Additivo per il sistema di Riduzione Catalitica Selettiva (SCR)
Unione Europea - Euro 4 y Euro 5
L' Unione Europea sforzando per limitare il problema d' inquinamento ambientale, ha stabilito da ottobre 2006 la legislazione-conosciuta come euro 4-che permette le emissioni di NOx fino a 3,5 gr/kWh. La seguente direttiva - conosciuta come euro 5- che deve essere adatta non oltre da ottobre 2009, permette le emissioni di NOx fino a 2,0 gr/kWh. Le industrie automobilistiche hanno scelto la soluzione di Riduzione Catalitica Selettiva (SCR). Il vantaggio principale della tecnologia SCR é la riduzione delle emissioni degli ossidi di azoto NOx a 90%- Idrocarboni HC e Monossido di carbonio CO at 50-90% - PM at 30-50%.
. Come Riduzione Catalitica Selettiva (SCR) funziona
Questo metodo combina la combustione ottimizzata del motore in collaborazione con un sistema di trattamento finale delle emissioni di gas di scarico, con lo scopo la riduzione dei livelli dell´emissione del´ossidio di azoto (NOx). Il fattore fondamentale della procedura é il uso di AdBlue. Questa diluizione si spruzza nel tubo di scarico prima di arrivare al catalizzatore. L' alta temperatura che si produce a quel punto converte AdBlue in ammoniaca. Poi, mentre l' ammoniaca e i nocivi ossidi di azoto attraversano il catalizzatore, reagiscono tra di loro e si convertono in azoto e in vapori acquei, due elementi che non sono nocivi per l' atmosfera. Per soddisfare la legislazione corrente - conosciuta come euro 4- il additivo deve essere 3-4% della quantitá di combustibile e per la direttiva euro 5 é 5-7%
É importante riferirsi alla qualitá di AdBlue che deve essere alta. Il uso di un additivo che non soddisfa le esigenze delle norme DIN 70070 and ISO 22241 causerá vari problemi che possono cominciare con l' aumento di emissioni di gas di scarico e fino alla destruzione totale del catalizzatore. Causerá anche vari problemi al motore a causa della pressione aumentata dei emissioni di gas siccome non possono rimuovere correttamente dal catalizzatore. Ciò accade a causa della bassa qualitá di AdBlue che riduce la dimensione di pori del catalizzatore e disattiva gli elementi catalitichi nell' interno.
Voulis Chemicals é disponibile per fornire AdBlue di alta qualitá e per qualsiasi informazione specializzata che puó volere.
AdBlue is a non-toxic urea solution used to chemically reduce NOx-emission from heavy-duty diesel powered vehicles. AdBlue is neither explosive nor harmful to the environment and is classified under the minimum-risk category of transportable fluids. Since AdBlue is corrosive, certain materials are required for its handling and storage.
All major trucks and buses manufacturers in Europe has models that require AdBlue. More specific AdBlue is stored in a separate tank and it is not mixed with diesel or other kind of fuel. Its use is made through a system which is called SCR Selective Catalytic Reduction .
It is very important Ad Blue to fulfill those standards in order to achive a good function of SCR system.
AdBlue® is a registered trademark owned by the VDA (Verband der Automobilindustrie) and is used under license.
- AdBlue is non-toxic and poses no serious risk to humans, animals or the environment if properly handled. The product is slightly alkaline with a pH of approximately 9.0 so should not be kept in contact with aluminum, brass, mild steel. Stainless steel and plastic tanks and fittings are recommended.
- The personal precautions when dealing with AdBlue include to avoid contact with skin and eyes. Also if it is spilled on the floor it causes a slipping hazard.
- The methods for cleaning up are to take up mechanically and collect in suitable container for disposal. Dispose of in compliance with local and national regulations. After cleaning, flush away traces with water.
- AdBlue is not flammable.
- Freezing of AdBlue starts at minus 11.5 °C
- AdBlue can be used once it has frozen. Once AdBlue has melted, it can be used without problems.
- The best way to remove crystallisation or spillage is to rinse with water. When you rinse with water be sure that the is well sealed in order to prevent any contamination of the dilution.
- If AdBlue liquid is spilled on automotive paint you should rinse the surface with water and cleaned from paint. In case AdBlue is left to dry and crystallise on the paint, surface corrosion might take place.
The manufacturer has studied the catalyst to accept fumes of different types with heavier elements. As a result if someone does not use AdBlue the engine needs higher mechanical energy in order for the fumes to pass another type of hives of the catalyst. This practically means:
- higher fuel consumption 5-7%, thus higher financial expense.
- quick damage of the catalyst because of blocked hives.
- loss on the "best function" and performance of the engine
- higher burden on the atmosphere.
- expensive fines in case of fume measurement.
European Union in its effort to reduce the environmental pollution caused by heavy vehicles established certain rules about the vehicle's emissions. All vehicle manufacturers already meet those requirements. Starting October 2006 the legislation - known as euro 4 - permits NOx emissions up to 3.5 gr/kWh.
