Taguchi-Based Optimization of Air-Gap Membrane Distillat

This study investigates the performance optimization of an air-gap membrane distillation (AGMD) system using Taguchi-based orthogonal experimental design (OED).Four key operational parameters feed temperature (T₁), coolant temperature (T₂), feed flow rate (V₁), and coolant flow rate (V₂) were examined at two levels each, following an L₈ fractional factorial array.Three performance indicators were evaluated: permeate flux, distillate mass, and product conductivity.Experiments were conducted under steady-state conditions with T₁ at 70 and 80 °C, T₂ at 20/25 °C, and flow rates between 100-150 L/h.Results showed permeate flux ranging from 36.72 to 122.11 L/h, distillate mass from 0.158 to 1.328 kg, and conductivity from 1.23 to 3.69 µS cm⁻¹.Taguchi analysis identified feed temperature (T₁) as the most influential factor, contributing 56.4% to flux variation and 69.8% to distillate mass.Contrary to conventional expectations, raising T₁ from 70 °C to 80 °C reduced both flux and yield by over 60%, likely due to boundary-layer polarization and partial membrane wetting.Conductivity increased with higher T₁ and T₂ but was unaffected by V₁, suggesting temperature-driven membrane integrity loss.The optimal trade-off-maximizing flux 118 L/h while maintaining high product quality 1.3 µS cm⁻¹ was achieved at T₁ = 70 °C, T₂ = 20 °C, V₁ = 150 L/h, and V₂ = 100 L/h.The OED approach cut experimental effort by 50% versus full factorial design, demonstrating its efficiency and reliability for optimizing AGMD systems powered by low-grade or renewable thermal energy.

Hali tarjima qilinmagan