Producing aromatic-enriched oil from mixed plastics through catalytic pyrolysis has been experimentally studied. The effect of biochar catalysts has been investigated, and the possible dominating catalytic mechanisms of biochars activated with different chemical agents have been discussed. Results indicated that when waste plastics were pyrolyzed with raw biochar, the alkene fraction in the oil product increased to 54.9%. When biochar was activated by ZnCl₂, KOH, and H₃PO₄, the oil product showed high selectively toward aromatics, and the proportions of aromatics were up to 47.6, 44.7, and 66.0%, respectively. Benzene, 1,1′-(1,3-propanediyl) bis- was the main composition in aromatics, the proportion of which could be up to 25.1% when KOH-activated biochar was used. The enrichment part of aromatics was mainly bicyclic aromatics and C₁₅–C₁₆ compositions, the maximum proportions of which could reach 92.5 and 28.1% by KOH-activated biochar. High surface functional group (e.g., C═O) content and low metal content of KOH-activated biochar promoted hydrogen transfer reaction of alkenes to alkanes and aromatics, whereas the aromatization process promoted by Lewis acid sites and Brønsted acid sites on ZnCl₂- and H₃PO₄-activated biochar, respectively, significantly increased aromatic yield.

中文翻译：

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活性生物炭为催化剂，由混合塑料生产富含芳香的油

实验研究了由混合塑料通过催化热解制备富含芳香剂的油。研究了生物炭催化剂的作用，并讨论了用不同化学试剂活化的生物炭可能的主要催化机理。结果表明，将废塑料与原始生物炭热解后，油品中的烯烃含量增加到54.9％。当生物炭被ZnCl ₂，KOH和H ₃ PO ₄活化时，该油产品对芳族化合物选择性较高，芳族化合物的比例分别高达47.6％，44.7％和66.0％。苯，1,1'-（1,3-丙二基）双-是芳烃中的主要成分，当使用KOH活化的生物炭时，其比例可高达25.1％。芳香族化合物的富集部分主要是双环芳香族化合物和C ₁₅ -C ₁₆组成，通过KOH活化的生物炭，其最大比例可以达到92.5和28.1％。高的表面官能团（例如，C = O）KOH活化的生物炭的含量和低金属含量促进烯烃到烷烃和芳族化合物的氢转移反应，而芳构化过程通过在氯化锌路易斯酸位点和布朗斯台德酸位点促进₂ -和高₃PO ₄活化的生物炭分别显着提高了芳烃收率。