Catalytic converters are designed to reduce all three:. Gallon for gallon, new lawn mower engines contribute 93 times more smog-forming emissions than new cars. It's no wonder that the EPA and the state regulators of California are trying hard to get golf ball-sized catalytic converters into lawn mower and other small engines. However, just like in the s, the lawmakers are being met with a powerful lobby. Four smaller lawn mower engine manufacturers have refuted this charge.
California democrats and the EPA think it has more to do with the bottom line. Pending regulations proposed in California could reduce emissions by the equivalent of , cars per day [source: Barringer ].
In chemistry, a catalyst is a substance that causes or accelerates a chemical reaction without itself being affected.
Catalysts participate in the reactions, but are neither reactants nor products of the reaction they catalyze. In the human body, enzymes are naturally occurring catalysts responsible for many essential biochemical reactions [source: Chemicool ]. In the catalytic converter, there are two different types of catalyst at work, a reduction catalyst and an oxidation catalyst.
The idea is to create a structure that exposes the maximum surface area of catalyst to the exhaust stream, while also minimizing the amount of catalyst required, as the materials are extremely expensive. Some of the newest converters have even started to use gold mixed with the more traditional catalysts. Catalytic converters in diesel engines do not work as well in reducing NOx. One reason is that diesel engines run cooler than standard engines, and the converters work better as they heat up.
Some of the leading environmental auto experts have come up with a new system that helps to combat this. They inject a urea solution in the exhaust pipe, before it gets to the converter, to evaporate and mix with the exhaust and create a chemical reaction that will reduce NOx. Urea, also known as carbamide , is an organic compound made of carbon, nitrogen, oxygen and hydrogen.
It's found in the urine of mammals and amphibians. Urea reacts with NOx to produce nitrogen and water vapor, disposing more than 90 percent of the nitrogen oxides in exhaust gases [source: Innovations Report ]. A standard catalytic converter contains several hundred dollars worth of platinum, palladium and rhodium. The ground clearance on trucks and SUVs makes for easy access to the converters, so all a thief needs is a reciprocating saw and about 60 seconds.
This trend has police on the lookout in many parts of the country where this kind of theft has been a problem. Police caution SUV and truck drivers to park in busy, well-lit areas. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe.
Under the Hood. How Catalytic Converters Work. A large pile of platinum lined catalytic converters. See more green living pictures. James L. Pollutants Produced by a Car Engine " ".
Nitrogen gas N2 - Air is percent nitrogen gas, and most of this passes right through the car engine. Carbon dioxide CO2 - This is one product of combustion. The carbon in the fuel bonds with the oxygen in the air. Water vapor H2O - This is another product of combustion. The hydrogen in the fuel bonds with the oxygen in the air. Carbon monoxide CO is a poisonous gas that is colorless and odorless. Hydrocarbons or volatile organic compounds VOCs are a major component of smog produced mostly from evaporated, unburned.
Nitrogen oxides NO and NO2, together called NOx are a contributor to smog and acid rain , which also causes irritation to human mucus membranes.
Are lawn mowers next? How Catalytic Converters Reduce Pollution " ". Controlling Pollution and Improving Performance The third stage of conversion is a control system that monitors the exhaust stream, and uses this information to control the fuel injection system. What this all amounts to is less smoke and odour coming out of the exhausts of cars now than before catalytic converters were mandated by UK authorities.
It is also worth noting catalytic converters are one reason we must use unleaded fuel in cars today, as leaded fuel, which is no longer sold in the UK, prevents the catalysts from breaking down the pollution in the exhaust gases.
Some environmental concern bodies, such as the Intergovernmental Panel on Climate Change , have claimed that due to the amount of nitrous oxide they produce they are doing more long-term harm to the environment than they are good. However, newer catalytic converters produce far less nitrous oxide than older ones, and the effect they have on reducing the emissions of hydrocarbons, carbon monoxide, and nitrogen oxides is certainly noticeable.
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