The disposal of waste plastics has become a major worldwide environmental
problem. The USA, Europe and Japan generate annually about 50 million tons of
post-consumer plastic waste, previously landfilled, generally considered as a
non-sustainable and environmentally questionable option. Landfill sites and their
capacity are, moreover, decreasing rapidly, and legislation is stringent. Several
European directives and US legislation concern plastic wastes and the required
management. They are briefly discussed in this paper.
New processes have emerged, i. e., advanced mechanical recycling of plastic
waste as virgin or second grade plastic feedstock, and thermal treatments to recycle
the waste as virgin monomer, as synthetic fuel gas, or as heat source (incineration
with energy recovery). These processes avoid land filling, where the
non-biodegradable plastics remain a lasting environmental burden.
The paper reviews these alternative options through mostly thermal processing
(pyrolysis, gasification, and waste-to-energy). Additional research is, however,
still needed to confirm the potential on pilot and commercial scale.
Key words: plastic waste, re-use, thermal valorization, legislation