Environmental Assessment of the Recycled Paper Production: The Effects of Energy Supply Source

Abstract

The main aim of the study was to assess the environmental performance, through the application of the life cycle assessment, of a recycled paper production process focusing on the energy aspect. The production process occurred in a paper mill that produces packaging paper using paper and cardboard from source separation of municipal solid waste as raw materials. Two scenarios (S1 and S2) were defined by their energy supply sources. A cogeneration (CHP) system using natural gas for the combined production of thermal and electric energy was the source in S1. The Italian electricity grid (using the Italian country mix) and a natural gas boiler were the separate sources for electric and thermal energy, respectively, in S2. Finally, in order to evaluate the environmental effects on the results of the study about the variation in the natural gas supply source, four alternative Italian import mixes (M1, M2, M3, and M4) were defined by varying the contribution of the supplier countries. The environmental impacts were evaluated with ReCiPe 2016 (H) using both midpoint and endpoint approaches. The results showed that for both the scenarios, the energy consumption was the main cause of impacts mainly because of the natural gas contribution. The presence of the cogeneration (CHP) system generated significant environmental benefits compared with the use of energy provided by more conventional sources. The production and use of chemicals as well as the disposal of waste produced during the paper production were other environmental hotspots. The variation in the composition of the Italian import mix of natural gas, in terms of the supplier country’s contribution, had a significant influence on the results. The import of natural gas from Russia was the most impactful option. Since Russia is the country that contributes to the Italian import mix the most, in the next years, the use of natural gas in Italy could become increasingly impactful. Therefore, the replacement of natural gas with renewable sources is an urgent priority.