Waste Gas Treatment with LARCH (Oxidation/Pyrolysis) at the Point-Of-Use

DAS  Process Waste Gas Treatment LARCH
Process Waste Gas Treatment with LARCH for LED Processes

LARCH is our latest Point-of-Use waste gas treatment system especially designed for MOCVD processes. It is capable of treating large flows of Hydrogen and Ammonia as well as small flows of metal-organics and dopants, which are typically found in common LED processes. The treatment combination of oxidation und pyrolysis extends DAS´ technology portfolio in a sustainable way.

Low investment and operating costs, a simple, robust design and low environmental impact (no CO2 emissions, minimum NOx emission) characterize LARCH. The maintenance interval is expected to exceed six months.

LARCH Operating Principle

The system operates in three steps. Firstly, the process waste gases are introduced through a special packed inlet into the decomposition zone. There decomposition of Ammonia (2NH3 à N2 +3H2) takes place. Subsequently the Hydrogen is electrically ignited and oxidized. The waste gases are burned and oxidized within the reactor (2H2 + O2 à 2H2O). Finally the waste gases are cooled (< 60 °C). They can be released into the environment without any further treatment as they meet the strict German standards for air pollution (TA Luft).  

The following equipment options are available for all LARCH systems:

  • Power Supply: 3 x 400 V/50 Hz or 3 x 208 V/60 Hz
  • Process Tool Interface
  • Signal Tower
  • Drip Pan
  • Earthquake Safety Kit
Principle Waste Gas Treatment with LARCH by DAS
Operating Principle of LARCH

Your Advantages

  • No CO2 emissions: no greenhouse gases, low NOx emissions
  • No Wastewater: no trouble with NH4+ wastewater limits
  • Treatment of H2 at the Point-of-Use: Maximum Security regarding H2
  • Simple and robust Design: low investment costs, low CoO, low maintenance
  • Internal Security: H2 dilution in case of fire

Technical Data

  • Dimensions (W x D x H):
    1200 mm x 1000 mm x 1900 mm
  • Access to maintenance area on front and back side
  • Gas entry: DN40
  • Gas outlet: DN300 (standard)
  • Exhaust:
    -8 bis -10 hPa, ~ 3000 m3/h, T < 60 °C
  • Heat load from Waste Gas (H2 + NH3): 
    < 100 kW
  • Emissions:
    H2 Exhaust Concentration < 0,1 LEL,      NH3 Exhaust Concentration meet TA-Luft


  • H2 up to 300 slm + NH3 up to 100 slm
  • Only H2: up to 500 slm
  • Only NH3: up to 250 slm
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If you would like to get in contact with us, please use the following e-mail form or simply call us.

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+1 844 862-1662Give us a call! We are looking forward to providing a further information on our products for waste gas treatment.