The TWC purifies engine exhaust by oxidising CO and HC to CO2 and H2O, and reducing NOx to N2. A matrix of thousands of parallel channels gives modern monolith TWCs the desired combination of large surface area and low-pressure drop. Large surface area is needed for high reaction rates, and pressure drop must be small to not adversely affect engine performance. The substrate, made of cordierite, is coated with a very high surface area washcoat comprising mainly of alumina, ceria, is dispersed over the washcoat.
The converter uses two different types of catalysts, a reduction catalyst and an oxidization catalyst. The reduction catalyst It uses platinum and rhodium to help reduce the nitrogen oxide emissions. When such molecules
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In addition, the introduction of catalytic converters led to the introduction of unleaded gasoline, since catalytic converters do not work with leaded gasoline. As an also caused atmospheric levels of lead particulates to drop.
The catalytic converters sole purpose is to reduce the amount of harmful pollution produced by the combustion of hydrocarbon-based fossil fuels in cars.
Catalytic converters decrease hydrocarbon emissions by about 87 percent, carbon monoxide by 85 percent and nitrous oxide by 62 percent during the expected life of a vehicle.
4.1.2 DISADVANTAGE:
The disadvantages, however, are that they are very expensive to get/replace. In addition, because carbon dioxide is a product of the reaction that takes place inside catalytic converters, widespread use of catalytic converters has also contributed to increased atmosphere levels of carbon dioxide.
Catalytic converters decrease the fuel efficiency of a car and the increased price of unleaded gas costs consumers more in the long run.
4.2 Application of catalytic
However, under normal driving conditions an engine will encounter lean conditions when cruising on the highway (better mileage) and rich conditions when accelerating (better power). The lean condition results in oxide and harmful nitrogen production. Rich conditions result in carbon monoxide production. For this reason, catalytic converters are used on an engine’s exhaust. The catalyst material in a cat is a wire mesh or honeycomb.
chain. The use of lead in gasoline was phased out in '73 which caused lead
The emission of carbon dioxide has contributed to 80% to the heating of the earth atmosphere. Carbon dioxide is produced due the burning of fossil fuels such as natural gas, coal and oil. The burning of fossil fuel is very important in our society today, because it is used for cooking, used to produce electricity, for heating, for cooling and also for transportation. The industrialization has led to the use of fossil fuel for running machines and driving cars. The building of fossil fuel contributes towards 80-90% of the carbon dioxide we find in our atmosphere today. When the ecosystems are altered and vegetation is either burned or took out, the carbon stored in them is relinquished to the atmosphere as carbon dioxide (What causes global climate change, 2005). Methane is another gas being produced in the process which all have served to increase the greenhouse effect in our atmosphere. Methane is produced from the cultivation of rice, from the burning of coal and from cattle, it has increased by 145% due to human
The tradeoffs of using gasoline for cars are large emission of carbon dioxide and required large amount of chemical t...
...ns use in their homes, the fewer chemicals that power plants use the fewer that will have to be emitted in to the air. Today there are laws on how much pollution is allowed to be put out in the air these laws have made significant changes. Catalytic converters in cars help reduce emissions. There has been reduction in the amount of acid rain causing pollutant to the air by humans. Eastern Canada set a cap of 2.3 million tons of sulphur dioxide to be met by 1994 and maintained until 2000. In Canada several sulphur dioxide reduction targets for provinces to the east of Manitoba-Saskatchewan to meet this cap. Roughly halve of the sulphur dioxide emissions were intended to be cut by this reduction.
When the problems with gasoline use are considered, the catastrophic environmental effects are the primary concern. Automobile use consumes 70 percent of the United States oil supply and is responsible for one-third of the nation’s carbon emissions (Lovins 173). This results in pollution, global warming, and health problems for the people, plants, and animals. The search for alternative fuel is powered by the increasingly evident environmental problems and long-term health of the planet (Povey 17). Fortunately, reducing emissions globally is predicted to have a positive effect and offset previous harms (Backer).
Gasoline fueled cars produce a number of pollutants. The most damaging pollutants that come from gasoline fueled cars are particulate matter. Particulate matter is a sequence of organic materials and inorganic substances. It includes ingredients such as lint and minerals. Nitrogen dioxide, produced when fuel is burned at high temperatures, can cause damage to the lungs and cause chest pains. One might ask, “Why are Americans still driving gasoline cars?” knowing the damage that they are subject to cause. I personally maintain that the government should push people to p...
