Diesel Exhaust Fluid (DEF) is a non-toxic mix of high-purity urea and deionized water. It’s used in Selective Catalytic Reduction (SCR) systems to reduce nitrogen oxide emissions from diesel engines.
DEF is critical for meeting emission regulations and keeping SCR systems working properly. This article covers DEF composition, how DEF manufacturing works, quality control, and proper handling procedures.
What’s in DEF?
DEF isn’t just anything you squirt into the tank of your diesel truck. It’s a carefully calibrated mixture of high-purity urea and deionized water.
Key components
- Urea concentration: DEF is made up of 32.5% high-purity urea and 67.5% deionized water.
- Purity: High purity is essential to prevent contamination, which can lower DEF’s effectiveness.
The Role of ISO 22241
ISO 22241 defines the quality standards DEF must meet, from manufacturing to handling, storage, and transportation.
How is DEF made?
DEF manufacturing is a precise process. Here’s a quick guide:
- Sourcing: High-purity urea and deionized water are essential. Both have to meet ISO 22241 standards.
- Mixing: The urea is dissolved in the deionized water. This takes specialized mixing tanks and blending systems. Automation helps make sure the mixture is always the same.
- Quality Control: The urea concentration and water purity get checked regularly. This ensures a high-quality product.
Maintaining DEF Quality: Filtration and Contamination Prevention
Filtering DEF is vital to keeping your SCR system working reliably and efficiently. DEF filters catch contaminants measured in microns, or μ.
Trace elements and improper handling can contaminate DEF, which can reduce its effectiveness and cause the SCR system to fail.
For these reasons, it’s important to use a high-quality DEF and follow best practices when handling it.
Storing DEF
DEF has to be handled carefully to avoid contamination and degradation.
Here are some tips for storing DEF:
- Use ISO-compliant containers, pumps, and tanks.
- Keep DEF in a cool, dry place, away from sunlight and extreme temperatures.
- Use airtight containers and clearly label everything.
Frequently Asked Questions
Why is there a DEF shortage?
DEF shortages have occurred primarily due to disruptions in the supply chain of key components, particularly ammonia and urea, which are essential for DEF production. Increased demand, coupled with production slowdowns and logistical challenges, can exacerbate these shortages. Geopolitical events and trade restrictions can also play a role.
Can I make my own DEF fluid?
While technically possible, it’s strongly discouraged to make your own DEF. DEF requires a precise mixture of high-purity urea and deionized water. Improper mixtures or the use of impure ingredients can damage your vehicle’s SCR system, leading to costly repairs. It’s always best to purchase DEF from a reputable supplier to ensure quality and compliance with industry standards.
Who is the largest manufacturer of DEF?
Identifying the single “largest” manufacturer of DEF can be difficult as market share fluctuates and companies operate globally. However, prominent DEF manufacturers include Yara International, CF Industries, and Koch Fertilizer, among others. These companies have significant production capacities and distribution networks.
How many miles will 1 gallon of DEF last?
DEF consumption varies depending on factors like engine size, driving conditions, and vehicle load. Generally, a light-duty diesel vehicle will use DEF at a rate of about 1-3% of fuel consumption. This translates to roughly 300-400 miles per gallon of DEF. Heavy-duty trucks may consume DEF at a higher rate.
The Bottom Line
If you operate diesel engines with SCR systems, you need DEF. It’s essential to carefully manufacture, handle, and store it according to ISO 22241. Proper filtration is also critical to DEF quality and preventing SCR system damage.