film el...
Article
Evidence for the presence of lignin-carbohydrate bonds of the benzylic ether type in wood and pulps may be obtained by use of ozonation treatment to selectively degrade the lignin. It was found that the benzyl ether bond in 3-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxy-phenoxy)-3-(methyl-β-d-glucopyranosid-6-O-yl)-1-propanol was rather stable during o...
Article
The process of solid-state fermentation was used to produce a cocktail enzyme of Trichoderma reesei ATCC 66587 and Aspergillus tubingensis KRCF 700-33. Wheat bran, corncob, and sugi pulp were supplemented with ammonium sulfate as an enzyme-producing medium using T. reesei and A. tubingensis. The corncob blend ratio, duration of incubation, and ammo...
Article
平成18年後半,政府は2030年までに国産バイオマスを原料としてガソリン使用料の1割を代替できるバイオエタノールを製造することを目標に掲げ,その中で木質から生産するエタノールを目標200万kLとした。この200万kLのエタノールを製造するためには,約400万tのセルロースが必要となるが,そのような莫大なセルロースを生産できる技術は紙パルプ業界以外にあり得ない。よって,森林総研はソーダアントラキノン蒸解法で製造したパルプを酵素糖化と発酵によりバイオエタノールに生産する技術の開発に着手し平成20年に秋田県北秋田市に実証プラントを建設するに至った。プラントは平成21年6月に完成し,その後数度の実証運転を行いいくつかの問題点を抽出した。それらの中で,糖化・発酵工程におけるパルプ懸濁液の輸送や撹拌は,...
Article
In order to utilize lignocellulosic biomass as a feedstock for bioethanol, ozone pretreatment was conducted on Japanese cedar sawdust and three other lignocellulosic wastes. Successful lignin degradation was accomplished by ozone pretreatment of the Japanese cedar sawdust and over 90% of polysaccharides were converted to monomeric sugars by enzymat...
Article
The effect of lignosulfonate (LS) on electrochemical reaction of lead electrode (as a model of negative electrode) has been investigated in 1M, 3M, or 7.1M H2SO4 aqueous solution with 0, 10, 100 or 1000mgl−1 of LS using cyclic voltammetry (CV) combined with in situ electrochemical atomic force microscopy (EC-AFM), as well as rotating ring disk elec...
Article
Our group has proposed producing bioethanol from lignocellulosics using alkali pretreatment and enzymatic saccharification. Our previous studies showed that low-cost materials must be used to reduce the production cost. In this study, we evaluated the suitability of low-cost lignocellulosics, such as waste and recycled lignocellulosics, for bioetha...
Article
In this study, we investigated the applicability of 4-O- methylglucuronoxylan (xylan) and cellouronate as raw materials for preparing hexenuronic acid groups by alkali-cooking. We also investigated the generation of AOX during chlorine dioxide (ClO 2) treatment of the prepared hexenuronic acids. Based on Teleman's procedure, suitable conditions for...
Article
現状では有効利用が十分進んでいない未利用材や建設発生木材に相当する木質バイオマスを用いたアルカリ前処理および酵素糖化を行い,これら木質系バイオマスのバイオエタノール原料としての適性を検討した。樹皮が残ったままのスギ枝は,スギ材に比べるとグルコース収率はやや低かったが,バイオエタノール原料として十分に使用することができると考えられた。フェノール樹脂接着剤が使用されたPWは,アルカリ前処理により接着剤のほとんどを除くことができたと考えられ,酵素糖化が阻害されることはなくスギ材と同様の高いグルコース収率を与えた。このためにこのようなPWは,バイオエタノール原料として適すると考えられた。メラミン・ユリア共縮合樹脂接着剤が使用されたPBは,スクリーン粕が多く発生したために,パルプ収率を上げることができ...
Article
Woody biomass has become important for a raw material of bioethanol production. Alkaline pre-treatment on the woody biomass is an advantage method for the large scale production of the bioethanol. In this study, the cellulase production using the alkaline treated woody biomass was investigated. And the bioethanol was produced from the alkaline trea...
