Most highway trucks built in the U. S. from 2010 onward will use urea to control emissions. Extremely tight Tier 4 emissions standards in the U. S. have forced engine makers to think of bold new ways to achieve 90 per cent nitrous oxide reduction from Tier 3 standards. The leading technique is to spray a liquid urea solution into the exhaust. This mix then goes through a catalytic filter that uses the urea to convert nitrous oxides (NOx) into nitrogen and water vapour.
Joe Suchecki, media contact for the Engine Manufacturers’ Association, says all but one company (Navistar) have indicated they will go with this urea system.
The big question for truck fleet owners is where they’ll fill up with urea (or “diesel exhaust fluid” as it’s called.) Engines will burn two or three litres of urea for every 100 litres of diesel, so they won’t need a urea top up at every diesel stop, but some stations will set up urea stores. Trucks will have an electronic system that kills the engine if the urea tank runs empty, so urea will be available in small emergency jugs.
The big question for farmers is what this new demand will mean for overall urea prices. Gerry Kroon, industrial manager for Agrium, says the North American market for urea in trucks is forecast to reach two million tonnes, but that won’t be for a few years when most of the trucks on the road are using this emissions-control system. Europe, which has similar emissions standards, will use similar amounts. This represents a significant market for Agrium and the other urea manufacturers. Total agricultural use of urea in North America is currently six to seven million tonnes per year, Kroon says.
Tier 4 standards will also apply to off-highway diesels, including farm tractors, in the next five years or so. Interim tier 4 standards for off-highway kick in by 2011, and the more stringent final standards by 2014. John Deere and Cummins do not plan to use the urea system in their interim Tier 4 engines. But what they’ll do to meet final Tier 4 standards has not been publicized at this point. Suchecki says all companies are “looking at” the urea system as an option, but are hoping something better comes along before 2014.
For more on how Tier 4 engines with urea systems work, read the article on page 38 of this issue.