The CL.AIR Exhaust After-Treatment System for GE’s Jenbacher gas engines is a thermal regenerative post-combustion system for engine exhaust gases. Since no catalytic reactions take place during the thermal treatment of the exhaust, as it is insensitive to impurities in the fuel gas, the CL.AIR system is particularly suitable for use with critical gases such as biogas, for which catalytic converters either cannot be used or are used only to a limited extent. In addition CL.AIR decomposes the unburned methane in the exhaust gas and provides extra exhaust heat. The CL.AIR Exhaust After-Treatment System is applicable to Type 2, 3, and 4 Jenbacher gas engines.
- Once exhaust gas is heated to approximately 1,472 °F (800 °C), uncombusted hydrocarbons, formaldehyde, and CO oxidize to form water vapor and CO2
- Catalytic reactions are eliminated during the thermal treatment of the exhaust
- Only minimal power supply is required
- Resistant to contaminants in the fuel gas
- Minimal maintenance costs
- Suitable for operation with critical gases
- Resistant to deposits
- Constant emission values throughout the entire lifecycle
- No additional fuel gas cleaning required
- Additional heat generation (about 20-30°C increase in exhaust temperature)
GE’s CL.AIR Exhaust After-Treatment System is based on a regenerative heat exchange, and consists of a reaction chamber holding two scrubbers and a switching unit.
- At approximately 986 °F (530 °C), exhaust gas flows from the engine via the switching unit into the first scrubber, where it is heated to 1,472 °F (800 °C)
- In the reaction chamber, exhaust gas reacts with the oxygen it contains, oxidizing carbon monoxide and HC to produce carbon dioxide and water
- Exhaust gas emits heat again as it passes through the second scrubber, at a temperature of around 1,022 to 1,058 °F (550 to 570 °C) reaches the switching unit
- Switching unit directs heat to the smokestack or a downstream waste heat boiler