While the Tier IV engine emission standards for off-highway diesels aren't scheduled to take effect for a few more years, AGCO Corp. unveiled its new engine technology on February 3. The company says the technology has already been proven in Europe and by introducing it early, AGCO customers will have the opportunity to reduce their fuel use and improve their overall productivity. It also gives the number three largest farm equipment maker a head start on its competition.

The company says it plans to begin shipping the new units to its dealers in March for all three of its brands of high-horsepower tractors - AGCO, Challenger and Massey Ferguson - in the 270-350 horsepower range.

The company is branding the new off-road diesel engine technology as e3, which stands for energy, economy and ecology. The new diesels utilize SCR (selective catalytic reduction) technology that the company describes as "a simple, robust and proven method for treating diesel exhaust emissions to achieve EPA emissions standards."

Selective Catalytic Reduction (SCR)

SCR is a proven emission-control system designed to lower emissions of nitrogen oxide (NOx) and particulate matter (PM) from the exhaust gases of diesel engines.

e3 is a post-combustion, after-treatment process that takes place within the exhaust system itself. With the e3 system a NOx reducing agent, or Diesel Exhaust Fluid (DEF), is injected into the exhaust gas upstream of the e3 catalyst chamber.

When heated, a liquid urea solution, the active ingredient in DEF, turns to ammonia and reacts with NOx from the exhaust to convert the pollutants into nitrogen, water vapor and tiny amounts of carbon dioxide (CO2). The company reports that e3 technology alone can achieve NOx reductions in excess of 90%.

The key to the success of e3 is the fact that it's a post-combustion process. It stays out of the way of what the engine is built to do - provide power. After the exhaust leaves the engine, all that remains is to reduce the nitrogen oxides (NOx). Because only the exhaust gases are treated, e3 SCR technology allows engineers to use the most efficient engine settings for optimum power and fuel economy.

A Proven Technology

AGCO SISU POWER and AGCO engineers selected SCR technology because, the company says, it is widely acknowledged as the most effective and fuel-efficient method of meeting present and future EPA emissions requirements. SCR exhaust gas after-treatment was originally used to reduce NOx emissions from coal-fired power plants and has been widely used in the trucking industry.

In North America, several truck manufacturers have selected SCR, including Mack, Volvo, Cummins, PACCAR and Detroit Diesel, to meet the 2010 emission control standard for on-road diesel engines.

AGCO reports that it is currently used on more than 500,000 diesel-powered vehicles in Europe. It is also the system preferred by leading on-highway vehicle manufacturers including the market leader – Mercedes-Benz as well as BMW, Audi, Volkswagen, Mini, Hyundai, Kia, and Jeep.

Diesel Exhaust Fluid (DEF)?

Diesel Exhaust Fluid (DEF) is a solution of purified water and 32.5% automotive-grade urea. DEF works with the heat of the exhaust in the catalytic chamber and converts nitrogen oxide (NOx) from diesel exhaust into nitrogen and water.

DEF is metered in precise quantities and then injected, via a Bosch control system, into the exhaust system that includes a catalytic chamber. The DEF is carried in a separate tank on board the tractor and is consumed at a rate of about 3% DEF/gallon of diesel fuel.

It is the equivalent to 3% of the fuel used. Therefore, for every 100 gallons of fuel used, 3 gallons of DEF will be consumed. Typically a farmer will fill his DEF tank every second fuel fill up.

In Europe, DEF is marketed as AdBlue.

According to AGCO, thousands of supply locations are springing up across North America. Since the trucking industry has already adopted SCR technology to meet the EPA Tier IV emissions requirements, availability at truck stop chains is spreading nationwide. DEF will also be available through AGCO, Massey Ferguson and Challenger dealerships.