李怡晶, 贾含琼, 郝文明, 马静红, 李瑞丰. Y型分子筛上9, 10-二氢菲低温加氢裂化性能研究[J]. 燃料化学学报(中英文). DOI: 10.1016/S1872-5813(24)60480-9
引用本文: 李怡晶, 贾含琼, 郝文明, 马静红, 李瑞丰. Y型分子筛上9, 10-二氢菲低温加氢裂化性能研究[J]. 燃料化学学报(中英文). DOI: 10.1016/S1872-5813(24)60480-9
LI Yijing, JIA Hanqiong, HAO Wenming, MA Jinghong, LI Ruifeng. Low temperature hydrocracking of 9, 10-dihydrophenanthrenes over Brønsted acidic Y zeolites[J]. Journal of Fuel Chemistry and Technology. DOI: 10.1016/S1872-5813(24)60480-9
Citation: LI Yijing, JIA Hanqiong, HAO Wenming, MA Jinghong, LI Ruifeng. Low temperature hydrocracking of 9, 10-dihydrophenanthrenes over Brønsted acidic Y zeolites[J]. Journal of Fuel Chemistry and Technology. DOI: 10.1016/S1872-5813(24)60480-9

Y型分子筛上9, 10-二氢菲低温加氢裂化性能研究

Low temperature hydrocracking of 9, 10-dihydrophenanthrenes over Brønsted acidic Y zeolites

  • 摘要: 由于日益严重的原油重质化和劣质化问题,引起催化裂化柴油(轻循环油LCO)品质恶化,其显著的特点是多环芳烃含量高,因此,将LCO中的多环芳烃经加氢转化为轻质芳烃原料是解决柴油过剩和轻质芳烃短缺的理想途径。为此本工作选择部分加氢的9, 10-二氢菲作为多环芳烃的代表性模型分子,以具有不同酸性的Y型分子筛为催化剂,探索了在250−350 ℃反应温度和4.0 MPa氢气压力下,反应温度和Y分子筛的质子酸酸性对9, 10-二氢菲通过加氢裂化向轻质芳烃转化路径的影响规律。结果表明,加氢裂化产物中不仅有代表9, 10-二氢菲边环开环裂化的产物萘、四氢萘和茚满等,同时还有联苯的产生,说明9, 10-二氢菲可以通过中间环直接开环裂化生成单环芳烃。两条路径的竞争可通过反应温度的控制和酸性的调变进行控制。较高的反应温度和增加分子筛表面酸量均可通过抑制氢转移反应而增强开环反应的进行,但是过高的反应温度则会导致反应物过度加氢裂解。同时,分子筛酸性的增强有利于环烷基环的开环、异构以及脱烷基反应,从而促进单环芳烃的生成。研究结果的获得为多环芳烃通过加氢裂化向单环芳烃转化催化剂和工艺的设计提供了一条新思路。

     

    Abstract: Facing the escalating challenge of processing heavier and lower-quality crude oils, the utilization of light cycle oil (LCO) derived from fluid catalytic cracking units is constrained by its high aromatic content. The transformation of LCO into lighter aromatic hydrocarbons through catalytic conversion emerges as a more advantageous and valuable strategy, addressing the surplus of diesel and the scarcity of light aromatics. Consequently, the hydroconversion of 9, 10-dihydrophenanthrenes (9, 10-DHP), serving as a representative molecule of polycyclic aromatic hydrocarbons (PAHs), over metal-free zeolite Y catalysts with varying acidity, has been investigated in a stirred batch reactor. The experiments were conducted at temperatures ranging from 250 to 350 ℃ under a pressure of 4.0 MPa. The study delved into the impact of reaction temperature and the Brønsted acidity of zeolite Y on the reaction pathway. Product analysis revealed the formation of a diverse array of products, including biphenyls, naphthalenes, tetralins, indanes, alkylbenzenes, benzene, and minor alkanes, during the hydrocracking of 9, 10-DHP. The reaction pathway for the hydrocracking of 9, 10-DHP to monocyclic aromatic hydrocarbons (MAHs) over acidic zeolite Y was proposed to follow two potential routes: one involving hydrogen transfer leading to the formation of phenanthrene and tetrahydrophenanthrene, followed by terminal ring opening; the other characterized by a direct central ring opening. The interplay between these two pathways is contingent upon the reaction temperature and the acidity of the employed zeolite. Promoting central ring opening and suppressing hydrogen transfer can be realized by manipulating the reaction temperature and enhancing the acid density of the zeolite. However, excessive hydrogenation and cracking are observed with further increases in reaction temperature. Additionally, augmenting the strength of acidic sites is beneficial for ring opening and isomerization of hydrogenated aromatics, as well as dealkylation to produce MAHs. The findings underscore a promising approach for the design of PAHs hydrocracking catalysts and reaction techniques.

     

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