Process optimisation and techno-economic analysis of vacuum ultraviolet photolysis for ethylene removal in apple storage.

This study investigates vacuum ultraviolet photolysis (VUV) for the removal of ethylene in apple storage to reduce spoilage and extend shelf life. A coupled mass–energy balance model was developed for a VUV reactor, achieving strong agreement with experimental data (R² = 0.909). The model captured characteristic temperature and conversion trends but excluded hydroxyl radical effects. A Box–Behnken design examined the influence of humidity (0–90%), lamp power (3–9 W), and initial ethylene concentration (5–50 ppm) on percentage ethylene removal (PER), achieving R² = 0.982. Results showed that moderate humidity enhanced removal efficiency, while excessive moisture suppressed oxidation due to photon competition. Parametric cost optimization identified an optimal lamp wattage minimizing energy and spoilage costs, confirming economic viability at ~0.6% of retail value. The integrated modelling framework offers a quantitative basis for the design and operation of energy-efficient VUV photolysis systems for postharvest ethylene control.