Low-temperature upcycling of polyolefins into liquid alkanes via tandem cracking-alkylation

Selective upcycling of polyolefin waste has been hampered by the relatively high temperatures that are required to cleave the carbon-carbon (C-C) bonds at reasonably high rates. We present a distinctive approach that uses a highly ionic reaction environment to increase the polymer reactivity and lower the energy of ionic transition states. Combining endothermic cleavage of the polymer C-C bonds with exothermic alkylation reactions of the cracking products enables full conversion of polyethylene and polypropylene to liquid isoalkanes (C6 to C10) at temperatures below 100 degrees C. Both reactions are catalyzed by a Lewis acidic species that is generated in a chloroaluminate ionic liquid. The alkylate product forms a separate phase and is easily separated from the reactant catalyst mixture. The process can convert unprocessed postconsumer items to high-quality liquid alkanes with high yields.

Automated summary

We propose a unique approach to selectively upcycle polyolefin waste by utilizing a highly ionic reaction environment, which increases polymer reactivity and reduces energy required for breaking carbon-carbon bonds. By catalyzing endothermic cleavage and exothermic alkylation reactions, we are able to convert polyethylene and polypropylene to liquid isoalkanes at temperatures below 100 degrees C. This process offers a high yield conversion of unprocessed postconsumer items into high-quality liquid alkanes.