Staged combustion of a low heating value fuel gas for driving a gas turbine

A combustor for combusting a low heating value fuel gas comprising:

• a) first dividing means for dividing a low heating value fuel gas feed into a burner portion and a combustion chamber portion;
• b) means for mixing said combustion chamber portion and a combustion air to form an air/fuel mixture;
• c) second dividing means for dividing said air/fuel mixture into a first portion and a second portion;
• d) a burner nozzle in fluid communication with said first dividing means having a burner nozzle outlet and a burner nozzle inlet for receiving said burner portion;
• e) a burner port in fluid communication with said second dividing means and having a burner port outlet and a burner port inlet for receiving said first portion of said air/fuel mixture;
• f) a flame zone in fluid communication with and downstream of said burner nozzle outlet and said burner port outlet for receiving and combusting said burner portion and said first portion of said air/fuel mixture to produce flame zone products;
• and
• g) an oxidation zone in fluid communication with and downstream of said flame zone for receiving said flame zone products and said second portion of said air/fuel mixture and for combusting said second portion of said air/fuel mixture in the presence of said flame zone products to produce combustion products.

A process for converting a lighter hydrocarbon gas to heavier hydrocarbons comprising:

• a) reacting a first portion of an air feed and a lighter hydrocarbon feed gas to produce a synthesis gas comprising hydrogen and carbon monoxide;
• b) reacting said synthesis gas in the presence of a hydrocarbon synthesis catalyst to produce heavier hydrocarbons, a tail gas and water;
• c) dividing said tail gas into a burner portion and a combustion chamber portion;
• d) conveying said combustion chamber portion and a second portion of said air feed into a mixing zone to form an air/fuel mixture;
• e) conveying said burner portion into a flame zone through a burner nozzle while conveying a first portion of said air/fuel mixture into said flame zone through a burner port;
• f) contacting said burner portion and said first portion of said air/fuel mixture in said flame zone to combust said burner portion and said first portion and produce flame zone products;
• g) conveying said flame zone products into an oxidation zone downstream of said flame zone while conveying said second portion of said air/fuel mixture into said oxidation zone and combusting said second portion in said oxidation zone in the presence of said flame zone products to produce combustion products;
• h) generating mechanical power with said combustion products;
• and
• i) compressing said air feed with said mechanical power.