Paper waste - Recycling, incineration or landfilling? A review of existing life cycle assessments

ArticleinWaste Management 27(8):S29-46 · February 2007with67 Reads
DOI: 10.1016/j.wasman.2007.02.019 · Source: PubMed
Abstract
A review of existing life cycle assessments (LCAs) on paper and cardboard waste has been undertaken. The objectives of the review were threefold. Firstly, to see whether a consistent message comes out of published LCA literature on optimum disposal or recycling solutions for this waste type. Such message has implications for current policy formulation on material recycling and disposal in the EU. Secondly, to identify key methodological issues of paper waste management LCAs, and enlighten the influence of such issues on the conclusions of the LCA studies. Thirdly, in light of the analysis made, to discuss whether it is at all valid to use the LCA methodology in its current development state to guide policy decisions on paper waste. A total of nine LCA studies containing altogether 73 scenarios were selected from a thorough, international literature search. The selected studies are LCAs including comparisons of different management options for waste paper. Despite claims of inconsistency, the LCAs reviewed illustrate the environmental benefits in recycling over incineration or landfill options, for paper and cardboard waste. This broad consensus was found despite differences in geographic location and definitions of the paper recycling/disposal systems studied. A systematic exploration of the LCA studies showed, however, important methodological pitfalls and sources of error, mainly concerning differences in the definition of the system boundaries. Fifteen key assumptions were identified that cover the three paper cycle system areas: raw materials and forestry, paper production, and disposal/recovery. It was found that the outcome of the individual LCA studies largely depended on the choices made in some of these assumptions, most specifically the ones concerning energy use and generation, and forestry.
    • "This requires that compared systems are equivalent with respect to the goods and services they provide, both the primary service (in our case waste management) and secondary services/co-products (in our case e.g. recovered materials, fertilizers, heat and electricity) (Villanueva and Wenzel, 2007). Thus, it is of importance to identify all essential functional outputs from the studied systems and assure that compared systems are modeled in such a way that they overall deliver the same functional outputs. "
    [Show abstract] [Hide abstract] ABSTRACT: A review of existing life cycle assessments on food waste management was made with two main aims. Firstly, to make an overview of the assessments of the global warming potential from the treatment alternatives incineration, landfill, anaerobic digestion and compost in studies reported in literature. Secondly, to identify decisive factors in general and related to system boundary settings in particular, in reviewed studies. A number of criteria were constructed for identification of relevant comparative lifecycle assessments, resulting in selection of nineteen studies, containing 103 different scenarios. The systematic investigation of the studies show examples of several methodological differences as well as choices in systems boundary setting causing misleading comparisons between different treatment options, but also large variations in used input data for modeling of similar processes. The review also shows that the most significant differences in global warming results in many cases can be explained by assumptions made in relation to the background system, rather than by differences in data on emissions surging from to the foreground system. Especially assumptions on the interaction of the waste management system with the background energy system and/or bio-system were found to be decisive to the results. This highlights the importance of identification of induced and displaced marginal products in the modeling of system expansion, as well as need for increased transparency and use of sensitivity analyses related to assumptions made in background system modeling, in order to reveal under which set of assumptions results gained in the assessment are valid.
    Full-text · Article · Feb 2016
    • "Currently, some paper companies pay $ 25–$ 80/(wet) ton for disposal of the fines (Scott and Smith 1995; Villanueva and Wenzel 2007; Laurijssen et al. 2010 ). Besides their cost advantage, the supply of fines from paper mills is fairly homogeneous and thus there is minimal influence of seasonal-or weatherrelated supply challenges compared to other agricultural biomass (Villanueva and Wenzel 2007; Laurijssen et al. 2010). A number of different processes including incineration, gasification and pyrolysis may be used for treating this waste fines stream (Monte et al. 2009). "
    [Show abstract] [Hide abstract] ABSTRACT: A significant fraction of short fibers commonly called “reject fines” is produced while recycling wastepaper at paper mills producing linerboard. These fines are usually rejected into the solid waste stream that further requires land filling and poses environmental problems. The major component of these rejects is cellulose that can be a potential source of fermentable sugars for biofuels, bioplastics or other products. Therefore, a feasible process for converting these reject fines into sugars can profit the paper mills by producing value for their waste products while simultaneously mitigating their adverse environmental impact by avoided solid waste. Additionally, the sugar feedstocks can be used to reduce fossil carbon contributing to the sustainability of the industry. Enzymatic conversion of rejects fines from paper mills was achieved using commercial cellulases from Trichoderma reesei. The presence of mineral particles along with the cellulosic fines was found to have potent inhibitory effects on enzyme hydrolysis. The mineral particles are kaolin and calcium carbonate and originate from the fillers used in the wastepaper. The adsorption of the cellulase onto these mineral components was measured and quantified by the slope of the adsorption isotherm. The application of a nonionic surfactant Tween-80, decreased the adsorption of cellulase and this improved the hydrolysis yield of sugars. Enzymatic hydrolysis of rejects from recycled paper mills is feasible and provides a source of sugars for biofuels and bioplastics. However, the presence of mineral particles can be detrimental to this bioconversion. Calcium carbonate which occurs as a filler in waste paper shows high adsorption affinity to the cellulase enzymes and thus reduces the available enzyme for cellulolysis. This can be remedied by the application of surfactants which preferentially occlude to the mineral surfaces and thus increase enzyme availability in solution. The non-ionic surfactant, Tween-80, shows the best hydrolysis enhancement at a dosage of 3 % based on the dry weight of the biomass.
    Full-text · Article · Dec 2015
    • "For example, the Intergovernmental Panel on Climate Change (IPCC) has not only adopted a default decomposition factor (i.e., DOC f — fraction of degradable organic carbon dissimilated ) of 50% for all degradable materials placed in landfills (including paper) for inventory purposes (IPCC, 2006), but also allows reporting of methane emissions based on well documented country specific data. Biodegradability data are also used to support life cycle assessments of GHG impacts of consumer paper products (e.g., Dahlbo et al., 2005; Villanueva and Wenzel, 2007) and to estimate the effects of changes in MSW composition (due to the increased recycling and reuse) on changes in methane production and emissions from landfills (e.g., Levis et al., 2014). Limited studies have attempted to measure the decomposition and carbon storage of different paper products under simulated or field landfill conditions. "
    [Show abstract] [Hide abstract] ABSTRACT: The objective of this study was to measure the anaerobic biodegradation of different types of paper products in laboratory-scale landfill reactors. The study included (a) measurement of the loss of cellulose, hemicellulose, organic carbon, and (b) measurement of the methane yields for each paper product. The test materials included two samples each of newsprint (NP), copy paper (CP), and magazine paper (MG), and one sample of diaper (DP). The methane yields, carbon storage factors and the extent of cellulose and hemicellulose decomposition all consistently show that papers made from mechanical pulps (e.g., NPs) are less degradable than those made from chemical pulps where essentially all lignin was chemically removed (e.g., CPs). The diaper, which is not only made from chemical pulp but also contains some gel and plastic, exhibited limited biodegradability. The extent of biogenic carbon conversion varied from 21 to 96% among papers, which contrasts with the uniform assumption of 50% by the Intergovernmental Panel on Climate Change (IPCC) for all degradable materials discarded in landfills. Biochemical methane potential tests also showed that the solids to liquid ratio used in the test can influence the results. Copyright © 2015 Elsevier B.V. All rights reserved.
    Article · Nov 2015
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