Bipolar Membrane Electrodialysis for Cleaner Production of Diprotic Malic Acid: Separation Mechanism and Performance Evaluation

Abstract

Bipolar membrane electrodialysis (BMED) is a promising process for the cleaner production of organic acid. In this study, the separation mechanism of BMED with different cell configurations, i.e., BP-A, BP-A-C, and BP-C (BP, bipolar membrane; A, anion exchange membrane; C, cation exchange membrane), to produce diprotic malic acid from sodium malate was compared in consideration of the conversion ratio, current efficiency and energy consumption. Additionally, the current density and feed concentration were investigated to optimize the BMED performance. Results indicate that the conversion ratio follows BP-C > BP-A-C > BP-A, the current efficiency follows BP-A-C > BP-C > BP-A, and the energy consumption follows BP-C < BP-A-C < BP-A. For the optimized BP-C configuration, the current density was optimized as 40 mA/cm2 in consideration of low total process cost; high feed concentration (0.5–1.0 mol/L) is more feasible to produce diprotic malic acid due to the high conversion ratio (73.4–76.2%), high current efficiency (88.6–90.7%), low energy consumption (0.66–0.71 kWh/kg) and low process cost (0.58–0.59 USD/kg). Moreover, a high concentration of by-product NaOH (1.3497 mol/L) can be directly recycled to the upstream process. Therefore, BMED is a cleaner, high-efficient, low energy consumption and environmentally friendly process to produce diprotic malic acid.

Techno-Economic Analysis of Bipolar Membranes Electrodialysis for the Hexacyanocobalic Acid Green Conversion

“…By incorporation of membranes into these processes, the need for the addition of chemicals can be significantly minimized or even eliminated. This reduction in chemical reagent usage leads to a decrease in the generation of hazardous waste, thereby alleviating the environmental burden caused by the disposal of such waste. , Furthermore, membrane technology enables the separation and purification of H 3 Co­(CN) 6 without the need for chemical reagents, which can often produce harmful byproducts. This intrinsic property of membranes can result in the prevention of chemical pollution and the preservation of ecosystem integrity.…”

Phosphates Transfer in Pristine and Modified CJMA-2 Membrane during Electrodialysis Processing of NaxH(3−x)PO4 Solutions with pH from 4.5 to 9.9

“…The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/membranes13070647/s1, Figure S1: SEM images of (a) surfaces and cross-section of the heterogeneous MC-40 membrane (b). The heterogeneous membrane MA-41 has a structure similar to that of MC-40; Figure S2: The distribution of species of the orthophosphoric acid (in mole fractions) vs. the pH of the solution; Figure S3: Cross-section of the ion exchange membrane volume in the framework of microheterogeneous model; Figure S4: Schematic of the unit for measuring the diffusion permeability of membranes: (1) two-compartment cell, (2) membrane under study, (3,4) flow-through compartments of cell 1, (5) tank with distilled water, (6) tank with an electrolyte solution of the set concentration, (7) pumps, (8) conductometer, (9) immersion conductometric cell, (10-13) connecting hoses, ( 14) pH meter, and (15) combined glass electrode for pH measurements; Figure S5: Schematic design of the experimental setup (a) and plexiglass frames with special comb-shaped guides that separate the membranes (b): a flow-through four-compartment electrodialysis cell containing an anion-exchange membrane under study (AEM*) and two auxiliary membranes, an anion-exchange and a cation-exchange membranes; tank with 0.02 M electrolyte solutions (1); additional tank (2) for determination of ion transport numbers; valves (3,4); the Luggin capillaries (5); Ag/AgCl electrodes (6); platinum polarizing the working and counter electrodes (7); Autolab PGSTAT100N (8); flow-through cell with a pH combination electrode (9); pH meter pHM120 MeterLab (10) connected to computer; pH meter (10); combined electrode for pH measurements (11) connected to pH meter (10); conductivity cell (12) connected to a conductometer; titration device (13) for maintaining a constant pH in the solution circulating through tank (2); desalination compartment (14); the solid purple lines show schematic concentration profiles in two neighboring compartments separated by the membrane under study; Figure S6 S1: The values of pK a (at 25 • C) of the orthophosphoric acid various species, which may be present in the membrane systems under study; Table S2: The rate constants of proton-transfer reactions (5)- (10) for the weak acids under study; Table S3: Some of the characteri...…”

“…Membrane bioreactors and modules for dialysis, electrodialysis (ED), and capacitive deionization contain these membranes. Already, these membrane technologies are promising for the processing of fermentation broths or waste fermentation effluent [ 1 , 2 , 3 , 4 ], agricultural, industrial streams and natural waters [ 5 , 6 , 7 , 8 , 9 ], the selective separation of various acids [ 10 ]; tartrate stabilization of wine; demineralization of milk whey; reagent-free correction of the pH of juices and wines [ 11 ], or conversion of salts to polybasic acids and vice versa [ 12 , 13 ]. Citrates [ 2 , 11 , 14 , 15 ], malates [ 10 , 14 ], tartrates [ 13 ], oxalates [ 7 ], chromates [ 16 , 17 ], vanadates [ 18 ], and sulfates [ 19 ] are the most common objects of the application of processes in which ion-exchange membranes are involved.…”

“…Membrane bioreactors and modules for dialysis, electrodialysis (ED), and capacitive deionization contain these membranes. Already, these membrane technologies are promising for the processing of fermentation broths or waste fermentation effluent [1][2][3][4], agricultural, industrial streams and natural waters [5][6][7][8][9], the selective separation of various acids [10]; tartrate stabilization of wine; demineralization of milk whey; reagent-free correction of the pH of juices and wines [11], or conversion of salts to polybasic acids and vice versa [12,13].…”

A Commemorative Special Issue in Honor of Professor Victor Nikonenko

“…Jinfeng He et al [ 3 ] compared the conversion ratio, current efficiency and energy consumption in the electrodialysis production of diprotic malic acid from sodium malate using different membrane stack configurations. They were BP-A, BP-A-C and BP-C (BP, bipolar membrane; A, anion exchange membrane; C, cation exchange membrane).…”