Integrated Fischer-Tropsch and power production plant with low CO2 emissions
View Patent ↗A plant for producing Fischer-Tropsch liquids and electrical power with greatly reduced emissions of carbon dioxide to the atmosphere is made up of a syngas generator unit, an air separation unit, a Fischer-Tropsch unit, a CO 2 removal unit, and a combined cycle electricity generation unit. Each of Fischer-Tropsch liquids, carbon dioxide, and electrical power can be recoverable under proper economic conditions. Electrical power is recoverable by the use of a gas turbine fueled by predominantly hydrogen and a steam turbine powered by steam generated by cooling exhaust gases from the gas turbine. Sequestration of CO 2 and fueling the gas turbine with hydrogen reduces the amount of greenhouse gases emitted to the atmosphere.
1. A process comprising:
introducing a carbonaceous raw material, water and oxygen into a syngas generator under syngas forming operating conditions to form a syngas;
introducing a portion of the syngas into a Fischer-Tropsch reactor and forming primarily aliphatic hydrocarbons and carbon dioxide;
separating liquid hydrocarbons from the carbon dioxide, unconverted carbon monoxide, and hydrogen, which are Fischer-Tropsch tail gases;
introducing a portion of the syngas along with water and the Fischer-Tropsch tail gases into a water-gas-shift reactor to produce primarily hydrogen and carbon dioxide;
scrubbing the carbon dioxide from gases emitted from the shift reactor using a CO 2 scrubber;
collecting the carbon dioxide for sale or sequestration; and
burning the gases rich in hydrogen from the CO 2 scrubber in a gas turbine combustor of a combined cycle plant to drive a generator mechanically coupled to the gas turbine during a production of electricity.
2. The process of claim 1 , wherein said syngas forming operating conditions comprise a syngas generator temperature operating from about 2400° F. to about 2700° F.
3. The process of claim 1 further comprising desulfurizing the syngas before it enters the Fischer-Tropsch reactor.
4. The process of claim 1 , wherein the gas turbine produces a stack gas having a low CO 2 content.
5. The process of claim 1 further comprising a catalyst of unsupported precipitated iron to be used in the Fischer-Tropsch reactor.
6. The process of claim 5 , wherein the Fischer-Tropsch catalyst is doped with potassium and copper.
7. The process of claim 6 , wherein the weight ratio of potassium to iron in the catalyst is between about 0.007 and about 0.010.
8. The process of claim 6 , wherein the weight ratio of copper to iron in the catalyst is between about 0.005 and about 0.015.
9. A process comprising:
separating oxygen from nitrogen from the air in an air separation unit;
introducing a carbonaceous raw material, water and oxygen from the air separation unit into a syngas generator under syngas forming operating conditions to form syngas;
introducing a portion of the syngas into a Fischer-Tropsch reactor and forming primarily aliphatic hydrocarbons and carbon dioxide;
separating liquid hydrocarbons from the carbon dioxide, unconverted carbon monoxide, and hydrogen of Fischer-Tropsch tail gases;
introducing a portion of the syngas along with water and the Fischer-Tropsch tail gases into a water-gas-shift reactor to produce primarily hydrogen and carbon dioxide;
scrubbing the carbon dioxide from effluent from the shift reactor using a CO 2 scrubber;
collecting the carbon dioxide for sale or sequestration; and
burning the gases rich in hydrogen from the CO 2 scrubber in a gas turbine combustor of a combined cycle plant to drive a generator mechanically coupled to the gas turbine during a production of electricity.
10. The process of claim 9 , wherein said syngas forming operating conditions comprise a syngas generator temperature operating from about 2400° F. to about 2700° F.
11. The process of claim 9 further comprising desulfurizing the syngas before it enters the Fischer-Tropsch reactor.
12. The process of claim 9 , wherein the gas turbine produces a stack gas having a low CO 2 content.
13. The process of claim 9 further comprising a catalyst of unsupported precipitated iron to be used in the Fischer-Tropsch reactor.
14. The process of claim 13 , wherein the Fischer-Tropsch catalyst is doped with potassium and copper.
15. The process of claim 14 , wherein the weight ratio of potassium to iron in the catalyst is between about 0.007 and about 0.010.
16. The process of claim 14 , wherein the weight ratio of potassium to iron in the catalyst is between about 0.005 and about 0.015.
17. A process comprising:
separating oxygen from nitrogen from the air in an air separation unit;
introducing a carbonaceous raw material, water and oxygen from the air separation unit into a syngas generator under syngas forming operating conditions to form syngas;
introducing a portion of the syngas into a Fischer-Tropsch reactor having an iron-based catalyst, and forming primarily aliphatic hydrocarbons and carbon dioxide;
separating liquid hydrocarbons from the carbon dioxide, unconverted carbon monoxide, and hydrogen, which are Fischer-Tropsch tail gases;
introducing a portion of the syngas along with water and the Fischer-Tropsch tail gases into a water-gas-shift reactor to produce primarily hydrogen and carbon dioxide;
scrubbing the carbon dioxide from gases emitted from the shift reactor using a CO 2 scrubber;
collecting the carbon dioxide for sale or sequestration; and
burning the gases rich in hydrogen from the CO 2 scrubber in a gas turbine combustor of a combined cycle plant to drive a generator mechanically coupled to the gas turbine during a production of electricity.
18. The process of claim 17 , wherein said syngas forming operating conditions comprise a syngas generator temperature operating from about 2400° F. to about 2700° F.
19. The process of claim 17 further comprising desulfurizing the syngas before it enters the Fischer-Tropsch reactor.
20. The process of claim 17 , wherein the gas turbine produces a stack gas having a low CO 2 content.
21. The process of claim 17 , wherein the catalyst to be used in the Fischer-Tropsch reactor is unsupported precipitated iron.
22. The process of claim 21 , wherein the Fischer-Tropsch catalyst is doped with potassium and copper.
23. The process of claim 22 , wherein the weight ratio of potassium to iron in the catalyst is between about 0.007 and about 0.010.
24. The process of claim 22 , wherein the weight ratio of copper to iron in the catalyst is between about 0.005 and about 0.015.