New diesel engine standards call for reductions in particulate matter (PM) and nitrogen oxides (NOx) to near zero levels. Engine manufacturers have found solutions to these mandates in a variety of ways. One of the most common is the use of selective catalytic reduction (SCR) technology that utilizes diesel exhaust fluid (DEF). DEF is mixed with the exhaust in the presence of the SCR catalyst, changing the NOx into nitrogen and water that can be safely released into the atmosphere.
“DEF is an easy-to-use, non-hazardous fluid,” says Curt Dunafin, Manager, Energy Services at GROWMARK, “The challenge lies in properly handling and storing it. It is easy to contaminate, and impurities in DEF solution can cause premature failure of the catalyst in the SCR system, which can cost $15,000 to $20,000 to replace.”Dunafin provides these recommendations to avoid contamination of DEF.
Choose the right DEF supplier
As little as a tenth of a teaspoon of some minerals commonly found in dust, dirt, tap water, etc. are enough to contaminate an entire bulk storage tank of DEF. To prevent contamination, we recommend using a closed-loop system that provides evidence of tampering. For example, FS Member Cooperatives use Micro Matic dry disconnect couplers, which allow the storage tank and pumping system to be sealed off and protected.In addition to preventing contamination, FS Energy Specialists can also determine the right storage tank options for an operation’s size and DEF needs.
Store DEF properly to increase shelf life and prevent impurities
Storage life varies for DEF, but in proper conditions it can maintain quality up to 12 months. DEF should be:• Stored in stainless steel, coated carbon steel or specific high-density plastic containers, as DEF can corrode other materials and introduce contaminants• Kept in a temperature-controlled location and out of direct sunlightDEF is best stored between 12- and 86-degrees F (-11 and 30- degrees C). Since it is water based, DEF can freeze into a solid state. Freezing DEF has no effect on its quality or performance, but it can expand up to 7 percent when frozen. Dunafin cautions DEF users not to completely fill vehicle or storage tanks in freezing conditions. This allows for expansion, which prevents tanks from cracking.
Prevent contamination during DEF use
Do not use funnels, jugs or other equipment to fill tanks with DEF. Using funnels or jugs that have been used for other fluids or refilling previously used DEF containers will not maintain the pharmaceutical-grade purity needed in the SCR system. Additionally, don’t add any other fluids, including tap water, to DEF. Keep an eye on and change filters as needed. The injectors that meter DEF into exhaust are similar to fuel injectors.Each component of the dispensing system, including the tank, piping, pump, filter and filling stations must be used exclusively for DEF to prevent cross-contamination.
Use API licensed DEF
GROWMARK is an American Petroleum Institute licensee. The API DEF Certification Program is for suppliers who have demonstrated that their products meet the required specifications.“FS Energy Specialists not only make sure that you have the equipment you need, but we will also work with you to find the right type of DEF system for your operation,” says Dunafin. “Contaminated DEF can lead to expensive consequences, but it doesn’t have to be difficult to use. It’s all about finding the right system for your operation.”
Contact your local FS Energy Specialist today
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