March/April 2013
As they purchase new equipment, recyclers are learning how interim Tier 4 emission standards for off-road vehicles are likely to affect typical scrap processing operations.
By Christopher Doscher
Scrap processors have a reputation for holding on to their equipment as long as possible, so unless they’ve purchased new machines recently, they might not know how the U.S. Environmental Protection Agency’s interim Tier 4 emissions standards will affect their operations. The standards—which aim to reduce vehicle emissions of nitrogen oxides and particulate matter—are part of the federal government’s decades-long implementation of clean air regulations. Manufacturers of on-road vehicles transitioned their products from the interim to the final Tier 4 standards between 2007 and 2010; makers of off-road vehicles made the switch from Tier 3 to interim Tier 4 between 2008 and last year. Newly manufactured off-road diesel engines of 50 to 75 horsepower had to meet the standards in 2008; engines of 175 to 300 hp and 300 to 600 hp had to meet them in 2011; and those of 75 to 100 hp and 100 to 175 hp had to meet them last year.
Unlike the earlier tiers of standards, which manufacturers could meet by retrofitting existing engines, meeting interim Tier 4 standards required major technological changes, says the marketing manager for wheel loaders and heavy excavators at one Midwestern equipment manufacturer. Equipment makers have used two different technological approaches—or a combination of them—to produce engines that meet the standards. Those who are using such engines in a scrap processing environment say the changes will require recyclers to make a few adjustments in their operations and maintenance routines.
Though some smaller engines could meet the interim Tier 4 standards with fuel delivery changes, for engines of 75 hp or greater, the two primary technologies manufacturers developed to comply are cooled exhaust gas recirculation and selective catalytic reduction, explains a marketing manager for another equipment company. Manufacturers are not necessarily favoring one technology over the other: They might use CEGR in some types of equipment and SCR in others. One company, for example, advertises that its compact track loaders, excavators, forklifts, loader backhoes, loader/tool carriers, and skid-steer loaders use CEGR, while most of its wheel loaders use SCR. Either of the two technologies might be enough to meet the interim Tier 4 requirements, according to information another company has on its website, and individual machines might employ a combination of the two technologies to meet the more stringent final Tier 4 requirements. Most of the interim Tier 4-compliant scrapyard equipment on the market uses CEGR technology with a diesel particulate filter, or DPF, says Tom Hickson, equipment manager for The David J. Joseph Co. (Cincinnati), but to meet the final Tier 4 requirements, manufacturers are likely to use SCR with a DPF, as they did to bring on-road trucks into compliance. The DPF collects particulate matter in the filter and heats it at a high enough temperature to burn the excess in what’s called the regeneration process. This process typically will occur as the machines are operating, the marketing manager says, but when machines operate at a low number of revolutions per minute, at a low operating temperature, or under harsh conditions, the process cannot completely reduce the particulates to ash. In such cases, the operator might have to allow the machine to idle while a “forced” regeneration takes place.
The small amount of ash that remains in the filter after regeneration must be removed periodically with special equipment—every 4,500 hours of operation in one company’s engines, says the company’s marketing manager for skid-steers and compact track loaders. The DPF, which works with an oxidation catalyst, also is the main service item on a Southern company’s interim Tier 4-compliant equipment, says that company’s heavy equipment product manager for material handlers.
Recyclers will notice a few differences in the equipment depending on which technology it uses. Engines that use SCR run hotter than those that use CEGR to reduce the formation of particulate matter during fuel combustion. Such engines control nitrogen oxide levels by using a diesel exhaust fluid that, when injected into the exhaust stream, acts as a catalyst to turn much—but not all—of the nitrogen oxide into carbon dioxide, water, and nitrogen. With CEGR technology, the engine operates at a lower combustion temperature, producing less nitrogen oxide but more particulate matter, or soot, so it uses a DPF to reduce particulates. The DPF does often result in hotter exhaust temperatures due to the regeneration process, one company rep says.
Operators must use ultra-low-sulfur diesel fuel and API CJ-4 engine oil—what’s sometimes called “low-ash” oil—to prevent premature eroding of the filter, says the heavy equipment product manager. Further, “we’ll have a large cooling system on our machines because the system is running hotter. You have to increase your overall temperature to burn out the soot.”
Impact in the Yard
To date, DJJ’s five subsidiaries and 74 yards around the country have purchased several material handlers and wheel loaders that are interim Tier 4-compliant, Hickson says. It already had substantial experience with the technology in on-road vehicles, he points out, as it has been using some Tier 4-compliant trucks for several years. The company had to work closely with local equipment dealers to understand the operational and maintenance requirements of these new engines, Hickson says. “You have a learning curve at the user end, the dealer end, and with everyone involved.” He tells of confusion that arose after a dealer told a yard manager that a piece of machinery had to be “parked” for an hour every day to allow the regeneration process to run its course, while, in fact, if the machine is running, the regeneration process is much faster with no loss of production.
