About Tier 4 Diesel Regulations
Posted on Engineering News-Record web site. A good article that explains what is coming our way in turf equipment because of federal regulation. To learn more, see Jacobsen’s white paper “Tier 4 Standards Are On The Horizon” by clicking JAC Tier 4 Explanation
Next Round of Federal Regulations Has Suppliers Retooling Clean Diesel EPA’s Tier 4 tailpipe rule hits next year as new carbon rules linger on the horizon.
04/14/2010 By Mike Larson
The next phase of U.S. regulations aimed at cleaning up airborne emissions from off-road diesel engines will start taking effect in just nine months. The rule, called Tier 4, will all but eliminate the amount of diesel particulate matter (soot) and nitrogen oxides (NOx) that new construction equipment will put into the atmosphere.
Split into two subrules, the Tier 4 standard begins phasing in with an interim rule in January 2011 for engines from 175 horsepower to 750 hp and, in 2012, for engines from 75 hp to 175 hp. The Tier 4 rule cuts down the soot an engine may emit by 90% compared to the current Tier 3 standard, and it cuts the amount of NOx an engine is allowed to put out by 45%. What will follow in 2014 is an even tougher Tier 4 Final standard, which will cut NOx output by another 45%. Then, new construction equipment will emit virtually no NOx or soot.
Cleaning up the air will have a powerful effect on the health of millions of Americans. The EPA says diesel-powered off-road equipment now puts out 47% of the soot and 25% of the NOx spewed into the air by mobile sources nationwide. How much will the clean-air standards improve health? According to the U.S. Environmental Protection Agency, which drafted the rules, by 2030, when the country’s fleet of older, non-road diesel engines has turned over, the cleaner air will eliminate 12,000 premature deaths, 15,000 heart attacks, 200,000 cases of asthma symptoms in children and one million lost work days each year.
EPA’s clean-diesel standards, including the upcoming Tier 4 regulations, apply only to new off-road equipment sold for use in the U.S. Manufacturers are responsible for making sure the equipment they sell meets current standards. In general, equipment manufacturers are choosing between two strategies for reducing NOx and soot to meet the Tier 4 Interim standards. Their choices are based on engine size, power loads and individual application demands.
The first technology is a combination of a cooled exhaust-gas recirculation system (EGR) and a diesel particulate filter (DPF). EGR is an in-cylinder technology that cools some exhaust gas leaving the engine and routes it back into the cylinder, which reduces the combustion temperature and, in turn, cuts NOx formed during combustion. It is commonplace on most on-road diesels today.
Although this approach reduces NOx, it tends to create more soot. (Lower combustion temperatures result in more soot and less NOx; higher combustion temperatures result in the opposite.) Manufacturers using EGR will add a DPF to the tailpipe to trap and periodically incinerate soot.
Nearly all the major equipment manufacturers—including Caterpillar, Case/New Holland/Kobelco, Komatsu, Deere, Volvo, Terex and engine specialist Cummins—plan to use this approach on some or all of their interim models.
The other major technology for reaching Tier 4 Interim levels is running the engine hot enough so that combustion produces very little soot in the cylinder. This approach tends to create higher levels of NOx, so manufacturers using this method will employ selective-catalytic reduction (SCR) for the Tier 4 Interim standard. SCR converts NOx fumes to harmless nitrogen and water by dosing them with small amounts of diesel exhaust fluid (DEF), an aqueous urea solution sprayed downstream of the engine.
Manufacturers that say they plan to use this approach for meeting Tier 4 Interim clean-air requirements on some equipment include Case/New Holland/Kobelco and Terex. Only JCB has said it will meet the Tier 4 Interim clean-air standards for products in the 75-hp to 175-hp range without a DPF or SCR. However, JCB says it may add SCR to meet the Tier 4 Final rule.
Although only a few equipment manufacturers say they are definitely planning to use urea to meet the further reduced NOx levels required by the Tier 4 Final standard coming in 2014, some indicated that, at this point, the use of urea, along with a particulate filter, appears to be likely. “Using SCR and a particulate filter is the sure way to meet the Tier 4 Final standards,” says Graham Weller, diesel-product group director for engine consultant Ricardo Inc.
The Cost of Cleaner Air
The challenge of developing technology to satisfy EPA’s Tier 4 standards sits on the shoulders of the manufacturers, but the burden of paying a higher initial purchase price for the new technology will fall to construction equipment buyers.
