What is the purpose of catalytic converter?
Exhausts of vehicles with internal combustion engines are include some harmful and toxic gases. The aim of the catalytic converter is to convert harmful exhaust gases coming from the exhaust to harmless.
In order to reduce these emissions, which are harmful to the environment and living things, boundary have been introduced by the law.
The two main emission standards accepted in the automotive industry in the world are the USA and European Emission Norms.
USA Emission Standards are the first exhaust emission norm applied in the world. Emission values are given in grams / mile.
European emission values are given in grams / km. Last manufactured vehicles are allowed to export to European countries if they meet the current euro standards, otherwise they are not allowed into the country.
Nowadays, European countries and the European emission norms in Turkey is taken as reference. To reduce harmful exhaust emissions, equipment such as Diesel Oxidation Catalyst (DOC), Catalytic Converter, Nitrogen Oxide Storage Catalyst, Diesel Particulate Filter (DPF) (Diesel) and SCR System (Diesel) are used in the exhaust line.
What are the different types of catalytic converter and for each one precious metals ?
1.Three-Way Catalytic Converter (Gasoline engine)
The catalytic converters used today are called three-way catalytic converters because they can convert three different exhaust gases (carbon monoxide, hydrocarbons and nitro oxide) to harmless. Unleaded fuel should be used, otherwise the lead will stick to the surface and block the holes.
Catalysts that accelerate chemical reactions in the catalytic converter are Platinum, Palladium, Iridium and Rhodium. Owing to platinum and rhodium, the emission of nitro oxide chemical into the air is prevented. The operating temperature is between 400 and 500 ° C.
2.Diesel Oxidation Catalyst (DOC) (Diesel engine)
The catalytic converter used in diesel engines is called Diesel Oxidation Catalyst. This type of catalytic converter is called a two-way catalytic converter. Because they cannot remove nitrous oxide from the exhaust. For this reason, two methods are used to reduce nitrogen oxide emission in diesel engines. These are EGR system and SCR systems. Mercedes BlueTec, Volkswagen BlueMotion-BlueTDI are environmentally friendly diesel engine exhaust emission technologies with SCR system.
In diesel oxidation catalyst, as catalyst; platinum, palladium and aluminum oxide are used. It’s purpose is to react unburned carbon and carbon monoxide in vehicles with platinum and aluminum oxides and then combine them.By this way, harmful gases are converted into harmless.
3. Nitrogen Oxide Storage Catalyst (Diesel-Gasoline)
Conventional three-way catalytic converters fail to reduce nitrogen oxide emissions. For this reason, an Nitrogen oxide storage catalyst is additionally used in the exhaust system. In some diesel vehicles, the catalyst with Nitrogen oxide storage can be in the same box as the diesel particulate filter.
The aim of the nitrogen oxide covered catalyst is to store nitrogen dioxide (NO2). It’s structure is just like oxidation catalyst.
There is a ceramic structure inside, there are hundreds of thin canal inside the ceramic structure. The surfaces of the canals are platinum, palladium and rhodium, which are catalyst materials. Unlike this covering, barium oxide is also found. Barium oxide ensures the storage of nitrogen dioxide (NO2). It performs it’s storage task in the most efficient way between 200 and 400 ° C.
Due to the sulfur (S) contained in the fuel in diesel vehicles, sulfur oxides (SOx) occur in the exhaust gas as a result of combustion. Sulfur products are stored as barium sulfate in the nitrogen oxide storage catalyst. Barium sulfate reduces the capacity of the catalyst over time. In this case, barium sulfate must be broken down and a special regeneration process is performed. In order to prevent damage to the system, diesel fuel with a low sulfur (S) amount should be used.
Which cars are most likely to have catalytic converter stolen?
The price of precious metals such as rhodium, palladium, platinum and iridium in catalytic converters has become the target of thieves due to the increase in prices and easy access.
According to the Guardian report, Toyota, 2004-2009 and 2009-2016 Prius and 2012-2018 Auris Hybrid models have become a special target for thieves. These models have two power supplies, an electric motor and a gasoline or diesel engine. For this reason, catalytic converters are used less frequently to treat pollutants. This means that the metals in it are less rusty and higher in value. So it becomes more valuable for thieves. Catalytic converter recycling is a great way to both protect the environment and save money from old scrap.
Catalytic Converter Price Range
Quantities and rates of PGMs are depend on the vehicle’s age and model. PGM rates and current prices are affect catalytic converter prices.
Cars, light trucks and motorcycles have an average of 2-6 grams of PGM. On larger engines and trucks, their average can range from 6-30 grams.
For this reason, while catalytic converter prices are around $ 200 for newer or smaller cars, it can go over $ 600 for larger and older vehicles.
Catalytic Converter Recycling Machine
1- Decanning unit; First, the catalytic converter is separated honey comb from the exhaust.
2- Milling Unit: The sample from the decanning unit is brought to the desired size. Thus, the surface area is increased and it is ready to reach high chemical efficiency.
3- Vacuum transfer unit: It is added to the process according to the customer’s demand. The ground sample is transferred to the desired place by vacuum transfer.
4- Double Conic Mixer: It is added to the process according to the customer’s request. It provides a homogeneous mixture of 2 or more materials of low, medium or high quality.
5- Roasting unit: At this stage, the sample is cleaned from high-temperature impurities before chemical treatment.
6- Leaching Unit: We need to dissolve in leaching solution in order to reduce the amount and get only precious metals in high purity.
7- Refining Unit: At this stage, chemical processes such as Pt, Pd and Rh, which we have taken into Leach solution, are applied separately. Each one is recovered in high purity.
8- Waste Water Treatment Unit: It’s consist of neutralization and Activated Carbon unit. Waste sludge from the chemical unit is made compatible with environmental laws.
As Proses Makine Team,
Eliminates the impossibilities in recycling all types of catalytic converters. The customer’s sample goes through the physical and chemical process in the R&D laboratory.
It guarantees to recover at least 90% purity rhodium with 99.95% purity platinum and palladium.
As the Proses Makina team, we develop recycling methods on this road that we set off with the vision of zero waste and meet the demands of our customers in the international arena with our machines that suit with EU standards.