Liu Sibao, Kots Pavel A, Vance Brandon C, Danielson Andrew, Vlachos Dionisios G
Catalysis Center for Energy Innovation, University of Delaware, 221 Academy St., Newark, DE 19716, USA.
Center for Plastics Innovation, University of Delaware, 221 Academy St., Newark, DE 19716, USA.
Sci Adv. 2021 Apr 21;7(17). doi: 10.1126/sciadv.abf8283. Print 2021 Apr.
Single-use plastics impose an enormous environmental threat, but their recycling, especially of polyolefins, has been proven challenging. We report a direct method to selectively convert polyolefins to branched, liquid fuels including diesel, jet, and gasoline-range hydrocarbons, with high yield up to 85% over Pt/WO/ZrO and HY zeolite in hydrogen at temperatures as low as 225°C. The process proceeds via tandem catalysis with initial activation of the polymer primarily over Pt, with subsequent cracking over the acid sites of WO/ZrO and HY zeolite, isomerization over WO/ZrO sites, and hydrogenation of olefin intermediates over Pt. The process can be tuned to convert different common plastic wastes, including low- and high-density polyethylene, polypropylene, polystyrene, everyday polyethylene bottles and bags, and composite plastics to desirable fuels and light lubricants.
一次性塑料对环境造成了巨大威胁,但其回收利用,尤其是聚烯烃的回收利用,已被证明具有挑战性。我们报道了一种直接方法,可在氢气中、低至225°C的温度下,将聚烯烃选择性地转化为包括柴油、喷气燃料和汽油馏分烃在内的支链液体燃料,在Pt/WO/ZrO和HY沸石上的产率高达85%。该过程通过串联催化进行,首先主要在Pt上对聚合物进行初始活化,随后在WO/ZrO和HY沸石的酸性位点上进行裂解,在WO/ZrO位点上进行异构化,并在Pt上对烯烃中间体进行氢化。该过程可进行调整,以将不同的常见塑料废物,包括低密度和高密度聚乙烯、聚丙烯、聚苯乙烯、日常聚乙烯瓶和袋以及复合塑料,转化为所需的燃料和轻质润滑剂。