Patent ID: 8049036

Claim:
A multi-stage method for preparing C 3 -C 8 alkenes from corresponding C 3 -C 8 alkanes, comprising the steps of: (A) combining 5-30% by weight of a C 3 -C 8 alkane, and a stoichiometric amount of molecular oxygen, fully oxidizing the alkane to produce carbon dioxide, water vapor, and unreacted alkane; (B) combining the carbon dioxide, water vapor, and unreacted alkane to form a combined feed stream; and (C) contacting the combined feed stream with one or more steam cracking catalysts at a temperature of from 700° C. to 1000° C. and a residence time of no greater than 100 milliseconds, to produce the corresponding C 3 -C 8 alkene, wherein the one or more steam cracking catalysts comprise a catalyst system cumulatively effective at converting the C 3 -C 8 alkane to its corresponding C 3 -C 8 alkene and comprising: (1) at least one metal selected from the group consisting of: Ag, Au, Ir, Ni, Pd, Pt, Rh, Ru, alloys thereof and combinations thereof; and (2) at least one modifier selected from the group of metal oxides including the metals Bi, In, Mg, P, Sb, Zr, Group 1-3 metals, lanthanide metals and combinations thereof, wherein the one or more steam cracking catalysts further comprise (3) at least one oxide of a metal selected from the group consisting of: Cd, Co, Cr, Cu, Fe, Mn, Ni, Nb, Ta, V, Zn, and combinations thereof.