Application of pervaporation and osmotic membrane distillation to the regeneration of spent solutions from the osmotic food dehydration

Abstract

Application of pervaporation and osmotic membrane distillation to the regeneration of spent solutions from the osmotic food dehydration Results of pervaporation (PV) of sucrose and calcium chloride spent solutions were presented. Additionally, osmotic membrane distillation (OMD) of sucrose solutions was investigated. It was found that the regeneration of spent sucrose solution for the reuse is possible by using PV or OMD processes. However, OMD process produces another spent stream i.e. CaCl2. Pervaporation membranes showed fluxes in the range of 0.5 - 0.9 kg m-2 h-1 in contact with 40° Brix sucrose solution, whereas OMD water permeate fluxes were in the range of 4 - 5 kg m-2 h-1 for the same feed concentration. Two different hybrid processes were suggested: i) pretreatment followed by OMD reconcentration of spent sucrose solution and independently PV for CaCl2 regeneration; ii) membrane pretreatment (MP) followed by PV of sucrose solution. Based on the experimental results, the membrane areas for both systems were calculated and compared. MP-PV system seems to be a better solution for the spent mixtures management.

Membrane-Based Operations in the Fruit Juice Processing Industry: A Review

“…The industrial application of OD is still limited by the low productivity of the process and the management of the diluted stripping solution generated during the process. Membrane processes, including PV and OD, as well as atmospheric evaporation and direct contact evaporation with flue gas, have been proposed to regenerate spent solutions from the osmotic food dehydration [141][142][143]. However, this approach precludes the use of calcium chloride as the osmotic agent due to formation of calcium carbonate due to the presence of carbon dioxide in combustion gases.…”