The kraft process has been the mainstay of the paper industry for than 100 years, but the process is unsatisfactory in regard to environmental protection and a pretreatment method for lignocellulosic biomass. Thus there is growing interest in unconventional solvent pulping methods that are based on the use of organic solvents in pulping liquors. A variety of solvent pulping methods free of sulfur compounds has been explored. This paper deals only with solvent pulping methods at atmospheric pressure among which there are phenol pulping with a small amount of HCl, tetrahydrofurfurylalcohol pulping with HCl, acetic acid pulping with HCl followed by bleaching with peroxyacetic acid, formic acid-peroxyformic acid pulping, and acetic acid pulping with sulfuric acid.

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CO₂ was decomposed completely (100%) at 290-350°C with the oxygen deficient magnetite which had been prepared by passing the H₂ gas through the magnetite powder at 290-350°C. In this reaction, oxygen in CO₂ is transferred into the spinel structure of the oxygen-deficient site, and carbon is deposited on the surface of the magnetite. The activation energy estimated from Arrhenius plot is 75.0 kJ. When the carbon deposited on the magnetite was reacted with H₂O (400°C) and H₂ (300-500°C), H₂ and CH₄ were generated, respectively. The reactions found in this study will open the door to construct the chemical heat pump which can be applied to the power station to reduce the CO₂ emission.

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Reduction of NO_x emission from exhaust gas is mainly achieved by improvement in combustion technology and installation of SCR (Selective Catalytic Reduction) plant. This paper outlines mechanism of NO_x formation, current low NO_x combustion technology and SCR plant widely installed in power boilers.

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On Oct. 2224, 1990, No.32 EUCEPA INTERNATIONAL SYMPOSIUM titled “Additives, Pigments and Fillers in the Pulp and Paper Industry” was held at the Congress Centre in Barcerona Spain. This paper is summary of this Symposium.
In Europe, mineral Consumption for papermaking is much more than North America's. On the contrary, paper production in Europe is smaller than that of North America. It becomes more important to improve retention further more.
According to many lectures, researchers' efforts are being made steadily in order to improve paper quality and to reduce its production cost by using conventional materials with new application or by using new materials. Almost of their efforts are being done taking care of environmental issues.

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The aim of this study is to elucidate post-elastic mechanism and the nature of failure of a machine-made paper under the condition of uniaxial tensile or edgewise compression loading. In order to obtain a direct evidence of the inelastic deformation of the sheet related to its structural changes, observations were made both at the sheet surface and on cross sections of the sheet after reaching prescribed strain levels.
In this study, the oriented 80 g/m², and the 240 g/m² NBKP machine-made sheets were used. The damaged sites, that is microcracks, on the specimen surface were clearly detected as bright spots, known as electron charging, under SEM observing conditions. From the preliminary test, it was found that these charging spots were not caused by artifacts, but were generated only by the applied external force. The damages occurring within the sheet under loading were counted by using a digitizer along a set of scan lines depicted on the enlarged photo mosaic, which covered the whole sectional view of the test specimen.
As a result, the strain at elastic limit of the tested sheets was 0.2%, and the residual strain was increased proportionally as increment of the applied strain. The sheets always behaved as a orthotropic body such as a oriented-fiber reinforced material. This may suggest that mechanical properties for MD and CD highly depend on the amount of load-bearing fibers, thick-walled fibers, laid down in MD and CD, which correspond to the framework components within a sheet. On the other hand, the matrix components, such as thin-walled fibers, fines, loosened fibrils, and exudated hemicelluloses etc., should contribute to carry or to redistribute stress concentrated locally among the load-bearing fibers. As the strain increased into the inelastic regime of the stress-strain curve, partial debondings at the interfiber crossings took place and developed into the minute cracks. The number of the damages increased drastically in the inelastic region. As the strain level approached to the failure point, the fiber breakages began to take place, and they always occurred on the thin-walled fiber aligned parallel to the direction of loading. This damage-developing process was clearly observed on the CD specimen. Furthermore, the internal structure of a sheet also changed by means of the externally applied force. The bonding-ratio (BR) of specimen strained close to the failure point was approximately 7% less than that of the unstrained specimen.
These experimental evidences strongly suggest that the post-elastic region of sheet deformation is characterized by the permanent interfiber deformation, accompanying with the partial debonding between the load-bearing fibers and the matrix substances, and the breakage of fiber itself.
On the contrary, compression failure is a very localized phenomenon. The appearance of the failure zone shows pronounced out-of-plane deformation such as creases of bucklings. At the failure zone, fiber debondings and fiber bucklings were prominent, but there is no evidence of such damages even at the site 2 mm apart from the crease.

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Blistering resistance during web-offset printing was studied by using a double coating procedure, styrene-butadiene latexes with different gel contents, and an electron probe X-ray microanalyzer (EPMA) to analyze the coating layer. The blistering resistance was highest at the precoated weight of 4 g/m² (both sides) and when the styrene-butadiene latex with the lowest gel content was used in the precoat. The gel content of the latex in the top coat has no effect on blistering resistance. The resistance to blistering phenomenon seems to depend on the properties of the coating layer near or on the substrate fiber. Based on the EPMA analysis of the single-coated paper, little calcium carbonate was found near the substrate fiber. It is possible that the uneven distribution in the z direction has an influence on the blistering tendency.

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