AD BLUE

AD BLUE
As global concerns for environment deepen, the motoring industry is taking more steps to ensure that new cars are producing cleaner emissions. For diesel vehicles, the introduction of AdBlue has been commonplace, with many manufacturers equipping their newer models with systems that use the fluid to produce less harmful emissions.
If you have recently bought new diesel vehicles for your fleet, you may well have noticed the presence of a smaller blue or black cap adjacent to the main fuel cap — this is for AdBlue. This product is set to play a big part in the greener future of the industry, so it is important that you know what it is and what you need to do with it.

What is AdBlue?
AdBlue is a colourless liquid that is made from a mixture of high-purity urea (32.5%) and deionized water (67.5%). The solution is an essential component of selective catalytic reduction (SCR) technology, which is one of the most effective systems for reducing the nitrogen oxide (NOx) levels in the exhaust fumes that are outputted by diesel engines. NOx is one of the most harmful pollutants emitted by engines, as it reacts with other gases in the atmosphere to form small particles and ozone, both of which can damage sensitive lung tissue in humans and animals.
When the fuel is burned by the engine, AdBlue is injected into the SCR catalyst in order to convert the NOx into a less harmful mixture of nitrogen and water vapour. The solution is stored in its own tank, separate from the diesel, before being added to outgoing exhaust gas by a dosing control system that supplies enough AdBlue to make up 2–6% of the total fuel consumption. In the SCR catalytic converter, the urea present becomes ammonia when heated, reacting with the NOx in the emissions to convert the pollutants into nitrogen, water, and a small amount of carbon dioxide —elements that are already natural to the air that we breathe.

Is AdBlue a fuel or fuel additive?
AdBlue is not a fuel itself or a fuel additive: it has its own tank and is stored completely separately to your vehicle’s fuel. It works as part of a selective catalytic reduction system (SCR), which you can see in the diagram below:

Why is AdBlue so important?
As AdBlue is one of the most efficient ways of keeping the NOx levels in fuel emissions to a minimum, it has an incredibly important role to play in the future of diesel vehicles. SCR technology was first prescribed for diesel truck engines that had to meet the requirements of the fuel legislation, which was introduced by the European Union (EU) through a series of directives. These directives aim to define acceptable levels for exhaust emissions in new vehicles produced within the EU and European Economic Area (EEA) member states.
The newest EU standard for cars and light commercial vehicles is Euro 6, which was introduced for new type approvals in September 2014 and for all new cars in September 2015. Heavy-duty vehicles like trucks and buses have their own standards, with the latest being Euro VI, first enacted in December 2013. Both of these regulations have even more ambitious targets for keeping exhaust emission levels low in both petrol and diesel vehicles.
Within the dual standards system, there are categories for different sizes, where larger vehicles, like buses and trucks, are allowed a larger output of NOx than cars and light commercial vehicles. The Euro 6/Euro VI diesel standard NOx limits are as follows:

How long does a tank of AdBlue last?
The length of time that a full tank of AdBlue will last depends on a number of factors, including what type of vehicle you are driving, your driving style, the length and type of journey, road and weather conditions, and how heavy the load is you are moving. As it is a legal requirement that all diesel emissions must meet the Euro 6 limits, every time you burn any fuel you will be outputting fumes, and therefore AdBlue will be used.
Obviously, if you undertake regular lengthy journeys with your vehicle, such as those undertaken by a long-haul truck driver, you will need to refill your AdBlue a lot more regularly than someone who drives a diesel car just at the weekends. You can conserve your levels by practising efficient driving, which will make sure that you burn through less fuel and less AdBlue.
Your AdBlue should last for at least a few refills of diesel, as only a small amount is injected into your exhaust system compared to the amount of fuel used. After a period of typical use, you should be able to anticipate when you might be in need of a top-up.

How much AdBlue do I need?
When the time comes to refill your AdBlue, the amount that you need will depend on the type of vehicle you are driving. Large trucks and coaches will have a much larger capacity than passenger cars to accommodate the larger volumes of the solution that will be used. If you are only running a car, then a standard 10L pack which can be found at most forecourts will be enough to refill to a comfortable level. A larger vehicle with a bigger tank will require several smaller packs or a larger volume from a barrel, IBC or AdBlue dispensing system.
It is also worth bearing in mind that if you are caught in a pinch with no AdBlue, most vehicles require a minimum amount to be refilled before the engine will function again — consult your owner’s manual or check with your manufacturer for more information.