Many hazardous pollutants escape from the internal combustion of the engine. Conventional gas powered vehicles use irreplaceable fossil fuels to run. When burned, these fossil fuels create numerous toxins like carbon dioxide (Larminie 246). Carbon dioxide is considered the main greenhouse gas that creates the foundation for global warming (hybridcars.com, pollutants). This harmful pollutant may not have a serious effect on people at first, but it does have consequential effects on the environment that in turn put people in danger (Nutramed.com). The major consequence caused by global warming is the rise in average temperature. This results in a domino...
The automobile has had a tremendous impact on society and the environment since its development in the beginning of the 20th century. Today, there are over 500 million motor vehicles on the earth. The automobile's efficiency, style, and performance have changed over the years, but there is one thing that has not - the pollution the automobile generates. Because of the pollution, people find themselves asking whether this technology has helped our society or hurt it. Should the consequences of the automobile be cause to eliminate it? Or should science develop technology to eliminate the pollution caused by the car?
Depends on Where You Plug In” Paul Stenquist (2012) explains that the dangerousness of electric cars on the environment relies on where the electricity that people use to charge their cars comes from. The author reports that the amount of greenhouse gases -carbon dioxide- produced from charging the car 's battery can have effect on variation of the climate. Moreover, Stenquist states that the impact of electric vehicles on the environment depends on the amount of the greenhouse gases released from the car into the air, which varies with the source of the electricity that charges the car. Further, The U.C.S report demonstrates that there are possibilities for the electric cars to reduce carbon dioxide emissions in places where the electric utility counts on natural gas, nuclear, hydroelectric or renewable sources to run its dynamo. On the other hand, places where the dynamo powered by burning coal, electric cars might not be as good as gasoline cars for the atmosphere. In other words, the author says that places that has immaculate electricity sources might produce less greenhouse gas emission than today’s gasoline engine vehicles. However, the author mentions that gas-powered cars are getting cleaner and better, and electric cars will become cleaner if the electricity for charging the cars cames from natural and renewable sources. Indeed, Stenquist believes that the automotive industry must deliver applicable alternative to the oil-fueled internal- combustion, which is producing vehicles which boasts less emissions (Stenquist,
Car pollutants cause immediate and long-term effects on the environment. Car exhausts emit a wide range of gases and solid matter, causing global warming, acid rain, and harming the environment and human health. Engine noise and fuel spills also cause pollution. Cars, trucks and other forms of transportation are the single largest contributor to air pollution in the United States, but car owners can reduce their vehicle's effects on the environment. Car pollution is one of the major causes of global warming. Cars and trucks emit carbon dioxide and other greenhouse gases, which contribute one-fifth of the United States' total global warming pollution. Greenhouse gases trap heat in the atmosphere, which causes worldwide temperatures to rise.
To begin the negative effects of automobiles are very mild and should not be taken too seriously although it sounds bad the positive outweighs the negative. Automobiles deplete a good amount of natural resources such as steel, aluminum, copper, lead, zinc, and rubber (The Environmental Impact of Automobiles). Because of automobiles air pollution has lost wheat, corn, soybean, peanut crops about one point nine to 4 billion dollars in crops (The Environmental Impact of Automobiles). The U.S alone uses over 10.8 million barrels of oil each day just to keep automobiles running (The Environmental Impact of Automobiles).
can cause a lot of carbon dioxide to be released. Every time we burn fossil fuels, we release more
Electric cars help lower emissions because they have completely clean motors. As time progresses, emission standards rise and will become harder to meet for automakers. Electric motors will always have zero emissions and auto makers won't have to spend extra money to make their engines cleaner and more fuel efficient. Originally, when the internal combustion engine was invented, pollution wasn't a problem. After hundreds of years and the many combustion engines created, all the exhaust has built up. Today, pollution is one of the largest problems in our environment. Every year the average miles driven rises for everyone. When this rises, the pollution rises as well. Toni Marzotto, in "The Evolution of Public Policy: and the Environment," explains how air pollution will continue to keep on increasing:
It is clear that the US consumption of polluting substances like lead, platinum and rubber has dropped due to improvements in the environmental friendliness of auto manufacturing, since these materials have been in use for cars since the 1950s. By replacing materials with those of a lower density has also made an important impact on fuel economy. Studies show that making 10% reduction in mass yields 5% improvement in fuel economy. Indeed, the US automakers in the last 25 years have responded to the government regulations Corporate Average Fuel Economy by changing materials to lighter ones like aluminum and plastics. Newer developments using other components like Magnesium, polymer composites, and ceramics also are helping to make further improvements to fuel