Life cycle assessment applied on alternative production of carbon-based sorbents – A comparative study

Abstract

Carbon-based sorption materials have excellent performance in numerous applications, and for their high porosity and sorption performance, these materials are irreplaceable in the industry; however, their manufacturing is demanding and usually fossil-dependent. This comparative study applies the life cycle assessment (LCA) analysis on the alternative production of carbon-based sorption materials and highlights its environmental benefits. The chosen raw materials are softwood pellets (SWP) and solid recovered fuel (SRF) from the local municipal waste collector. The analysis showed interesting equality of these two materials in terms of primary energy demand, specific energy consumption, and environmental impact. The overall favour of the SWP over the SRF is nearly negligible and not always damning. Also, the matter of emissions into the air was hardly distinguishable, with the most significant deviation equal to 1.7% (inorganics into the air). A similar statement applies to environmental impact determination using two life cycle impact assessment methodologies: ReCiPe 2016v 1.1 (H) and Environmental Footprint 3.0. Specific energy consumption of each process was also investigated and compared to better understand the requirements and environmental impact of the selected route of alternative sorbent production. As a result, gasification (3 kWh∙kg−1) appears to be less energy-demanding than hot-steam activation (4.5 kWh∙kg−1) due to scaling and the ability to process excessive amounts of material. The analysed procedure suggests a promising alternative for sorbent manufacturing toward sustainability and a lesser environmental footprint.