Abstract Inadequate electricity access in developing countries causes approximately 30% food waste, highlighting the urgent need for off‐grid refrigeration. This study presents a solar adsorption ice maker using Maxsorb III activated carbon/ethanol as a high‐performance working pair. Maxsorb III possesses an exceptionally high BET surface area (3045 m 2 /g) and total pore volume (1.70 cm 3 /g), significantly exceeding conventional activated carbons. The Dubinin–Radushkevich (D–R) equation accurately characterized the adsorption isotherms, yielding parameters X ₀ = 1.412 kg/kg and D = 2.84 × 10 −6 K −2 with a prediction error below 3.8%. A 1 m 2 flat‐plate solar collector system was designed, constructed, and validated through 85 field experiments in Mosul, Iraq during summer (July–September), representing typical semi‐arid climatic conditions. Two ethanol‐to‐adsorbent mass ratios (0.8 and 1.2 kg/kg) were evaluated at evaporator pressures of 3 and 5 kPa. Under optimal conditions (mass ratio 0.8 kg/kg, 3 kPa), the system condensed 0.714 kg of ethanol, maintained the evaporator below 0°C for 5.8 h, achieved a maximum COP of 0.583, and produced 2.1 kg of ice per day representing a 110% increase in daily ice yield and 35.6% COP improvement over the conventional 3‐NORIT PK1/methanol benchmark. The superior performance is attributed to Maxsorb III's highly developed microporous structure, uniform adsorption enthalpy distribution, and the low saturation pressure of ethanol at sub‐zero temperatures. The system provides a cost‐effective, electricity‐free solution for food preservation and vaccine cold‐chain maintenance in semi‐arid off‐grid regions.
Soheel et al. (Wed,) studied this question.