Hydrocarbon conversion system with enhanced combustor and method

• US 6,265,453 B1
• Filed: 06/15/2000
• Issued: 07/24/2001
• Est. Priority Date: 07/01/1999
• Status: Expired due to Fees

• Current Assignee: REG Synthetic Fuels, LLC (Chevron Corp.)
• Original Assignee: Syntroleum Corporation (Chevron Corp.)
• Inventors: Kennedy, Paul E.
• Primary Examiner(s): Richter, Johann
• Assistant Examiner(s): PARSA, JAFAR F
• Application Number:
  US09/596,285
• Time in Patent Office: 404 Days
• Field of Search: 518/700, 518/702, 518/703, 518/704, 518/705
• US Class Current: 518/703
• 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 method for converting light hydrocarbons into heavier hydrocarbons, the method comprising the steps of:

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 to drive the compressor section of the gas turbine.

2. The hydrocarbon conversion method of claim 1 further comprising the step of developing energy by recovering waste heat from the expansion section of the gas turbine with a heat recovery steam generating unit (HRSG).

3. The hydrocarbon conversion method of claim 1 wherein the step of delivering a portion of the compressed air to a Fischer-Tropsch hydrocarbon conversion unit comprises delivering up to 65 percent of the compressed air developed by the compressor section of the gas turbine to the Fischer-Tropsch hydrocarbon conversion unit.

4. The hydrocarbon conversion method of claim 1 wherein the step of delivering a portion of the compressed air to a Fischer-Tropsch hydrocarbon conversion unit comprises delivering between 35 and 65 percent of the compressed air developed by the compressor section of the gas turbine to the Fischer-Tropsch hydrocarbon conversion unit.

5. The hydrocarbon conversion method of claim 1 wherein the step of extracting thermal energy from the combustor comprises the steps of using a heat exchanger to create steam and delivering the steam to the Fischer-Tropsch hydrocarbon conversion unit.

6. The hydrocarbon conversion method of claim 1 wherein the step of extracting thermal energy from the combustor comprises using a heat exchanger that is part of a steam methane reformer to remove heat from effluent of the combustor.

7. The hydrocarbon conversion method of claim 1 wherein the step of converting light hydrocarbons into heavier hydrocarbons in the Fischer-Tropsch hydrocarbon conversion unit comprises:

preparing a synthesis gas and wherein this step comprises using at least in part the thermal energy extracted from the combustor, and

converting the synthesis gas through a Fischer-Tropsch reaction to heavier hydrocarbons (predominantly C5+).

8. The hydrocarbon conversion method of claim 7 wherein the steps of extracting thermal energy, preparing synthesis gas and converting the synthesis gas comprise the steps of:

preparing a first synthesis gas with a steam methane reformer that is thermally coupled to the combustor of the gas turbine;

preparing a second synthesis gas with an autothermal reformer; and

delivering the first synthesis gas and the second synthesis gas to a Fischer-Tropsch reactor for conversion to heavier hydrocarbons.

9. The hydrocarbon conversion method of claim 8 further comprising the step of developing energy by recovering waste heat from the expansion section of the gas turbine with a beat recovery steam generating unit (HRSG) unit.

10. The hydrocarbon conversion method of claim 9 wherein the step of delivering a portion of the compressed air to a Fischer-Tropsch hydrocarbon conversion unit comprises delivering up to 65 percent of the compressed air developed by the compressor section of the gas turbine to the Fischer-Tropsch hydrocarbon conversion unit.

11. The hydrocarbon conversion method of claim 9 wherein the step of delivering a portion of the compressed air to a Fischer-Tropsch hydrocarbon conversion unit comprises delivering between 35 and 65 percent of the compressed air developed by the compressor section of the gas turbine to the Fischer-Tropsch hydrocarbon conversion unit.