Patent ID: 8395004

Claim:
A sequential two-step process for producing light olefins from a synthesis gas comprising: a first step of performing a Fischer-Tropsch reaction of a synthesis gas at 200-400° C. and 5-25 atm and a flow rate of 500-8,000 GHSV in the presence of an iron catalyst to produce hydrocarbon compounds, wherein the iron catalyst comprises 0.01-0.1 mol of a metal selected from the group consisting of: copper, manganese, chromium, vanadium and zinc, based on 1 mol of iron, and, wherein the hydrocarbon compounds produced comprise 50-90 carbon mol % of olefin compounds; and a second step of cracking all the hydrocarbon compounds produced in the first step at 300-700° C. and 0.1-5 atm in the presence of a zeolite catalyst to produce C 2 -C 4 light olefins, wherein the hydrocarbon compounds produced in the first stet) are not purified prior to the second step of cracking.