Diesel exhaust fluid (DEF) is an additive used in conjunction with a selective catalytic reduction (SCR) system. It helps reduce harmful pollutants omitted from diesel exhaust. When DEF is used with a SCR, it eliminates 94% of the pollutants identified as being the most hazardous. The two most offensive pollutants are particulate matter and nitrogen oxides.
- Particulate Matter (PM) – PM is the term for a mixture of solid particles and liquid droplets found in the air. EPA – Particulate Matter PM
- Nitrogen Oxides (NOx) – NOx is a generic term for the various nitrogen oxides produced during combustion. ScienceDaily
“On May 11, 2004, EPA signed the final rule introducing Tier 4 emission standards, which are phased-in over the period of 2008-2015.” DieselNet
Staying compliant with the environmental protection agency (EPA) and the Tier 4 Standards are critical for many industry companies to remain operational. The Tier 4 Standards include all off road vehicles as well as the semi-trucks used on everyday highways. By 2015, all vehicles will be required to be compliant with Tier 4 Standards. This means diesel engines will need to find a solution to omit these pollutants.
A lot of questions still remain regarding the new systems developed and how to manage the little things that can cause operational interruptions.
One of the newly identified problems is that DEF needs to be stored in a controlled environment. Many storage options are available including large underground tanks, IBC totes, and one-gallon containers. The shelf life of DEF should be around a year if it is stored between 12°F and 86°F.
Many environmental zones can drop several degrees below 12°F, which requires a solution for keeping DEF from freezing. Fortunately, there are companies who have had the insight and engineering expertise to tackle this problem and have come up with viable solutions.
A few of these companies are:
All of these companies have designed storage aids to prevent DEF from freezing and to promote the longevity of DEF shelf life.