OPTIMIZED HYDROCARBON SYNTHESIS PROCESS

1 . A process to produce hydrocarbons comprising the steps of:

passing a diluted synthesis gas through one or more Fischer-Tropsch reactors in series wherein the CO conversion in at least one of the Fischer-Tropsch reactors is greater than 60% and the overall CO conversion is at least 90%.

2 . The process of claim 1 , wherein the synthesis gas is generated by partial oxidation or auto thermal reforming of light hydrocarbons with air or oxygen-enriched air.

3 . The process of claim 1 , wherein the synthesis gas is generated by gasifying coal, petroleum coke, residual hydrocarbons, or biomass with air or oxygen-enriched air.

4 . The process of claim 1 , wherein the synthesis gas stream is scrubbed to remove trace contaminants such as NH 3 and HCN to a level below about 300 ppb.

5 . The process of claim 1 , wherein the synthesis gas is generated at a pressure sufficient to flow directly to the FT reactor(s) without further need of compression.

6 . The process of claim 1 , wherein the synthesis gas is generated at a pressure that is lower than a first Fischer-Tropsch reactor(s) and is therefore compressed to a pressure from 200 psig to 600 psig and fed to the first stage FT reactor.

7 . The process of claim 1 , wherein a heavy hydrocarbon product is removed through internal filters located in a slurry zone.

8 . The process of claim 1 , wherein a heavy hydrocarbon product is removed through external filters.

9 . The process of claim 1 , wherein an overhead stream is cooled to an intermediate temperature to remove a portion of a condensable products as a liquid.

10 . The process of claim 1 , wherein a product is recovered from a tail gas of a final reactor stage by a cryogenic process, absorption, or adsorption.

11 . The process of claim 1 , wherein the CO conversion in at least one Fischer-Tropsch reactor is greater than 60% and less than about 80%.

12 . The process of claim 1 , wherein the CO conversion in at least one Fischer-Tropsch reactor is between about 70% and about 80%.

13 . The process of claim 1 , wherein the CO conversion in at least one Fischer-Tropsch reactor is between about 72% and about 76%.

14 . The process of claim 1 , wherein the overall CO conversion is at least 92%.

15 . The process of claim 1 , wherein the overall CO conversion is at least 94%.

16 . The process of claim 1 , wherein the partial pressure of water in each Fischer-Tropsch reactor(s) is less than 60 bar.

17 . The process of claim 1 , wherein the partial pressure of water in each Fischer-Tropsch reactor(s) is between about 40 bar and about 60 bar.

18 . The process of claim 1 , wherein the partial pressure of water in each Fischer-Tropsch reactor(s) is between about 50 bar and about 60 bar.

19 . The process of claim 1 , wherein the partial pressure of water in each Fischer-Tropsch reactor(s) is about 55 bar.

20 . The process of claim 1 , wherein the diluted synthesis gas comprises about 30% nitrogen by volume.

21 . The process of claim 1 , wherein the diluted synthesis gas contains between about 20% and about 60% nitrogen by volume.

22 . The process of claim 1 , wherein the Fischer-Tropsch reactor(s) contains a Fischer-Tropsch reaction catalyst comprising cobalt supported on alumina.

23 . The process of claim 1 , wherein the Fischer-Tropsch reactor(s) contains a Fischer-Tropsch reaction catalyst comprising cobalt and ruthenium supported on alumina.

24 . The process of claim 1 , wherein the Fischer-Tropsch reactor(s) is operated at temperatures of between about 380 and about 500° F.

25 . The process of claim 1 , wherein the Fischer-Tropsch reactor(s) is operated at pressures of between about 15 and about 40 atmospheres.

26 . The process of claim 1 , wherein the synthesis gas is diluted with one or more gasses selected from the group consisting of nitrogen, carbon dioxide, and methane.

27 . The process of claim 1 , wherein at least one of the Fischer-Tropsch reactors has a CO conversion of at least 90%.