Green Technology - SCR - The Benefits of DEF
Because SCR uses diesel exhaust fluid (DEF), we are able to avoid the disadvantages associated with increasing EGR to the extreme levels necessary to meet the EPA requirement of near-zero NOx emissions (0.2g/bhp-hr).
DEF is an aqueous solution of 32.5% urea and 67.5% de-ionized water. It is clear, non-toxic, biodegradable and non-flammable. What's the big advantage of DEF? Maximized fuel efficiency. The higher oxygen levels DEF provides offer more efficient combustion resulting in clean nitrogen and water emissions.
Fast facts about DEF
- Non-toxic, biodegradable and non-flammable
- A 32.5% urea solution
- DEF freezes at 12° Fahrenheit
- DEF is not damaged when frozen and is usable when thawed
- Vehicle is fully operational when DEF is frozen
- Weight: 9.21 lbs. per gallon
- Shelf life: approximately 6-18 months depending on storage temperature
- DEF is expected to cost the same as diesel fuel
- You will use approximately 2 gallons of DEF for every 100 gallons of diesel fuel
- Container sizes include 2.5-gallon, 55-gallon tote, 275-gallon tote and bulk
- Bus will not shut down if DEF tank is empty
- Available from your local Thomas or Cummins dealer, truck stops and the same distribution channel where you buy other shop fluids
