| abstract |
The sulfur content of liquid cracking products, particularly cracked gasoline, is reduced by the use of a sulfur reduction additive comprising a porous molecular sieve containing a metal having a degree of oxidation above zero inside the sieve's pore structure. The molecular sieve is normally a large pore size zeolite such as USY or zeolite beta or a medium pore size zeolite such as ZSM-5. The metal is normally a metal of period 3 of the periodic table, preferably zinc or vanadium. The sulfur reduction catalyst may be used in the form of a separate particulate additive or as a component of a composite cracking / sulfur reduction catalyst. |