Oxygen Enriching Membranes for Reduced Cold Start Emissions 1999-01-1232
Nearly 80% of all emissions from an automobile during the Federal Test Procedure (FTP) occur within the first two minutes of the test because the engine is running rich and the catalyst has not reached peak operating temperature. Research at Compact Membrane Systems, Inc. have proven the benefit of using the engine's natural vacuum to drive a membrane module to supply Oxygen Enriched Air (OEA) during initial start up. The benefit of the OEA has shown to decrease emissions of carbon monoxide (CO) and hydrocarbons (HC). In addition, OEA helps to maintain the combustion flame stability when the engine is operated in a lean mode or at a low engine speed. There is evidence that OEA may also account for to a shorter warmer up time for the catalyst.
A 3 inch diameter by 9 inch long module, (7.5 cm dia. × 23 cm) with a small regenerative blower, was installed to an accessory port on the intake manifold of a truck engine. A 30 second idle period was run on the engine and exhaust emissions were recorded. When the engine was supplied 23% and 25% OEA, a reduction of 25-50% in HCs and CO were realized with no measurable loss in power.