Technological Challenges in Plastic Recycling. Can technological innnovation tackle the problem of plastic waste?

Abstract. Plastic materials were a major milestone that led to improvement in the quality of the lives of human beings. Plastic became very important material and in the last decade production passed the 320 million tons worldwide. It is estimated that less than 50% of plastic was consigned to landfill or recycled and from the remaining some are still in use, the rest 10-12 million tons are entering every year the oceans, breaking down into small pieces, microplastics. The exponential increase of plastics worldwide and the inadequate management led inevitably to massive amounts of rubbish accumulating in landfills and oceans. Policy makers in developed countries are under immense pressure to find ways to slash plastic usage and organise better recycling shemes. Corporations are pressurised to turn to more environmentally friendly measures, biopalstics and efficient recycling due to consumer demand. For example, 5 trillion plastic bags were produced yearly worldwide and only recently the campaign to reduce them drastically started in many countries. Sweden has advanced recycling policies with 6,000 municipal recycling drop off stations that separate and recyclable waste, especially plastics. Almost all types of plastic can be recycled. However the extent to which they are recycled depends upon technological methodologies, but also economic and logistic factors. At present there are numerous research projects worldwide and innovative discoveries to separate and recycle the vast amounts of solid municipal and industrial plastic waste with mechanical and chemical methods. The technology of mechanically sorting plastic waste has gone through a technological “revolution”, where old plastic are separeted and used to make new products at a positive cost/benefit balance. Chemical recycling is progressing fast with technological innovations for efficient recovering energy, production of valuable new chemical products such as monomers or petrochemical feedstocks. Technological advances have been achieved on the depolymerization of plastic waste to turn one type of plastic into another that is more valuable. Thermal and catalytic cracking pyrolysis into liquid fuels is advancing with promissing results. Innovative bioplastics which are fully recyclable and environmentally friendly are under intense researtch in many industrial and university laboratories. Despite the progress, the plastic waste represents a challenging and technologically difficult problem. The reduction of single-usage plastic and throw away culture has to change drastically in orde to face the “menace”of plastic waste and the advesrse effects on wildlife and marine pollution.

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