11 June 2003

The California Air Resources Board (ARB) has verified the CleanAIR Systems diesel particulate filter, PERMIT™, for use in stationary emergency generators. The filter was verified as a Level 3 device, providing at least 85% PM emission reduction.

The PERMIT™ device is a passive diesel particulate filter, catalyzed with a noble metal catalyst which facilitates filter regeneration at elevated exhaust gas temperatures. The filter requires a temperature of above 300°C for at least 30% of operating time (or 2 hours, whichever is longer), to properly regenerate. The filter can be used on emergency generators powered by a variety of engine types of PM emission/certification level of not more than 0.1 g/bhp-hr (ISO 8178 D2), operated using ultra-low sulfur diesel fuel (≤15 ppm S).

The 300°C temperature requirement is approximately equivalent to a 40% engine load factor. Emergency generators are usually operated over short periodic maintenance sessions, which can be performed under load or at idle. In the latter case, the filter must be regenerated every 12...24 sessions by increasing the engine load, such as by connecting an electrical load bank to the generator.

CleanAIR’s PERMIT™ filter is the first Level 3 device verified by the ARB for a nonroad engine application.

ARB equipment verification page
PERMIT™ verification letter

Source: California ARB