Plastic waste recycling

As a result of an intensive R&D undertaking started in 1983, several waste recycling plants have been working throughout the last years (the first one in Japan for more than 8 years), having proven to be successful and economically viable, with virtually uninterrupted operation.

The system uses liquefaction, pyrolysis and the catalytic breakdown of plastics, a process whereby scrap and waste plastic are converted into liquid hydrocarbons that can be used as fuels. It can handle almost all the plastic that is currently being sent to landfills.

Pyrolysis is a process of degradation in the absence of oxygen. Plastic waste is continuously treated in a cylindrical chamber and the pyrolytic gases condensed in a specially-designed condenser system to yield a hydrocarbon distillate comprising straight and branched chain aliphatics, cyclic aliphatics and aromatic hydrocarbons. The resulting mixture is essentially equivalent to petroleum distillate.

The density of “green” distilled fuels is close to that of regular diesel, as well as its other characteristics. Green Fuel contains the same energy content as conventional diesels, but with significantly reduced emissions levels for environmentally sound operation. Existing diesel engines can run fully effectively on these fuels with no engine modification.

Plastics Suitability for Treatment

Note: The system can handle almost all the plastic that is currently sent to landfills, including co-mingled municipal and manufacturing wastes, chemical and oil drum/bottles, MSW plastics including wraps, packaging, bottles and toys as well as milk crates, silage wraps, irrigation tubing and polypiping. There is no need to identify plastics by type for it to be used in the process. It is only necessary to separate the commingled plastic stream away from the general waste stream.

A major advantage of the the process is its ability to handle unsorted, unwashed plastic waste.

This means that heavily contaminated plastics such as mulch film can be processed without difficulty. The same applies to silage wrap, trickle tape and other agricultural plastics. Other normally hard to recycle plastics such as laminates of incompatible polymers, multilayer films or polymer mixtures can also be processed with ease unlike in conventional plastic recycling techniques. In fact, most plastics can be processed directly even if contaminated with dirt, aluminium laminates, printing inks, oil residues, etc. During the pyrolysis process, non-plastic materials fall to the bottom of the chamber and will be eliminated later.

The char residue produced is about 5% of the output for relatively clean polyolefin feedstocks and up to 8–10% for PET-rich feedstocks. Since the char passes acid leaching tests it can simply be landfilled.

This patented technology distributed with exclusive rights by Ozmo Energy Ltd in several markets will be introduced in various European countries in the next period of time, as a series of new plants will be put into operation. The applied process is a truly sustainable waste recycling solution, diverting plastic waste from landfills, utilising the embodied energy content of plastics and producing a highly usable commodity that, due to its cleaner burning characteristics, is in itself more environmentally friendly than conventional distillate.