Assessing potential financial and environmental benefits of a newly developed waste traceability system in Flanders

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International HISER Conference on Advances in Recycling and Management of Construction and Demolition Waste

21-23 June 2017, Delft University of Technology, Delft, The Netherlands

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Assessing potential financial and environmental benefits of a newly developed waste traceability system in Flanders

Wim Debacker1, Sofie De Regel1, Omar Amara1, Wai Chung Lam1, Jef Bergemans2, Kris Broos2 and Annelies Vanden Eynde3

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VITO, Smart Energy and Built Environment, Thor Park 831, 3600 Genk, Belgium, Phone (+32) 14 33 58 94; E-mail: wim.debacker@vito.be

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VITO, Sustainable Materials, Boeretang 200, 2800 Mol, Belgium 3

VCB, Lombardstraat 34-42, 1000 Brussels, Belgium Abstract

Most of the mixed stony demolition waste within Flanders ends up as aggregates for foundation and road works. In order to recover waste for higher value applications, selective demolition and waste management practices need to be improved.

The aim of this paper is to assess the potential environmental and financial benefits and drawbacks on selective demolition and waste management activities of a waste traceability system (Tracimat), currently developed within Flanders.

The selective demolition and waste treatment in 2015 of an old milk factory in Flanders has been taken as a representative case-study. Business-as-usual demolition, sorting, transport and waste management activities were closely monitored and taken as reference for a virtual case-study in which the application of the Tracimat system was simulated. In addition, a local demand of separated masonry and concrete debris for high value recycling purposes has been assumed within the virtual case. Life cycle assessment and life cycle costing analysis were used to calculate environmental impacts and financial costs over the entire time span of both cases.

Compared to the business-as-usual practice, the Tracimat supported case leads to an important decrease (50%) in operational waste treatment costs and to a significant decrease (7-14%) in potential impact related to some environmental categories.

In order to further improve the environmental and financial profile of selective demolition and waste treatment practices in Flanders, measures decreasing the importance of heavy machinery and trucks, in addition to the use of the Tracimat system, need to be taken into account.

Keywords: supply tracking, LCA, LCCA, selective demolition, hotspot analysis. Introduction

In 2015, construction and demolition waste was responsible for more than 35% of the total waste generation in Belgium. More or less 90% of demolition waste in Flanders consists of stony fractions, typically used as aggregates for foundation and road works [1]. In order to recover waste for higher value applications, enhancing selective demolition and waste management practices is of crucial importance.

Within the HISER project, technological and non-technological solutions are developed in order to guarantee a higher efficiency in the recovery of priority waste streams. Within this paper screening results are discussed of a comparative environmental and financial assessment of (1) a monitored business-as-usual selective demolition (BaU-SD) of an old milk factory in Flanders in 2015 and (2) a virtual selective demolition of the same building,

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but using the Tracimat waste traceability system and assuming a local demand of separated masonry and concrete debris for high value recycling purposes.

Methodology

To assess and compare environmental and financial characteristics of both selective demolition cases, life cycle assessment (LCA) and life cycle costing analysis (LCCA) have been used. Within the environmental assessment fourteen impact categories are calculated, according to the European PEF Guide [2]. The Belgian environmental assessment method MMG [3] is used within sensitivity analyses. Within the economic assessment, financial costs are divided into two major groups: capital expenditures (CAPEX) and operational costs (OPEX). For both comparative assessment studies the same functional unit has been used: i.e. the (selective) demolition of the old milk factory in Gierle (Belgium) in 2015 and the related sorting (on-site), disposal and recovery of 11577 ton of demolition waste coming out of the building. System boundaries for the Tracimat supported selective demolition case are shown in the block flow diagram in Figure 18.

Figure 19: Block flow diagram of the virtual Tracimat selective demolition case

Results

Important insights. Looking at the contribution of the different stages (i.e. C1, C2, C3, C4

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negligible from an environmental as well as from a financial perspective; each of them is a hotspot in at least one environmental impact and financials cost category.

