[en] Recycling of paper mill sludge by means of composting is becoming an acceptable practice for converting organic residues into useful soil amendments, while eliminating negative environmental impacts. The main chemical structures of paper mill sludge composted materials produced by industrial-scale and pilot-scale in-vessel processes were investigated in order to better understand the chemical changes occurring during composting. Chemical and spectroscopic methods were used to characterize the composition of the paper mill sludge composted materials. The spectroscopic data revealed that the major components identified in the paper mill sludge were lipids, sterols, lignins, nitrogen-compounds, and carbohydrates. In the pilot-scale process, organic matter loss was approximately 50% higher than in the industrial-scale process. By the end of composting, the concentrations of nitrogen-compounds remained relatively unchanged in the pilot-scale process, whereas in the industrial-scale process, nitrogen-compounds continually decreased indicating that the biochemical transformations of organic matter were not completed. Thus, composting of paper mill sludge can be successfully achieved if key operating parameters are optimized to reduce losses of nitrogen. (author)

[en] Using the two criteria of potential CO₂ reduction and cost of CO₂ reduction, technical energy measures in Swedish pulp and paper mills are investigated. Principal CO₂-reducing measures analysed are: decreased specific energy utilisation, fuel switch, and CO₂ capture and sequestration. Among the investigated measures, conventional technologies for electricity conservation and improved electrical conversion efficiency in existing systems for cogeneration of heat and power are identified as the most cost-effective alternatives that also have large CO₂ reduction potentials. For commercially available technologies, the results indicate an accumulated reduction potential of up to 8 MtCO₂/y (14% of the Swedish net emissions). If emerging technologies for black liquor gasification (BLG) with pre-combustion CO₂ capture and sequestration are considered, the CO₂ reduction potential increases by up to 6 MtCO₂/y (10% of the Swedish net emissions). Commercialised BLG, CO₂ capture and reliable CO₂ sequestration technologies are identified as important potential contributors to Swedish compliance with Kyoto Protocol targets, especially in a scenario of nuclear power closure. (author)

[en] The structure of the lignocellulosic materials and the chemical composition of their main constitutive polymers, cellulose, hemicelluloses and lignin are described. The most promising transformation processes according to the type of biomass considered: hardwood, softwood an herbaceous and the perspectives of biotechnological processes for bio pulping, bio bleaching and effluents decolorisation in the paper pulp industry are also discussed. (Author) 7 refs

[en] Lignin has great potential for the production of valuable aromatic compounds and has attracted considerable attention. The development of high value applications for Kraft lignin would boost the profitability of pulp and paper operations. A potential solution is the pyrolytic conversion of lignin to valuable liquids and solids. However, Kraft lignin is a thermally sensitive powder which tends to agglomerate under pyrolysis conditions. A mechanically fluidized reactor (MFR) can be used to monitor both the generation of vapours and gas during pyrolysis and how cohesive a feedstock becomes when pyrolyzed. The MFR was, therefore, used to evaluate alternative solutions to improve Kraft lignin behaviour by mixing it with non-problematic feedstocks or by modifying its bed material. Finally, Kraft lignin behaviour and products were compared to those of hydrolysis lignins from different origins. (author)

[en] Microbial deposits (slime or biofilm) formation is one of the most important problems in the paper industry. Slime formation cause a reduction of the final product quality (spots, holes, odors), as well as in the production and equipment life, due to a greater number of web breaks, down time for cleaning and maintenance of the machinery, corrosion, etc. Microbiologically-induced corrosion cause and important economic losses due to the reduction of the equipment life. In microbially-induced corrosion studies is basic the rapid and precise determination of the evolution of slime growth on metallic surfaces. Thus, the goal of the present work have been the development of a methodology that leads to characterize the population of aerobic bacteria that compose the slimes of a board mill by means of multi parametric flow cytometry, using two different angles of light scattering and the total protein content as parameters as first step of the studies of microbiologically-induced corrosion. (Author) 13 refs

