Evaluating the environmental sustainability of biomass-based interfacial solar evaporators: Life cycle and cost assessment perspective

Interfacial solar evaporation (ISE) is an emerging technology for freshwater production that relies on solar energy; however, ISE systems often rely on complex materials that are not environmentally friendly or economically viable. This study presents a cradle-to-gate life cycle analysis (LCA) and economic analysis (EA) of biomass-based interfacial solar evaporators to enhance the sustainability of freshwater production. The evaluation was conducted in accordance with ISO 14040 and 14044 standards, using the software SimaPro with the ReCiPe 2016 Midpoint (H) v1.07 methodology and the Ecoinvent 3.11 database. Two carbonized agricultural biomass materials, biochar from moringa seed (BMS) and biochar from date palm fiber (BDPF), were investigated to enable a comparative evaluation for LCA and EA. The LCA revealed that the total global warming potential (GWP) was 2.62 × 10 -2 kg CO 2 eq for the BMS evaporator and 2.33 × 10 -2 kg CO 2 eq for the BDPF per evaporator unit. Electricity consumption during fabrication dominated environmental impacts across most categories, accounting for nearly 55% of GWP. Toxicity-related impacts, particularly terrestrial ecotoxicity and human non-carcinogenic toxicity, were among the highest, highlighting the influence of upstream emissions in polymer manufacturing and energy generation. However, the EA revealed a substantial cost difference between the two evaporators, with the MS evaporator costing $0.071 and the BDPF evaporator costing $0.045 for a single evaporator. Furthermore, both evaporators demonstrated good potential for sustainable desalination, reflecting the suitability of agricultural materials for ISE.