DPF-FAP-GPF-SCR-CAT

Our offer includes chemical cleaning of particulate filters for use in diesel (DPF/FAP) and petrol (GPF) vehicles, as well as trifunctional catalytic converters and SCR catalysts. We deal with structures used in passenger and commercial vehicles as well as trucks, commercial vehicles and buses. DPF cleaning is carried out in a purpose-designed machine according to an appropriately developed method that is safe for the cleaned catalytic converter or filter. In the event of mechanical damage to the inside of the filter or catalytic converter, we are usually able to propose its regeneration, which involves replacing the filter element.

Genesis and application.

The history of exhaust gases aftertreatment systems in automobiles is a long one, linked to increasing environmental awareness and regulations that aimed to reduce air pollution.

In the 1960s, the problem of air pollution caused by cars began to receive attention in the United States. California, especially Los Angeles, had serious smog problems. In 1966, California introduced the first regulations to control car emissions. This was followed in 1970 by federal emission regulations under the Clean Air Act.

First trifunctional catalysts emerged in the 1970s, mainly in response to tighter emissions regulations in the USA. Trifunctional catalysts were able to reduce three main pollutants: nitrogen oxides (NOx), carbon monoxide (CO) and hydrocarbons (HC).

In the 1980s, a more advanced emission control systemssuch as exhaust gas recirculation (EGR), fuel injection and oxygen sensors (lambda probes), which improved the efficiency of catalytic converters. European countries also began to introduce their emission regulations, such as Euro 1 in 1992.

The 1990s were a period of further tightening of emission standards in both the USA and Europe. Euro 2 (1996), Euro 3 (2000) and Euro 4 (2005) standards were introduced, which required increasingly advanced flue gas cleaning technologies, including the use of oxidation catalysts and diesel particulate filters (DPF/FAP) in diesel cars.

The increased popularity of diesel cars has necessitated the introduction of new flue gas cleaning technologiessuch as selective catalytic reduction (SCR) systems, which use AdBlue® (aqueous urea solution) to reduce NOx. It has also introduced particulate filters GPFs, which are used in petrol engine cars. Today's regulations, such as Euro 6d standards in Europe, require the use of even more advanced exhaust after-treatment technologies, including a combination of SCR catalysts, DPF/FAP filters and ammonia (NH3) neutralisation systems.

Construction and principle of operation.

Three-way catalytic converter and oxidation catalytic converter.

The three-function catalytic converter (also known as a three-way catalyst or catalytic reactor) is one of the most important components in a system of exhaust gas cleaning in modern cars with petrol engines. Its job is to convert the three main harmful substances produced during fuel combustion into less harmful compounds:

1. Nitrogen monoxide (NOx) - reduction to nitrogen (N2) and oxygen (O2)
2. Carbon monoxide (CO) - oxidation to carbon dioxide (CO2)
3. Hydrocarbons (HC) - oxidation to carbon dioxide (CO2) and water (H2O) 

The trifunctional catalytic converter consists of:

1. The core, made of ceramic or metal, has a honeycomb structure that provides a large contact surface for chemical reactions.
2. An active layer covering the core, consisting of precious metals such as platinum (Pt), palladium (Pd) and rhodium (Rh).
3. The housing - usually metal, which protects the catalytic converter and holds it in the correct position in the exhaust system.

For a trifunctional catalytic converter to work effectively, it must operate under certain conditions:

1. Temperature - The catalytic converter reaches its full efficiency at temperatures between approximately 250°C and 900°C. At too low a temperature, the chemical reactions do not proceed fast enough.
2. Composition of the air/fuel mixture - The optimum mixture composition (air/fuel ratio) is approximately 14.7:1 (stoichiometric ratio). Too rich a mixture (too much fuel) or too poor a mixture (too much air) can reduce the efficiency of the catalytic converter.
3. Oxygen sensors (lambda sensors) - Located upstream and downstream of the catalytic converter, it monitors the oxygen level in the exhaust gas, allowing the engine management system (ECU) to fine-tune the fuel-air mixture.

While trifunctional catalyst is used in the exhaust system of petrol engines, diesel engines usually have an oxidation catalyst. It oxidises carbon oxides and hydrocarbons, but lacks the ability to reduce NOx due to the fact that diesel engines run on lean mixtures.

Diesel particulate filters (DPF/FAP) and petrol engines (GPF).

Particulate filter (DPF - Diesel Particulate Filter) is a key component used in diesel cars to reduce particulate emissions, which are one of the main sources of air pollution. 

DPF is usually made of materials with a porous structure, such as silicon carbide (SiC) or cordierite. The structure of the filter resembles a honeycomb with inlet and outlet channels closed alternately, forcing the exhaust gases to pass through the porous walls of the filter. Particulate matter (soot, ash) is trapped on the porous walls and the rest of the exhaust gas escapes from the filter. As particulates build up inside the filter, the resistance to exhaust flow increases, leading to a decrease in engine performance. The engine controller monitors how full the particulate filter is by, among other things, a differential pressure sensor, comparing the exhaust gas pressure upstream and downstream of the filter. When the programmed values are exceeded, it triggers procedures to help DPF cleaning (regeneration). Frequent driving over short distances prevents effective regeneration of the DPFwhich can result in it being overfilled and the engine not running properly.

