Mercedes Mullins
Diesel exhaust fluid (DEF) is a liquid used to reduce air pollution created by diesel engines. It is a 32.5% solution of urea and 67.5% deionized water. DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in the diesel exhaust emissions. DEF is offered to consumers in a variety of quantities and is often sold under the trademarked name AdBlue. DEF tanks are now a common feature in heavy-duty trucks and buses, and some countries like South Korea have made it mandatory for diesel cars to use urea solutions to control emissions.
| Characteristics | Values |
|---|---|
| Full form | DEF (Diesel Exhaust Fluid) |
| Other Names | AUS 32, AdBlue, BlueDEF, BlueHDI, BlueTec, FLENDS |
| Composition | 32.5% urea and 67.5% deionized water |
| Function | Reduces air pollution created by a diesel engine |
| Use | Injected into the diesel exhaust stream |
| Usage | Depends on the specific after-treatment system, typically 2-6% of diesel consumption volume |
| Storage | Stored in a separate DEF tank from the diesel fuel tank |
| Refilling | Needs to be refilled regularly, at similar intervals as diesel fuel |
| Temperature | Freezes at −11 °C (12 °F) |
| Standards | ISO 22241, published by the International Organization for Standardization |
| Related Programs | API Diesel Exhaust Fluid (DEF) Certification Program, Marine Diesel Exhaust Fluid Certification Program |
Explore related products
What You'll Learn
Diesel exhaust fluid (DEF) is a liquid used to reduce air pollution
Diesel exhaust fluid (DEF), also known as AUS 32 and sometimes marketed as AdBlue, is a liquid used to reduce air pollution from diesel engines. It is a 32.5% solution of urea and 67.5% deionized water. DEF is consumed in a selective catalytic reduction (SCR) system, which lowers the concentration of nitrogen oxides (NOx) in diesel exhaust emissions.
The SCR system mixes urea (DEF) and diesel exhaust over a catalyst bed inside the exhaust system. This process reduces NOx emissions into harmless nitrogen and water before they exit the tailpipe. DEF is injected into the hot exhaust gas stream, where the water evaporates and the urea thermally decomposes to form ammonia and isocyanic acid. The specific chemical reactions that occur depend on the presence of NO or NO2, and the temperature of the exhaust gas.
DEF is offered to consumers in various quantities, from containers for single or small usage to bulk carriers for larger demands. DEF tanks are designed to accommodate the vehicle's diesel fuel consumption, ensuring that both the diesel and DEF tanks are refilled at similar intervals. Commercial vehicles, such as trucks and buses, tend to have larger DEF tanks to cater to their higher fuel consumption rates and longer distances between refills.
The proper functioning of the SCR system and compliance with environmental standards depend on regularly refilling the DEF tank. If the DEF tank is empty, the SCR system will not be able to convert harmful NOx emissions into less toxic substances, potentially affecting the vehicle's performance and ability to meet emissions regulations.
Diesel Fuel Octane Ratings: What You Need to Know
You may want to see also
Explore related products
DEF is a 32.5% solution of urea and 67.5% deionized water
Diesel Exhaust Fluid (DEF) is an aqueous urea solution made with 32.5% urea and 67.5% deionized water. It is a liquid used to reduce the amount of air pollution created by a diesel engine.
DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in the diesel exhaust emissions from a diesel engine. In this process, the urea breaks down into ammonia, and the SCR process then converts nitrogen oxides into nitrogen, water, and small amounts of carbon dioxide – all of which are harmless emissions.
DEF is injected into the hot exhaust gas stream, where the water evaporates and the urea thermally decomposes to form ammonia (NH3) and isocyanic acid (HNCO). The highest conversion rates are achieved when equal amounts of NO and NO2 are present, especially at temperatures between 200°C and 350°C.
DEF is offered to consumers in various quantities, from containers for single or repeated small usage to bulk carriers for large-scale consumers. DEF tanks are designed to match the vehicle's diesel fuel consumption, with larger tanks for commercial vehicles like trucks and buses.
DEF is essential for vehicles with SCR systems to meet emissions regulations and maintain performance. It is also known as AUS 32 and sometimes marketed as AdBlue.
Poison Ivy Problems? Try Diesel Fuel
You may want to see also
Explore related products
DEF tanks are separate from diesel tanks and need regular refilling
Diesel Exhaust Fluid (DEF) is a liquid used to reduce the amount of air pollution created by a diesel engine. It is a 32.5% solution of urea, with the remaining 67.5% being deionized water. DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in the diesel exhaust emissions from a diesel engine.
