Catalysis is a unique and highly valuable chemical process in which a catalyst is used to initiate or speed up a reaction between two or more chemicals or substances. In many cases, the catalyst used provides the groundwork for the reaction to take place. Without the catalyst, there would be no reaction. In these cases, the catalyst literally sparks or starts the reaction through its own activation energy. The value of this is evident to anyone who understand chemical engineering. In many cases, though, a catalyst is used to speed up a reaction that is already taking place. This is one of the most valuable functions of these substances. Some reactions would simply take too long to occur to be at all useful. But thanks to catalysts, these reactions can be completed much more quickly, allowing many products and other substances to be created rapidly. One of the most significant areas in which a catalyst is used to create a product is in the development of plastics. Many plastics are made from chemicals through a catalytic process. For example, polyethylene is made from ethylene gas that interacts with a catalyst. This substance is used to create plastic bags and bottles, as well as other materials that serve a wide variety of functions around the home and in commercial environments. It's safe to say that, as a result of the use of catalysts, substances such as that are made affordable and readily available to all. This is just a single example of the usefulness of catalysts. Another well known industry in which catalysts are used frequently is natural gas refining. Most oil and gas products can only be created through the use of catalytic substances. If you've driven a car lately, you've enjoyed the end result of a number of chemical reactions, many of which involved catalysts. Fossil fuels of many varieties are prepared for consumer use through extensive chemical processing, and many such processes require the use of catalysts. Catalysts are highly important in the development of many products that are commonly used all around the nation and the world. The catalytic item most consumers are best familiar with is the catalytic converter that can be found on most any recent car or other vehicle. Catalytic converters are used to scrub harmful toxins from the exhaust that these vehicles create. They do this through catalysis. When the emissions pass through a filter lined with catalytic substances, a reaction occurs. Many of the harmful emissions are transformed into less harmful forms through this chemical process. Catalytic converters have significantly decreased the overall emissions produced by vehicles all over the world, thus reducing harmful emissions and helping stave off continued pollution. We should be thankful for the widespread use of these catalysts.