20 August 2004
San Leandro, CA-based Cleaire Advanced Emission Controls announced that the California Air Resources Board (ARB) and the Environmental Protection Agency (EPA) have verified its “Longview” diesel emission retrofit system for use on most onroad heavy-duty diesel engines manufactured between 1994 and 2002.
Last year, Cleaire received Longview system verification for a limited number of engine models. Current verification, issued in July, extends the applicability of the system for more engines. The system can be used in California diesel retrofit programs as a “Level 3” device (i.e., achieving at least 85% reduction in PM emission) and at least 25% reduction of NOx emissions.
The EPA approval has been issued under the recent reciprocity agreement by which the federal EPA and the California ARB mutually recognize their verifications. The EPA verification classifies the Longview at 85% reduction in PM, 25% reduction in NOx, and 85% reduction in both CO and HC.
The Longview system includes an active lean NOx catalyst followed by a catalyzed diesel particulate filter. The lean NOx catalyst uses diesel fuel, injected upstream of the system, as a NOx reductant. The system replaces the muffler in the exhaust system of a diesel vehicle. Vehicles retrofitted with the Longview system must be operated on ultra low sulfur diesel fuel (15 ppm S). The ARB estimated that the system might incur a fuel economy penalty of 3-7% depending on the application.
The Longview system has been in use on over 400 diesel buses and trucks throughout California, including vehicles owned by the California Department of Transportation, San Francisco’s Municipal Railway, and the Central Contra Costa Transit Authority, said Cleaire.
Two other Cleaire products, the “Lonestar” and the “BUGtrap”, are currently in the verification process. The Lonestar resembles the Longview, but is configured to reduce only NOx reductions. The BUGtrap is a particulate filter designed for emergency back-up generators and other standby equipment.