Article
Guaiacylglycerol-β-guaiacyl ether (GG), which contains a predominant inter-unit linkage of lignin, could be converted into a corresponding glycerol type enol-ether (EE), 3-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-2-propenol, by the heat treatment in ionic liquids. EE is believed to be the unstable intermediate of the lignin decomposition pr...
Article
Hydrogen peroxide is generally determined by an iodometric titration method. This method is determining the oxidation-ability of a sample solution. If any compounds that have oxidation-ability toward iodide are involved in the sample solution, the oxidation-ability of those compounds will be counted as a part of hydrogen peroxide. Accordingly, when...
Article
Bioethanol fuel for motor vehicle use is currently produced from sugar cane and corn starch. However, the production costs of such crops in Japan are much higher than in Brazil and North America. Therefore, Japanese bioethanol fuel production from such crops is very limited. On the other hand, lignocellulosic biomasses, especially woody biomasses,...
Article
Density and hardness of the negative pastes of lead–acid batteries, to which organic compounds with or without quinone structures have been added, are investigated by means of the stick insertion depth test. Results show that the density and hardness of a paste containing anthraquinone are almost the same as one containing anthracene. By contrast,...
Article
The influence of quinone structures related to the formation of the “colloidal deposit” on Pb electrode immersed into water containing lignin preparations or pure organic compounds has been investigated. It was found that quinone structures in lignin preparations, as well as in pure organic compounds, play an important role in the formation of the...
Article
Decreases in AOX during chlorine dioxide bleaching at high temperatures and under acidic conditions were investigated. When the temperature in the chlorine dioxide bleaching stage was raised from 70°C to 95°C, a certain decrease in AOX was detected. AOX is formed by a chlorine substitution reaction with mainly lignin and chlorine that was generated...
Article
There are two undesirable reactions that occur during ozone bleaching of kraft pulp. One is hydroxyl radical formation that occurs when ozone decomposes prior to reaction with lignin. The other one ix one-electron oxidation of dissociated phenolate in lignin, from which an hydroxyl radical is also formed as in the decomposition reaction of ozone. T...
Article
In order to utilize lignocellulosic biomass as a raw material of bioethanol, ozone pretreatment was conducted on Japanese cedar (sugi) sawdust and the enzymatic susceptibility was evaluated. On treating the sawdust with ozone, it was found that the moisture content of the sample greatly affects the efficiency of ozone consumption. By adjusting the...
Article
A method for isolation and analysis of benzyl ether type lignin-carbohydrate bonds (LCC bonds) has been developed. The yield of the acidic fraction which contained LCC bonds were increased by extending ozonation and using weak anion exchange resin for anion exchange chromatography. Many products in acidic fraction which was isolated from wood gave...
Article
Full-text available
Chlorine-free bleaching was carried out on kraft pulp from oil palm empty fruit bunches (EFB) with an oxygen (O2) - acid (H2SO 4) - ozone (O3) - hydrogen peroxide (H2O 2) bleaching sequence. The K-number (= an indicator of lignin content) of the pulp was reduced considerably after these processes indicating that most of the lignin present in the pu...
Article
A novel method for analysis of benzylic ether type lignin–carbohydrate bonds has been developed by using model compounds. Four diastereomers of model compound 3-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-3-(methyl -d-glucopyranoside-6-O-yl)-1-propanol (GGMGP), were ozonized in acetic acid/water/methanol 16:3:1 for 1h at 0C. The product from o...
Article
Chloroform was readily converted to formic acid through the nucleophilic attack of hydroxyl anion under the certain reaction conditions (pH>12, temp.>70°C). When guaiacol was reacted with hypochlorite at such reaction conditions, the generation of chloroform was almost completely reduced. Successful reduction of the chloroform generation was also o...
Article
Kraft pulp and sulfite pulp bleaching mills using chlorine, chlorine dioxide (D) and other chlorin-ated compounds are under surveillance of the dioxins regulation in Japan from 15 January 2000. The bleaching mills are regarded as “notified establishments” which may pollute water quality. According to it. the dioxins are composed of polychlorinated...
