Systems and methods for operating a gasifier

A method for operating a gasifier, comprising:

• circulating particulates through a gasifier;
• increasing a temperature within the gasifier from an initial temperature to an intermediate temperature by introducing a first combustion gas to the gasifier, wherein the first combustion gas is produced by combusting a first start-up fuel, and wherein the intermediate temperature is sufficient to auto-ignite a second start-up fuel;
• introducing the second start-up fuel directly to the gasifier after the gasifier is at the intermediate temperature, wherein the second start-up fuel is introduced to the gasifier downstream relative to the first combustion gas;
• combusting at least a portion of the second start-up fuel within the gasifier to increase the temperature within the gasifier to an operating temperature, wherein the operating temperature is sufficient to gasify a hydrocarbon feedstock;
• stopping introduction of the first combustion gas after introduction of the second start-up fuel begins;
• introducing the hydrocarbon feedstock to the gasifier after the gasifier is at the operating temperature;
• gasifying at least a portion of the hydrocarbon feedstock within the gasifier to produce a syngas;
• and
• stopping introduction of the second start-up fuel after introduction of the hydrocarbon feedstock begins.

A system for gasifying a hydrocarbon feedstock, comprising:

• a gasifier having a riser disposed therein;
• a start-up burner for combusting a first start-up fuel to produce a first combustion gas;
• a transfer line in fluid communication with a combustion gas outlet of the start-up burner and a combustion gas inlet of the riser for introducing the first combustion gas to the gasifier;
• a second start-up fuel nozzle disposed on the riser and adapted to introduce a second start-up fuel to the gasifier;
• a hydrocarbon feed line in fluid communication with the riser downstream of the combustion gas inlet and upstream of the second start-up fuel nozzle;
• and
• a particulate recycle line in fluid communication with the riser at a location downstream of the combustion gas inlet and upstream of the hydrocarbon feed line.