864 research outputs found
Wood polymer composites and their contribution to cascading utilisation
Due to a shortage of resources and a growing competition of land use, sustainable and efficient resource utilisation becomes increasingly important. The application and multiple, cascading utilisation of renewable resources is aimed at to ensure an allocation and future availability of resources. Wood polymer composites (WPCs) are a group of innovative materials consisting of mainly renewable resources. By means of summarizing recent research, it is shown how WPC can potentially contribute to an enhanced cascading utilisation. For the production of WPC, waste materials and by-products from wood and agricultural industry, e.g. offcuts, sawdust, residues from board manufacturing, pulping sludge, can serve as a raw material. Furthermore, the cited literature presents the use of recycled polymers and biopolymers as a potential alternative for the polymer component of WPC. By using biodegradable polymers, a fully biodegradable composite can be formed. In addition to using recycled materials and potentially being biodegradable, it is pointed out that WPC furthermore offers the possibility of being recycled itself, therefore being considered as a “green composite”. Although the influence of contaminated waste streams and mixed filler and polymer types on the properties of WPC made with such recyclates is yet not fully understood and no collection systems exist for post-consumer WPC, in-house recycling on the production sites is identified as a promising option as it reduces production costs and enhances resource efficiency and cascading utilisation. On the basis of cited life cycle assessments, the eco friendliness of WPC is assessed resulting in the conclusion that WPC cannot compete with solid wood with respect to environmental impact but is an environmentally friendly alternative to neat plastics in several applications
Best Available Techniques (BAT) Reference Document for the Production of Pulp, Paper and Board. Industrial Emissions Directive 2010/75/EU (Integrated Pollution Prevention and Control)
The BAT reference document entitled ‘Production of Pulp, Paper and Board' forms part of a series presenting the results of an exchange of information between EU Member States, the industries concerned, non-governmental organisations promoting environmental protection, and the Commission, to draw up, review and, where necessary, update BAT reference documents as required by Article 13(1) of the Directive 2010/75/EU on industrial emissions. This document is published by the European Commission pursuant to Article 13(6) of the Directive. This BREF for the production of
pulp, paper and board covers the activities specified in Sections 6.1(a) and 6.1(b) of Annex I to Directive 2010/75/EU, i.e. the integrated and non-integrated production in industrial installations of:
(a) pulp from timber or other fibrous materials;
(b) paper or cardboard with a production capacity exceeding 20 tonnes per day.
In particular, this document covers the following processes and activities:
- chemical pulping:
(a) kraft (sulphate) pulping process
(b) sulphite pulping process
- mechanical and chemimechanical pulping
- processing paper for recycling with and without deinking
- papermaking and related processes
- all recovery boilers and lime kilns operated in pulp and paper mills.
Important issues for the implementation of Directive 2010/75/EU in the pulp, paper and board industry are the emissions to air of nitrogen oxides, sulphur oxides, dust, total reduced sulphur and ammonia; emissions to water of organic carbon, suspended solids, nitrogen, phosphorus and adsorbable organically bound halogens. The BREF contains nine chapters. Chapters 1 and 2 provide general information on the pulp, paper and board industry and on the common industrial processes and techniques used within the whole sector. Chapters 3, 4, 5, 6 and 7 correspond to the following specific sectors: kraft (sulphate) pulping process, sulphite pulping process, mechanical and chemimechanical pulping, processing of paper for recycling with and without deinking, and papermaking and related processes. For each sector, these five chapters provide information and data concerning the applied processes and techniques; the environmental performance of installations in terms of current emissions, consumption of raw materials, water and energy, and generation of waste; the techniques to prevent or reduce the environmental impact of installations; and the emerging techniques. In Chapter 8 the BAT conclusions, as defined in Article 3(12) of the Directive, are presented for the pulp, paper and board industry. Chapter 9 is dedicated to concluding remarks and recommendations for future work regarding the sector.JRC.J.5 - Sustainable Production and Consumptio
Penghilangan Tinta Kertas Koran Bekas Dalam Pembuatan Papan Komposit Plastik
The objective of this research were to evaluate the effect of paper deinking on physical and mechanical properties of plastic composite board (fiber plastic composite). Deinking process using detergents with a concentration of 0%, 10%, 15%, 20%, and 25%. Clean pulp produced an acceptable material, while lathering ink that leaves the pulp was an rejected ingredient. The resulting composite board tested and their mechanical and physical properties compared to standard JIS A 5905-2003 hardboard S20 and JIS A 5908-2003 particleboards type 13. The results showed that the value of the density, moisture content, water absorption, thickness swelling, MOE, MOR, and IB were respectively from 0,61-0,69; 4,58-5,93; 29,62-39.81; 5,09-9,89; 0,96-1,22; 6,56-8,70; and 0,77-0,98. Testing that fulfill the standard requirement were testing the density, thickness swelling, and internal bond
Visualization of toner ink adsorption at bubble surfaces