Article
Methylβ-d-xylopyranoside was allowed to react withβ-O-4-type quinone methide without a catalyst to elucidate the reactivities of secondary hydroxyl groups at the C2, C3, and C4 positions. Benzyl ether-type lignin-carbohydrate complex (LCC) compounds linked at the C2 and C4 positions were predominant, at a ratio of 2∶3. However, the reactivity of th...
Article
Recent rapid progress of the biosynthetic study of lignan, especially finding a new type of protein that regulates the stereo structure of lignan,(1) seems to "re-create" an interest in the investigation of optical activity of lignin, although lignin has long been assumed to be optically inactive.
Article
To investigate the bleaching mechanism, a lignincarbohydrate complex (LCC) model compound, a vinyl ether-type lignin model dimer, and a hexeneuronic acid model compound were treated with dilute sulfuric acid of different pHs. Beech kraft pulp and red pine kraft pulp were also treated with dilute sulfuric acid and then extracted with aqueous alkali....
Article
The purpose of this study was to investigate the behavior of lignin and carbohydrates in kraft pulps during sulfuric acid bleaching. Beech kraft pulp and red pine kraft pulp were bleached with dilute sulfuric acid at pH 1.3 with addition of sodium nitrate and sodium nitrite at 100°C for 1 h. The pulps were then extracted with aqueous sodium hydroxi...
Article
To develop a new nonchlorine bleaching technology, hardwood and softwood kraft pulps, before and after oxygen-alkali predelignification, were treated with dilute sulfuric acid solutions (pH 1.0-1.8) at 100°C for 1 h and then extracted with aqueous sodium hydroxide at 70°C for l h. Hardwood kraft pulp was successfully bleached. The delignification s...
Article
Some lignin-carbohydrate model systems were investigated to elucidate the effects of lignin on cellulose degradation during the ozone bleaching of kraft pulps. In the presence of lignin model compounds with free phenolic hydroxyl groups, cellobiose degradation was accelerated until the lignin model compounds were consumed by the reaction with ozone...
Article
Recently, one of the greatest concerns of the world wide pulp and paper industries has been organo-chloro compounds discharged from bleach plants which use chlorine based bleaching chemicals. Although there are some debates on toxicities of organo-chloro com-pounds, we can find a distinct tendency in developing kraft pulp bleaching technologies whi...

Citations

... The utilization of oil palm biomass, especially EFB in the production of bleached and unbleached pulp and paper products have been studied since the 1970s. The utilization oil palm biomass for pulp and paper production has been studied extensively including the production of totally chlorine-free (TCF) full bleached pulp from oil palm EFB fibre (Jiménez et al. 2009;Leh et al. 2005) with comparable properties to the commercial mixed hardwood pulp. ...
... In spite of potential environmental and economic benefits, the application of ozone leads to drawbacks, the most critical being the degradation of cellulose below a DP, which affects the mechanical properties of the final product (Kang, Zhang, Ni, & Van Heiningen, 1995;Ragnar, Eriksson, & Reitberger, 1999;Rautonen, Rantanen, Toikkanen, & Malinen, 1996). Although it is well documented that pulp ozonation generates radicals, which degrade cellulose (Gierer & Zhang, 1993;Magara, Ikeda, Tomimura, & Hosoya, 1996;Ragnar, Dahllöf, & Lundgren, 2005), it is admitted that another cause of cellulose depolymerization is the generation of carbonyl groups during the Z stage, which are responsible for cellulose chain cleavage (␤-elimination) in subsequent alkaline stages, such as in the http alkaline extraction (E stages) or the peroxide (P) stages and their combinations (Fuhrmann, Li, & Rautonen, 1996). Those groups might also induce some yellowing (Chirat & De la Chapelle, 1999;Sjöström & Eriksson, 1968). ...
... The main components of saccharified Japanese cedar are the hexose sugar D-glucose and the pentose sugars D-xylose and L-arabinose. Ethanol-producing yeast such as Saccharomyces cerevisiae efficiently utilizes hexoses; however, the inability to utilize pentoses hinders the development of economic strategies for bioethanol production from saccharified Japanese cedar (Ikeda et al. 2009). ...
