The Problem
Once tires become worn or damaged, they are no longer fit to be used on vehicles. Unfortunately, used tires present a major problem when it comes to disposing of them. Landfills are restricting the number of tires they accept due to both the environmental and health risks associated with stockpiling scrap tires. One major risk factor is the pollution of groundwater. As a result, most states now ban the disposal of whole tires in their landfills. Some even refuse to take chipped or shredded tires. However, because of the durability and resilience of the materials used to make tires, scrap tires can be recycled to make a number of other practical products. With the market for used tires growing, new industries -- often supported by local and state governments -- are finding creative and novel ways to put this form of waste to valuable uses.
Recycling Methods
There are several different processes used to recycle tires. Using scrap tires for fuel is a growing market in the U.S. today. Combustion of tires produces intense heat, therefore, a number of industries are either supplementing or substituting fuels such as coal, wood and natural gas with tires which are consumed in utility boilers or cement kilns. Tires are also being used as fuel at wood and paper mills throughout the nation. In most cases, the steel is separated from tires for recycling before the tires are consumed as fuel. Pyrolysis is another technique that heats shredded tires at high temperatures in a vacuum without oxygen. Tires are melted down inside a reactor unit. Within a few hours a vapor forms, which is then sent to a water-cooled unit where it condenses into a liquid fuel. By-products of this process include kerosene, diesel fuel and benzene. While the actual process is similar to how distilling works, the primary problem related to this method of decomposition is that sometimes the by-products are of low quality. A newer process involves microwaving shredded tires to break the material back down into its original components. The method is economical and converts solid waste material to a gas. During the cool-down process organic liquids separate from lighter gases, forming diesel and other fuel oils. Ultrasound is still another recycling process that uses high pressure and heat to produce a new material similar to rubber that can be used to mold new products.
Additional Alternatives
Other solutions for reducing tire waste is for manufacturers to improve the materials used in making tires so that they last longer. Manufacturing better quality products will increase the life of a tire before it needs to be replaced. The U.S. Environmental Protection Agency reports that about one-sixth of the approximately 300 million tires scrapped every year are now being used to make vehicle tire retreads. Retailers and manufacturers are also developing return policies for old tires when replacement tires are purchased. This helps to prevent tires from being stockpiled or disposed of unsafely. At the opposite end of the spectrum, consumers can do their part by maintaining the tires on their vehicles by having them routinely rotated to increase their wear time. Once a tire has been utilized fully, recycling programs designed to either combust used tires or process the waste into new products are reducing waste and hazardous, illegal dumping sites. On a positive note, government reports show that markets currently exist to utilize more than 75 percent of all scrap tires.
Tags: scrap tires, shredded tires, used tires, being used, materials used, tires their, used make