Breath of fresh air: engine makers are meeting the challenge of new EPA diesel engine emissions standards.

Environmental regulators are very interested in off-road engines and equipment, including machines used in the recycling industry. For engine manufacturers, regulations have increased machine complexity. More emphasis is being placed on maintenance and after-treatment strategies. Retrofitting existing fleets to clean up their emissions, especially in non-attainment zones, is also likely to grow.

Here's the good news for recycling companies: In the United States, the burden of meeting emission standards is squarely on the shoulder of the engine manufacturer. (Canadian regulations are mirroring U.S. laws). In other words, equipment buyers are not responsible for meeting emissions regulations. When recyclers buy new equipment, it will automatically meet the emissions standards in place at the time the unit was manufactured. However, state and local regulatory bodies may offer incentives, such as access to jobs or higher payments, for companies using the cleanest machines.

Fault codes should be heeded and repairs made as soon as possible to ensure engines operate as the manufacturer intends. Equipment owners also are strongly encouraged to keep accurate maintenance

BACKGROUND

Clean-air legislation has been around for years. Prior to 1955, cities, counties and states all carried air-quality laws on the books. The Air Pollution Control Act of 1955 turned air-quality regulation into a federal matter. In the 1960s, U.S. regulations established standards for automobile emissions. The basis for today's rules and regulations is the Clean Air Act of 1990. The first tier of emission regulations for off-road diesel engines arrived in 1994. Additional tiers define increasingly tighter emissions requirements.

Internal combustion engines produce four major emissions: nitrogen oxides (NOx), particulate matter (PM), hydrocarbons and carbon monoxide. For diesel engines, the regulatory focus is on NOx and PM.

Both the U.S. Environmental Protection Agency and the European Union (EU) implemented two separate standards--one for on-highway truck engines, another for off-road use--regulating emissions.

The off-road standards are being phased in over a number of years, gradually reducing the legal levels of emissions for various sizes of diesel engines. In the United States, these phases are identified as "Tiers" (Tier 1-Tier 4).

In the EU, they are identified as "Stages" (Stage I--Stage IIIB). In time, the differences between on-highway and off-road standards will narrow, and the two sets of standards will eventually converge.

The EPA estimates that by 2010, Tier 3 standards will reduce NOx emissions from diesel engines by about 1 million tons per year, an effect similar to taking 35 million passenger cars off the road. Tier 4 standards are even more stringent, reducing NOx emissions by 90 percent beyond Tier 3 regulations.

Manufacturers met Tier 1 levels through relatively minor engine modifications, including changes in fuel rates, timing and compression. Air-to-air after-coolers and turbos made Tier 2 engines visually distinct from earlier engines.

But Tier 3 requirements forced manufacturers to take a big leap in engine development. That was when Caterpillar introduced engines with ACERT technology.

The core concept behind ACERT technology is advanced combustion. The combustion process is carefully controlled to reduce pollutant levels, while maintaining performance and efficiency.

Other companies introduced engines with various forms of exhaust gas recirculation (EGR), a process that returns exhaust gases to the combustion chamber.

To meet Tier 4 requirements, Caterpillar is focused on deep machine integration, electronic controls and after treatment. Other manufacturers will also need to make changes to reach Tier 4 goals.

VARIED REGULATIONS

Emissions regulations vary throughout the world, which introduces a layer of complexity to moving machines across borders. Certification labels must be attached to diesel engines before they are allowed into the United States. Customs officials inspect off-road equipment at the port of entry and will not allow machines without labels that correspond to the tier level in place at time of manufacture. These labels must remain on the engine and they must be easily visible in case of inspection or if equipment is to be resold.

That means recyclers won't be able to import new machines originally sold outside the United States without an EPA label. They will, however, be able to import used machines that do have the label.

NON-ATTAINMENT ZONES

The EPA has designated more than 470 counties non-attainment areas in the United States--locations where air pollution levels persistently have exceeded national air quality standards. State and local governments that used to set their own standards are now involved in planning to meet the federal standards.

Diesel engines have been retrofitted to meet Tier 2 requirements in on-highway and off-road applications. Cat dealers, for instance, have installed diesel oxidation catalysts on buses and catalyzed converter mufflers on landfill tractors. Other retrofit solutions can even include installing new engines in existing machines. In some instances federal assistance has been used to retrofit older diesel engines.

With equipment manufacturers bearing the responsibility for complying with air emissions regulations for off-road equipment and on-highway vehicles, recyclers can concern themselves with the task at hand: efficiently processing and handling material.

This article was submitted on behalf of Caterpillar Inc., Peoria, Ill.

RELATED ARTICLE: Less pain at the pump.

For recyclers that run their own on-highway truck fleets, recent fuel tests comparing a Caterpillar engine to a competitive engine with cooled-EGR shows that Cat engines with ACERT Technology deliver more than 5 percent better fuel economy.

In late 2005, a fuel test conducted by an independent consultant found that the Cat C15 achieved 5.8 percent better fuel economy than the Cummins ISX, according to a press release from Caterpillar.

The two-day test run from Denver to San Antonio, compared vehicles specified to manufacturers' recommendations pulling identical 53-foot air-ride dry van trailers loaded to 79,000 GVW, driving at posted speed limits. The Cat C15 was a 435-hp, multi-torque engine with 1,550-1,750 pounds per foot of torque. The comparable Cummins ISX had e 450-hp engine with 1,650 pounds per foot of torque. The Cat engine was mated to a 3.25 rear axle, and the Cummins was mated with a 3.36 rear axle ratio as recommended.

A second test also was conducted, this time using SAE Type III (J1526) test standards. The results showed a 3.2 percent fuel economy advantage for the C15 as compared to the Cummins ISX, according to Caterpillar.

"These were single unit tests with identical specifications and conditions. The results were verified by the independent consultant who ran the tests," Greg Gauger, director, Caterpillar On-Highway Power Systems, says in a press release. "It validates what customers have been telling us all along--when you spec them right and drive them right, Cat engines with ACERT Technology get the best fuel economy."

He adds, "Independent tests are just a way to prove what many of our customers already know--Cat engines with ACERT Technology are outperforming engines with cooled-EGR."

More information about Cat engines is available online at www.cat.com.