Chemical Industry

Chlor-Alkali Process: Electrolysis & Dechlorination Analysis

2026-08-10 3

The electrolysis section is the heart of chlor-alkali production, where brine is converted into chlorine, hydrogen, and caustic soda. Ensuring the integrity of the ion-exchange membrane and maintaining stringent hydrogen safety standards are paramount for stable, continuous operation. MZD Analytik provides high-speed, accurate instrumentation to mitigate explosion risks and optimize electrolysis efficiency.

1. Key Process Control Points

Electrolysis and downstream dechlorination require real-time tracking of critical safety and quality parameters.

Item	Process Location	Parameter	MZD Analytical Strategy
1	Anolyte Loop	pH	Membrane-protected pH control to prevent membrane scaling.
2	Cathode Hydrogen Pipe	O2 Content	High-speed optical oxygen monitoring (safety limit ≤0.5%).
3	Electrolyzer Outlet	Dissolved Oxygen	Fluorescence-based DO analysis for monitoring electrode status.
4	Dechlorination Tower	Cl2	UV-based gas analysis for process monitoring & environmental safety.
5	Chlorine Header	Moisture	Trace moisture analysis (prevent corrosion in pipework).

2. Advanced MZD Instrumentation for Electrolysis & Safety

Optical Oxygen Analyzers (Hydrogen Safety)

The risk of hydrogen-oxygen explosion in the hydrogen header is a critical concern. MZD’s optical oxygen analyzers provide near-instantaneous response times to detect oxygen breakthrough into the hydrogen stream.

BaroSense™ Technology: Our analyzers include integrated pressure compensation, ensuring that measurements remain immune to atmospheric pressure fluctuations—a common cause of drift in standard electrochemical cells.
Calibration Stability: Eliminating the need for frequent gas-based calibrations, these sensors maintain accuracy under harsh process conditions for extended periods.

Membrane-Protected pH Analyzers

In the corrosive anolyte environment, traditional pH sensors often fail due to chlorine gas infiltration. Our membrane-protected pH analyzers utilize a specialized isolation barrier that permits precise H⁺ ion measurement while physically blocking chlorine and other oxidizing agents from poisoning the electrode.

UV Gas Analyzers (Dechlorination)

Efficient dechlorination is essential to prevent chlorine loss and protect the downstream environment. MZD's UV analyzers are highly selective to Cl2 and are unaffected by high concentrations of water vapor or CO2 in the process stream, providing stable, long-term monitoring of residual chlorine levels.

3. Operational Benefits

Explosion Prevention: MZD's high-speed O2 tracking provides an early warning system, preventing the formation of explosive H2/O2 mixtures in the hydrogen headers.
Process Stability: Precise control of anolyte pH extends the operational lifetime of expensive ion-exchange membranes by reducing degradation and scaling.
Enhanced Safety & Compliance: Our UV and optical technologies ensure that chlorine emission levels at the dechlorination unit remain strictly within environmental regulatory limits.

For detailed technical datasheets or site-specific application consultation, please contact our support team at sales@mzdd.de.

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