甲苯与甲醇择形催化制对二甲苯技术进展

Development of shape-selective alkylation of toluene with methanol to para-xylene

对二甲苯是一种重要的芳烃原料,在石油化工行业中有着举足轻重的地位。近十年来,我国对二甲苯的需求保持持续增长的态势,为了保障我国对二甲苯产业健康、稳步的发展,迫切需要开发更为低成本、高效的对二甲苯生产工艺。甲苯与甲醇择形催化制对二甲苯是目前最具前景和竞争力的新技术之一,然而如何在保持高选择性的前提下提高催化剂的稳定性是该技术面临的严峻挑战。低碳烯烃的生成是导致催化剂积炭失活的主要原因之一。本文通过对催化反应机理和催化剂研究进展的介绍,认为开发高选择性、高稳定性的催化剂可以从合成既有择形效应又有优良扩散特性的分子筛母体、协同调控分子筛的孔结构和酸性质以及抑制低碳烯烃的形成三个方向发力。

Para-xylene is an important aromatic material in petrochemical industry. In recent decades,China’s demand for para-xylene has been growing. In order to ensure the healthy and steady development of para-xylene industry in China, it is urgent to develop a more low-cost and efficient para-xylene production process. Shape-selective alkylation of toluene with methanol to para-xylene is one of the most promising and competitive new technologies for para-xylene production. However, how to improve the stability of the catalysts while maintaining their high selectivity is still challenging. The formation of lowcarbon olefins is one of the main reasons for the deactivation of the catalysts. Based on the discussion of the catalytic reaction mechanisms and research progress of the catalyst, we believe that the exploitation of highly selective and stable catalysts can be driven from three directions: synthesis of molecular sieve parent of shape-selective effect and excellent diffusion property, coordinated regulation of the pore structure and acid properties of molecular sieves, and inhibition of the formation of low-carbon olefins.