SITA UK, one of the country’s leading recycling and resource management companies and a subsidiary of Suez Environment, has signed an exclusive agreement with Cynar Plc to build Britain’s first fully operational plants to convert end of life plastic into diesel fuel. Cynar is a UK company established to commercialize the ThermoFuel technology exclusively licensed to it in the UK and Ireland by its owners, Ozmotech Pty Ltd. The waste plastics to hydrocarbon fuels liquefaction technology is based on pyrolysis and distillation.
Cynar’s first plant is built and operating in Portlaoise, Ireland. The objective of the new agreement is 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 end 2011.
Suez Environment will commission the first of the plants by the end of 2011 in the greater London area. SITA UK aims to construct at the rate of two to three plastic to diesel conversion plants per year depending on planning.
Each plant is 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 4 million liters (1.056 million gallons US) of specification diesel fuel.
Suez Environment’s venture fund Blue Orange will contribute to the financing scheme together with SITA UK.
The waste plastic recovery process is expected to be produced at below the cost of normal diesel and the fuel itself is expected to have a lower carbon footprint than conventional diesel. The fuel qualities of the recycled diesel will be on a par with conventional diesel, without the need for any further refining and therefore suitable for commercial use.
Cynar system. Plastic waste is continuously treated in a cylindrical chamber and the pyrolytic gases condensed in a specially-designed condenser system to yield predominantly straight chain aliphatic hydrocarbons with little formation of by-products. These hydrocarbons are then selectively condensed and cleaved further catalytically to produce the average carbon chain length required for distillate fuel.
The plastic is pyrolized at 370 ºC-420 ºC and the pyrolysis gases are condensed in a 2-stage condenser to produce a low-sulfur distillate. (Pyrolysis is a process of thermal degradation in the absence of oxygen.)
The system consists of stock infeed system, pyrolysis chambers, contactors, distillation, centrifuge, oil recovery line, off-gas cleaning, and residual contamination removal.
Waste plastics are loaded via a hot-melt infeed system directly into main pyrolysis chamber. Agitation evens the temperature and homogenizes the feedstocks. Pyrolysis then commences and the plastic becomes a vapor. Non-plastic materials fall to the bottom of the chamber.
The vapor is converted into the various fractions in the distillation column, the distillates then pass into the recovery tanks. From the recovery tanks, the product is sent to a centrifuge to remove contaminants such as water or carbon. The cleaned distillates are then pumped to the storage tanks.
(A hat-tip to Harold!)