System and method of increasing synthesis gas yield in a fluid catalytic cracking unit
View Patent ↗Systems and methods of reducing refinery carbon dioxide emissions by improving the overall synthesis gas yield in a fluid catalytic cracking unit having a reactor and a regenerator are discussed. In one example, a method comprises introducing spent catalyst and a feed gas comprising oxygen to the regenerator at gasification conditions. The method further comprises heating the spent catalyst to burn coke therefrom to produce a synthesis gas. The method further comprises combining the synthesis gas with a dry gas comprising hydrogen, creating the overall synthesis gas and thereby increasing the yield of the overall synthesis gas produced in the FCC unit.
1. A method of increasing the yield of an overall synthesis gas in a fluid catalytic cracking unit having a reactor and a regenerator, the method comprising:
introducing spent catalyst and a feed gas comprising oxygen to the regenerator at gasification conditions;
heating the spent catalyst to burn coke therefrom to produce a synthesis gas from the regenerator;
separating dry gas comprising hydrogen from another refinery unit or reactor product vapors in a gas condensing section of the fluid catalytic cracking unit;
combining the synthesis gas with the dry gas, thereby increasing the yield of the overall synthesis gas produced in the fluid catalytic cracking unit; and
reforming the overall synthesis gas in a secondary reforming unit, thereby increasing the hydrogen content in the overall synthesis gas.
2. A method of claim 1 wherein the feed gas further comprises steam.
3. A method of claim 2 wherein the feed gas has a mole ratio of about 3 moles of steam per mole of oxygen.
4. A method of claim 1 wherein the feed gas further comprises carbon dioxide.
5. A method of claim 4 wherein the feed gas has a mole ratio of about 3 moles of carbon dioxide per mole of oxygen.
6. A method of claim 1 wherein the dry gas further comprises at least one member selected from the group consisting of methane, ethane, and ethylene.
7. A method of claim 1 wherein the synthesis gas from the regenerator comprises at least one member selected from the group consisting of hydrogen, carbon monoxide, carbon dioxide and steam.
8. A method of claim 1 further comprising:
hydrotreating the overall synthesis gas to reduce the amount of olefinic compounds in the overall synthesis gas.
9. A method of claim 1 further comprising:
hydrotreating the overall synthesis gas to remove hydrogen sulfide present in the overall synthesis gas.