Vehicle manufacturers use two main diesel particulate filter solutions:

• "dry" filters
• "wet" filters

'Dry' filter systems do not use any chemical additives and the increased flue gas temperature needed to regeneration of the particulate filter and emptying it of accumulated soot particles is achieved by procedures such as increase in fuel injection rate, injection delay, deactivation of the exhaust gas recirculation system, etc. Some manufacturers have also used solutions in the form of an additional injector mounted in the exhaust system, which feeds fuel directly into the exhaust stream upstream of the particulate filter during its regeneration phase.

Systems with a 'wet' filter use a special additive which, when added to the fuel, reduces the combustion temperature of the soot, allowing the process to take place DPF regeneration at a lower temperature. Soot accumulated in DPF normally requires a high temperature (around 600°C) for combustion. The additive lowers this temperature to around 450°C, making the regeneration process easier and faster, especially at lower engine speeds and temperatures. The fluid is stored in a special tank or reservoir in the car and automatically dosed into the fuel tank in small quantities. The engine management system (ECU) controls the dosage of the additive to ensure the correct amount in the fuel. When the fuel is burned in the engine, the cerium contained in the additive remains as particles, which are captured by the DPF along with the soot. When cerium particles accumulate in the DPF filter, they reduce the temperature at which the soot starts to burn. Thanks to this regeneration of the particulate filter can occur effectively even during normal urban driving.

Today's vehicle manufacturers are striving for the most efficient yet compact exhaust aftertreatment system possible. The result is SCR-coated particulate filter designs that combine the functions of two components - the DPF i SCR catalytic converter.

The particulate filter (GPF) is also used in petrol engine cars, especially those with direct injection. This is because these engines emit higher levels of particulate matter compared to traditional indirect-injection engines. Many countries, especially in the European Union, have increasingly stringent emission standards, such as Euro 6. These standards require vehicles to emit less particulate matter, forcing manufacturers to use technology such as GPF to meet these standards. GPF is designed to effectively capture these particles, reducing PM emissions from the exhaust system. As in DPF, the exhaust gases flow through the filter and the particles are retained on its porous walls. In contrast to DPF filters, the GPF poses fewer problems because the exhaust gas temperature in petrol engines is usually higher. Regeneration of particulate filter involves the combustion of accumulated soot particles, which takes place automatically during normal engine operation, particularly at higher loads and temperatures. 

SCR catalytic converters.

It is a key component of the Selective Catalytic Reduction (SCR) system, where chemical reactions take place to convert NOx into nitrogen (N2) and water (H2O). This is made possible by dosing the exhaust gas stream with pre SCR catalytic converter a special reducing agent such as aqueous urea solution (AdBlue®). There is often a special mixer (blender) in the exhaust system upstream of the SCR catalytic converter, which is used to mix the injected additive thoroughly and evenly into the exhaust gas.

Its structure is similar to that of a trifunctional or oxidation catalyst. SCR catalytic converter has a core of ceramic or metal honeycomb material coated with a catalytic coating. It contains compounds such as metal oxides (e.g. aluminium oxide, titanium oxide) and precious metals (e.g. platinum, palladium).

What is particulate filter regeneration?

Our service consists of chemical cleaning of DPF, particulate filters and catalytic converters by a safe, fast and effective method. The filter, which has been removed from the vehicle, undergoes a cleaning process using chemicals and a water jet at the appropriate temperature and pressure. This removes all PM10 particles, oil and cerium deposits (in the case of 'wet' filters). This is a very effective method, which does not pose the risk of damaging the filter cartridge (as can happen with cleaning methods based on high temperature). This method guarantees that the filter performance is restored to a level even 98% without any interference with its structure. The device allows the flow level through the filter to be measured before and after the cycle. DPF cleaning and printing out the results of these trials, allowing the effectiveness of the process to be clearly assessed.

This method cleaning of the particulate filter compared to so-called service remanufacturing shows a number of advantages:

• no increased mechanical load on the engine due to high speed operation during the service regeneration process
• no increased heat load on components in the exhaust system (turbocharger, catalytic converter, particulate filter core)
• no need to change the engine oil, which is required after service regeneration

The only condition for the process cleaning of DPF is the absence of mechanical damage, particularly to the filter core. Every filter we accept undergoes a thorough condition check and a visual inspection of the filter cartridge carried out using an endoscopic camera. If mechanical damage to the inside of the filter or catalytic converter is found, we are often able to offer a regeneration of the particulate filterby replacing the filter cartridge.

Causes and types of damage

Symptoms of a damaged or clogged particulate filter/catalytic converter:

1. Decrease in engine performance
2. Uneven engine running at low revs
3. Increased fuel consumption
4. Engine ("check engine") or filter (DPF/SCR) light on
5. Smoke from the exhaust system

The most common particulate filter/catalytic converter failures:

1. DPF contamination - leaks of engine oil, coolant, excessive saturation of the particle filter with soot or ash
2. Overheating - abnormal combustion of fuel, malfunction of injection system, exhaust gas recirculation, engine tuning, etc.
3. Mechanical damage to the core - exposure to heat, thermal shock, impacts, vibration.

Opt for professional filter cleaning and regeneration

Don't wait until your vehicle goes into breakdown mode or a costly filter replacement occurs. Professional cleaning of DPF-FAP-GPF-SCR-CAT filters and effective regeneration of the particulate filter at Turbo-Tec is the solution to restore efficiency even in the 98% - quickly, safely and fully in line with the manufacturer's technology.Contact us to arrange a DPF cleaning - regain engine power, lower combustion and the confidence that your car will stay running for miles to come.