The (relative) importance of demolition and sorting on-site to the environmental impact and financial costs (for the demolition company) is not to be considered negligible, because the building has never been designed and built to be easily de-constructed (from building to components) and disassembled (from components to materials). The BaU SD case in Flanders shows that a lot of (fossil) energy, time, heavy equipment and space were needed to tear down the studied complex non-residential building and to separate different materials/waste fractions on-site. A supply tracking system, whether or not supported by BIM technology, may highlight potential issues related to the contamination of certain waste fractions. However, there is not a strong guarantee that certain waste fractions will be actually separated on-site – unless it is easy to do so AND there is an economic incentive for demolition contractors, based on a strong demand for the separated fraction(s). Although the monitored Flemish building was not designed to be easily deconstructed/disassembled, most masonry debris was relatively easily separated from other fractions. But, because there was at that moment no actual demand to recover masonry debris as a separated fraction, it was added during the on-site sorting to the mixed stony fraction. Introducing valuable applications for masonry debris, such as substitution of primary resources in brick manufacturing, may change this. Because there is an actual demand for a low contaminated concrete fraction, for example as aggregates in new concrete, demolition companies have often a financial incentive to separate (low contaminated) concrete fraction from others.

Comparative assessment. Compared to the BaU SD practice, the Tracimat supported SD

case leads to an important decrease (50%) in (operational) waste treatment costs, i.e. lower fees paid by the demolition companies to the crushing companies, thanks to a higher amount of separated concrete and masonry fractions on-site and the assumed (local) demand for it. From an environmental perspective the recycling of a higher amount of sorted concrete aggregates and sorted masonry aggregates within the Tracimat supported SD led to a significant decrease in potential impact related to the environmental categories "acidification" (14%), "terrestrial eutrophication" (10%), "marine eutrophication"(7%) and "photochemical ozone depletion" (7%), based on PEF calculations. Similar conclusions are drawn, when the MMG impact assessment methods are used.

Comparing both alternatives, the Tracimat supported selective demolition reduces overall costs with 6% compared to the BaU selective demolition. Within the Tracimat supported SD case we assume that the same demolition and sorting technology and kind of labour is used compared to the BaU practice, but the mixed stony fraction is reduced to a minimum and accordingly concrete and ceramics are separated from each other. This leads to lower absolute costs to get the demolition waste treated (C3) or disposed (C4). Although the (absolute) costs paid by the demolition company to crushing (and recycling) companies is reduced by more than 50% – taking into account the assumption that there is a substantial demand for sorted masonry debris aggregates and sorted concrete aggregates for new (building product) applications – the biggest expenses are still attributed in both cases to the demolition and sorting stage (C1) and waste disposal stage (C4). This means that also other measures should be taken to reduce the economic burden related to demolition and waste management practices, based on this representative Flemish case.

Improvement steps. Based on the initial screening results, the following measures should be

investigated, in order to further improve the environmental and financial profile of the selective demolition practice in Flanders:

• a better preparation of demolition and sorting works, in order to plan operation of machinery and personnel, as best as possible. A mandatory pre-demolition audit within the Tracimat system would support this.

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• a better sorting on-site, in order to have high value separated waste/materials fraction • opt for local (or – if possible – on-site) crushing/recycling facilities,

• use other transport modes to deliver waste/materials fraction to the recycling, waste treatment and waste disposal facilities, e.g. through barge (allowing transport of a bigger amount of waste in a single trip)

• less idle operation of demolition and sorting machinery • other fuel choice for machinery and heavy trucks, if possible Conclusion

Although the absolute impact results and calculated costs within the conducted analyses show that the Tracimat supported SD will probably lead to environmental and financial improvements compared to the BaU-SD solution, it is imperative to take into account additional measures decreasing the importance of heavy machinery and trucks, in order to take (more) important steps in enhancing the environmental and financial profile of the systems under study.

Acknowledgement

This research is part of the HISER project (www.hiserproject.eu). The HISER project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 642085.

References

[1] http://www.vlaanderen.be/nl/publicaties/detail/monitoringsysteem-duurzaam-oppervlaktedelfstoffenbeleid-jaarverslag-2013: MDO report (2014)

[2][http://ec.europa.eu/environment/eussd/pdf/footprint/PEF%20methodology%20final%20dr aft.pdf: PEF Guide (2013)

[3]http://www.ovam.be/sites/default/files/atoms/files/Environmental%20profile%20of%20bu ildig%20elements.pdf: MMG impact assessment (2013)