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Diesel Exhaust Fluid (DEF) Facts Unveiled At TMC

ORLANDO, Fla. - Members of a Technology and Maintenance Council task force studying Diesel Exhaust Fluid (DEF) have unveiled answers to some key questions concerning the storage and use of the truckin...

ORLANDO, Fla. –Members of a Technology and Maintenance Council task force studying Diesel Exhaust Fluid (DEF) have unveiled answers to some key questions concerning the storage and use of the trucking industry’s newest fluid.

The material is key to the technology that most engine manufacturers plan to adopt to meet the US Environmental Protection Agency’s tighter standards on truck exhaust, to be introduced on new vehicles beginning in 2010. The DEF will be introduced into the exhaust stream just above a catalyst in a process known as Selective Catalytic Reduction (SCR), converting NOx into harmless gases.

What is Diesel Exhaust Fluid made from?

Diesel Exhaust Fluid, also known as Diesel Emission Fluid, is largely a pure form of agricultural fertilizer, consisting of 2/3 water and 1/3 urea. It is not listed as a hazardous material.

How long will a supply of DEF last?

Since DEF has a shelf life of about 18 months, every jug will come with a date stamp and an API symbol to ensure that it meets the required standards. Those who store bulk supplies will be able to monitor the condition of the fluid with nothing more than a refractometer.

At what temperatures should it be stored?

Under ideal situations, it will be stored at temperatures between -11.5 and 30 Celsius. At colder temperatures, it tends to turn into a slushy mixture, but it is not supposed to degrade once it thaws. It would need to be stored for extended periods of time above 30 Celsius before the shelf life would be affected. Suppliers such as Terra Environmental Technologies in Courtright, Ont. have also unveiled special storage sheds for bulk containers.

How much fluid will a truck need to carry?

The fluid will last about 330 miles per US Gallon (.78 litres per 100 kilometres), and the US Environmental Protection Agency mandates that each truck will need to carry enough fluid for two fill-ups of diesel fuel. So far, manufacturers seem to be leaning toward one of three sizes of tanks on their vehicles -six gallons (22.7 litres) to last about 2,900 km;13 gallons (49 litres) to last 6,275 km; and 23 gallons (87 litres) to last 11,000 km.

How much does it weigh?

Each US gallon (3.785 litres) of the fluid will weigh 9.2 lbs (4.17 kilograms).

What will happen if a truck runs out of urea?

New warning lights attached to the fuel gauge will help drivers to monitor the levels of fluid in their tanks. Once the tanks drop to the final 5-10% of their volume, a yellow warning lamp will appear. Below 5%, a flashing red lamp will appear and the engine will de-rate, setting the top speed at 55 mph (88.5 km/h) in the process. And once the de-rated truck comes to a stop, the top speed will drop to 5 mph (8 km/h). The de-rated engines and 55 mph speeds will last a maximum of 1,000 miles (1,600 km) or 20 hours. Ironically, the SCR-equipped trucks used in Europe do not have this de-rating feature.

What if the tank is filled with something other than DEF, such as water?

Levels of NOx will be measured as gases enter and exit the system, so the equipment will be able to determine if the tank was filled with a bad fluid or water. If the levels of NOx are not dropping, the de-rating will occur.

How much will it cost?

Purchase prices have not been set, but suppliers at the Technology and Maintenance Council’s trade show suggest that the cost will probably be around $5 or $6 per US gallon.

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