Plans to recycle polystyrene in the pipeline
August 6, 2007 at 11:23 am
Each year British landfills receive almost three thousand tonnes of waste polystyrene. In an attempt to deal with the problem, Purex International is embarking on a project to develop machines which can “thermally densify” polystyrene. The new technology, known as Styromelt™, will allow waste polystyrene, otherwise destined for landfills, to be converted into a form that can be used to produce fuels and other materials.
Polystyrene (or expanded polystyrene (EPS) as it is technically known) is manufactured from liquid hydrocarbons commonly in the chemical industry. This material has a number of uses. Polystyrene has gained popularity as a packing material due to its physical properties; it is light, yet highly impact resistant. In addition, fast-food restaurants often use polystyrene containers to package food as the material also provides good insulation when it comes to keeping food warm.
However, polystyrene does not decompose easily and it is therefore harmful to the environment. Whilst a number of cities in the United States have banned the use of polystyrene, little has been done to combat the problem in the UK. Few companies are interested in recycling the waste polystyrene they generate because of the substantial costs involved. In most cases, waste EPS eventually makes its way to landfills across the country. In addition, because polystyrene has a very low density, its volume is significantly greater than its weight – the 300,000 tonnes of waste polystyrene created in the UK in a year would fill up to 15,000 Olympic swimming pools.
Until now, polystyrene has not been recycled widely, as many manufacturers remain unaware about the facilities available. The Styromelt™ machine, according to its manufacturers, provides an efficient way of dealing with waste polystyrene: “The machine has a loading area of approximately two cubic metres, which is filled with EPS, the door is then closed and locked and the machine switched on. Two temperature controlled thermal plates then heat the EPS to melting point where it releases all the air and other gases it contains forming a thick liquid, which is collected in a tray where it cools. Once cool, the now solidified block is removed from the tray and stored for recycling.” The process, once complete, reduces the waste polystyrene to 95% of its original volume. The compressed polystyrene can now be transformed into a whole variety of products, ranging from coat hangers and CD cases to picture frames and disposable cameras. It can also be used to produce environmentally-friendly fuel such as green diesel and LPG. Compressed polystyrene can also be burnt. This process releases a considerable amount of energy – almost twice as much as an equal volume of coal.
How do I recycle cooking oil please?