The Environmental Protection Agency has dictated standards that now allow a tiny fraction of NOx compared with just 15 years ago.
After more than 15 years of work, the end is in sight. A steady stream of emission standards from the Environmental Protection Agency has prompted AGCO, Cummins, Fiat Powertrain Technologies, John Deere and other makers of off-road diesel engines to develop cleaner technologies. Today, manufacturers are preparing for Tier 4 Final compliance.
The Tier 4 Interim standard required a 90% reduction in particulate matter and a 50% reduction in nitrogen oxides. The final standard requires no further reduction in particulate matter but calls for an additional 80% reduction in nitrogen oxides (NOx).
These latest requirements are significant—particulate matter and nitrogen oxide levels must be reduced to near zero for most power categories by 2014. But original equipment manufacturers (OEMs) have stepped up to the challenge.
Selective catalytic reduction (SCR) and exhaust gas recirculation (EGR) are the primary means companies have used to meet Tier 4 Final standards. Some have blended the two technologies for a hybrid solution.
Case IH and New Holland, working alongside sister company Fiat Powertrain Technologies, have developed an SCR technology. SCR is an engine exhaust after-treatment that works outside the engine, unlike EGR or hybrid alternatives, and offers benefits beyond reduced emissions.
Fiat Powertrain Technologies 8.7-Liter Tier 4 Final Engine
"Case IH SCR-only systems help reduce the need for oil changes and cut fuel consumption compared to previous-generation emission systems," says David Stark, North American sales and product trainer for Case IH. "These types of changes can make a real, positive economic impact over time. Case IH SCR technology has provided high horsepower levels while using less fuel.
"When the emission components from the engine are removed, the engine can breathe and produce high levels of horsepower," he adds. "There are no emission components on the engines, which is one reason for the higher horsepower levels."
The right fit
John Deere has developed an Integrated Emissions Control system on engines of 75 hp and above that combines a diesel oxidation catalyst, diesel particulate filter and SCR, and which will be paired with its proven EGR system. John Piasecki, the company’s director of worldwide marketing, says this setup will deliver "power, performance, ease of operation, fluid efficiency, reliability and economical operating cost.
John Deere PowerTech PSS 9.0-Liter Tier 4 Final Engine
"At John Deere, we continue to offer the right combination of technologies at the right time to meet increasingly stringent emission regulations and customer needs," he says.
- Machinery Guide 2013