EMOS® SIL2 Safety system


The common cause of most cell room incidents is “hot” cell operation: the top of a membrane melts, the hydrogen and chlorine mix, and the cathode and anode are short circuited. Next, cells start to burn, and explosive gas mixtures ignite in the cell or further downstream in the chlorine production process.

“Hot” cell operation can be the result of an insufficient electrolyte flow to a single cell because of a blocked feed system, a high cell resistance caused by an abnormal coating aging, or a general failure.

cell explosion

Precise and Advanced Detection

We can perform advance detection of all known electrolyser malfunctions in real-time by precisely measuring and analyzing the voltage : current : time relationship of each individual cell.

Injury to personnel and irreversible damage to equipment can thus be prevented by triggering an emergency shutdown of the individual power supplies.

The EMOS® SIL2 SAFETY SYSTEM analyzes the voltage of each individual cell. The accepted voltage range is calculated in real-time based on the:

  • Rectifier current
  • Performance of neighbouring cells
  • Technology specific constraints
  • Electrochemical boundaries

The EMOS® SIL2 SAFETY SYSTEM helps prevent and protect against irreversible damage caused by all known events.

The 4 Pillars of the EMOS® SIL2 SAFETY SYSTEM

MODA – An Intelligent Data Acquisition Sensor

The MODA was especially designed for the cell room environment. It features a high degree of data acquisition precision, a fast sampling rate, temperature compensated measurements, and noise filtering algorithms. An ATEX version of the MODA is also available for installation in zones rated for potentially explosive atmospheres.

SILCAM – A Logic Solver

The SILCAM contains the controller logic responsible for triggering the plant emergency shutdown system whenever an electrolyser or one (or more) of its cells are operating outside of their recommended safety parameters.

EMOS® SIL2 SAFETY ALGORITHMS – Protection Against All Known Events

For over two decades we have been monitoring electrolytic cells, which has enabled us to develop and integrate advanced algorithms which can help protect against irreversible damage caused by a variety of issues such as:

  • Anode coating loss
  • Cathode coating loss
  • Electrode passivation
  • Membrane poisoning
  • Insufficient electrolyte feed
  • Cell temperature control failure
  • Electrolyte concentration control failure
  • Differential pressure out of range
  • Cell leakage
  • Membrane pinholes, tears and blisters
  • Short circuits

EMOS® VIEW – A Human-Machine Interface

EMOS® VIEW is an application designed to monitor and manage process data obtained from the EMOS® SIL2 SAFETY SYSTEM, PINHOLE DETECTOR, SINGLE CELL TEMPERATURE and EARLY DETECTION ENGINE. or any other OPC compliant system. It is a streamlined user interface specifically tailored to the needs of the operators that displays key performance indicators such as raw and normalized voltages, cell temperatures, and feed. It offers reporting tools for alarms and cell voltages, the ability to trend process data like voltages or cell temperatures, and much more!


MODA Datasheet

The MODA is an intelligent data acquisition sensor. Designed specifically for the cell-room environment, the MODA incorporates sampling algorithms that synchronize with the fundamental rectifier frequency, removing any unwanted noise…


ATEX MODA Datasheet

The ATEX MODA is an intelligent data acquisition sensor that complies with the IEC 60079-7:2015 standard for zones rated for potentially explosive atmospheres. Designed specifically for the cell-room environment, the ATEX MODA incorporates sampling algorithms that remove any unwanted noise…


SILCAM Datasheet

R2’s SILCAM (SIL Communication & Alarm Module) is is the logic solver and communication manager of the R2 safety system..


VIDEO: Detection of Short Circuit

EMOS® SIL2 Safety System



EMOS® View: New HMI for EMOS® System


EMOS® View Datasheet

EMOS® (Electrolyser Management, Optimization and Safety) View is the HMI software of the EMOS® SIL2 Safety System and its related tools.


Data Acquisition Precision for the Chlor-Alkali Process

The following paper focuses on data acquisition precision for equipment used to measure cell voltage in the chlor-alkali process and how precision is at the heart of EMOS® functionality.


Safe Operation of Electrolytic Cells

This white paper explains the importance of measuring precisely individual cell voltage to detect electrolyser malfunctions as early as possible. In addition, it discusses…



Case Study: Why Covestro invested in the EMOS® Safety System

Covestro, a major chlor-alkali producer, explains the safety benefits they derive from using the EMOS® Safety System.