| In the 1980s Illinois microbiologist Paul Baskis improved | | | | products but it is difficult to safely dispose of or |
| the process called hydrous pyrolysis to beyond the | | | | recycle. That is until recently. |
| break-even point for converting waste products into oil. | | | | With thermal depolymerization the situation changes. |
| By the break-even point I mean the point where the | | | | Now it is feasible to take old vinyl siding from houses |
| cost of production equals the profit. This is the point | | | | and subject it to intense heat and pressure to break it |
| when the process known as thermal depolymerization | | | | down into long organic compounds that in turn can be |
| or TDP became a commercially viable process. | | | | converted to oil. This means that where once plastic |
| In 2001 Brian S. Appel of Changing World Technologies | | | | was considered a bad and environmentally unfriendly |
| took the theory of thermal depolymerization and | | | | product it can now be considered as a valuable |
| turned it into a business reality. His company set up the | | | | resource, as a source of energy. Considering the |
| first plant using the new technology to make crude oil | | | | amount of waste modern societies produce thermal |
| from turkey offal. The plant was so successful it | | | | depolymerization could make lots of cities and other |
| managed to produce oil at 10% cheaper than the | | | | urban areas self-sufficient in energy terms. |
| market price. Approximately 20% of the offal | | | | Previously it was felt that we should abandon using |
| produced energy was required to power the plant. | | | | plastics. Plastic is made from petroleum and was |
| This was an amazing moment. Suddenly the future | | | | believed to be a wonder material in the 1950s because |
| looked different for the world. Waste disposal is a | | | | it was cheap, durable and versatile. uPVC or |
| huge problem facing mankind. The United States | | | | unplasticised Poly Vinyl Chloride was particularly |
| Environmental Protection Agency estimated that in | | | | popular because it withstood the corroding power of |
| 2006 there was 251 million tons of municipal waste in | | | | hot and wet weather much better than timber. As a |
| the USA. Much of this goes into landfills. Much of this | | | | result it was mass produced for uPVC or vinyl |
| waste is plastic and doesn't biodegrade. A big problem | | | | window frames and as siding for houses all over the |
| is accidental fires in landfill sites which release lots of | | | | United States. It is an ideal material for building because |
| toxic gases into the atmosphere. | | | | it doesn't expand or shrink and because it is low |
| One of the biggest problems for effective waste | | | | maintenance and easy to wash. |
| disposable and recycling is plastic; and in particular | | | | 60 years on world leaders were beginning to despair |
| plastics containing PVC or poly vinyl chloride. The | | | | at what could be done to safely recycle uPVC. The |
| chlorine in the plastic makes it very carcinogenic | | | | answer is now at hand. Turn it into oil. What was once |
| because of dioxin emission when the PVC is burnt. | | | | a problem is now part of the solution thanks to World |
| PVC is safe as uPVC windows and plastic credit | | | | Changing Technologies and Paul Baskis. |
| cards and records and thousands of other consumer | | | | |