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2009 May JAPAN TAPPI JOURNAL


Vol.63 No.5 Abstracts



Present State of Overseas Plantation
-Forest Tree Improvement Beginning with Selection of Target Species-

Kazuya Ito
Forestry Research Institute, Research & Development Division, Oji Paper Co., Ltd.

  Sources of imported wood chips to Japan have gradually been replaced with trees out from plantation in accordance with increasing area of overseas plantation. Quantity and quality of wood fiber should affect not only cost of manufacturing but also quality of papers. As breeding can improve characteristics of forest trees, it attracts much more interest to get superior trees with much better cost performance or unique characters to make differentiated manufactures. Fast growing trees such as Eucalyptus and Acacia are main target species for overseas plantation. Introduction of clones into their plantation has been resulted to be better growth performance of trees planted. As one of main target for breeding is getting much more pulp from unit area of plantation, improvement of wood quality such as basic density and pulp yield should be important for getting such a target. Moreover, hybrids between species may create trees with much resistant to stresses such as drought and disease. Methods for early selection of superior trees may accelerate process of breeding to get final results with less time.

Keywords: Eucalyptus, Acacia, Breeding, Clone, Hybrid, Basic density, Pulp yield


Variety of Lignin Structure in Wood Cells and Its Effects on Delignification

Yuji Matsumoto
Wood Chemistry Laboratory, Graduate School of Agricultural and Life Sciences,
The University of Tokyo

  Wide variety of lignin structure is observed not only among different wood species, but also in different layers within a single cell wall, or, in different types of cell in a same wood. General rule found for the wide variety of lignin structure among different wood species can be also found for different cell wall layers, or, different type of cells. Namely, when a certain cell wall layer, or, certain type of cell has lower lignin content, its lignin is richer in ƒÀ-O-4 structure, especially of erythro type, and, syringyl type of aromatics. Because these characteristics found together with lower lignin content are favorable for delignification reactions during pulping and bleaching, anatomical aspect of lignin structure is important to understand the pulpability of woods.

Keywords: lignin, delignification, pulping, cell structure


Historical Development of Kraft Pulp Cooking

Kazuhiko Ando
Production Dep., Nippon Paper Industries Co., Ltd.

  Many digesters in Japan were installed in the 60fs and the 70fs which were called the highly economic growth era. They are around 30 to 40 years old or too old. However many of them are still operating by now. They are getting further old year by year. But we have maintained the high competitiveness of them as taking several maintenances and upgrades. On the other hand, recently, many brand-new large fiberlines have been installed in South America or Southeast Asia. Such competitors will threaten us with higher competitiveness by brand-new equipments. In this report, I introduce a summary of the kraft pulp cooking methods last 40 years which consists of Conventional cooking, MCC, Lo-solids cooking, Compact cooking and so on. New model of digester are made several improvements for the yield, the quality, the maintenance, simplification and so on. On the other hand, AQ and PS were improved well and the new electrolysis polysulphide generator has been developed to raise the concentration of PS recently. We would like to make further improvement for the kraft pulp cooking with the pulp & paper industries, the machinery industries and the chemical industries together.

Keywords: Conventional Cooking, Lo-Solids Cooking, Compact Cooking


Trend of Bleaching in Kraft Pulp

Yosuke Uchida
Research Development Div., Pulp & Paper Research Laboratory, Oji Paper Co., Ltd.

  Chlorine and chlorine compounds had been used for bleaching of kraft pulps for many years. Since 1990s, many kraft pulp mills in all over the world have converted conventional bleaching with chlorine to ECF (Elemental Chlorine Free) bleaching in order to eliminate AOX (Absorbable organic halogens) produced in bleaching process, which have influence on the environment.
  In this report, the trend of bleaching agents in kraft pulps is reviewed from the point of relationship between these agents and the residual lignin structures in kraft pulps.


Modern Kraft Pulping Technology Developed by Metso Paper

Yan Ju
Process TechnologyCFiber Business Line, Metso Paper Japan Co., Ltd.

  Metso Paper has developed modern kraft pulping technology in which COMPACT COOKINGTM G2 cooking system, pressure diffuser (PDW), DeltaKnotterTM, DeltaScreenTM, TwinRoll PressTM, oxygen delignification stage-OxyTracTM, and high consistency ozone bleaching stage - ZeTracTM, etc. are included. With Metsofs modern kraft pulping technology it can be fully meet the requirement for a fiberline with huge capacity up to 5000ADt/day, homogenous cooking with the mixed chips, increasing pulp yield. And it can reduce water and energy consumption, minimize discharge of filtrate which is related to decrease the environmental load. Moreover, it can also be easy to convert the bleaching plant from element chlorine free bleaching (ECF) to total chlorine free bleaching (TCF). With installation of ZeTracTM stage it will be easy to recover a part of filtrate from the bleaching plant, and change bleaching plant to total effluent free bleaching (TEF) when development of a suitable way to minimize the problem of accumulation of non-process elements in the system in the future.

