Life cycle assessment environmental comparison

Peters, G.M., Rowley, H.V., 2009. Environmental comparison of biosolids management systems using life cycle assessment. Environmental Science Technology 43,2674—2679. 

This report discusses the options for feedstock recycling of plastics waste, including aspects of the environmental and economic pros and cons relating to feedstock recycling in comparison with incineration or mechanical recycling of municipal solid waste, based on a number of life cycle assessments. Particular reference is made to the experience of the TNO-CML Centre of Chain Analysis.485 refs. 

Assessing the environmental impact of textiles allows both informed consumer choice and useful comparison of different materials as well as processing methods in engineering applications. Applying life cycle assessment (LCA) to production processes can identify hotspots contributing disproportionaUy to environmental impact, elucidate trade-offs between production systems and serve as a decision support tool to producers and policymakers. 

Life cycle assessment (LCA) is the preeminent method for the estimation of the complete carbon and water footprints associated with products, including energy resources. LCA is a system-level approach that accounts for all such activities from cradle to grave , with well-defined guidelines specified by ISO [1]. In addition to permitting environmental comparisons of alternative energy sources, LCA facilitates the elucidation of the relative environmental impacts of particular operations over the life cycle of the product under investigation. 

During the last two decades, there has been increasing interest in use of life-cycle assessment techniques to evaluate the environmental trade-offs associated with manufacturing and purchasing decisions. The philosophy behind life-cycle assessment is that the entire life cycle of a process or producL from acquisition of raw materials to eventual waste disposal, must be considered in evaluating the effects of that process or product on the environment. If only a portion of the life cycle is considered, then decisions about which of two alternatives has lesser adverse environmental impacts may be flawed, as looking at only a portion of the life cycle may result in ignoring serious impacts and lead to comparisons that are not accurate. 

Life cycle assessments were also applied to analyse the environmental effects related to the production and disposal of loose fill made out of Mater-Bi pellets in comparison to those made by expanded polystyrene (EPS) [25]. The life cycle included raw material acquisition, the... 

It is sometimes assumed in that polymers from renewable resources are by definition environmentally friendly , or in modern parlance, sustainable . One definition of sustainable suggests that the development of new products for the benefit of society should not have an unacceptable effect on resource depletion and environmental pollution. However, unacceptable is a relative term and invites comparison of one material with another by life-cycle assessment (LCA). Companies engaged in the development of degradable polymers from renewable resources have initiated life-cycle assessment comparisons of their products with the commodity synthetic polymers, notably polyethylene. It has not so far been shown unambiguously that bio-based polymers are more environmentally sustainable than the present range of commodity polymers . This results from the same reason that led to concern in the 1980s namely lack of consistency and uniformity of the assumptions made. In some cases they actually contradict one another. 

The fact that environmental considerations have been and will continue to be an important motivation to develop and introduce biopolymers calls for a comparison of their environmental performance with their petrochemical counterparts. To this end, life cycle assessment (LCA) can be applied, which is a standardised method to quantify environmental impacts. LCA studies, however, do not address environmental risks (e.g. related to outcrossing of genetically modified species) and they neither cover ethical, social, and economic aspects. 

Once the life cycle inventory has been quantified, the effects of the environmental emissions are characterized and assessed in a life cycle impact analysis. While the life cycle inventory can, in principle at least, be readily assessed, the resulting impact is far from straightforward to assess. Environmental impacts are usually not directly comparable. For example, how can the production of a kilogram of heavy metal sludge waste be compared with the production of a ton of contaminated aqueous waste A comparison of two life cycles is required to pick the preferred life cycle. 

Owing to its comprehensiveness, LCA is a powerful tool for comparing different options/products with respect to their potential impacts on the environment, and for identifying the critical points within the product life-cycle that contribute most to these impacts [15]. This approach can be used, for example, for comparing a product that includes ENMs with similar products without ENMs. The added benefits of the use of ENMs may be reflected in the differences in the energy consumption for production of materials or products [29, 30], or in the use of scarce resources in the production processes. In other words, LCA may be used to assess the relative environmental performance of nanoproducts in comparison with their conventional equivalents. Thereby, LCA may also quantify the expected positive potentials of nanoproducts for the substitution of hazardous chemicals, the reduction in the use of materials, and energy consumption, in addition to waste reduction. 

A recent example of an attempt to determine whether using a renewable bio-logicaUy-based process for making a particular product exhibits a better environmental profile in comparison to using a synthetic pathway is the comparison of two different processes for the manufacture of the pharmaceutical intermediate 7-aminocephalosporic acid (7-ACA) as a case study [33]. The methodology used for the assessment integrates environment, health, safety, and life cycle aspects... 

It is important to note that LCA is a tool to evaluate all environmental effects of a product or process throughout its entire life cycle. This includes identifying and quantifying energy and materials used and wastes released to the environment, assessing their environmental impact, and evaluating opportunities for improvement. LCA can also be used in various ways to evaluate alternatives including in-process analysis, material selection, product evaluation, product comparison, and policy-... 

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