Energy Consumption and Process Optimization in the Production of Cornelian Cherry (Cornus mas L.) Distillate as a Function of Ethanol Concentration in the Distillate

Abstract

Energy consumption in batch distillation is affected by the final ethanol concentration when the daily volume of collected product is fixed. This study evaluated an Excel-based material and energy balance for the production of 10 L day⁻¹ of Cornelian cherry (Cornus mas L.) distillate at 36–42% vol. ethanol. The model assumed an initial mash ethanol content of 8% vol., 85% ethanol recovery, a mash density of 0.98 kg L⁻¹, an effective heat capacity of 4.0 kJ kg⁻¹ K⁻¹, heating from 20 to 90 °C, an effective vaporisation duty of 2.0 MJ kg⁻¹ mash, and 20% process losses. Firewood, natural gas, and electricity were evaluated as alternative energy sources using assumed efficiencies of 55%, 80%, and 95%, respectively. Across the investigated concentration range, the calculated mash volume increased from 52.94 to 61.76 L day⁻¹, while total heat demand increased from 141.95 to 165.61 MJ day⁻¹. Equivalent requirements increased from 17.21 to 20.07 kg day⁻¹ for firewood, 4.96 to 5.78 m³ day⁻¹ for natural gas, and 41.51 to 48.42 kWh day⁻¹ for electricity. The increase in heat demand was linear, at approximately 3.94 MJ day⁻¹ per percentage point of ethanol concentration. Under these modelling assumptions, 36% vol. was the minimum-energy point within the evaluated range. These results represent an engineering sensitivity analysis rather than measurements from an operating distillery and require experimental validation.