Environmental and socio-economic assessment of cork waste gasification: Life cycle and cost analysis

Catalonia is one of the most important world producers of cork, a natural material from which wine stoppers, champagne stoppers and derived products are produced. Within this process, approximately 15% of the extracted raw cork ends up as forestry waste, while considerable shares of the processed cork are also considered cork residues, as for instance defective stoppers or agglomerate plates. Indeed, cork residues are usually sent to landfill with no recovery or second use. In this study, gasification is used as a thermal strategy to convert cork wastes into energy, in order to demonstrate the valorisation of cork waste. This contributes to the implementation of the Waste Framework Directive (2008/98/CE) following the objectives and goals of the Roadmap for a Resource-Efficient Europe. Technological, R&D and industrial partners were gathered under the framework of the LIFE + Ecorkwaste Project and thus, a gasification plant with capacity to treat 15 kg of cork residues per day was designed. The ultimate goal was to develop and optimize the experimental procedure so that the gasification plant could be implemented at an industrial scale. In order to assess the environmental, techno-economic and social impacts of this technology, life cycle assessment (LCA) and life cycle cost (LCC) were performed, as well as a socio-economic matrix integrating various aspects of the technique was developed. The functional unit was the production of 1 MWh by means of cork valorisation through gasification technology and a comparison with the conventional scenario of using the national electricity grid was performed. Three scenarios of possible management strategies for the produced wastes were modelled for the LCA using Simapro Developer and two scenarios of different operation regimes were considered for the LCC under the CAPEX-OPEX concept. As main findings it was shown that the gasification strategy has a sustainable profile with lower environmental impacts than the conventional scheme of energy production. Moreover, this thermal scheme entails lower costs than the conventional scheme and allows net savings in the order of several hundred thousand €, for a 20-year lifespan of the plant.