Techno-Economic Evaluation and Process Optimization of Zero-Liquid-Discharge Systems with Solar Energy Integration

This study evaluates the integration of solar energy into Zero Liquid Discharge systems, assessing the trade-offs between emissions and cost under varying solar capacities and seasonal conditions. Simulating both Minimal and Near-Zero Liquid Discharge configurations, the study analyzes energy demands, emissions, and economic implications associated with renewable penetration from 0% to 100%. The analysis accounts for solar generation profiles based on seasonal variation and battery storage capacity for night-time demand. While renewable energy reduces emissions substantially, costs tend to escalate sharply beyond 90% renewable share, particularly for NZLD configurations employing brine crystallizers or electrodialysis. The seasonal analysis reveals worsening performance in winter months due to reduced solar availability. During winter months, reduced solar irradiance leads to increased reliance on battery storage and grid electricity, resulting in a 21% rise in grid energy use and over 40% increase in storage draw, in addition to higher emissions and treatment costs.