关键词: 介孔ZSM-5分子筛, 制备, 催化汽油, 加氢精制, 酸性

Abstract: The mesoporous H-ZSM-5 zeolite with moderate pore structure and acidity was prepared by optimization of crystallization time, crystallization temperature and mass ratio of rubber latex-3/silicon in gel（R） using cheap rubber latex-3 as the mesoporous template，followed by steaming/citric acid combination treatments. The hydrogenation performance of FCC gasoline was evaluated for the octane number recovery catalyst prepared on the basis of this molecular sieve. The characterization results indicated that the optimum value of crystallization time, crystallization temperature and R was 48 h, 190 ℃ and 0.26, respectively. In addition, the combination treatments not only markedly increased the mesoporous ratio of H-ZSM-5 zeolite but also regulated its acidity in a wide range. The FCC gasoline with a sulfur content of 113 μg/g and a olefin volume fraction of 40.9% was used for the evaluation of the octane recovery catalyst. The hydrotreated gasoline by newly prepared catalyst, compared with that of industrial catalyst, had lower volume fraction of alkenes by 2.2 percentage points, higher volume fraction of iso-alkanes by 1.1 percentage points, higher volume fraction of aromatics by 1.1 percentage points,whilet he desulfurization rate increased by 11.5 percentage points, and the loss in research octane number (RON) decreased by 0.5 unit with the same liquid yield. The results indicated that the bigger average pore, higher ratio of strong Lewis acidity/Bronsted acidity and more weak acidity contribute to decrease olefin and sulfur content, to hold RON and to increase liquid yield of hydrotreated FCC gasoline product. Moreover, the bigger average pore is beneficial to the dispersion of active metals in mesoporous molecular sieves, so as to make it show higher desulfurization performance for FCC gasoline.

Key words: mesoporous ZSM-5, preparation, FCC gasoline, hydrofining, acidity