Catalytic converters are a vital part of any automotive emission system. These devices use heat to chemically react (catalyze) with harmful emissions like carbon monoxide, nitric oxides and unburnt hydrocarbons and convert them to more inert forms. They've been required on all cars sold in the united states since 1975, and have helped to change the landscape of the automotive industry worldwide.
Catalytic converters were first developed in the 1950s by Eugene Houdry, a French-American engineer. They first entered production for use on automobiles in 1973, and were legislated as mandatory in 1975. Other industries soon jumped on the green wagon, applying converters to practically anything with an engine, including forklifts, generators and battleships.
All catalytic converters function on essentially the same principal. The converter housing contains a grid-like substrate that is designed to reach extremely high heat, finishing the combustion process begun by the engine and vaporizing contaminants. Many converters store excess oxygen from the catalytic process, using it to speed up the reaction under high-stress conditions. The inside of some converters can reach over 1,000 degrees under normal operation, and significantly more under meltdown conditions.
Older converters used a lead pellet design to capture heat, forcing the exhaust to flow through and around the metal balls, which were trapped in a containing matrix. More modern converters use honeycomb-shaped matrices of platinum-palladium alloy, coated with a wash-coat of silica and alumina, which helps increase efficiency. The newest converters use a ceramic honeycomb which lasts longer, is more efficient and contains little or no precious and expensive platinum alloy.
Older catalytic converters were very heavy and restrictive, costing precious horsepower in the deficit days of the '70s and reducing fuel mileage by as much as 10 percent. The newest high-flow honeycomb designs, however, flow significantly better than lead-pellet types. Converters often produce harmful emissions of their own: hydrogen sulfide and ammonia are the most common, but some also produce the organic toxin dioxin.
Cash for Cats
Catalytic converter theft is rampant in some areas, since older units contain great quantities of the aforementioned precious metals. A typical catalytic converter contains over $200 worth of platinum, palladium and rhodium. But don't break out the reciprocating saw and retirement plan just yet; according to the EPA, the cost to extract these precious metals from used converters makes recycling them for the platinum only slightly more economical than simply refining more.
- Photo Credit Image by Flickr.com, courtesy of Chris Keating
Why Do You Need a Catalytic Converter?
Practically every car sold in the United States since the mid 1970s has been equipped with a catalytic converter. These exhaust system...
What Are Catalytic Converters Worth?
Every car part has its purpose and the catalytic converter is no different. Designed as a mechanical method of reducing engine emissions...
Resonator Vs. Catalytic Converter
Resonators and catalytic converters are parts that are installed in the exhaust systems of vehicles. When both devices are used properly, they...
What Is the Purpose of a Catalytic Converter?
A catalytic converter is an exhaust emissions device used to lower a vehicle's exhaust emissions output. Similar in size and shape to...
How Hot Does a Catalytic Convertor Get?
The catalytic converter is an important element of a modern vehicle exhaust system. It uses the catalytic action of precious metals to...
Why Does a Car Need Two Catalytic Converters?
Catalytic converters were first put into use in the 1970s in response to the growing pollution problem in cities throughout the U.S....
Why Does My Car Have Multiple Catalytic Converters?
Catalytic converters refer to devices used to reduce emissions in internal combustion engines. Many cars come standard with one catalytic converter. Some...
How to Size a Catalytic Converter
Catalytic converters are essentially ovens that bake harmful exhaust emissions like carbon monoxide, unburned fuels and oxides of nitrogen into more inert...
The Average Cost to Replace a Catalytic Converter
According to the Environmental Protection Agency, a catalytic converter is the single most important pollution control device on your car. Because proper...
What Causes Catalytic Converters to Fail?
Catalytic converters are required in all automobiles by the Environmental Protection Agency. Cars burn fuel that release harmful gases. The catalytic converter...
Metals Used in Catalytic Converters
By weight, catalytic converters are one of the most expensive components on your car. Selling a single pound of the pure palladium...