Limonene is significant feedstock and how to abundantly acquire or convert into high-value chemicals is crucial. Waste tire pyrolysis oil (TPO) rich in limonene provides an alternative route. To address its difficult separation from other compounds in TPO, especially p-cymene, a new route to convert limonene into α-terpinyl methyl ether (TME) with high boiling point was proposed by alkoxylation over heteropolyacid-modified Hβ zeolite. Strong Brønsted acid centers can attain high efficiency in alkoxylation in limonene-p-cymene binary compounds. 89.24 % conversion was achieved after 5 h at 60 °C while TME yield is the highest (71.70 %) after 3 h with no reaction of p-cymene. Above 80 % limonene is transformed in real fraction of 160–180 °C of TPO and TME yield exceeds 60 %. Initial separation of TME and aromatic was achieved by vacuum distillation. The possible mechanism of limonene alkoxylation was proposed. This work provides a new approach to efficient utilization of limonene.

中文翻译：

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在杂多酸改性 Hβ 分子筛上通过轮胎热解油催化烷氧基化合成 α-萜品基甲基醚


柠檬烯是重要的原料，如何大量获取或转化为高价值化学品至关重要。富含柠檬烯的废轮胎热解油 （TPO） 提供了一种替代途径。为了解决其与 TPO 中其他化合物（尤其是对环孢烯）分离困难的问题，提出了一种通过在杂多酸改性的 Hβ 分子筛上烷氧基化将柠檬烯转化为高沸点α-萜品酰甲基醚 （TME） 的新路线。强 Brønsted 酸中心可以在 limonene-p-cymene 二元化合物中实现高效的烷氧基化。在 60 °C 下 5 小时后实现 89.24% 的转化率，而 3 小时后 TME 产率最高 （71.70%），对伞绿没有反应。高于 80% 的柠檬烯在 160–180 °C 的 TPO 的实际馏分中转化，TME 产率超过 60%。TME 和芳烃的初步分离是通过真空蒸馏实现的。提出了柠檬烯烷氧基化的可能机制。这项工作为柠檬烯的高效利用提供了一种新的方法。