Search

Unprinting of paper can reduce multiple life-cycle stages in the recycling of paper to yield significant environmental impact. Laser-unprinting has been demonstrated for uncoated paper but causes significant damage to coated paper. This work explores a scalable optical (non-laser) process for unprinting coated paper. Printed coated paper is exposed to pulsed broad-spectrum Intense Pulsed Light (IPL) from a xenon lamp and the toner is then removed by dabbing gently with an ethanol wipe. While black toner is easily unprinted, unprinting of colored prints (red, blue, green) is best realized by incorporating an initial overprint of black toner. An unprinting throughput on the order of mm2/s is achieved. Three distinct regimes of unprinting are identified based on the extent of toner removal and damage of the paper. The optical properties of the unprinted paper, characterized via UV–Visible spectrophotometry, are correlated to these regimes to understand the potential for in-situ optical process monitoring. Scanning Electron Micrography and Fourier-Transform Infrared Spectroscopy are performed to understand the underlying mechanisms that govern the occurrence of the different unprinting regimes. Further, the potential impact of the developed approach on recycling of paper is discussed in the context of the capabilities of current optical unprinting approaches and the potential elimination of life-cycle stages in conventional paper recycling. • Intense Pulsed Light can scalably unprint toner from coated paper with minimal chemical usage. • Our overprinting approach enables colored prints to be removed as well. • Unprinting throughput of mm2/s is achieved. • Three distinct unprinting regimes exist, depending on process parameters and toner types. • Thermal weakening of toner-coating bonds and cracking are the primary governing mechanisms. [ABSTRACT FROM AUTHOR]

Thermal and catalytic pyrolysis of aluminum plastic laminate over zeolite catalysts were performed to produce high quality oil. Thermogravimetric analysis of aluminum plastic laminate indicated that the decomposition kinetics of aluminum plastic laminate were changed by interactions between the polymer components during the thermogravimetric analysis of aluminum plastic laminate. The effects of aluminum foil on the aluminum plastic laminate decomposition kinetics were negligible. The catalytic pyrolysis of aluminum plastic laminate over the acid catalysts using tandem-micro reactor-gas chromatography/mass spectrometry produced large amounts of aromatics due to the properties of the main polymers, polyethylene and poly (ethylene terephthalate), in aluminum plastic laminate. Among three catalysts, HZSM-5 (SiO 2 /Al 2 O 3 , 23), HY(30), and Al-MCM-41 (20), HZSM-5 (23) had the highest efficiency on aromatics production followed by HY(30) and Al-MCM-41 (20). Co-feeding aluminum plastic laminate to the catalytic pyrolysis of paper over HZSM-5 (23) and HY(30) was also effective on aromatics production, highlighting the potential use of aluminum plastic laminate to enhance the synergistic aromatics formation during the catalytic pyrolysis of biomass. • Interaction between polymers changed kinetic behavior of aluminum plastic laminate. • Catalytic pyrolysis of aluminum plastic laminate produced aromatics efficiently. • HZSM-5 was the most effective catalyst on aromatics formation. • Co-feeding aluminum plastic laminate and paper produced additional aromatics. [ABSTRACT FROM AUTHOR]

This work assesses six different agricultural residues with the aim of finding alternative raw materials for a soda semichemical pulping process: stems of bell and chili pepper ( Capsicum annuum ), broad bean ( Vicia faba ), asparagus ( Asparagus officinalis ), pea ( Pisum sativum ), and okra ( Abelmoschus esculentus ). Pulping yields higher than 60% (m/m) were obtained, except for pea stems (43%). The drainability of all the pulps, expressed as the Schopper-Riegler index (ºSR), had values of over 70 ºSR. The Kajaani analyses of the fibers showed acceptable fiber lengths in all cases (0.64–0.92 mm), but on average shorter than the lengths of pulps from a commercial fluting paper (Old corrugated Container, OCC), that was found to be 1.27 mm. Handsheets of paper were produced both with the pulps under study and with mixtures of these pulps with OCC pulp. Several properties were measured to assess the use of the new fibers in a paper for cardboard production. The property showing the greatest differences was the Gurley porosity, ranging from 25 mL/min (asparagus) to 1300 mL/min (broad bean). Of the six residues tested, the okra residue fiber showed better properties than the commercial paper fiber (Concora Medium Test indexes: 1.5 N m 2 /g and 1.1 N m 2 /g respectively, Burst Indexes: 2.3 kPa m 2 /g and 1.7 kPa m 2 /g, respectively), yielding similar mechanical properties to those of high quality fibers obtained from miscanthus ( Miscanthus giganteus ). Broad bean residue could also be a promising raw material, though its properties are not as good as okra’s. [ABSTRACT FROM AUTHOR]

Abstract: Product-oriented policies gain more and more attention in environmental policies. In this framework, we studied cases (here presented only housing and computers and paper) in a life cycle perspective in order to determine their environmental impacts (in terms of GHG emissions, resource use and waste production) over the period 1990–2010. We also evaluated their potential for improvement up to 2010 by applying product-oriented strategies. We identified clear technical (theoretical) potential for improvement, especially for housing, packaging and computers and paper in offices. We then carried out a Delphi-based survey among stakeholders in order to investigate potential measures. [Copyright &y& Elsevier]

Abstract: This article contributes to the theoretical and empirical discussions on how it could be possible to transform technical eco-efficiency into reduced environmental impact of consumption. The rebound effect is an important concept in this context. The relevance of consumer behaviour is addressed within three important sectors for the Zero Emissions Techniques and Systems: shopping of paper products, energy use in household and waste management. It is not only important how much the consumers buy, but also what kinds of products they buy and how they use and dispose of them. However, the responsibility for a sustainable development should not entirely be put on the shoulders of the individual consumer. [Copyright &y& Elsevier]

In this paper, the Life Cycle Assessment (LCA) methodology is applied to Portuguese printing and writing paper in order to compare the environmental impact of the use of two kinds of fuels (heavy fuel oil and natural gas) in the pulp and paper production processes. The results of inventory analysis and impact assessment show that the pulp and paper production processes play an important role in almost all of the analysed parameters, which do not always result in an important contribution to the corresponding impact categories. The substitution of heavy fuel oil by natural gas in the pulp and paper production processes seems to be environmentally positive. [Copyright &y& Elsevier]

In accordance with global estimations, approx. 15 million tons of residues are yearly generated from paper and pulp industry, which are traditionally used as biofuels or just disposed in landfills. However, residues composition and laws in force urge producers to search for new waste management strategies. From another point of view, the construction industry uses more than 33% of total natural resources, worldwide which has led several governments to limit the use of natural raw materials for building. In particular, fired brick industry produces yearly approx. 1600 billion bricks which represents millions of tons of natural resources consumption. Therefore, the goal is to contribute to reduce the amount of used clay. Thus, this paper explores the mineral and technological properties of brick made by using different percentages of paper pulp residues and fired at 900 °C. Results indicate that by increasing the replacement ratio, blend requires larger amounts of water which leads to a proportional increasing of shrinkage during drying. In spite of mineral transformations are not influenced by paper pulp residue, the porosity is linearly increased which leads to reduce compressive strength and thermal conductivity up to 30% for 20% of replacement ratio, in both cases. Thus, it is concluded that series made by replacing up to 10% show compressive strength above 5 MPa, water absorption beyond 20% and toxicity indexes meet the mandatory requirements. [ABSTRACT FROM AUTHOR]