BASF Technology Enables Carmakers to Meet Evaporative Emissions Standards

Technology developed by BASF provides carmakers with an additional tool to meet increasingly stringent California and federal standards for evaporative emissions.

Evaporative emissions are hydrocarbon vapors from cars that come from sources outside the exhaust system - such as the air intake system, fuel rail, exhaust gas recirculation system and the gas tank.

With today's efficient exhaust emission controls and cleaner gasoline formulations, the United States Environmental Protection Agency (EPA) estimates that evaporative emissions can account for the majority of the total hydrocarbon pollution from current model cars on hot days when ozone (smog) levels are highest.

BASF's hydrocarbon-trapping technology, which prevents a large amount of evaporative emissions from reaching the environment, enables automakers to comply with the tough new regulations. The technology is another example of BASF helping its customers to be more successful. In this case, BASF developed a proprietary zeolite based on its earlier successes in reducing "cold- start" emissions (pollution that escapes a car in the first minute or so after ignition.) The new zeolite, which is coated onto a substrate for excellent adhesion, has a high capacity to trap hydrocarbons within its pores and channels.  

This "hydrocarbon trap" is placed between a car’s air cleaner and engine, where it can capture hydrocarbons that are escaping through the air intake. This position is optimal because the air intake system contributes as much as 50% of total evaporative emissions.

The trap absorbs hydrocarbons that are emitted when the engine is stopped. Once the car is started and driven, the trap releases the hydrocarbons into the engine where they are burned. In this way, the new hydrocarbon trap continually regenerates itself.

The hydrocarbon trap is designed to remain effective for 150,000 miles, and is tamper-proof so it avoids the use of costly on-board diagnostics equipment. The trap also has minimal impact on airflow into the engine and can withstand exposure to ice, water, salt, dust, air filter surfactant and engine backfire.