Carb outlines crackdown on stationary diesel engines

Diesel Fuel News, Jan 21, 2002 by Jack Peckham

California Air Resources Board (CARB) last week outlined proposed emissions standards for diesel-fueled stationary engines and transport refrigeration units (TRUs).

Once approved, the standards would require drastic reductions in particulate matter (PM) emissions and inevitable conversion to ultra-low-sulfur diesel (ULSD).

At workshops, CARB termed these as "air toxic control measures" for in-use stationary engines over 50 horsepower and new stationary engines, as well as for new engines (both under and over 50 hp). These engines could be either primary power engines or emergency standby engines.

A separate workgroup is "evaluating strategies for agricultural engines," CARB says.

The tentative plan is that by 2004-2005 -- depending upon model year and availability of PM control technology -- in-use stationary engines would either have to be retrofitted with "level 3" technologies achieving at least 85% PM reduction, or else new, cleaner engines would replace old, "dirty" engines.

New engines over 50 hp for primary power, emergency standby power, agricultural engines and "select" portable engines would have a 0.01 grams/brake horsepower-hour limit on PM emissions, while HC, NOx and CO limits would match other CARD off-road diesel limits for the applicable model year.

If the engine owner is replacing an existing emergency standby engine over 50 hp, then PM limits would be 0.15 g/bhp-hr until 2007, then 0.01 g/bhp-hr after 2007, with HC, CO and NOx limits matching CARB non-road limits for those model years.

CARB hasn't figured out yet what the PM limits should be for new stationary engines under 50 hp, although HC, CO and NOx limits would match model-year non-road limits.

A 2007 technical review would determine whether advances in technology justify even tougher limits. The new regulation likely will be drafted by April and brought to the CARB board for approval by next year.

Separately, CARB aims to figure out what sort of PM control technologies might be applied to diesel TRU/transport refrigeration engines ("reefers") used on trucks and rail cars. The agency hopes to come up with a staff report and recommendations by October, with board action following in December.

Jack Peckham