Catalytic Converter (Natural Gas Engines)

The two types of catalytic converters used in natural gas engines are lean-burn and rich-burn. Lean-burn natural gas engines use a catalyst to oxidize carbon monoxide (CO) in the exhaust gases, while rich-burn natural gas engines use non-selective catalyst elements due to the small percentage of oxygen, normally present in the exhaust stream. Non-selective catalysts, also referred to as three-way catalysts, use catalyst reactions to breakdown unwanted nitrogen oxide, CO, hydrocarbons, and formaldehyde molecules into more desirable water, carbon dioxide, and nitrogen molecules in the exhaust gas stream.

See also Lean-Burn Natural Gas Engine; Rich-Burn Natural Gas Engine.