Air Pollution and Catalytic Converter

Categories: Air Pollution


Catalytic converter is a piece of equipment that converts harmful compounds using a catalyst into harmless compounds. There are three harmful compounds: hydrocarbons, carbon monoxide and nitrogen oxides. The catalyst (in the form of platinum and palladium) is covered in a catalytic converter on a ceramic honeycomb or ceramic beads that are stored in a muffler-like box attached to the exhaust pipe. The catalyst supports in converting carbon monoxide to carbon dioxide. The hydrocarbons are converted into carbon dioxide and water.

It also converts nitrogen oxides back to nitrogen and oxygen.

Eugene Houdry, a French mechanical engineer and expert in catalytic oil refining who lived in the U.S. round the 1950s, invented the catalytic converter. When the results of early smog studies in Los Angeles were published, Houdry became concerned about the role of smoke stack exhaust and vehicle exhaust in air pollution and founded Oxy-Catalyst.Houdry developed a catalytic first. Houdry first designed catalytic converters for smoke stacks called small animals.

Then he developed catalytic converters for storage forklifts that used low-grade unleaded gasoline. In the mid 1950s, he began research into the development of catalytic converters for gasoline engines used in cars. For his work, he was awarded the United States Patent 2742437. Broad adoption of catalytic converters did not exist until tighter pollution control laws required the elimination of the anti-knock chemical, tetraethyl, from most fuel, as lead was a 'catalyst toxin' which would inactivate the converter by creating a coating on the catalytic converter surface, essentially crippling it.

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Catalytic converters were later developed by a variety of engineers including John J. Mooney and Carl D. Keith at Engelhard Industries, becoming the first catalytic converter in 1973. Dr. William C. Pfefferle invented a catalytic combustor for gas turbines at the beginning of the 1970s, allowing for combustion without substantial accumulation of nitrogen oxides and carbon monoxide.

The design and creation of gasoline-fueled motor vehicles have had a significant influence upon human culture, supplying transport to consumer goods and employment for thousands and deciding where and how we stay, function and play. Today, more than half of the 300 million gallons of gasoline used every day to fuel more than 150 million passenger vehicles was provided by catalytic cracking technology in the United States. High-octane gasoline paved the way for high compression ratio vehicles, improved engine efficiency and better fuel economy. Most dramatic advantage of the early Houdry units has been the development of 100-octane aircraft gasoline just before the outbreak of World War II. Houdry plants supplied great gasoline for mixing with insufficient high-octane parts, as well as by-products that could be converted to higher-octane quantities by other methods. Improved performance meant that Allied aircraft were better than Axis aircraft by an average of 15 to 30 percent of engine power for take-off and climbing; 25 percent of payload; 10 percent of top speed; and 12 percent of operating altitude.

During the first six months of 1940, during the Battle of Britain, 1.1 million barrels a month of 100-octane aviation fuel were delivered to the Allies. Houdry plants produced 90% of this catalytically cracked gasoline in the first two years of war. Originally Houdry method represented many groundbreaking chemical and engineering principles that had far-reaching implications. For example, an increase in the octane rating with catalytic processes has shown that the chemical composition of the fuel limits the efficiency of the engine. In addition, aluminium silicate catalysts have been shown to be effective in raising octane ratings because they have produced more highly concentrated isoparaffin and aromatic hydrocarbons responsible for high octane ratings. From an economic point of view, the catalysts could be regenerated after a short period of use, thereby returning the catalyst to full service without the need to add additional content. The original Houdry process units were outmoded through technological developments that turned the fixed bed into more economical fluidized bed systems and introduced the need for crystalline aluminosilicate catalysts to supply high yields of gasoline. It is noteworthy, however, that seventy years after Houdry's discovery of the catalytic properties of activated clay to transform petroleum fractions to gasoline, the same basic principles that made the process such success are still the primary basis for the manufacture of gasoline worldwide.

The catalytic converter is connected to the exhaust pipe on the engine. A metal shell comprises a honeycomb of ceramic. The honeycomb is filled with a combination of platinum (Pt), palladium (Pd) and rhodium (Rh). These noble metals are perfect for oxidation, corrosion and acid resistance. This ensures that they can stand up to bad weather and all the chemicals generated by a car engine. Noble metals in catalytic converters serve as catalytic converters. Catalysts are materials that can cause a chemical reaction without harming themselves. The honeycomb arrangement within the catalytic converter maximises the surface area where reactions will occur. Catalytic converters are using oxidation and reduction (redox) reactions to eliminate toxic emissions. They use a reduction catalyst made up of platinum and rhodium. It helps to eliminate nitrogen oxides (NOx) by eliminating nitrogen atoms from nitrogen oxide molecules (NO and NO2). This allows the free oxygen to enter the oxygen gas (O2). The nitrogen atoms attached to the catalyst react with each other. This reaction is caused by nitrogen gas (N2).

