DEF is made through a controlled manufacturing process that involves combining two main components: purified water and automotive-grade urea. Here is a general overview of how DEF is made:

Urea Production: Urea, the critical ingredient in DEF, is primarily derived from synthetic ammonia. Synthetic ammonia is produced by combining nitrogen and hydrogen under specific conditions. The ammonia is then reacted with carbon dioxide to produce urea.

Purified Water: High-quality, purified water is an essential component of DEF. It goes through a rigorous purification process to remove impurities, minerals, and contaminants, ensuring that the water used in DEF manufacturing meets the required standards.

Mixing and Quality Control: The urea and purified water are mixed in precise proportions to achieve the desired concentration of urea in the DEF solution. During this process, the mixture is carefully controlled during this process to ensure the correct urea-to-water ratio is maintained.

Filtration and Quality Assurance: The DEF mixture goes through filtration to remove any particles or impurities that might affect its quality. Additionally, manufacturers perform quality assurance tests to verify that the DEF meets the specified standards, including the ISO 22241 standard for DEF purity and composition.

Packaging: Once the DEF has been manufactured and quality checked, it is packaged into various container sizes for distribution and sale. These containers range from small bottles or jugs for individual use to larger drums, totes, or bulk storage tanks for commercial and industrial applications.

It’s important to note that DEF production follows strict guidelines and quality control measures to ensure its effectiveness and compliance with industry standards. Manufacturers adhere to specific regulations, such as ISO 22241, to maintain consistent quality and guarantee that the DEF meets the required specifications for use in SCR systems of diesel engines.

Selective Catalytic Reduction (SCR) is an advanced emissions control technology used in diesel vehicles to reduce nitrogen oxide (NOx) emissions. It is an after-treatment system that works in conjunction with the diesel engine’s exhaust system.

Here’s how Selective Catalytic Reduction (SCR) works in diesel vehicles:

1. Injection of DEF: Diesel Exhaust Fluid (DEF) is injected into the exhaust stream of the vehicle. DEF is a mixture of urea and deionized water.
2. DEF and NOx Reaction: The DEF, when heated, breaks down into ammonia (NH3) and carbon dioxide (CO2). The hot exhaust gases containing NOx pass through a catalytic converter, where the ammonia reacts with the NOx in the presence of a catalyst (typically made of platinum or palladium). This chemical reaction converts the NOx into nitrogen (N2) and water vapor (H2O).
3. SCR Catalyst: The SCR catalyst is the component where the chemical reaction between the ammonia from the DEF and the NOx takes place. It is located in the exhaust system after the diesel particulate filter (DPF) or other exhaust treatment devices.
4. Control System: An electronic control system monitors various factors such as exhaust gas temperature, NOx levels, and DEF injection rate. It adjusts the DEF dosing rate to optimize the conversion of NOx into nitrogen and water, ensuring effective emissions reduction.
5. Additional Components: The SCR system also includes components such as DEF storage tanks, dosing modules, pumps, and sensors to manage the injection of DEF into the exhaust stream accurately.