New on-line analyzer systems for HCl burners

New on-line analyzer systems for HCl burners

The synthesis of hydrogen chloride or hydrochloric acid ( HCl ) is performed by combustion of hydrogen and chlorine gas. Both the reaction and absorption heat in water are highly exothermic. Hydrogen gas and chlorine gas are fed into a burner at controlled rates. The burner consists of two concentric tubes with chlorine flowing through the inner tube and hydrogen through the outer annulus. Above the burner, the gases are ignited to produce hydrogen chloride gas. A hydrogen flow of at least 5% stoichiometric excess is recommended to ensure that a complete synthesis takes place. The hydrogen chloride gas, at a temperature of 2,000 to 2,500°C , flows from the combustion chamber into an integrated isothermal falling-film absorber. The hydrogen chloride gas is then absorbed by water or weak acid. The hydrochloric acid is normally produced with less than 1 ppm free chlorine. By adjusting the absorption water (weak acid) supply rate, the desired hydrogen chloride solution concentration is obtained.

The following on-line analyzer systems can be offered to control the performance and the safety of the HCl burner:

  1. Measurements in the chlorine ( Cl2 ) gas feed to the HCl burner:
  • On-line hydrogen ( H2 ) in dry chlorine ( Cl2 ) by high temp reactor ( H2 + Cl2 ◊ 2HCl ) where hydrogen chloride ( HCl ) is formed and measured by multi-wavelength InfraRed analyzer system
  • On-line chlorine ( Cl2 ) in dry chlorine ( Cl2 ) by multi-wavelength UV analyzer system
  • On-line oxygen ( O2 ) in dry chlorine ( Cl2 ) by Alternating Pressure Paramagnetic or Tunable Diode Laser ( TDL ) analyzer system
  1. Measurements in the hydrogen (H2) gas feed to the HCl burner:
  • On-line hydrogen ( H2 ) in hydrogen ( H2 ) by Thermal Conductivity ( TCD ) analyzer system ( explosion proof conform NEC or ATEX )
  • On-line oxygen ( O2 ) in hydrogen ( H2 ) by Electrochemical cell- or Alternating Pressure Paramagnetic- or Tunable Diode Laser ( TDL )analyzer system
  1. Measurement in the gas vent of the HCl burner:
  • On-line hydrogen ( H2 ) in vent of the hydrogen chloride ( HCl ) burner by Thermal Conductivity ( TCD ) analyzer system ( explosion proof conform NEC or ATEX )
  1. Measurements in the liquid HCl :
  • On-line chlorine ( Cl2 ) in hydrogen chloride ( HCl ) solution by wet chemical Universal Process Analyser UPA®colorimetric analyzer system
  • On-line iron ( Fe ) in hydrogen chloride ( HCl ) solution by wet chemical Universal Process Analyser UPA®colorimetric analyzer system
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