The emission of hydrocarbons has become the bane for automotive industries. Increased awareness of global warming and its impact on climate change had led to the popularity of hybrid and electric vehicles. However, way before we considered commercial alternatives to petroleum and diesel engines, catalytic converters have continued to play an essential role in minimizing emissions.
Let’s understand why we need vehicle catalytic converters and how it helps reduce harmful exhaust gases.
Pollution from Car Engines
The regular car engines run on fuel like petrol and diesel. The fuel is mixed with air to combust and release energy to drive. This results in the generation of exhaust gases that are released in the air through the vehicle exhaust system.
Since fuel is basically a chain of hydrocarbon atoms, burning it with oxygen from air usually results in carbon dioxide and water.
CH + O2 = CO2 + H2O
Carbon dioxide is already an unavoidable consequence of burning fuel. Although a greenhouse gas, it is not as harmful as the other by-products, which are formed due to present additives and incomplete combustion, resulting in nitrogen oxides and carbon monoxide.
To reduce the emission of poisonous and harmful gases, catalytic converters are employed in the exhaust system.
Catalytic Converters
Catalytic converters are now a part of every vehicle exhaust system that uses the internal combustion system. The simplistic design makes use of a ceramic honeycomb structure covered with catalysts.
Three precious metals, platinum, rhodium and palladium are used to oxidise or reduce the toxic gases to convert them to less harmful gases.
How catalytic converter works
A car’s catalytic converter functions in a straight forward way. When the engine produces hot exhaust gases, it passes the catalytic converter. The hot gases help the ceramic housing maintain high temperature for proper reaction whereas the honeycomb structure offers greater surface area for the passing gases to react quickly with the catalyst.
It’s important to understand the work of catalysts, as the word catalytic converter is derived from the function of the catalysts. Catalysts are used to speed up the reaction by lowering the amount of activation energy required to start the reaction. During the process, catalysts are sometimes consumed and regenerated through proceeding reactions. Hence, only a small amount of catalyst is required.
Platinum and rhodium are used in combination to act as reduction catalyst while platinum and palladium act as oxidation catalyst. The following equations show how toxic gases are converted to less harmful gases by the catalytic converter
- Reduction of harmful nitrogen oxides into nitrogen and oxygen: NO = N2 + O2
- Oxidation of poisonous carbon monoxide into carbon dioxide: CO + O2 = CO2
Dangers of Pollutants
The pollutants from exhaust gases can have a drastic impact on the environment and health. Furthermore, some of these gases result in acid rain, a crucial environmental factor to harm vehicles too. Let’s take a look at some of the negative effects of emissions, which makes the use of catalytic converters essential for a better life.
Nitrogen Oxides
- NO in the air can result in smog, which is dangerous to the lungs
- With sulphur dioxide in the air, NO can result in acid rain that can corrode structures, cars and harm marine life
- It is a greenhouse gas resulting in global warming
Carbon Monoxide
- An odourless and poisonous gas
- It can cause flu-like symptoms on top of being fatal
- CO is a greenhouse gas
Lead in Fuel
Although lead is widely banned from car fuel, the presence of lead can invalidate the work catalytic converter. It can coat the catalyst surface, rendering them useless and increasing the overall emission with the addition of poisonous lead.
Symptoms of a Failing Catalytic Converter
If your catalytic converter fails or gets choked, your car will emit more hazardous gases. The following signs may be an indication of catalytic converter failure:
- Engine check light
- Lose of acceleration
- Engine misfire
- Emission test failure
- Blackened smoke
Since some of the symptoms can also direct toward a problem with the engine, get your car inspected by a professional to diagnose the root cause.
Catalytic Converter Theft
The catalytic converter contains expensive metals as catalysts including platinum, palladium and rhodium. This makes them an easy target for theft. Especially in vehicles like SUVs with better ground clearance.
Fortunately, such a trend is not common in the UAE. Strict surveillance and the presence of law enforcement keep your property safe.
FAQs
Does a catalytic converter affect exhaust sound?
Since the catalytic converter reduces the impact of exhaust gases, along with the muffler, it can further reduce the level of sound. In fact, a car without a catalytic converter will have a louder exhaust sound.
What does a vehicle catalytic converter do in a car exhaust?
A catalytic converter converts the harmful car exhaust into less toxic. This becomes possible with the help of a combination of catalysts, which make the process of oxidation and reduction faster by lowering the required activation energy.
In short, catalytic converters rely on the simple process of reduction and oxidation, which converts the unwanted exhaust gasses. There are strict rules regarding emissions in the UAE. If your catalytic converter is not working, you may not pass the emission test. This can also result in fines due to pollution.
This concludes our catalytic converter guide. If you are looking for environmentally friendly cars like hybrid and electric cars, browse through our collection of used cars for sale in the UAE to find some good options in that category.
Stay tuned to the UAE’s leading auto blogs for more information on car parts, market trends and automotive technology.
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