London – Recycling company Sita is to build Britain’s first fully operational plants to convert end-of-life plastic into diesel fuel using liquefaction, pyrolysis and distillation technology developed by Cynar.
The company plans to build 10 UK plants dealing with 60,000 tonnes of mixed plastic waste per year and to commission the first plant in London by the end of 2011.
The company then aims to construct two to three plastic-to-diesel conversion plants per year, depending on planning consent.
Each plant will be designed to convert approximately 6,000 tonnes of mixed waste plastic annually, specifically targeting mixed waste plastic diverted from landfill, and to produce in excess of four million litres of diesel fuel.
The Cynar system consists of a stock infeed system, pyrolysis chambers, contactors, distillation, centrifuge, oil recovery line, off-gas cleaning and residual contamination removal.
In use, waste plastics are loaded via a hot-melt infeed system directly into a main pyrolysis chamber. Agitation commences to even the temperature and homogenise the feedstocks. Pyrolysis then commences and the plastic becomes a vapour. Non-plastic materials fall to the bottom of the chamber.
The vapour is then converted into the various fractions in the distillation column and the distillates then pass into the recovery tanks. From here, the product is sent to a centrifuge to remove contaminants such as water or carbon. The cleaned distillates are then pumped to storage tanks.
Sita says that the recycled diesel will be comparable in quality with conventional diesel, without the need for any further refining; it will, therefore, be suitable for commercial use.
David Palmer-Jones, chief executive of Sita, said: ’Traditionally, mixed waste plastic has been sent to landfill as no economically viable alternative way of treating it has been developed. This can now be given a second life as a sustainable alternative to diesel.’