... In spite of potential environmental and economic benefits, the application of ozone leads to drawbacks, the most critical being the degradation of cellulose below a DP, which affects the mechanical properties of the final product (Kang, Zhang, Ni, & Van Heiningen, 1995; Ragnar, Eriksson, & Reitberger, 1999; Rautonen, Rantanen, Toikkanen, & Malinen, 1996). Although it is well documented that pulp ozonation generates radicals, which degrade cellulose (Gierer & Zhang, 1993; Magara, Ikeda, Tomimura, & Hosoya, 1996; Ragnar, Dahllöf, & Lundgren, 2005), it is admitted that another cause of cellulose depolymerization is the generation of carbonyl groups during the Z stage, which are responsible for cellulose chain cleavage (-elimination) in subsequent alkaline stages, such as in the alkaline extraction (E stages) or the peroxide (P) stages and their combinations (Fuhrmann, Li, & Rautonen, 1996). Those groups might also induce some yellowing (Chirat & De la Chapelle, 1999; Sjöström & Eriksson, 1968). ...
... The effect of ozone bleaching on pulps has been comprehensively reflected in the litera- ture (e.g., Chirat and Lachenal 1997;Zhang et al. 2000;Shatalov and Pereira 2007) and by carbohydrate model compound studies (e.g., Pan et al. 1995;Olkkonen et al. 2000). The effect on chromophores has been described with regard to lignin model compounds ( Kang et al. 1995;Magara et al. 1998Magara et al. , 2005Pipon et al. 2007), but not with regard to the carbohydrate-derived, especially reso- nance-stabilized chromophores 1-3 studied in the pres- ent paper. Degradation of the chromophores in the Z-stage appeared to form products that behaved adversely to pulp integrity, being likely of acid or hydroxyacid types. ...
... [7] As a preliminary study for evaluating dispersibility to real cement, three types of amphiphiles were prepared from soda lignin (SL), which was a by-product from soda pulping of cedar as a delignification process for enzymatic saccharification of Japanese plantation softwood. [10] EPEG-SL showed the highest dispersibility to the cement among the SL-based derivatives and LS. [11] In this study, such amphiphiles were prepared from kraft lignins and black liquors of kraft pulping, because such raw materials are commercially available all over the world, whereas AL and SL (used in our previous work) are not obtained so easily on an industrial scale. ...
... The use of nitrobenzene for oxidizing isoeugenol into vanillin was patented in 1927 [25]. NBO of lignins was actively developed in the works of Hibbert, Leopold, and other authors [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]; new inquiries into the process are still being made [27,28] (Table 1). The process takes place in alkaline media at 160-180 • C lasting 2-4 h [23]. ...
... During the formation of arylglycerol-β-aryl ether structures (β-O-4 structures), a β-O-4-linkage is formed by a radical coupling reaction between a monolignol and the phenolic end of a growing lignin to produce a QM intermediate, which houses a chiral center, the β-carbon atom (Scheme 1). 10 The β-O-4-aryl ether QM bearing the β-asymmetric carbon is aromatized by the water addition at the prochiral α-carbon, affording either the erythro or threo forms of the β-O-4 structure. The generation of erythro or threo forms depends on which face of the QM reacts faster with water. ...
... Another method in a study used a ligand exchange-type column for the separation of H 2 O 2 . The column was packed using a sulfonated polystyrene/divinylbenzene cation-exchange [119]. Steinberg et al. used the principle of reverse-phase chromatographic techniques in HPLC to determine H 2 O 2 . ...
... It is also interesting to note that after the H 2 O 2 sequence, the brightness has been increased drastically whilst maintaining the paper strengths at acceptable levels. Opacity, which is the ability of paper to hide or mask a color or object in back of the sheet, obtained for the bleached handsheet in this study is found to be at a comparable level with that of a hardwood KP, which has almost the same value in brightness 8 . ...