Carb's 15 Ppm Ulsd Rule Proposal Due In July

Diesel Fuel News, Feb 19, 2001 by Jack Peckham

Los Angeles -- By July, California Air Resources Board (CARB) aims to propose a formal rule mandating ultra-low-sulfur diesel (ULSD, 15 ppm sulfur cap) statewide in mid-2006.

CARB aims to go forward even though U.S. EPA's new ULSD rule faces a separate court challenge brought by National Petrochemical & Refiners Association (NPRA), CARB officials told a public workshop here.

Because of related CARB-mandated diesel retrofit rules phasing-in between now and 2006, many California diesel operators will have to use ULSD long before the official mid-2006 statewide ULSD mandate on all highway and off-highway users. Only railroads and marine sectors are (at least for now) exempt from the CARB ULSD mandate.

For example, CARB this month is drawing-up new diesel emissions limits for new and existing stationary and portable engines for both agricultural and non-farm operators, part of its "airborne toxic control measures" plans. These engines likely will require ULSD and exhaust retrofits.

Meanwhile, California regulators are under new pressure to slash emissions from the huge increase in diesel generator-set usage, because of California's electric power crisis. Eventually, this could require retrofits and ULSD for thousands of gen-sets, a heretofore unexpected source of ULSD demand (see separate story, p16).

Asked by a Tosco official whether CARB plans to speed-up diesel emissions retrofits to compensate for higher emissions from new, desperately-needed electric generators, CARB official Dean Simeroth quipped that it "sounds like a good idea, but I don't know about that." A survey for CARB by California Energy Commission (CEC) will try to forecast supply and demand for ULSD between now and 2006, in order to stimulate early production.

The CEC survey is supposed to be complete before the July ULSD rule proposal, CARB officials said here.

Anticipating results from CEC's ULSD demand survey, Tosco (just bought by Phillips Petroleum) promised here that it would be "quick to the table" to make ULSD available well before 2006.

Besides retrofits, part of the rationale for ULSD is to enable new vehicles to meet EPA and CARB light- and heavy-duty highway emissions limits later this decade, with sulfur-sensitive catalysts for particulate matter (PM) and nitrogen oxides (NOx) control.

"This [CARB ULSD] Proposal appears to be linked to the EPA rule, but will CARB go forward regardless of delays by court action?" asked Ellen Shapiro of Alliance of Automobile Manufacturers.

"We can't see the future," CARB's Simeroth responded, "but our retrofit rules mean we have other motivations [for ULSD requirements] besides new vehicles" that must use ULSD starting in late 2006. "We're motivated to move at our pace. Our diesel fuel rule is linked to stationary and mobile source programs, including retrofits. We many need to motivate [pre-2006] ULSD production -- maybe without regulation," depending on results of the CEC ULSD supply/demand survey.

Aside from the 15 ppm sulfur limit, CARB isn't proposing any changes to the aromatics limits in today's "CARB diesel" fuel. Most California refiners choose to meet this requirement via an "alternative" performance standard certification that produces emissions equivalent to the 10% default aromatics limit. This usually means CARB diesel has lower-than-normal sulfur levels, and much higher cetane levels than normally found in EPA-specification highway diesel.

CARB isn't proposing a four-year, 2006-2010 phase-in scheme for ULSD, unlike EPA's ULSD scheme. Nor are there any special provisions for small refiners "at this time," as CARB official Tony Brasil explained here.

Refiners with "alternative" CARB diesel certifications would be allowed to continue using the same certification, except for the 15 ppm sulfur limit. CARB aims to propose a rule on CARB fuel certification procedures by November.

Aside from those "grandfathered" certifications, CARB might require future candidate CARB ULSD fuels to be "better identified as actually produced" for the market rather than just certified, he said.

"Right now, we would grandfather existing formulations with cetane, aromatics, nitrogen, and polycyclic aromatics the same," he said.

Test Engine Change?

Asked whether the certification engine itself should be updated, CARB's Simeroth responded that "it needs to be considered, but we have no [new] engine in mind. We have a lot of experience with that engine" at Southwest Research Institute and "it's about the average age of the diesel fleet." However, if engine makers "could give us some guidance," then CARB may consider a certification engine change, he said.

Assuming EPA's mid-2006 ULSD rule survives legal or administrative challenges, the problem of inter-state, truckers having a "dirty-fuel" cost advantage over California-only truckers using CARB ULSD in 2006 would disappear. But depending upon how CARB structures its diesel fleet retrofit rules, it's still possible that lower-cost "dirty" fleets could steal business from "clean" operators, unless California adopts well-thought-out incentive programs (see related story, p11).