AppliTek NV

Online monitoring solutions for the fast determination of hydrogen in wet chlorine - Monitoring and Testing

The purpose of fast determination of hydrogen in wet chlorine is to set up an early warning system against high hydrogen levels, thereby protecting the chlorine production plant against hydrogen explosion incidents. The hydrogen concentration in wet chlorine is very critical, especially for membrane and diaphragm cell type production of chlorine. A breakthrough of hydrogen in the chlorine by membrane or diaphragm damage can occur within a few seconds. Depending on the concentration, a mixture of H2 and Cl2 gas can be flammable or explosive. For this reason hydrogen needs to be monitored continuously, primarily on the main wet chlorine header, in order to keep the gas composition within the flammability limits.

AppliTek’s on-line monitoring system for hydrogen in wet chlorine using multi-wavelength infrared can be considered as Best Available Technology (BAT) and is HAZOP approved by most of the major chlorine manufacturers.

Other application fields

Safety critical monitoring systems, especially for hydrogen, are also used for: hydrogen in dry chlorine (after drying), hydrochloric acid synthesis.

Parameters: Hydrogen

  • Field proven technology (up-time > 99.5%)
  • Fast response (T90 = 30 seconds)
  • No influence of changes in matrix
  • Selective measurement
  • Excellent results during early start-up of cell room
  • HAZOP approved by Sabic Innovative Plastics (formerly GE), Solvay, Sadaf, Westlake, Olin, Ineos

Typical measuring ranges
On analyzer display 0 – 5 vol% HCl
~ 0 – 2.5% H2 by UV reactor (Cl2 + H2 Š 2HCl)

On analyzer display 0 – 2 vol% HCl
~ 0 – 1% H2 by UV reactor (Cl2 + H2 Š 2HCl)

On analyzer display 0 – 1 vol% HCl
~ 0 – 0.5% H2 by UV reactor (Cl2 + H2 Š 2HCl)

Analysis method
Multi-wavelength infrared

Detection limit

Response time
30 seconds
(T90, without ModuPlex® stream selection)

Better than ± 2 % full scale range