Keywords: COMPACT COOKINGTM G2, OxyTracTM, ZeTracTM, DeltaKnotterTM, DeltaScreenTM


Andritz Latest Fiber Line Technology

Kanji Hagiwara, Chiaki Kawakami
Andritz Latest Fiber Line Technology, Andritz K.K.

  Andritz has developed new technology for the fiber line over decades. This paper presents (1) Botnia, Frey Bentos Mill in Uruguay, one of the latest Kraft Mills (2) Evolvement of pulping technology and latest technology of cooking process (3) Andritz pulp washing equipment (DD Washer, DD-10, AWP Wash Press) (4) IDEAS Computer Simulator and the patented BrainWave advanced control system.


Expectation to the Paper Industry in the Oil Resources Exhaustion Century
-Learn from a Past-

Hiraku Nihei
Japan Paper Association

  The Japanese pulp and paper industry has made energy-saving efforts since the two oil crisis in 1973 and 1979, becoming one of the most energy-efficient in the world pulp and paper industry. Also the industry has promoted conversion from heavy oil boiler to new energy boiler. As a result, there are limited options for global warming measures.
  High oil prices in recent years has eliminated the industryfs efforts made in the past. Volatility of oil prices seems to signal the beginning of oil exhaustion. Oil prices will continue to fluctuate greatly.
   In Japan, pulp and paper mills are deployed nationwide. Therefore, the industry can make efficient use of biomass which is distributed widely in small quantities nationwide. For sustainable development of the industry, biochemical industry which makes full use of wood chemistry will play an important role.


Energy Utilization of Biomass

Kenichiro Hada
Environment, Natural Resource and Energy Division,
Mizuho Information & Research Institute, Inc.

  Bioenergy has been anticipated for the significant contribution to the mitigation of greenhouse gas and the energy security. Bioenergy is more competitive than the other renewable for its can produce liquid, solid, and gaseous fuels. This paper gives the some topics of the bioenergy, as shown below; (1) an overview of both national and international trends of bioenergy, (2) the developments of cellulosic-derived liquefied biofuels, (3) sustainability for utilization of bioenergy.

Keywords: bioenergy, biofulel, BTL


Basic Concept of Pulping Technology for Recovered Paper

Masakazu Eguchi
Stock Preparation Engineering Dept., Voith-IHI Paper Technology Co., Ltd.

  Recently, Japan is struggling with severe circumstances with regard to waste paper handling - recycled paper cost has increased due to the outflow of waste paper to overseas markets, along with the energy cost increase brought by the high oil price. On the other hand, the sudden economy recession hits papermakers to face the dramatic drop of the total demands for both graphic and board papers. Furthermore, the papermakers have to be aware of the additional costs as they cannot ignore the growing concern to the environmental protection at the world wide level. Accordingly, there seem only negative factors increasing the production costs. However, even under these circumstances, there are many possibilities for operation cost down in the stock preparation process.
   At first, the technology in the secondary fiber system is a technology to remove contaminants. As you know, there are lots of contaminants and fibers in waste paper. They should be separated depending on the differences of the own property in each stage. For this purpose, generally three methods are applied. 1) Screening and/or washing process - removing contaminants by the difference of their shapes. 2) Cleaning process - removing contaminants by the difference of their gravity. 3) Flotation process - removing contaminants by the difference of their hydrophilicity.
   If paper can be perfectly defibered prior to these methods, it would be more efficient to remove all kinds of contaminants, which would result in saving the energy. This process to defiber the raw material is called gsecondary pulping processh and a pulper is an essential component in this process.
   In this paper, we will introduce new pulping technology, the low consistency gIntensa Puplperh and the high consistency gTwinDrumh, and our basic concept for handling recycled paper.


Andritz Waste Paper Treatments Pulper System Technology

Yosuke Takeshita
Sales & Technical Group 2, Andritz K. K., Japan

  Today the recycled fiber cost is increasing due to more export to China and in addition the recycled fiber resources are getting scarce, and consequently the cost of recycled fiber has considerably increased. Andritz has developed and improved the Fiber solve Tab type pulper & FiberFlow Pulper design with new PRO concept over the recent years. This report shows the Theses Fiber solve pulper and FiberFlow PRO concept. The new FiberFlow Drum Pulper is able to accept more lower grade recycled fibers and improve the pulping capacity more than 40-50% compared with conventional FiberFlow Drum and also minimize the fiber loss as low as 0.5%. It is possible to improve and upgrade the existing conventional FiberFlow Drum Pulpers with the new PRO technology. Andritz has upgraded already many conventional FiberFlow Drum Pulpers overseas with the PRO technology for improving performance.


Pulping Concept for Deinking Plant
-The AIKAWAfs Theory and the Newest Technologies-

Kazumi Fujita
Technical & Engineering Department, AIKAWA IRON WORKS CO., LTD.

