Performance of a liquid desiccant-assisted solar juice concentration system for barberry juice

Abstract A closed-loop solar juice concentration system equipped with a liquid desiccant bed was investigated for barberry juice concentration and compared with the conventional evaporation processes. An unglazed flat plate solar collector was used for simultaneous regeneration of the desiccant solution. Experimental evaluation of the designed system was carried out at different flow rates of moving air as the circulating gas. The results showed that concentration time decreased from 480 to 360 min when the flow rate increased from 0.006 to 0.014 kg/s. Furthermore, raising the flow rate caused a decrease of 40% in effectiveness of dehumidification and an improvement of 33% in moisture evaporation rate. A minimum specific energy consumption of 3.33 MJ/kg was achieved at the air flow rate of 0.006 kg/s. The results indicated that all concentration methods significantly (p  L* , a* , b* , hue angle, chroma and total color difference) of barberry juice. Although color quality of the concentrated juice by the rotary evaporator was better than the other methods, the solar juice concentration system at the lowest flow rate can be proposed for fruit juice processing industries with regard to energy consumption and acceptable and competitive color quality of the processed juices.