[en] The main advantage of excimer lasers when processing materials, its the emission of a radiation with wavelength in the ultraviolet region. This characteristics allows an extremely accurate and very well defined shape of material removal as well as total absence of heat affected zone and alterations in the material structure. In excimer laser paper and parchment cleaning, the mud is removed by breaking the physical-chemical bonding between this last one and the material to be cleaned not affecting neither its structure nor the chromatic pigment existing in some samples. (Author) 3 refs

[en] Present investigation was carried out to assay the effects of industrial effluents on different varieties of soybean. For that purpose Textile effluent and Paper and Board effluent were chosen. Concentrations used for both the effluents were 0, 10, 20, 40 and 60%. On the other hand 5 varieties of Glycine max viz., PSC-82, NARC-2, NARC-5, NARC-7 and William-82 were used. Physicochemical characteristics of these effluents revealed that both of them contained high amounts of sulphates, nitrates, calcium, various heavy metals etc., while DO was very low, which confirms their highly polluted conditions. Maximum improvement in seedling length was found in 60% of textile effluent (NARC-2, NARC-7 and Williams-82), and in paper and board effluent (NARC-2, NARC-5 and NARC-7). For others varieties, lower concentrations enhanced the growth. Number of leaves was unaffected and remained same in all concentrations of the two effluents. Overall seedling lengths of PSC-62, NARC-2 and NARC-5 were comparatively longer in paper and board effluent as compared to textile effluent but it was other way round for the varieties NARC-7 and Williams-82, while there was no set pattern for the weight parameters. (author)

[en] This project constituted an intensive effort devoted to producing, from the white-rot fungus Tramets Cingulata, a lignin degrading enzyme (lignin depolymerase) that is directly able to biobleach or delignify softwood kraft pulp brownstock. To this end, the solutions in which T. cingulata was grown contained dissolved kraft lignin which fulfilled two functions; it behaved as a lignin deploymerase substrate and it also appeared to act as an inducer of enzyme expression. However, the lignin depolymerase isoenzymes (and other extracellular T. cingulata enzymes) interacted very strongly with both the kraft lignin components and the fungal hypae, so the isolating these proteins from the culture solutions proved to be unexpectedly difficult. Even after extensive experimentation with a variety of protein purification techniques, only one approach appeared to be capable of purifying lignin depolymerases to homogeneity. Unfortunately the procedure was extremely laborious; it involved the iso electric focusing of concentrated buffer-exchanged culture solutions followed by electro-elution of the desired protein bands from the appropriate polyacrylamide gel segments

[en] The recovery boilers of pulp mills are today the most significant producers of wood energy. The power-to-heat ratio of the power plant process, i.e., power yield, is poor in existing applications. In the study, an alternative of improving the power yield of conventional pulp mills significantly was studied by applying solutions used in power plants to a pulp mill. Extensive conversion of wood energy into electricity is possible only in the recovery boiler of the pulp mill and in a large combustion boiler of bark, wood waste and wood chips integrated to this boiler. Hence, the harvest and transports of wood raw materials, i.e. pulp wood and energy wood, are integrated, and the fraction going to cook and the energy wood fraction are separated at the pulp mill. The method guarantees competitive supply of energy wood. As a result a SELLUPOWER mill was designed, where the recovery boiler combusting black liquor and the large power plant boiler combusting energy wood are integrated to one unit and constructed to a power plant process with a high power-to-heat ratio. Necessary technical solutions, project costs and economical feasibility compared to a conventional pulp mill were determined, and the effect of different production-economical parameters was also studied. (orig.)

[en] Power production alternatives were surveyed in conjunction with the new Joutseno Pulp mill of United Paper Mills. The work was financed by Jaakko Poeyry Oy and by the Finnish Ministry of Trade and Industry. Joutseno Pulp and Imatran Voima Oy also participated in the project. A fuel survey and the assessment of the various power plant alternatives were included in the work. On the basis of the fuel survey, dimension calculations for four different power plant concepts were prepared and investment costs of the power plant assessed, and the economical feasibility and competitiveness of the power production was estimated. (orig.)