The long arm of CARB
Even out-of-state truckers are faced with retrofitting exhaust systems, courtesy of the Air Resource Board, if they plan to run in the Golden State

By Paul Abelson, senior technical editor

Oh, for the good old days, when you bought a truck from a dealer and it remained a legal truck (provided it was maintained) for its entire useful life. When the National Highway Traffic Safety Administration and the Environmental Protection Agency made their rules, they applied to all vehicles manufactured after a certain date. If your truck was made before that date, the new regs did not apply.

With the emphasis on the environment, that has changed, at least at the state level.

California was allowed to set its own restrictions and regulations on pollution. The state has taken that authority and is now requiring retrofitting some older equipment.

If you run regionally or plan to avoid operating in California, you can disregard this information – at least until some other states follow the Golden State.

But for now, if you will be entering California for as little as one day a year, you need to be familiar with the California Air Resources Board’s Final Regulation Order, Section 2025, “Regulation - to Reduce Emissions of Diesel Particulate Matter, Oxides of Nitrogen and Other Criteria Pollutants, from In-Use Heavy-Duty Diesel-Fueled Vehicles.”

If you think the title is long, try plodding through the 55 pages of its text. Thankfully, it doesn’t all apply to long-haul transport. Only a portion does, but you have to be familiar with that portion, even if you aren’t based in California.

Small fleets (one to three trucks) can get an exemption for one vehicle per fleet, per year. You must apply at least three days in advance. CARB will try to respond within three days, but in case they don’t, copies of an application that was submitted either online, by email or by fax will keep you legal. If you want to run more than one vehicle into California, or enter the state more than once, you’ll have to comply with the reporting requirements just as if you were domiciled there.

In addition to registration and paperwork requirements, the regulations require truck operators “to install exhaust retrofits that capture pollutants before they are emitted to the air, and to accelerate vehicle replacements to those with cleaner engines.”

Vehicles can be upgraded three ways to meet the regulations. First, you can install devices to capture particulate matter and/or replace vehicles or engines. This can be phased in on model year basis starting next year. Second, you can retrofit a minimum number of engines each year with approved particulate matter reduction devices or replace older engines with those meeting 2010 EPA emissions standards. The third way applies to larger fleets. It involves fleet averages for particulate matter and nitrogen oxide.

Both families of pollutants are by-products of diesel combustion. Particulates – soot and unburned hydrocarbons – are created when diesel burns at too low a temperature. Nitrogen oxide is created when diesel (or other hydrocarbon fuel) burns under high temperature and pressure.

Particulates are irritants. They can cause lung diseases when inhaled. Nitrogen oxide reacts with ultra-violet radiation to form smog, and is classified as respiratory irritant.

Particulate matter is relatively easy to control. It can be physically filtered from exhaust. Diesel particulate filters (DPFs) were developed to meet 2007 federal EPA requirements when allowable PM was reduced 90 percent, from 0.1 grams per horsepower-hour (g/hp-hr) to 0.01 g/hp-hr.

Like most emissions control devices, DPFs must be sized and certified for each individual engine. CARB has a Retrofit Device Verification Database. It lists devices by engine maker, model and purpose for each engine. Simply enter the year, make and displacement of any on-road, off-road or stationary engine, and the database will display all approved devices.

For small fleets the first truck must have a particulate matter device no later than Jan. 1, 2014. The second must be on by Jan. 1, 2015, and the third must be on by New Year’s Day 2016. Devices must meet California’s best available control technology (BACT) standards.

In addition to retrofitting BACT devices, there are reporting requirements depending on engine model year. All fleet owners operating in the state must comply by Jan. 1, 2014. Some specialized engines may meet PM regulations using a flow-through filter with a diesel oxidation catalyst, but they provide limited filtration, typically a 20 to 30 percent reduction compared with 85 to 90 percent a DPF provides.

DPFs are made of porous ceramic material. Rather than having open, flow-through construction, they have closed chambers. That forces exhaust gas to flow through fine openings in the ceramic walls. Soot and ash are trapped in the closed cells. Periodically, the soot must be removed by burning it at 500 degrees F (260 C) to convert it to harmless carbon dioxide gas. The incombustible ash must be removed physically, using specialized machinery.

When engines operate with an exhaust temperature above 500 F, this regeneration is “passive.” If exhaust is cooler, “active” regeneration is needed. done by spraying diesel fuel over a catalyst. That creates intense heat. Regeneration is included in the DPF.

NOx is more difficult to control. It requires fundamental engine design, which includes exhaust gas recirculation (EGR), often coupled with selective catalytic reduction (SCR).

The first strategy, EGR, mixes inert exhaust gas with incoming air to provide a slower, cooler burn that creates less NOx. SCR treats the exhaust gas after it has left the turbocharger to chemically convert the NOx to harmless nitrogen gas.

For small fleets of one to three trucks, starting Jan. 1, 2015, all 1993 and older engines must be brought up to EPA 2010 standards. In 2016, 1994 and 1995 engines must be compliant with 2010. By 2020, add 1996 through 1999 engines followed by 2000 through 2004 in 2021. By 2022, 2005 and 2006 engines must comply. Finally, in 2023, all 2007 and newer engines must be brought to EPA 2010. Larger fleets have different compliance deadlines.

The engine modifications and updates are not jobs for shade-tree mechanics. They must be certified, and are best done by authorized dealers and distributors. Often, remanufactured engines will wind up being most economical.

And when you repower a truck, sell it or add a new one and you plan to run in California, don’t forget to update your paperwork. LL