How can I estimate how much AdBlue I need for my fleet?
When it comes to estimating the amount of AdBlue you will need for a fleet of vehicles, you will have to consider factors like:

• how far each vehicle will travel,
• the fuel economy for each vehicle,
• how many vehicles are in your fleet, and
• your vehicles’ AdBlue consumption rate.

AdBlue consumption is usually between 2–6% for most vehicles, with diesel vans and lorries tending to inhabit the upper half of this range at 4–6%. Another way to picture this is that for every 100 gallons of fuel burned, 4–6 gallons of AdBlue will be used to reduce NOx levels in the emissions. It is possible to work out approximately how much AdBlue you will need to order for your fleet using a calculation similar to the one in the typical examples below.
Once you have the information about your vehicles and operations at hand, you should be able to work out your own estimation.

Short haul light commercial vehicle (< 3.5 tonnes)

Note: These are typical estimates only. Results will vary for different enterprises.

How do I check the AdBlue level in my vehicle?
Thankfully, most new vehicles will have a driver information system on board, which notifies you if there is a particular error or if you are running out of oils or fluids, including AdBlue. This system will usually give you a series of warnings as it becomes depleted, so it is important to get a refill as soon as you can. If you need to check the level of your AdBlue manually, check the owner’s documentation for guidance or contact the manufacturer for further advice.

What happens when my AdBlue runs out?
If you allow your supply of AdBlue to run out, your SCR system will not be able to function, which will lead to limited vehicle performance or your engine not running at all. As your vehicle has been manufactured to meet Euro 6 or VI standards, it is required by law to meet its acceptable emissions level at all times, even when your car has run out of AdBlue. This means that when your SCR system is not able to perform its task, it will prevent you from burning more fuel either by keeping your engine below the threshold or stopping it altogether. This failsafe is in place to protect both the driver and the environment.

How should I store AdBlue?
If you want to keep your own supply of AdBlue, you need to make sure it is kept in the right conditions to maintain its optimum condition. It needs to be kept out of direct sunlight, and between the temperatures of -6°C and 25°C. You should also ensure that the container in which you are storing it is clean and sealed to avoid any chance of contamination that could damage your SCR system upon use. Urea solutions are harmful to surface and groundwater, as well as having the ability to corrode metals like aluminium alloys, copper, bronze, and iron.
You need to make sure that your container, pipes, and dispensing equipment are all suitable for the storage of AdBlue:

• Only use storage containers that are high-density polyethylene, polypropylene or stainless steel.
• Polyisobutylene, free of additives, can be used for seals and hoses. PFA, PVDF and PTFE, also free of additives, can be used as sheet lining for chemical equipment and support rings, as well as seals.
• Additive-free copolymers of (P)VDF and HFP (viton) can be used for the insulation of wires, seals, and o-rings.
• Under no circumstances should you use corrosive metals, such as copper, nickel, zinc, or aluminium.

Does AdBlue have a shelf-life?
Provided that it is kept in the optimal conditions — out of direct sunlight and at a temperature between -6°C and 25°C — your AdBlue can last up to 18 months in storage. If you store it at a higher temperature than this or in a vented container, the shelf-life will only be around 6 months.

How can I keep my AdBlue clean and pure?
As we have discussed, allowing your AdBlue to become contaminated before putting it into your tank can have undesirable consequences for your vehicle’s SCR catalyst. Your solution also needs to be clean so that it can do its job — contaminated AdBlue can reduce its effectiveness at converting harmful emissions, increasing damage to the environment.
Take extra care when handling AdBlue, guarding against contamination at all times. There are many things that can get into your solution and cause problems, including fuel, oil, dirt, and dust, among many others. Try to keep the time that your AdBlue is directly exposed to the environment as short as possible to minimise the risk, and don’t allow anything in the container that shouldn’t be there. If you have to use another container or vessel to transfer the liquid to your vehicle, take extra care to ensure it is clean and has not been used for any other purpose. It is a good idea to keep a set of dedicated AdBlue equipment for this task.
When dispensing AdBlue, take extra care to put it into the right tank — it is not an additive to your fuel and has to be in its own tank to work. Before you begin filling up your vehicle, take a moment to check that the filling equipment you are using is in perfect working order and there are no signs that the solution within has been compromised. Watch out for signs of crystallisation, which can block nozzles on pumps and spouts on jerry cans, increasing the chances of spillage.
We strongly advise against using homemade AdBlue or a urea solution that does not have the AdBlue registered brand name. While the formula used to produce it is quite simple, the quality of the two ingredients is incredibly high. Very pure demineralised water is used alongside uncoated urea that is produced solely for the purpose of AdBlue. Other types of urea are often not up to the task and can cause damage to your SCR system, which can cost a lot of money to fix. In purchasing officially licensed AdBlue, you are also purchasing a product that has been tested and ratified for its exceptional quality.