Next directice -known as euro 5 - that the vehicle manufacturers should comply with the latest in October 2009 regulates emissions NOx at 2.0 grKh.
In the table below you can see the emission standards for both euro 4 and euro 5.
EURO Emission standard (g/kWh)
|EURO 4||EURO 5|
This method combines the optimized combustion of the engine in with a system of treatment the exhaust emissions, aiming the reduction of the level of pollutant emissions such as oxide of nitrogen (NOx).The basic factor of the procedure is the use of AdBlue®.
This dilution is sprayed in the exhausts before they reach the catalyst. The high temperature which occurs at that point converts AdBlue® into ammonia. Then; while ammonia and the inimical oxides of nitrogen pass through the catalyst, reacts with each other and converts into nitrogen and water vapours, two elements that are not harmful for the atmosphere.
The cost of AdBlue® varies depends on many factors. One of them is them is the quantity (10lt pot / 210lt barrel / 1000lt tank or bulk in fuel stations).
Also since the raw material needs a great amounts of energy in order to be produced ; the price of AdBlue® is relevant to the energy's cost globally.
According to the manufacturers ; vehicles that use the SCR system have fuel saving up to 6% in comparison with those vehicles which don't use AdBlue®.
So vehicles that use AdBlue® more less have the same expense to those which don't use the SCR system.
Regarding the quantity of AdBlue® which is required in SCR system, it varies according to the requirements we want to meet. Thus, in order to meet the current legislation - known as euro 4- the additive should be 3-4 % of the quantity of fuel and for the euro 5 requirements it is 5-7 %.
This is particularly positive method because the same method can meet future regulations without the need of any other expense for converting the engine.
It is important to refer to the AdBlue®’s quality, which should be high. The use of an additive that does not meet the requirements of DIN 70070 will cause various problems that may start from increased emission of exhausts and result in the total destruction of the catalyst.
It can also cause various problems to the engine due to the increased pressure of exhaust fumes since they can not removed correctly on time from the catalyst. This is a result of the low quality of AdBlue® that reduces the size of the catalyst’s pores and deactivates the catalytic elements in the internal.
The basic advantage of SCR technology is the reduction of of emissions of Oxides of Nitrogen NOx at 90% while at the same time it decreases the pollutants of Hydrocarbons HC and Monoxide of coil Coat 50-90% as well as PM at 30-50%.
Furthermore, Selective Reduction System (SCR) presents additional advantages .It requires minimum and low maintenance cost; it does not influence the rest vehicle's parts and the service periods. Last but not least, the the SCR system is less sensitive in low quality diesel fuel than the other methods which are proposed in order to fulfill the euro 4 & 5 directives.
Also the manufacturers managed to increase the engines' efficiency of the vehicles that use the SCR system in that way so they have around 5% fuel economy.
- Storage temperature should not exceed 30 °C. In case you exceed that temperature for long the product will cause hydrolysis to occur, reducing the strength and shelf life of AdBlue®
- The life time of AdBlue is at minimum 12 months.
- Storage temperature should not be less than -11 °C to avoid crystallisation.
- Sun light protection (to avoid growth of algae)
- Well designed closed containments to protect the containment as well as the solution from any contamination.
AdBlue® is offered in:
- 10 litres pots
- 210 Litres drums
- 1.000 litres tanks
- bulk in fuel stations
You may find AdBlue in almost all fuel stations located on the European-including Greek- highways.
Also in many fuel stations located in district streets.
In case you need an advice about finding a fuel station in a surtain area please contact us through e-mail.
Biodiesel and SCR are compatible even if 100% Biodiesel is used. Of course it is important that the truck manufacturer to allow the use of biodiesel.
Using biodiesel the exhaust gas emissions contains more NOx and the AdBlue® consumption of the SCR equipment will be slightly higher. So AdBlue®'s consumption might be increased in order to accomplish the euro 4 & 5 standards.
Advantages of the SCR technology over the EGR
- The SCR system does not affect the frequency and the cost of services, unlike the EGR system that has additional maintenance costs. More frequent oil and filters changing whilst the oil required for the EGR technology is of high quality which means high price compared to the SCR technology.
- Reduced fuel consumption. A vehicle with the SCR system and fuel discharge EURO 4 has a 2-3% less than an equivalent vehicle of EURO 3 specifications and 4-8% compared to the EGRn system.
- The SCR system allows the engine to work free without choke setting unlike the EGR and the engine is not in danger of damages due to the circulation of cold fumes, a fact very likely to happen in the EGR system.
- The transform into EURO 2 is manageable in case someone wants to sell it as a used vehicle.
In order to meet the requirments they chose 2 systems:
- SCR (Selective Catalytic Reduction)
- EGR ( Exhaust Gas Recirculation )
EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders.
Because in surtain countries and especially in Asia and Africa the availability of AdBlue is too low.
Yet, all truck manufacturers admit that SCR system is more simple,with less fuel consumption and it is a better choice for a new truck possible buyer.