Hydrocarbon conversion system with enhanced combustor and method

• US 6,989,135 B2
• Filed: 06/08/2001
• Issued: 01/24/2006
• Est. Priority Date: 07/01/1999
• Status: Expired due to Term

• Current Assignee: REG Synthetic Fuels, LLC (Chevron Corp.)
• Original Assignee: Syntroleum Corporation (Chevron Corp.)
• Inventors: Kennedy, Paul E.
• Primary Examiner(s): Doroshenk, Alexa
• Assistant Examiner(s): Patel, Vinit H.
• Application Number:
  US09/877,286
• Publication Number:
  US 20010044476A1
• Time in Patent Office: 1,691 Days
• Field of Search: 518/703, 422/211, 422/190, 60/390.5
• US Class Current: 422/198
• CPC Class Codes: C07C 1/0485 Set-up of reactors or accessories; Multi-step processes
• CPC Class Codes: C10G 2/30 from carbon monoxide with hydrogen
• CPC Class Codes: C10G 2/32 with the use of catalysts
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

A Fischer-Tropsch-based hydrocarbon conversion process involves compressing air in a compressor section of a gas turbine, delivering a portion of the compressed air to a combustor of the gas turbine, delivering a portion of the compressed air to a Fischer-Tropsch hydrocarbon conversion unit, extracting thermal energy from the combustor and delivering it to the Fischer-Tropsch hydrocarbon conversion unit, converting light hydrocarbons into heavier hydrocarbons in the Fischer-Tropsch hydrocarbon conversion unit, and delivering combustion gases from the combustor to an expansion section of the gas turbine. A heat recovery steam generator (HRSG) may also be used to harness waste heat from the expansion section. A conversion system for converting light hydrocarbons into heavier hydrocarbons includes a turbine from which heat energy is removed and used to assist in converting hydrocarbons and whereby greater throughput of the turbine is possible. Waste heat from the expander of the turbine may be recovered with a HRSG.

Claims

1. A Fischer-Tropsch-based system for converting light hydrocarbons into heavier hydrocarbons comprising:

a gas turbine having a compressor section, combustor, and expander section, and having a compressed air conduit fluidly coupled to the compressor section for receiving compressed air from the compressor section and delivering at least a portion of the compressed air to the combustor;

a Fischer-Tropsch hydrocarbon conversion subsystem for converting light hydrocarbons into heavier hydrocarbons;

a heat removal subsystem associated with the combustor for thermally coupling the hydrocarbon conversion subsystem to the combustor to deliver thermal energy from the combustor to the hydrocarbon conversion subsystem;

a process air conduit fluidly coupled between the compressed air conduit and the Fischer-Tropsch hydrocarbon conversion subsystem, the process air conduit for delivering a portion of the compressed air developed by the compressor section to the Fischer-Tropsch hydrocarbon conversion subsystem;

wherein the heat removal subsystem comprises a heat exchanger thermally coupled to the combustor; and

further comprising a steam methane reformer thermally coupled to the heat exchanger for using at least a portion of thermal energy from the combustor to prepare a first synthesis gas; and

wherein the Fischer-Tropsch hydrocarbon conversion subsystem comprises;

a synthesis gas unit for receiving natural gas, an oxygen containing gas, and steam and producing a second synthesis gas, and wherein the synthesis gas unit comprises an autothermal reformer, and

a Fischer-Tropsch synthesis unit fluidly coupled to the synthesis gas unit for receiving the second synthesis gas therefrom and fluidly coupled to the steam methane reformer for receiving the first synthesis gas and producing heavier hydrocarbons.

2. A Fischer-Tropsch-based system for converting light hydrocarbons into heavier hydrocarbons comprising:

a gas turbine having a compressor section, combustor, and expander section, and having a compressed air conduit fluidly coupled to the compressor section for receiving compressed air from the compressor section and delivering at least a portion of the compressed air to the combustor;

a Fischer-Tropsch hydrocarbon conversion subsystem for converting light hydrocarbons into heavier hydrocarbons;

a heat removal subsystem associated with the combustor for thermally coupling the hydrocarbon conversion subsystem to the combustor to deliver thermal energy from the combustor to the hydrocarbon conversion subsystem;

a process air conduit fluidly coupled between the compressed air conduit and the Fischer-Tropsch hydrocarbon conversion subsystem, the process air conduit for delivering a portion of the compressed air developed by the compressor section to the Fischer-Tropsch hydrocarbon conversion subsystem;

wherein the gas turbine is operable to drive a first load, and further comprising;

a heat recovery steam generator (HRSG) unit coupled to the expander section for receiving turbine exhaust therefrom and using the exhaust to drive at least partially a second load; and

wherein the heat removal subsystem comprises a heat exchanger thermally coupled to the combustor for receiving thermal energy from the combustor; and

wherein the Fischer-Tropsch hydrocarbon conversion subsystem comprises;

a steam methane reformer thermally coupled to the heat exchanger for using at least a portion of thermal energy from the combustor to prepare a first synthesis gas,

a synthesis gas unit for receiving natural gas, an oxygen containing gas, and steam and producing a second synthesis gas, and wherein the synthesis gas unit comprises an autothermal reformer, and

a Fischer-Tropsch synthesis unit fluidly coupled to the synthesis gas unit for receiving the second synthesis gas therefrom and fluidly coupled to the heat removal subsystem for receiving the first synthesis gas and producing heavier hydrocarbons.

3. The Fischer-Tropsch-based system of claim 2, wherein the HRSG unit comprises a burner portion, a steam generation portion for receiving thermal energy from the burner portion, and a steam turbine fluidly coupled to the steam generation portion for receiving steam therefrom and driving the second load.