What should I do if I put AdBlue into my diesel tank?
Firstly, do not start your vehicle, as this could cause damage to your fuel system. If you have put a large quantity of AdBlue into your tank, there is more chance that your vehicle’s fuel system will have suffered harm. Similar to putting petrol into your diesel vehicle, you will need to get the tank drained and dispose of the contents safely before you can refill it. Hopefully there is no lasting damage done, but if there is, you may have to contact your vehicle’s manufacturer to source replacement parts.

What should I do if I put diesel into my AdBlue tank?
The most important thing to remember if this happens is not to start your car. As we have established, diesel can have an undesirable effect on your SCR system, so putting any quantity of it into the tank could cause a lot of disruption. Switching on your engine will cause the diesel to run through the system, potentially compounding the damage. You will most likely need to have your AdBlue tank drained to solve the problem. If there is any lasting damage, you will have to get into touch with your manufacturer to find replacement AdBlue components.

Does AdBlue freeze?
Yes, but the freezing temperature is -11°C, and it won’t begin to freeze until -10°C. As the AdBlue tank on most vehicles is next to the exhaust, while the engine is running you shouldn’t have any problems. Vehicles that have the AdBlue tank situated elsewhere often have a system where it is heated with circulated engine coolant. Even if it does freeze, AdBlue will work perfectly well once it is thawed out.
Although temperatures rarely drop below -10°C in the UK, if you plan on driving your vehicle in a country where the climate regularly reaches this temperature or lower, it may be wise to take a couple of extra precautions:

• As liquid expands when frozen, leaving some extra room in your tank will give the AdBlue somewhere to expand. This means that if you are running low on the solution, it is better to refill the tank part of the way, rather than to the top.
• After nights where the temperature has been low, allow your vehicle’s engine to run for a few minutes to allow your AdBlue to warm up and thaw out.
• Keep any stored AdBlue in a location that is temperature regulated, instead of somewhere where the natural cold can freeze it. If you must keep it somewhere outdoors, you should allow space for freezing expansion in your tank or container.

Is AdBlue flammable or hazardous?
No, AdBlue is not flammable, nor is it considered a hazardous liquid. It is a water-based urea solution, and poses little risk to humans. If you have sensitive skin, it might be wise to wear gloves when handling the liquid to avoid any potential irritation.
You should avoid ingesting or inhaling AdBlue, as you may suffer from an allergic reaction. If you do get AdBlue in your mouth, rinse it out with water and take a few sips afterwards. Inhaling the fumes can sometimes leave some people light-headed, so if this happens, take a few moments to sit down and take in some fresh air while it passes. Eye contact can often cause discomfort — flush your eyes with water if this happens and seek medical attention if the irritation persists.

Where can I buy AdBlue?
If you usually pay for fixed-term servicing of your vehicle, then an AdBlue refill is often included as part of the maintenance. Should this not be the case or you find yourself running out between servicing, you should purchase it from an officially licensed vendor who is registered with the Verband der Automobilindustrie (VDA), the German Association of the Automobile Industry.
It is important to watch out for similarly branded products available for lower prices than officially branded AdBlue — they are often unlicensed and are not manufactured to the high standards of ISO 22241, which is issued by the International Standardisation Organisation (ISO).
Should you need AdBlue during a journey and you aren’t carrying any, you can often find vending pumps at service stations that allow you to refill as much or as little as you need to get on the road again. This option is convenient if you are making a one-off trip, however, if you are running a business that has multiple vehicles making regular journeys, it is definitely worth considering buying in bulk to enjoy the lower prices.