Application of molecular sieve in petroleum and petrochemical industry
The cracking reaction that occurs on the sour site under typical hydrocracking conditions tends to be the controlling step factor for the overall reaction rate. Therefore, the acidity of the catalyst is also the main factor affecting the reaction temperature and also the main factor affecting the activity of the catalyst. Such catalysts require moderate hydrogenation activity and strong acidity. In this type of catalyst, the content of zeolite is relatively high, accounting for 60%-80% of the catalyst. The cracking activity of the zeolite varieties used is ranked as follows: mordenite>B zeolite>Y zeolite>chabazite>erionite>X zeolite>A zeolite.
2.C5/C6 alkane isomerization
C5/C6 alkane isomerization can increase the octane number of gasoline. Since dimethylbutane with two methyl side chains has the highest octane number and is an ideal octane isomer, perforated Y zeolite and mordenite are selected. Mordenite has significant advantages over Y zeolite, because in the unit cell of mordenite, there are more five-membered rings in addition to four, six or eight-membered rings, and the main channel of the twelve-membered ring is a straight-through type. The pores can be further enlarged by modification.
3. Toluene disproportionation and transalkylation
Industrial toluene catalysts are all zeolite catalysts, and typical mordenite catalysts are TC-78, ZA-3, ZA-90 and other series of catalysts developed by Shanghai Petrochemical Research Institute.
4. Xylene Isomerization
The xylene isomerization production methods are roughly divided into three categories, namely, amorphous aluminum silicate catalytic isomerization method, zeolite catalytic isomerization method, and bifunctional catalytic isomerization method. Among them, the representative one is the xylene isomerization catalyst with hydrogen-type mordenite as active component developed by Toray Company of Japan.