Page 79 - Materials Chemistry, Second Edition

74 4. Life cycle sustainability assessment: An ongoing journey

For the same amount of materials demolished, the top-down method uses more technical
2
equipment (equipment: bobcat machine, wire crane, and 20t excavator; fuel: 4.12L/m GFA),
but less fuel consumption compared to the high-reach method (equipment: 30t excavator and
2
65t excavator; fuel: 4.63L/m GFA).
The costs for waste disposal and sale of recyclable materials were assumed to be the same
for both demolition methods because equal quantity and quality of materials are produced.
For both demolition methods, the highest cost was attributed to capital cost (hiring of tech-
nical equipment). The labor cost for top-down method was three times higher than that for the
high-reach method; however, the energy costs were comparable. In terms of social perfor-
2
mance, the top-down method created 0.43h/m GFA of employment whereas the high-reach
2
method created 0.10h/m GFA. The authors were confronted with methodological chal-
lenges including:
• computation of SLCA inventory the function unit;
• identification of connection points between inventories; and
• lack of easy access to data for the costs and social indicators for background processes.
To assess the strength and weaknesses of the LCSA template used in this case study, the
authors concluded that the template should be applied to more complex and data intensive
processes. In addition, detailed ELCA involves more inventory items (than used in this
study), which would be practicable to assess using LCC and SLCA.

4.4.2 Reuse of waste electrical and electronic equipment components

In assessing the reusability of waste mobile phone components from waste electrical and
electronic equipment (WEEE) in China, Lu et al. (2014) used LCSA to compare reuse to other
end-of-life strategies (such as materials recovery and disposal). The functional units used by
the authors were 100 waste mobile phones produced around the year 2010. The life cycle
impact was measured using Eco-indicator 99 (EI99). The Eco-indicator 99 is an endpoint
approach (Dreyer et al., 2003), which assesses environmental impact on human health, eco-
systems, and natural resources (Lu et al., 2014) whilst integrating LCA uncertainties (Pushkar,
2013). In assessing the economic costs, Lu et al. (2014) considered only the costs incurred by
stakeholders in the end-of-life stages. The social impacts of both recycling strategies on direct
and indirect workers were determined following the Guidelines for Social Life Cycle Assessment
Products and using mid-point evaluation indicators such as employment, housing and edu-
cation. The results of their LCA and LCC assessment revealed that reuse is environmentally
and economically friendlier than materials recovery but the SLCA does not show clear social
benefit of reuse. In terms of new raw materials consumption, both strategies contributed pos-
itively to the environment. They found that the formal recycling sector creates less employ-
ment but offers higher wages and social guarantee as well as better health conditions than the
informal sector. Many factors (such as time range, physical situation, speed of technology
innovation, etc.) were identified to affect reusability of end-of-life WEEE, which should be
considered in practice. The authors are of the view that LCSA could be used by waste
recycling practitioners to select suitable and sustainable end-of-life strategies but recom-
mends improvement in the integration of LCA, LCC, and SLCA.