Bipolar Membrane Electrodialysis with DAQIS Monitoring
How do you tell whether a bipolar membrane electrodialysis trial is progressing as expected? A single endpoint gives little context.
In a YASA ET trial with the DESALT® YTEDBM-32-60S, the acid and base circuits showed clear enrichment trends, while the salt and electrical records highlighted changes that needed further investigation. The trial illustrates why tracking each circuit matters when evaluating an EDBM process.
What the DESALT stack does
Bipolar membrane electrodialysis (EDBM, also called BMED or BPED) uses a DC electric field and ion exchange membranes to convert suitable dissolved salts into acid and base streams. The bipolar membranes split water into hydrogen and hydroxide ions. Selective membranes direct salt ions to the appropriate product circuits. This makes EDBM a candidate for chemical recovery from suitable industrial salt streams; feed composition, product purity and economics must be evaluated for each application.
Conductivity trends in the trial
Figure 1. Conductivity in the four circuits.
The salt conductivity spike at coordinate 65 is retained.
Acid conductivity rose from 34.12 to 352.63 mS/cm and base conductivity from 20.29 to 189.53 mS/cm.
Salt conductivity fell from 50.13 to 33.83 mS/cm overall, with a temporary rise to 66.17 mS/cm(Extra Solid Salt added).
These trends help identify sampling points for follow-up; conductivity alone cannot quantify salt conversion or product concentration.
What the pH and electrical records show
Figure 2. Measured pH, stack current and voltage.
Acid pH fell from 1.89 to 0.84, while base pH increased from 12.15 to 13.00. Both circuits already contained acid or base at the first reading. Net production therefore requires measurements of the initial and final inventories, including titrated concentrations and liquid volumes.
Across coordinates 20–45, the voltage stayed at 108.1 V while current declined from 92.8 to 68.3 A(Manully Adjusted).
What DAQIS adds to an EDBM trial
YASA ET’s Data Acquisition & Integration System (DAQIS) brings readings from configured instruments into a common record. The package can combine digital pH and conductivity probes, Siemens PLC integration, an HMI for live monitoring and parameter adjustment, and a compatible Modbus power module for voltage, current and energy data. The computer software records data and exports it to Excel for review. Available signals depend on the installed instruments and configuration.
A shared record makes it easier to compare product trends with electrical changes, identify gaps and decide when to take samples. In this trial, it also showed where the energy counter and stack readings needed reconciliation. For a pilot or feasibility study, pair the exported operating record with product titration, feed and product ion analyses, and a log of additions and operating changes.
Planning an EDBM trial?
Contact YASA ET at info@yasa.ltd with your feed composition, target acid and base specifications, and preferred monitoring points.
Comments