Environmental benefits of a circular economy : connecting waste type and geographic proximity
Creators: name: Keller, Regula
name: Itten, René
name: Stucki, Matthias
Publisher: name: ZHAW Zürcher Hochschule für Angewandte Wissenschaften
Year: 2018
Subjects: Sharebox
Environmental impact
Greenhouse gas savings
Symbiosis
363: Umwelt- und Sicherheitsprobleme
658.5: Produktionssteuerung

description: Introduction: The aim of a circular economy is to transform waste into resources. There is a plethora of waste and by-products that remain unused in the traditional linear industrial system. However, transformation from a linear to a circular system is challenging, limited by several constraints such as the availability of information on the specific composition of the waste, the availability in time and space, the quantity of waste, as well as limited knowledge of the usability of such waste products. These challenges are exacerbated by the initial effort needed for implementation before an economy benefits from economic, ecological or societal improvements. Nevertheless, a circular economy generates less waste and consumes fewer resources, which in return makes it more profitable due to cost savings enabled by efficient resource use. The goal of the SHAREBOX project is the development of a platform for the facilitation of synergies within the industry to enable a more circular flow of resources within the European process industries. The project consortium has 15 partners including research organisations, SMEs and industrial partners as well as market actors and is part of the EU framework program Horizon 2020. 

Materials and Methods: The SHAREBOX platform is a database of available waste and resources required by companies, enabling the transformation of waste to resources by matching of two demands. The platform also serves as the first point of contact between different partners in a circular system. Furthermore, the platform enables the identification of new synergies overarching the different subsectors of the industries as well as optimal matching from the perspective of a circular economy. The key objectives are the facilitation of circular synergies through information and communications technology, the provision of information required to realise circular synergies within European industries and the identification of new circular synergies. 

Results and Discussion: The results of circular industry systems facilitated by the National Industrial Symbiosis Program (NISP) in the United Kingdom show a substantial reduction in the consumption of resources and generation of emissions compared to linear systems. Nevertheless, if there is a plethora of different types of waste, there is also a plethora of different synergies. This leads to different results for each type of waste that is transformed to a resource. Furthermore, the life cycle stage of transformation also has to be included. A transformation such as the reuse of polyethylene terephthalate (PET) can lead to emissions or require additional auxiliary materials as well as transportation. Therefore, the potential benefit will never be equal to the total impact of the primary input because of the transformation stage and the associated environmental impacts of collection and beneficiation. We analysed the implications of the transformation of different waste types to resources when industries are located in different geographic locations under consideration of the life cycle stage of transformation. Figure 2 shows the most significant results of the net benefit within the set of analysed waste types: the transformation of PET and concrete waste. Waste PET can be transported up to 10 000 km by lorry and still provide a net benefit regarding greenhouse gas emissions due to circular use. However, in case of concrete, the results are very different. A net benefit only occurs if the additional transport distance compared to primary concrete is less than 5 km. As a reference, the median of the transported distance of completed transformations within the NISP in the United Kingdom according to Jensen et al. is indicated with a black cross. About half of the 979 transformations within NISP were realised within a radius of 33 km and only one quarter of the synergies involved distances greater than 64 km. 

Conclusions: Transformation from linear to circular systems can substantially reduce total resource consumption as well as emissions of the whole value chain and therefore contribute to a greener economy. However, matching industries for transformations leading to the substitution of primary materials is still a major challenge. In addition, the environmental benefits of the reuse of resources is limited by the life cycle stage of the transformation as well as by additional transportation that may be required. The analysed set of types of waste shows a broad range of potential benefits. For some types of waste, the net benefits are still considerable after the subtraction of the additional impacts due to the life cycle stage of transformation as well as additional transport requirements. However, for selected types of waste, the net benefit tends to be negligible. The completeness of the scope will be crucial for the assessment and generalisations overarching different types of waste remain challenging.