Life cycle assessment of surface-modified cellulose nanofiber packaging films from rice straw

Abstract The growing demand for sustainable packaging materials has driven research into biodegradable alternatives to traditional plastics, which pose significant environmental challenges. Cellulose nanofiber (CNF), extracted from lignocellulosic biomass through chemical, mechanical, or chemo-mechanical methods, is a promising renewable resource for eco-friendly packaging. Evaluating resource consumption, energy input, and emissions throughout the life cycle of these materials is essential to ensure they are environmentally safer alternatives. A comprehensive life cycle assessment (LCA) was performed for surface-modified cellulose nanofiber (CNF) packaging films derived from rice straw, with a functional unit (FU) of 350 kg of CNF film production. The system boundary, defined as cradle-to-gate, included the processes from the collection and transportation of rice straw to the fabrication of CNF thin films. Data for the foreground system were primarily based on laboratory-scale production and extrapolated to represent industrial-scale production. The total cumulative energy demand (CED) was 7.23 × 10⁴ MJ-eq, with rice straw transportation step (step 1) contributing 37.75%. The global warming potential for 100 years (GWP 100 ) was 4.63 × 10³ kg CO₂-eq, again dominated by Step 1 remarking 42.19%. The highest ozone depletion (OD) impact was observed in Step 3 (31.67%), while eutrophication (EP) peaked in Step 6 (17.67%), associated with intensive washing and processing stages. Eco-toxicity (ET) and human toxicity (HT) impacts were also largely driven by step 1, contributing up to 74.12% and 73.86%, respectively. Water use (WU) was highest in the CNF film drying step (step 16, 59.63%), while ionizing radiation (IR) was dominated by the bleaching step (step 9, 45.22%). Step 1 was also the major contributor to photochemical oxidant formation (POF) (45.40%). The results indicate that upstream processes, mainly raw material transportation and energy-intensive operations, are the dominant contributors to environmental impacts. High deionized water consumption and electricity usage significantly influenced on EP and other impact categories through indirect emissions. Additionally, chemical-intensive treatments and low cellulose extraction yields (⁓35%) further amplify the overall environmental burden. Although CNF films demonstrate advantages over fossil-based and some bio-based packaging materials, their sustainability is constrained by high energy demand, chemical usage, and low process efficiency. Improving cellulose yield (up to 45–60%), optimizing processing steps, and integrating cleaner energy sources are recommended as essential strategies to reduce environmental impacts and enhance the overall sustainability of CNF-based packaging at a commercial scale.