  The pulper is a process of the beginnings of the DIP plant, and it is important facilities having both two sides of "the impurities removing" and "ink detaching / dispersion ". Because the high consistency pulper system which had been developed by AIKAWA ahead of the world, had been adopted it by most of the European DIP plants, there is the history that the other pulper makers followed it. The newest HeliDisc rotor and Double Dumping Screen for the high consistency pulper system had been refined especially for impurities removing and energy saving, won the 2002 Sasaki Prize in Japan. This system was able to get very high support, and most DIP plants which have been equipped after 2002, adopted this system. In this report, I will explain AIKAWA's basic concept and our newest technology for the high consistency pulping system. And, I will explain comparison with our system and the conventional continuation type drum pulper.

Keywords: High Consistency Pulper, HeliDisc Rotor, Double Dumping Screen, Drum Type Continuance Pulper vs. High Consistency Batch Operation Pulper


Basic Concept of Screening Technology for DIP process

Masakazu Eguchi
Stock Preparation Engineering Dept., Voith-IHI Paper Technology Co., Ltd.

  The principle of screening is to remove contaminants from the difference of their shape. Key components are a basket, a wiper and a casing. Regardless of this simplicity, screens are commonly used as a most effective equipment to remove out contaminants, but because it is a simple principle, a variety of detail design changes or improvements are made time by time.
   Nowadays, it is a world-wide common sense that Centrifugal screens (=outward, Hereafter, referred to gCFh) are applied not only to DIP line but also applied to machine screens. However, only in Japan, this has not been a case, because, in Japan it has been ruled by a stereotype idea for long time, that HC slot screens, which are normally applied to Stock Preparation line, are not convenient and not suitable, if they are applied to machine screens in approach flow line. But such idea is not a correct idea - now the world wide fact shows that the improved CF approach screens are applied to the latest paper machines.
   This paper focuses on the basic and system concept of our CF screen and its system which have been developed through the various experiences in the world market.


Andritz Waste Paper Treatments Screen System Technology

Yosuke Takeshita
Sales & Technical Group 2, Andritz K. K., Japan

  Andritz has the leading technology of all kind pulp types treatments process, KP, MP, SP PMA and Waste paper application. For waste paper applications modern pressure screen technology is the key technology of pulp cleanness quality. Andritz Moduscreen series have a long period experience and a lot of installation for all kind pulping process. This report explains this Moduscreen family for waste paper applications. And explain the latest screen Basket technology Bar-tech-WM.


Screening Concept for Deinking Plant
-The AIKAWAfs Theory and the Newest Technologies-

Kazumi Fujita
Technical & Engineering Dept., AIKAWA IRON WORKS CO., LTD.

  The screen with narrow width slot cylinder is the essential facility for gsticky impurities removingh for a recent DIP plant. The answer of the proposition how remove the tinny stickies, was discovered in the energy saving technologies. In this report, I will explain AIKAWAfs concept that gthe achievement of the energy savingh must be compatible with gimprovement of sticky removal efficiencyh that is a good news for DIP screen facilities. And, I will explain the state-of-the-art of super energy saving screens, the outward type MaxFlow screen and the inward type GranFlow screen, which were developed according to our concept.

Keywords: MaxFlow Screen, GranFlow Screen, Two-Inlet Technology, Stock Dilution Part, NW Super-1&2 Screen Cylinders, Gladiator HC (GHC) Rotor, Outward Type Screen vs. Inward Type Screen


Alkali Pretreatment for Producing Bioethanol Fuel from Lignocellulosics Part 2
-Bioethanol Production from Waste and Recycled Materials-

Tsutomu Ikeda, Tomoko Sugimoto, Masanobu Nojiri, Kengo Magara, Shuji Hosoya and Kinji Shimada
Department of Biomass Chemistry, Forestry and Forest Products Research Institute

  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 bioethanol production.
  Sugi branches without debarking yielded a little lower glucose than sugi. However, it was suggested that sugi branches have sufficient potential as low-cost lignocellulosics for bioethanol production. Alkali pretreatment removed most of the phenol resin which was included in plywood, so enzymatic saccharification of plywood pulp proceeded smoothly, and the glucose yield of plywood was similar to that of sugi. A large amount of screen knots was produced after alkali pretreatment of particle board which contained melamine-urea resin, and small resin particles remained in the pulp hindered enzymatic saccharification. As a result, the glucose yield of particle board was less than half that of sugi. Medium density fiberboard (MDF) which contained urea resin gave a high pulp yield after alkali pretreatment. However, only a small amount of MDF pulp was saccharified after enzymatic saccharification, and the glucose yield of MDF was only about 10%. A large proportion of sugi leaf was dissolved by alkali pretreatment, so the pulp yield of sugi leaf was very low. Furthermore, only a limited part of sugi leaf pulp was saccharified, and the glucose yield of sugi leaf was only 2.8%. These results indicate that sugi leaf is not a good lignocellulosic for bioethanol production.

Keywords: bioethanol, pulp, branch, plywood, particle board, medium density fiberboard