Catalytic conversion of SPW and products upgrading

Chemical recycling is the emerging alternative to the well-established mechanical recycling toward the circular economy of solid plastic waste. Incorporation of catalysts into chemical recycling processes such as solvolysis, hydrothermal liquefaction, pyrolysis and gasification enables lower temperature operation and enhanced target product selectivity. Plastic waste, and/or thermochemically produced gaseous/liquid products, can be integrated into existing heterogeneous catalytic processes such as hydrogenolysis, Fischer Tropsch synthesis, methanol routes, catalytic cracking and hydroreforming (hydrocracking) by the action of metal and/or acid active sites to produce plastic monomers (ethylene and propylene), chemicals (benzene, toluene, ethylbenzene, xylene and methanol) and fuels (gasoline, jet fuel and diesel). In this review, catalytic processes directly or indirectly related with chemical plastic recycling are elaborated by discussing structure-performance relationships from the recent experimental and computational research performed over the last 10 years, assessing proposed catalytic reaction mechanisms and overviewing pilot to early commercial scale catalytic chemical recycling applications with projected future directions.