Combining ex-ante LCA and EHS screening to assist green design: A case study of cellulose nanocrystal foam

Abstract

The evaluation of environmental credentials for innovative products within the research and design phase of development presents a valuable yet challenging exploit. The research presented here aims to carry out the early-stage environmental assessment of a novel nano material – cellulose nanocrystals (CNC) foam by applying ex-ante life cycle assessment (LCA) supplemented by an environmental, health and safety (EHS) screening. LCA is applied to assess the cradle-to-factory gate environmental impacts along the R&D trajectory from the laboratory synthesis, conceptual design, bench-scale trial to the up-scaled process design. Non-renewable energy use (NREU), greenhouse gas (GHG) emissions and agricultural land occupation (ALO) are the three indicators analysed. The early-stage EHS screening provides a supplementary assessment since the toxicity information is usually missing in the ex-ante LCAs due to lack of information. The EHS screening was conducted in two steps: 1) the (eco)toxicological effects of CNC are analysed by applying in vivo zebrafish assays; and 2)A so-called “block list” scan is performed where all substances used in the production of CNC foam are scanned against valid regulations. The LCA results demonstrate that technology upscaling leads to a steady environmental impact reduction. It is observed that for per kg studied CNC foam, both NREU and GHG emissions were reduced by a factor of 10 along the R&D trajectory from lab scale to upgraded process design, as a result of the design improvements associated with energy-intensive processes and process energy optimisation. Along the studied R&D trajectory the potential ALO was decreased by 83% primarily due to a more efficient recycling of ethanol. The block list scan did not yield highly concerned substances in the manufacturing process. The in vivo zebrafish assay provided valuable insight into the ecotoxicological effects of CNC pointing towards the need for a more rigorous assessment.