Abstract: In order to prevent the silicon in naphtha from harming the catalysts used in hydrogenation and reforming processes, a scheme of treating high silicon naphtha in fluidized catalytic cracking unit was proposed. High silicon naphtha was desiliconized in a pilot riser unit. By adjusting the blending ratio, reaction residence time and feedstock properties, the industrial process conditions were preliminarily determined, and the reaction mechanism was explored. The industrial experiment was carried out in a 2.80 Mt/a catalytic cracking unit of SINOPEC Tianjin Company, and the effect of this scheme on the desiliconization of naphtha was further verified. The results showed that when the high silicon naphtha was injected as terminator with the blending ratio less than 1% and the reaction residence time more than 3 s, the treatment effect was the best. The program has excellent desiliconization effect of naphtha and can avoid impurity pollution caused by using silicon catcher or desilication protector.

Key words: catalytic cracking, naphtha, silicon, gasoline, diesel