The sulfur and thiol contents in cracking (FCC) gasoline are respectively 200~1600 ug/g, 30~200 ug/g. FCC gasoline is a major component of some refineries, its mixing ratios can even up to 80% ~ 90%. Therefore, the key to meet the new clean gasoline specifications is to reduce the sulfur content of the FCC gasoline and mercaptans. Hydrodesulfurization catalyst containing tungsten trioxide can be used to handle the full range FCC gasoline to produce low-sulfur gasoline. In which, the gasoline feedstock does not required to fractionate, also the intermediate separation process does not required after RSDS, with the simple process and easy to operate.

 

The preparation method of hydrodesulfurization catalyst containing tungsten trioxide is as follows:

A. Mix the zeolite and binder-inorganic oxide and extruded to bars, dry under 100°C~140°C for 8~15 hours, calcine under 400°C~600°C for 3~10 hours to prepare the carrier intermediate of catalyst;

B. Place the intermediate carrier in the water vapor atmosphere of water/solid volume ratio of 1:1~10:1, heat to 500~600 ° C for insulating hydrothermal treatment for 3~15 hours to obtain the final catalyst carrier;

C. Loading the transition metal (tungsten trioxide, molybdenum oxide) and lanthanum oxide by dipping method, then filtrate, dry, calcine to obtain hydrodesulfurization catalyst containing tungsten trioxide.

 

Low-grade gasoline feedstock including: FCC, catalytic cracking, coker, thermally cracked and other types of gasoline, all of their hydrofinishing can use tungsten trioxide hydrodesulfurization catalyst with the distillation range of 30°C~220°C. Its hydrodesulfurization process conditions are as bellow: reaction pressure of 1.0MPa~3.0MPa, reaction temperature of 360°C~400°C, hydrogen oil volume ratio of 500: 1~700: 1. This process environment can handle the high-sulfur and olefin of gasoline feedstock; finally get the low sulfur gasoline with 10ug/g or less of mercaptan sulfur, the total sulfur as low as 50ug/g or less.