The frequency of refilling a DEF tank depends on several factors, including tank size, engine efficiency, driving conditions, and load. On average, DEF consumption is around 2-4% of diesel fuel consumption. Heavy-duty trucks and commercial vehicles with larger engines tend to use more DEF due to their higher diesel fuel consumption. Smaller vehicles with diesel engines will need DEF added less frequently.
It is essential to keep the DEF tank regularly filled to ensure the SCR system works effectively and complies with environmental standards. If the DEF tank is empty, the SCR system will not be able to convert harmful nitrogen oxides (NOx) into less toxic substances, and the vehicle may fail to meet emissions regulations.
To avoid running out of DEF, drivers should monitor DEF levels and refill the tank before it runs empty. Warning messages or indicators on the vehicle's dashboard will typically notify drivers when DEF levels are low.
How to Decarbonize Diesel Fuel?
You may want to see also
Explore related products
DEF is offered in various quantities, from small containers to bulk carriers
Diesel Exhaust Fluid (DEF) is offered in a variety of quantities, catering to diverse consumer needs. It is available in small containers for single or repeated usage, making it convenient for those who require DEF in smaller amounts. This option is particularly useful for drivers who need to top up their DEF tanks periodically to ensure the proper functioning of their Selective Catalytic Reduction (SCR) systems.
For larger demands, DEF is also offered in bulk carriers. This option is ideal for consumers who require a substantial quantity of DEF, such as commercial vehicles like heavy-duty trucks and buses. The availability of bulk carriers ensures that these high-consumption vehicles can efficiently meet their DEF needs without frequent refills. The design of DEF tanks in such vehicles also accommodates their higher fuel consumption rates, with capacities tailored to match their diesel fuel consumption.
The accessibility of DEF in various quantities enhances its usability and ensures that consumers can acquire it based on their specific requirements. The option of small containers provides convenience and portability, while bulk carriers offer a cost-effective and time-saving solution for those needing larger amounts. This flexibility in packaging and distribution allows DEF to cater to a diverse range of consumers, from individual drivers to commercial fleets.
The distribution of DEF has evolved to include pumps at truck stops and fuel stations, making it more accessible to drivers. In Europe, the emergence of pumped dispensers at fuel stations has provided a sustainable alternative to disposable, single-use plastic containers. This distribution model targets commercial vehicles but is also becoming a solution for passenger cars requiring DEF by volume. The integration of DEF pumps adjacent to fuel pumps allows drivers to fill both tanks without moving their trucks, streamlining the refuelling process.
Additionally, companies like Fuel Logic in the United States offer specialised DEF delivery services. They provide bulk DEF fluid delivery, tank refill, and fleet monitoring solutions, adapting to the unique needs of businesses. With the option of 24/7 delivery, consumers can rely on a consistent supply of DEF to meet their diesel exhaust fluid requirements, ensuring the proper functioning of their vehicles and compliance with environmental standards.
Hydraulic Hoses and Diesel Fuel: A Safe Mix?
You may want to see also
Explore related products
DEF freezes at −11 °C (12 °F)
Diesel Exhaust Fluid (DEF) is an aqueous urea solution made with 32.5% urea and 67.5% deionized water. It is used to reduce the amount of air pollution created by a diesel engine. DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in the diesel exhaust emissions from a diesel engine.
DEF is offered to consumers in a variety of quantities, ranging from containers for single or repeated small usage to bulk carriers for consumers requiring large amounts of DEF. Commercial vehicles, such as heavy-duty trucks and buses, tend to have larger DEF tanks to accommodate their higher fuel consumption rates and longer distances between refills.
In 2015, South Korea mandated that diesel cars use urea solutions to control emissions, impacting 40% of registered vehicles. This led to a DEF shortage in 2021, causing havoc to the country's economy.
Fueling Your Jeep Grand Cherokee: Diesel Edition
You may want to see also
Frequently asked questions
Diesel exhaust fuel (DEF) is a liquid used to reduce the amount of air pollution created by a diesel engine.
DEF is a 32.5% solution of urea and 67.5% deionized water.
DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in the diesel exhaust emissions from a diesel engine.
DEF is offered to consumers in a variety of quantities, ranging from containers for single or repeated small usage to bulk carriers for those who require larger amounts. Many truck stops have DEF pumps adjacent to fuel pumps.