Catalytic converters now use an oxidising catalyst composed of platinum or palladium. This helps to minimise hydrocarbons (HC) and carbon monoxide (CO). For example, carbon monoxide and oxygen are mixed to form carbon dioxide (CO2). Then, unburned hydrocarbons and oxygen combine to form carbon dioxide and water.

Without the redox cycle of filtering and removing nitrogen oxides, carbon monoxides and hydrocarbons, the quality of the air (especially in big cities) is toxic to humans.

Nitrogen oxides: these compounds are in the same family as nitrogen dioxide, nitric acid, nitrous oxide, nitrate and nitric oxide. When NOx is emitted into the air, it reacts with organic compounds in the soil, induced by sunlight; the result is smog. Smog is a pollutant that has harmful effects on the lungs of kids. The NOx that reacts with sulphur dioxide creates acidic air, which is extremely harmful to anything on which it falls. Acid rain corrodes vehicles, trees, houses, national parks and poisoned lakes and streams with acidity unsuitable for animals. NOx can also bind to ozone to produce biochemical anomalies (such as smog) and limit light transmission.

Carbon monoxide: which is a toxic form of a natural gas, CO2. Odorless and colourless, this gas does not have a number of useful roles in daily operations. Hydrocarbons: inhalation of gasoline hydrocarbons, domestic cleaners, propellers, kerosene and other fuels can be lethal to infants. Many risks include dysfunction of the central nervous system and cardiovascular issues. The engine burns the hydrocarbon fuel in the presence of air while running. Several gases arise in the engine: CO, CO2, H2O, partly oxidised hydrocarbons, nitrous oxides (NOx) and unused hydrocarbons. The NOx production is especially high in older engines operating at higher temperatures.The these gases except CO2 and H2O are poisonous or hazardous to the environment. Even CO2 is problematic; it is a greenhouse gas that actively encourages the process of global warming. The full machine consists of two separate converters. The full machine consists of two separate converters. The key task of the catalytic converter is twofold: first, to decompose and reduce nitrous oxides to N2 (front converter) and, second, to oxidise hydrocarbons and CO which remain in the exhaust to water and, second, to oxidise less hazardous CO2 (back converter). CO2 is not a totally harmless drug, but it binds to haemoglobin in a reversible manner, it is also much less harmful than carbon monoxide. The use of converters will reduce CO & hydrocarbon emissions by an order of magnitude and NOx by two orders of magnitude.

The critical environmental problem is the loss of the ozone layer in the Arctic. As in the case of climate change, we have taken major measures to speed down the loss of ozone, and there has been considerable progress as a result of these actions. We will investigate the impacts of ozone loss on the risk of skin cancer and on primary crops of marine environments. Finally, we should consider exporting POPs from the tropics to the Arctic, where they will affect both human health and the biodiversity of the Arctic.

Environmental concerns:

Critical environmental problems related to air quality include brown smog and acid deposition. We're going to concentrate on airborne PM, an issue that usually plagues big cities with elevated traffic volumes, pollution from power plants, and other sources of small particulate matter. We will explore the sources of PM and how it affects human health.

Local issues: the existence of large point sources of emissions, such as smoke towers, poses a problem for many areas of the developed world. They must analyse the Met-Mex metal smelter in Mexico and find the impact of toxins such as lead on the local population. They will also look at the problems of transnational waste and environmental justice.

Household issues: historically, indoor air pollution has never been deemed a significant threat to the environment. We feel better now. Anyone who cigarettes or stays with a smoker is likely to be subjected to hundreds of possibly carcinogenic air contaminants on a regular basis. Certain examples of IAP include additives found in various consumer goods, particulate matter such as asbestos, moulds and toxic bacteria, and even odourless, tasteless radon gas capable of inducing lung cancer.

The catalytic converter does a fine job of reducing emissions, but it can also be greatly changed. One of the biggest drawbacks is that it only runs at a fairly high temperature. When you start your car cold, the catalytic converter does absolutely nothing to reduce the emissions of your exhaust. The catalytic converter does a decent job of reducing emissions, but it can also be substantially changed. One of the main disadvantages is that it only works at a reasonably high temperature. When you start your car cold, the catalytic converter does little to reduce the emissions of your exhaust. A easy approach to this issue is to push the catalytic converter closer to the pump. It ensures that the cooler exhaust gases enter the converter and heat up quicker, although this will also reduce the life of the converter by exposing it to excessively high temperatures. Most car makers put the converter under the front passenger seat, far enough away from the engine to keep the temperature down to a point where it will not be harmful.

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Air Pollution and Catalytic Converter. (2021, Oct 31). Retrieved from

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