FAQ

What is Diesel Exhaust Fluid (DEF)

• Diesel Exhaust Fluid (DEF) is a solution of 32.5% high-purity urea and 67.5% deionized water, used to reduce the amount of air pollution created by a diesel engine.
• It is a non-toxic, high quality and highly pure Aqueous Urea Solution that works with SCR (Selective Catalytic Reduction) technology to chemically change harmful nitrogen oxide (NOx) emissions from heavy-duty diesel vehicles into harmless nitrogen and water.
• Diesel exhaust fluid is a 32.5 % by weight solution of technically pure urea in deionized water. At this concentration the crystallization point reaches a minimum of minus 11°C (eutectic mixing ratio). High demands are made on the purity of the solution, not only during production, but also during handling, transportation and storage.
• Diesel exhaust fluid must be kept free of any metal ions (e.g., Na, K, Mg, Ca, Al and especially heavy metals), because their salts can clog the pores of the ceramic carrier material or poison the active centres of the catalyst thereby rendering it ineffective.
• The Diesel exhaust fluid confirms to the standard ISO 22241 (Part 1 to Part 4). Worldwide the same standard is being followed as far as this product is concerned.
• The quality of Urea used in production of Diesel exhaust fluid is highly pure and only M/s GNFC in India is allowed manufacture certain quantity of it. However, most of the Diesel exhaust fluid producers import the Technical Grade Urea from Abroad (China, Saudi Arabia and Taiwan etc.)

Brief description of the Diesel exhaust fluid (DEF) Manufacturing process :

• DEF production process involves dissolving solid urea in de-ionized water using mixing/blending units.
• While DEF production involves a simple blending process of technical grade urea (in crystals/pills) and DI water. Urea is 32.5% and balance DI water.
• Raw water from the storage tank is fed in to the De-Ionized plant/ unit. This can be an FRP/Sintex tanks of suitable capacity.
• The DI water this produced will be stored in DM water storage tanks.
• The DI water from the storage tank is fed in to a blending tank through on-line heating unit.
• Blending tank is a Stainless steel, conical bottom tank with agitator mounted.
• Urea stored in around 50kg-1000kg bags from the mezzanine floor is fed in to the blending tank in regulated proportion as per the blending process.
• 32.5% of Urea and balance DM water is mixed thoroughly in blending tank and blended until the desire quality of Diesel exhaust fluid product specifications are obtained. This blending process is an endo-thermic process and there will be amount of heat loss for the blended product.
• The blended Diesel exhaust fluid product, which is meeting the specifications is transferred in to the storage tanks
• From the storage tanks, the finished Diesel exhaust fluid product is taken to filling machines for filling in majorly following packs 10L, 20L pails, 210L barrels, 1000L IBC tanks, Bulk filling
• The packs thus filled will be stored in warehouse and then transported

Why should diesel exhaust fluid be tested to ISO 22241
ISO 22241-2 is the current used standard across Europe for AUS32 (chemical name for Diesel exhaust fluid). It is mandatory for new Diesel exhaust fluid to be tested to the specification to be sold as ISO 22241-2 compliant. The testing limits for ISO 22241-2 are as follows together when it is recommended to test for these parameters.

How much is the Diesel exhaust fluid consumption rate?
Diesel exhaust fluid consumption is expected to be approximately 4-6% of fuel consumption. It may vary depending on vehicle operation, duty cycle, geography, load ratings, etc

Are there any special storage requirements for Diesel exhaust fluid?

• Diesel exhaust fluid is corrosive in nature hence for storing do not use corrosive materials like copper, nickel, zinc, mild iron or aluminium.
• Do not use old diesel or oil containers or equipment to transfer Diesel exhaust fluid into the tank. Dedicated equipment should be used to handle Diesel exhaust fluid as even a small contamination of fuel/oil/lubricant can damage the SCR system of the vehicle.
• Dry, well-ventilated and properly covered area.
• Avoid direct sunlight
• Optimum storage temperature is 25 deg C (77 deg F), with temporary exposure to higher temperatures has little to no impact
• Being a corrosive liquid should only be stored in approved materials like high-density polyethylene (HDPE) or stainless steel
• Don't put Diesel exhaust fluid in packaging of plastics with additives or non-ferrous metals & their alloys and carbon steel.