Regeneration timing can be an issue. Ideally, operators should allow the regeneration process to take place automatically while the machine is in use so productivity doesn’t suffer, Hickson says. “If the operator constantly delays the regeneration, the engine will, after a certain number of delays, require that a parked regeneration takes place, requiring the operator to stop and regenerate while idling.” The equipment’s technology doesn’t acknowledge partial regeneration, so if the equipment cannot keep running until the process is complete, the operator will have to start the cycle over again the next time the equipment is in use. “If an operator is going to get off work at 4, and the machine tells him to regen at 3:45, he should wait until the next day,” Hickson says. “Otherwise, the machine will have to start over.”
Occasionally DJJ has needed to idle some equipment for an hour each day to allow the DPF regeneration process to finish, Hickson says. This increases operating costs, with other additional costs coming from the need for more operator training—in both the regeneration process and the new emissions-control technology—and fuel. The interim Tier 4-compliant equipment the company has purchased is itself slightly more expensive than previous models, he adds. Another operating factor the company has noticed is that the exhaust from the new equipment is much hotter, Hickson says. “So we have to be mindful of where we are.”
Interim Tier 4 changes also have made maintenance a challenge, Hickson says. The arrangement of engine components has changed, for one. “The DPF took the place of a muffler, [so] we didn’t lose a lot of space” with that change, but when manufacturers implemented SCR technology “they had to find room for it” in the engine compartment, “and they’re still trying to figure out where to put it.” One company rep says the larger cooling systems on CEGR machines are what require more space under the hood. Also, if some aspect of the emissions-control system breaks, it almost certainly will require a service call. “The in-house mechanic can’t fix most of this stuff,” Hickson says. “It’s way too technical, so you have to call the dealer in, and the dealers are still learning it.” The parts themselves can be expensive. Replacing the DPF costs about $1,000 if done through an exchange program that offers cleaned, previously used filters, Hickson says, and about $4,500 when purchased new.
To offset some of the costs associated with interim Tier 4-compliant equipment, manufacturers say they have made other improvements. One company released its first interim Tier 4-compliant wheel loaders and excavators in early 2011. One series of excavators uses CEGR, while a series of wheel loaders uses SCR. “Our decision to develop both SCR and CEGR technologies was about understanding our customers’ needs and choosing the right technology for the task,” the Midwestern marketing manager says. “We made sure power wasn’t compromised in improving the emissions and fuel economy of our engines.” The Southern equipment manufacturer began switching to interim Tier 4 technology with its larger equipment, says the heavy equipment product manager for material handlers. First was the material handler that’s one of the company’s top-selling products, followed by another material handler in that series. Both use CEGR technology. Representatives of another Midwestern company say there has been a “tremendous amount” of interest in its line of interim Tier 4-compliant products. The company also has upgraded the machines’ other technology, improved their fuel economy, and increased the efficiency of its products, the representatives say.
California Challenges
Although most scrap operations will encounter interim Tier 4 technologies only as they replace existing equipment or purchase new machines, California cargo-handling regulations for facilities in port areas call for companies to make all their equipment Tier 4 compliant by specific deadlines, says Elio Torrealba, director of air quality compliance for SA Recycling (Anaheim, Calif.). “We have a schedule depending on the year and make of the off-road vehicle, and every year we have to repower and/or retrofit a certain number of them,” he says. “Every year … our particulate material emissions have to be down. The only way you can do that is by retiring vehicles, repowering units, buying new vehicles, or scrapping units.”
SA looked into repowering existing material handlers with Tier 4 engines, but its efforts were unsuccessful because no Tier 4 engines were available in the horsepower levels it needed. Even if Tier 4 engines had been available, in most cases the company would have had to incur expenses to upgrade the older vehicles’ hydraulic and cooling systems because they were not compatible with the requirements of the new engines, Torrealba says. “The electronic systems in the old engines would have to be upgraded as well so that they could communicate with the electronic systems of newer Tier 4 engines.” That means affected companies must purchase all new diesel-powered equipment—if they can find it. “In most cases, Tier 4 engines are not available because the manufacturers haven’t made them yet,” Torrealba says. “Usually you [can] find Tier 4 engines in the lower horsepower range. Anything from 25 to less than 300 hp may be available, depending on the manufacturer,” whereas SA is seeking equipment with engines in excess of 300 hp.
Torrealba took his concern about equipment availability to an official with the Sacramento-based California Air Resource Board, which told the company it could repower older material handlers with Tier 3 engines if it also installs “verified diesel emissions-control strategies”—the most common of which is a DPF, CARB says—on the equipment and provides a letter or e-mail message from the manufacturer that attests that neither Tier 4 nor interim Tier 4-compliant engines are available for that equipment. Find a list of VDECS at www.arb.ca.gov/msprog/ordiesel/vdecs.htm.
Christopher Doscher is a Laurel, Md.-based freelance writer.