Integrated pyrolysis and entrained flow gasification systems and methods for low rank fuels

Patent metadata

Field	Value
Publication number	US-2016017801-A1
Application number	US-201314772797-A
Country	US
Kind code	A1
Filing date	Oct 17, 2013
Priority date	Mar 7, 2013
Publication date	Jan 21, 2016
Grant date	—

Abstract

In one aspect, a gasification system for use with low rank fuel is provided The system includes a pyrolysis unit positioned to receive a feed of low rank fuel, the pyrolysis unit being configured to pyrolyze the low rank fuel to produce pyrolysis gas and fixed carbon. The system also includes a gasifier configured to produce a syngas stream using the received fixed carbon, a cooler configured to receive and cool the syngas stream, and a first conduit coupled between the cooler and the pyrolysis unit. The first conduit is configured to recycle at least a portion of the syngas stream to the pyrolysis unit such that the recycled syngas stream is mixed with the pyrolysis gas to produce a hydrocarbon-rich syngas stream containing gasification by-products. The system also includes a by-product recovery system coupled to the pyrolysis unit for removing the gasification by-products from the hydrocarbon- rich syngas stream.

First claim

What is claimed is:

1 . A gasification system for use with low rank fuel, said system comprising:
a pyrolysis unit positioned to receive a feed of low rank fuel, said pyrolysis unit configured to pyrolyze the low rank fuel to produce pyrolysis gas and fixed carbon; a gasifier configured to produce a syngas stream using the received fixed carbon; a cooler configured to receive and cool the syngas stream; a first conduit coupled between said cooler and said pyrolysis unit, said first conduit configured to recycle at least a portion of the syngas stream to said pyrolysis unit, wherein the recycled syngas stream is mixed with at least a portion of the pyrolysis gas to produce a hydrocarbon-rich syngas stream containing gasification by-products; and a by-product recovery system coupled to said pyrolysis unit for removing gasification by-products from the hydrocarbon-rich syngas stream.

2 . The system of claim 1 , wherein said by-product recovery system comprises a tar recovery unit configured to remove tar from the hydrocarbon-rich syngas steam to form a partially treated syngas stream.

3 . The system of claim 2 , wherein said by-product recovery system further comprises an oil recovery unit configured to remove oil from the partially treated syngas stream to form a fully treated syngas stream.

4 . The system of claim 3 , further comprising a fluid tank in flow communication with said oil recovery unit and said tar recovery unit, said fluid tank is configured to receive a recycled fluid from said oil recovery unit and said tar recovery unit, and to provide recycled fluid to a slurry preparation unit.

5 . The system of claim 1 , wherein said first conduit is configured to recycle at least a portion of the syngas stream to said pyrolysis unit to facilitate heating low rank fuel within said pyrolysis unit.

6 . The system of claim 1 , wherein at least a portion of the pyrolysis gas is channeled to said gasifier to form the syngas stream.

7 . The system of claim 1 , further comprising a slurry preparation unit coupled in flow communication between said pyrolysis unit and said gasifier, said slurry preparation unit configured to receive fixed carbon and to produce a slurry feed that is conveyed to said gasifier.

8 . The system of claim 7 , further comprising a compression system coupled in flow communication between said pyrolysis unit and said slurry preparation unit, said compression system configured to condense at least a portion of the pyrolysis gas into a liquid that is channeled to said slurry preparation unit to facilitate producing the slurry feed.

9 . An integrated gasification combined-cycle power generation plant comprising:
at least one gasification system comprising:
a pyrolysis unit configured to receive low rank fuel, said pyrolysis unit further configured to pyrolyze the low rank fuel to produce pyrolysis gas and fixed carbon;
a gasifier configured to produce a syngas stream using the fixed carbon;
a cooler configured to cool the syngas stream;
a first conduit coupled between said cooler and said pyrolysis unit, said first conduit configured to recycle at least a portion of the syngas stream to said pyrolysis unit wherein the recycled syngas stream is mixed with the pyrolysis gas to produce a hydrocarbon-rich syngas stream containing gasification by-products; and
a by-product recovery system coupled to said pyrolysis unit for removing the gasification by-products from the hydrocarbon-rich syngas steam; and
at least one gas turbine engine coupled in flow communication with said cooler to receive at least a portion of the syngas stream.

10 . The plant of claim 9 , wherein said by-product recovery system comprises a tar recovery unit configured to remove tar from the hydrocarbon-rich syngas stream to form a partially treated syngas stream.

11 . The plant of claim 10 , wherein said by-product recovery system further comprises an oil recovery unit configured to remove oil from the partially treated syngas stream to form a fully treated syngas stream.

12 . The plant of claim 11 , further comprising a fluid tank coupled in flow communication with said oil recovery unit and said tar recovery unit, wherein said fluid tank receives a recycled fluid from said oil recovery unit and said tar recovery unit, and provides the recycled fluid to a slurry preparation unit.

13 . The plant of claim 9 , further comprising a slurry preparation unit coupled in flow communication between said pyrolysis unit and said gasifier, said slurry preparation unit configured to receive the fixed carbon and to produce a slurry feed that is conveyed to said gasifier.

14 . The plant of claim 13 , further comprising a compression system coupled in flow communication between said pyrolysis unit and said slurry preparation unit, said compression system condenses at least a portion of the pyrolysis gas into a liquid and channels the liquid to said slurry preparation unit to facilitate producing the slurry feed.

15 . A method of gasifying a low rank fuel, said method comprising:
providing a feed of low rank fuel to a pyrolysis unit; pyrolizing the feed of low rank fuel to produce pyrolysis gas and fixed carbon; channeling the fixed carbon to a gasifier; gasifying the fixed carbon to produce a syngas steam; mixing at least a portion of tie syngas stream with the pyrolysis gas to produce a hydrocarbon-rich syngas stream containing gasification by-products; removing the gasification by-products from the hydrocarbon-rich syngas stream using a by-product recovery system.

16 . The system of claim 15 , wherein removing the gasification by-products from the hydrocarbon-rich syngas stream comprises removing tar from the hydrocarbon-rich syngas stream using a tar recovery unit and forming a partially treated syngas stream.

17 . The system of claim 16 , wherein removing the gasification by-products from the hydrocarbon-rich syngas stream comprises removing oil from the hydrocarbon-rich syngas stream using an oil recovery unit and forming a fully treated syngas stream.

18 . The stem of claim 17 , further comprising channeling a recycled fluid between a fluid tank and the oil recovery unit and the tar recovery unit, wherein the fluid tank receives recycled water from the oil recovery unit and the tar recovery unit, and provides the recycled fluid to a slurry preparation unit.

19 . The method of claim 15 , further comprising providing the fixed carbon to a slurry preparation unit before the gasifier, mixing the fixed carton with a fluid to form a slurry stream, and providing the slurry stream to the gasifier.

20 . The system of claim 19 , further comprising condensing at least a portion of the pyrolysis gas into a liquid and channeling the liquid to the slurry preparation unit to facilitate producing the slurry feed.

Assignees

• Gen Electric

Inventors

• Xue Junli
• Hu Lishun
• Leininger Thomas Frederick
• Depuy Richard Anthony
• Bi Xijing

Classifications

• C10J3/466

  Entrained flow processes · CPC title

• C10J2300/0959

  Oxygen · CPC title

• C10J3/66

  by introducing them into the gasification zone · CPC title

• C10L2290/02

  Combustion or pyrolysis · CPC title

• C10J2300/1662

  to methane · CPC title