Environmental Benefits of Using Recycled PP Fibre Through a Life Cycle Assessment

In order to help decision makers choose reinforcing material that causes the lowest environmental impact, it is very important to carry out a comparative impact analysis. There are a variety of general and industry specific assessment methods, such as GMP-RAM (Jesus et al. 2006), INOVA Systems (Jesus-Hitzschky 2007), and fuzzy logic environmental impact assessment method (Afrinaldi and Zhang 2014). However, life cycle assessment (LCA) is the most comprehensive among the available tools and has been widely used. The LCA methodology is generally considered the best environmental management tool for quantifying and comparing the eco-performance of alternative products.

Perugini et al. (2005) undertook LCA of recycled Italian household plastic packaging waste and compared environmental performance with conventional options. Their results confirmed that recycling scenarios were always preferable to those of non-recycling. Arena et al. (2003) studied the collection and mechanical recycling of post-consumer polyethylene (PE) and polyethylene terephthalate (PET) containers. They found that the recycled PET can reduce energy by between 29 and 45%, compared to virgin PET production. Similar reductions in energy use were observed for recycled PE compared to virgin PE. Shen et al. (2010) also assessed the environmental impact of PET bottle-to-fibre recycling, and LCA results showed that recycled PET fibres offered important environmental benefits over virgin PET fibre.

Although these studies show promise, the literature on LCA of recycling plastic waste are actually very limited, and are strongly influenced by final product types, plastic sources, and by local characteristics of procedures for collecting and reprocessing plastic waste. Hence, these studies cannot be extrapolated to Australian conditions, where there is limited information on comparative LCA of recycling plastic waste. Moreover, recycling systems are typically multifunctional, which can constitute a challenge for LCA practitioners. LCAs of the same product can arrive at different conclusions when there are methodological differences or differences in life cycle inventory (LCI) data. It is therefore important to clearly © Springer Nature Singapore Pte Ltd. 2017

S. Yin, Development of Recycled Polypropylene Plastic Fibres

to Reinforce Concrete, Springer Theses, DOI 10.1007/978-981-10-3719-1_6

define the scope, LCA methodology, inventory data sources, and functional unit (FU) involved. These issues are discussed in greater detail by Sandin et al. (2014).

This chapter focuses on the use of PP fibres in reinforcing footpaths where currently steel reinforcing mesh (SRM) is used. Chapters 4 and 5 clearly showed that the recycled PP fibre has sufficient strength to be used as a replacement for virgin PP fibre, which has already been used to replace SRM in footpath applications. The recycled PP fibre considered is sourced from industrial PP wastes, which are scrap off-cuts and off-specification items from the nappy manufacturing industry. An alternative source of recycled plastic fibre is domestic PP waste, consisting mostly of packaging materials from kerbside recycling collections. Recycled PP fibre from domestic waste has not been used in the footpath applications, mainly because of higher reprocessing cost and lower fibre strength. However, it is still worth considering the life cycle impact of using domestic recycled PP fibre in footpath applications.

The objective of this chapter is to quantify the life cycle environmental benefits brought about by using 100% recycled PP fibres from domestic and industrial waste as compared to using typical materials for reinforcing concrete footpaths. Alternative reinforcing materials assessed include virgin PP fibre and SRM. This study is based on Australian conditions and quantifies the environmental impacts in terms of material consumption, water use, and emissions to the environment. The scope of this study is limited to the first stage of the fibre or SRM reinforced footpaths, namely, the production of PP fibres and SRM. The primary audience for this study is intended to be local governments, city councils, solid waste planners, and industries, such as plastic waste recycling and plastic fibre reinforced concrete industries, who are interested in pursuing positive economic and environmental outcomes.

 
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