Innovative extraction process for date fruits syrup (Dibs) using electro-thermal solar energy

Abstract

The traditional method (TM) of dates syrup (dibs) extraction takes long extraction period and has poor productivity. The TM depends on putting heavyweights above the heap of dates at room temperature, and wait until dibs extraction. This study aims to design two innovative solar electro-thermal energy systems with hydraulic pressure to extract dates syrup. The electro-thermal systems were used to heat and circulate dates dibs extraction medium, while hydraulic pressure (6 ± 1 and 7 ± 1 bar) was used to squeeze dates instead of traditional weights. Solar water bath (SWB) and solar air bath with rocks storage bed (SABWRSB) were used to catalyst the extraction process. The syrup dibs quality and quantity from different methods were evaluated. For innovative methods, the dates temperature inside the extraction tank was about 49–54 °C. The efficiency of the SWB and SABWRSB for syrup extraction was 48.87% and 13.16%, respectively. Using SWB saved time about 38%, and increased the productivity by 28.75% and 36.66% at a pressure of 6 ± 1 and 7 ± 1 bar, respectively, compared to TM. Heating with SWB increased the productivity by 3.6% and 5.68% compared to SABWRSB at 6 ± 1 and 7 ± 1 bar, respectively. The SWB is recommended for providing the appropriate environment for the dates dibs extraction.