Method and apparatus for recycling top gas for shaft furnace
AssigneeSynthesis Energy Systems, Inc.
InventorsJohn D. Winter, Haruyasu Michishita
Life of this patent
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Abstract
Method, apparatus and system for improved energy efficiency in a direct reduction iron production process which uses a direct reduction shaft furnace and syngas as the reduction gas. The method and system of the invention use a part of the top gas emanating from the shaft furnace as transport gas for the gasifier, and control the volume of the top gas used as recycled top gas or fuel for the gas heater. The present invention achieves high energy efficiency, and reduces the need to use additional CH4 source for the reduction gas.
Claims12
An apparatus for producing iron using a direct reduction iron production process, wherein iron ore fed into a shaft furnace is directly reduced with a reduction gas in a shaft furnace and a top gas emanates from the shaft furnace, the apparatus comprising:
- a first syngas delivery unit configured between a reactor of a fluidized bed coal gasification system and the shaft furnace for delivering syngas as at least a portion of the reduction gas, wherein the syngas is produced in the reactor in which carbonaceous materials react in a fluidized bed reactor under partially oxidized conditions with air and steam to produce syngas which comprises CO, H2, CO2 and CH4, and wherein a transport gas is used in the movement of the carbonaceous materials into the reactor, or movement and recycling of ash particles;
- a second syngas delivery unit configured between the reactor and a gas heater connected to the shaft furnace for delivering syngas as at least a portion of fuel gas to the gas heater to heat the reduction gas to a temperature sufficient for use in the direct reduction process;
- a first top gas delivery unit configured to recycle at least a portion of the top gas as a reduction gas to the shaft furnace;
- and
- a second top gas delivery unit configured between the shaft furnace and the reactor for using at least a portion of the top gas as transport gas in the reactor.
A system for producing iron using a direct reduction iron production process, comprising:
- a shaft furnace in which iron ore is directly reduced with a reduction gas, wherein a top gas emanates from the top thereof;
- a fluidized bed coal gasification system in which carbonaceous materials react in a fluidized bed reactor under partially oxidized conditions with air and steam to produce syngas which comprises CO, H2, CO2 and CH4, and wherein a transport gas is used in the movement of the carbonaceous materials into the reactor, and in the movement and recycling of ash particles;
- a first syngas delivery unit for using the syngas as at least a portion of the reduction gas;
- a second syngas delivery unit for using the syngas as at least a portion of fuel gas to heat the reduction gas to a temperature sufficient for use in the direct reduction process;
- a first top gas delivery unit configured to recycle at least a portion of the top gas as a reduction gas to the shaft furnace;
- and
- a second top gas delivery unit for using at least a portion of the top gas as transport gas in the fluidized bed reactor.
Dependencies are inferred from the claim text.