Flotation deinking involves interactions between inks particles and bubbles surfaces. These interactions are very difficult to observe directly or to quantify in bench-scale experiments or mill operations, making it difficult to evaluate effects of process conditions such as bubble size and solution chemistry on deinking efficiency. This paper presents images and measurements of toner ink interactions with bubble surfaces in laboratory-scale flotation processes. Stable adsorption of toner ink was observed at surfaces of stationary and suspended bubbles for several system chemistries. Interactions of toner particles and bubbles were quantified by high magnification and high temporal resolution digital videos obtained in bubble flow facilities creating both stationary and flowing bubbles. Large (>200 micron), flat toner particles adsorbed to bubble surfaces by single contact points. Smaller toner particles formed very stable complexes in fatty acid chemistries. Desorption of toner ink from bubble surfaces was not observed, even for vigorous flows. Bubbles were observed to be fully covered with toner after 4 minutes of residence time in the suspending bubble flow facility. Initial estimates indicate that bubbles with diameters of approximately 1 mm carry more than 1 mg of ink per bubble
The Influence of Single, Two, and Three Stage Bleaching on Fading Characteristic of Deinked Stock
A literature survey on the various bleaching methods used on deinked stock and the factors which influence the fading characteristic of deinked stock is compiled. Mention is also made of various additives which have an influence on the fading of a sheet. A description of the experimental work with caustic deinked stack of various groundwood content follows. Results indicate that the groundwood content has more effect upon fading of deinked stock than the number of stages of bleaching, although the increase in the number of stages of bleaching does reduce the amount of fading in a sheet. A greater effect by the number of stages of bleaching is obtained in the higher groundwood range
Internal Treatment of Process Waters in Paper Production by Dissolved Air Flotation with Newly Developed Chemicals. 1. Laboratory Tests
New chemicals, based on the synergistic effect between inorganic polyaluminium salts and organic cationic polyelectrolytes, have been tested for the chemical optimization of a dissolved air flotation (DAF) unit, used as internal treatment of process waters in a paper mill based on 100% recovered paper. Laboratory tests have demonstrated that polyamine modifications of the aluminum salts are the most efficient in the removal of contaminants, the combination of a polyaluminium nitrate sulfate salt and a polyamine being the most efficient. This chemical has been studied under different conditions, such as different dosages or in combination with a flocculant for the treatment of waters from different paper grades production, and the results have demonstrated a good performance at laboratory scale. Therefore, a field trial has been recommended for assessing its potential benefits at mill scale, which will be described in a future paper
Preliminary studies on enzymatic deinking
Results on enzymatic deinking of paper pulps are shown. The process includes paper pulping, with an enzymatic cocktail, followed by flotation and dewatering. Three different wastepaper samples were used and tested. The deinking of the pulp was monitored by image analysis. Physical, mechanical and optical properties of pulp and paper were also determined. The obtained data revealed the effectiveness of the assayed enzyme preparation. However, enzyme use needs further optimisation as paper strenght properties suffered important alteration
Characterisation and application of glycanases secreted by aspergillus terreus CCMI 498 and trichoderma viride CCMI 84 for enzymatic deinking of mixed office wastepaper
Two enzymatic extracts obtained from xylan-grown Aspergillus terreus CCMI 498 and cellulose-grown Trichoderma
viride CCMI 84 were characterised for different glycanase activities. Both strains produce extracellular endoxylanase
and endoglucanase enzymes. The enzymes optimal activity was found in the temperature range of 45-60 ºC.
Endoglucanase systems show identical activity profiles towards temperature, regardless of the strain and inducing
substrate. Conversely, the endoxylanases produced by both strains showed maximal activity at different pH values
(from 4.5 to 5.5), being the more acidic xylanase produced by T. viride grown on cellulose. The endoglucanase activities
have an optimum pH at 4.5-5.0. The endoxylanase and endoglucanase activities exhibited high stability at 50 ºC and
pH 5.0. Mannanase, β-xylosidase, and amylase activities were also found, being the first two activities only present for
T. viride extract. These two enzymatic extracts were used for mixed office wastepaper (MOW) deinking. When the
enzymatic extract from T. viride was used, a further increase of 24% in ink removal was obtained by comparison with
the control. Both enzymes contributed to the improvement of the paper strength properties and the obtained results
clearly indicate that the effective use of enzymes for deinking can also contribute to the pulp and paper properties
improvement.PRAXIS/BIO/1133/95.
BIC/3087/96, BD/3253/96
Enzymatic versus chemical deinking of non-impact ink printed paper
Enzymatic versus chemical deinking is examined for MOW and photocopy prints. Several enzymatic preparations and two
fibre/ink particle separation methods are tested. Deinking was monitored by image analysis and standard pulp and paper characterisation
procedures. The effectiveness of the fibre/ink particle separation method depends on the ink particle’s size: for smaller
particles a washing step is recommended whereas for larger particles, the use of flotation is necessary. The enzymatic treatment
is a competitive alternative for MOW and photocopy paper deinking. However, the process requires the selection of an adequate
enzymatic preparation for each paper grade
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