Chemical looping combustion method and apparatus for solid fuels using different oxygen carriers

Patent metadata

Field	Value
Publication number	US-9683737-B2
Application number	US-201414320805-A
Country	US
Kind code	B2
Filing date	Jul 1, 2014
Priority date	Jul 3, 2013
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A chemical looping combustion apparatus for solid fuels using different oxygen carriers is provided. The chemical looping combustion apparatus includes: a solid fuel chemical looping combustor configured to receive solid fuels and to produce carbon dioxide and steam by combustion of the solid fuels; a gaseous fuel chemical looping combustor configured to receive gaseous fuels and to produce carbon dioxide and steam by combustion of the gaseous fuels; and a devolatilization reactor configured to produce solids and gases by devolatilizing the solid fuels, and the solid fuels received by the solid fuel chemical looping combustor and the gaseous fuels received by the gaseous fuel chemical looping combustor are the solids and the gases produced by the devolatilization reactor, respectively. Accordingly, a reaction rate and an amount of oxygen transfer can increase, and necessity for low-priced oxygen carriers and a make-up cost of low-priced oxygen carriers can be reduced.

First claim

What is claimed is:

1. A chemical looping combustion apparatus for solid fuels using different oxygen carriers, comprising:
a solid fuel chemical looping combustor configured to receive solid fuels and to produce carbon dioxide and steam by combustion of the solid fuels;
a gaseous fuel chemical looping combustor configured to receive gaseous fuels and to produce carbon dioxide and steam by combustion of the gaseous fuels; and
a devolatilization reactor configured to produce solids and gases by devolatilizing the solid fuels,
wherein the solid fuels received by the solid fuel chemical looping combustor and the gaseous fuels received by the gaseous fuel chemical looping combustor are the solids and the gases produced by the devolatilization reactor, respectively,
wherein the solid fuel chemical looping combustor comprises:
an oxidation reactor;
a loop seal configured to receive a metallic oxide from the oxidation reactor;
a reduction reactor configured to cause the solid fuels flowing from the devolatilization reactor and the metallic oxide transferred from the loop seal to react with each other, thereby reducing the oxygen carriers;
a downcomer connected to an outlet of the loop seal and extending to a lower portion of the reduction reactor to receive the solid fuels,
wherein the oxygen carriers reduced in the reduction reactor are provided to the oxidation reactor such that the oxygen carriers are re-circulated, and
wherein the solid fuels are introduced into the reduction reactor from a middle point of a longitudinal length of the downcomer.

2. The chemical looping combustion apparatus of claim 1 , wherein oxygen carriers used in the solid fuel chemical looping combustor and oxygen carriers used in the gaseous fuel chemical looping combustor are different from each other.

3. The chemical looping combustion apparatus of claim 1 , wherein the oxygen carriers used in the solid fuel chemical looping combustor comprise any one of:
(i) iron ore, ilmenite, oxide scale, or bauxite;
(ii) an oxide of any one of iron ore, ilmenite, oxide scale, and bauxite;
(iii) limestone, dolomite, CaO, CaCO 3 , MgO, or MgCO 3 ;
(iv) a mixture of at least two of limestone, dolomite, CaO, CaCO 3 , MgO, and MgCO 3 ; and
(v) a mixture of a support and any one of (i) to (iv);
wherein the support is any one of:
bentonite, alumina, zeolite, silica, hexaaluminate, or zirconia; and
a mixture of at least two of bentonite, alumina, zeolite, silica, hexaaluminate, and zirconia.

4. The chemical looping combustion apparatus of claim 1 , wherein the oxygen carriers used in the gaseous fuel chemical looping combustor comprise any one of:
(i) Fe, Ni, Co, Cu, Mn, or Ce;
(ii) an oxide of any one of Fe, Ni, Co, Cu, Mn, and Ce;
(iii) limestone, dolomite, CaO, CaCO 3 , MgO, or MgCO 3 ;
(iv) a mixture of at least two of limestone, dolomite, CaO, CaCO 3 , MgO, and MgCO 3 ; and
(v) a mixture of a support and any one of (i) to (iv);
wherein the support is any one of:
bentonite, alumina, zeolite, silica, hexaaluminate, or zirconia; and
a mixture of at least two of bentonite, alumina, zeolite, silica, hexaaluminate, and zirconia.

5. The chemical looping combustion apparatus of claim 1 , further comprising a cyclone configured to receive the gases produced in the devolatilization reactor, separate solids remaining in the received gases, provide the solids to the devolatilization reactor, and provide the gases from which the remaining solids have been removed to the gaseous fuel chemical looping combustor.

6. The chemical looping combustion apparatus of claim 1 , wherein a first solid bed is formed on a lower portion of the reduction reactor and the metallic oxide conveyed from the loop seal is stacked on the solid bed, and
a height of the first solid bed that is measured from a bottom of the reduction reactor is maintained lower than a height of a second solid bed formed in the loop seal, wherein the height of the second solid bed means a height measured from the bottom of the loop seal.

Assignees

• Korea Energy Research Inst

Inventors

• Ryu Ho-Jung
• Jin Gyoung-Tae
• Yi Chang-Keun
• Shun Do-Won
• Park Jae-Hyeon
• Bae Dal-Hee
• Jo Sung-Ho
• Lee Seung-Yong
• Park Youngcheol
• Moon Jong-Ho
• Lee Dong-Ho
• Joo Ji-Bong

Classifications

• Y02E20/346

  Cross-Sectional Technologies · mapped topic

• F23C10/005

  comprising two or more beds · CPC title

• F23C99/00 Primary

  Subject-matter not provided for in other groups of this subclass · CPC title

• F23C2900/99008

  Unmixed combustion, i.e. without direct mixing of oxygen gas and fuel, but using the oxygen from a metal oxide, e.g. FeO · CPC title

• F23C10/18

  Details; Accessories · CPC title