Manufacturers have invested millions—in some cases, billions—of dollars developing the new technology. That cost will be passed on in the selling price. Many manufacturers acknowledge that initial equipment prices will go up over current Tier 3 models. But, to date, only Caterpillar has announced a specific level of increase: The company says it has spent $7.5 billion over the past six years developing products that will run more cleanly and productively. Its Tier 4 Interim equipment prices will go up 12% over the three years, starting with a 4% increase this coming January.
Although initial purchase prices will be higher than for current machines, several manufacturers say they expect their Tier 4 equipment to cost contractors less to own over the life of the machine, thanks to lower fuel costs, higher productivity and longer life.
“As we redesign equipment to meet Tier 4 requirements, we’re taking the opportunity to see what we can change for the better,” says Michael Unrein, senior director of product marketing for Case/New Holland. “We expect the total cost of ownership to be better with Tier 4 products.”
Many manufacturers say they expect fuel economy to go up by 5% or more thanks to the efficiency of the new engines. Cummins’ 20,000 hours of testing on its new engines has verified that its Tier 4 diesel get 5% better fuel economy, says spokesman Clint Schroer.
Although manufacturers talk about the productivity and technological advances of their new Tier 4-compliant equipment models, fleet owners still have questions. Nick Pfeifer, project manager for Granite Construction, voiced the same question many other contractors have asked: “What’s it going to take to maintain and operate it?”
In general, manufacturers tell ENR that maintenance intervals will be similar to those for existing equipment. John Bartz, emission solutions manager for Volvo, says, “Intervals for engine service remain the same. The engine oil will be different, but it will be a standard grade and backward compatible to existing machines.” The diesel particulate filter will need to be changed periodically as it fills with ash, suppliers note. The cleaning will have to be done by a certified dealer. Some manufacturers say they are setting up recycling programs to make it more convenient for equipment owners.
One maintenance item that is drawing concern from off-road equipment owners is the SCR system that some manufacturers plan to use for reducing NOx emissions. Although it’s now widely used in on-road heavy trucks, the urea-based SCR is entirely new to off-road equipment. Thad Pirtle, equipment chief at contractor Traylor Brothers, Evansville, Ind., says he would rather not see urea on his equipment because it’s another system to maintain. It may have other side effects: “It freezes at 27 degrees,” he says.
Unlike today’s truckers, who are becoming widely familiar with SCR, it is still unknown territory for the off-road sector. However, manufacturers are confident in the technology. “It’s effective—the right technology at the right time. All but one on-highway truck manufacturer are using it to meet the 2010 on-road standard. By 2014 when Tier 4 Final arrives, perceptions will have changed,” says Joe Mastanduno, a Deere product marketing manager, who says the Moline, Ill.-based vendor will use SCR for Tier 4 Final.
Some equipment owners wonder whether their Tier 3 and earlier equipment can be upgraded to Tier 4 standards… the answer varies by manufacturer. Some are planning to offer retrofitting and repowering options to help customers bring their older machines up to date. Others actually discourage it because electronic and other systems don’t synch as well as a new system designed to work together.
But where there’s a will and some skill, upgrades can be done, says Eric Schmidt, equipment superintendent, Sukut Equipment, Santa Ana, Calif. He has repowered 175 pieces of equipment in the company’s fleet. “We’ve even put a 2010-compliant on-road truck engine in a scraper. It meets the air-quality standard, and the machine works fine,” he says.
One reason Sukut repowers so much equipment is to make sure expensive machines, such as a $1.7-million scraper, meet the clean-air standards and can keep working in the nation’s toughest air-quality state, California.
More Smoke Signals
By 2014, on- and off-road diesels alike will run cleaner than ever, but it may not be enough. Based on the well-established pattern of on-road regulation working its way off-road, the EPA’s monitoring of carbon dioxide is only a few years away.
“Greenhouse gases will be the next frontier of regulation,” says Jacob Thomas, Terex vice president. “The amount of CO produced relates directly to how much fuel you burn, so reducing it comes down to getting better fuel economy.” California is now the only state the federal government permits to set its own stricter standards, which include clean-air requirements for older machines that work there. However, as many as 23 other states are waiting to adopt the California code if the federal government grants California the right to enforce it. That prospect could mean fleet owners across the country would have to bring the older equipment in their fleets up to a higher clean-air standard.
In another recent development, jurisdictions across the U.S. are writing in contract-specification requirements for clean construction equipment on projects funded by public money. This proviso could limit contractors from bidding on the work if they don’t have equipment that meets the current clean-air standards. Finally, because of the cost and complexity of the new emission controls, researchers are studying new options for powering clean, off-road equipment (see sidebar, above).
As off-road standards get tougher, it’s apparent that clean air doesn’t come dirt cheap. But construction workers and the public alike will be breathing easier.