A mechanistic investigation of a calcium-based oxygen carrier for chemical looping combustion

Journal Article · Fri Aug 15 00:00:00 EDT 2008 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2008.04.017· OSTI ID:21081129

Shen, Laihong; Zheng, Min; Xiao, Jun; Xiao, Rui ^[1]

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1. Key Laboratory of Clean Coal Power Generation and Combustion Technology of Ministry of Education, Southeast University, Nanjing 210096 (China)

Chemical looping combustion (CLC) has been suggested as an energy-efficient method for the capture of carbon dioxide from combustion. It is indirect combustion by the use of an oxygen carrier, which can be used for CO{sub 2} capture in power-generating processes. The possibility of CLC using a calcium-based oxygen carrier is investigated in this paper. In the air reactor air is supplied to oxidize CaS to CaSO{sub 4}, where oxygen is transferred from air to the oxygen carrier; the reduction of CaSO{sub 4} to CaS takes place in the fuel reactor. The exit gas from the fuel reactor is CO{sub 2} and H{sub 2}O. After condensation of water, almost pure CO{sub 2} could be obtained. The thermodynamic and kinetic problem of the reduction reactions of CaSO{sub 4} with CO and H{sub 2} and the oxidization reactions of CaS with O{sub 2} is discussed in the paper to investigate the technique possibility. To prevent SO{sub 2} release from the process of chemical looping combustion using a calcium-based oxygen carrier, thermochemical CaSO{sub 4} reduction and CaS oxidation are discussed. Thermal simulation experiments are carried out using a thermogravimetric analyzer (TGA). The properties of the products are characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffractometry (XRD), and the optimal reaction parameters are evaluated. The effects of reaction temperature, reductive gas mixture, and oxygen partial pressure on the composition of flue gas are discussed. The suitable temperature of the air reactor is between 1050 and 1150 C and the optimal temperature of the fuel reactor between 900 and 950 C. (author)

• OSTI ID: 21081129
• Journal Information: Combustion and Flame, Vol. 154, Issue 3; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
20 FOSSIL-FUELED POWER PLANTS
HYDROGEN
OXYGEN
CALCIUM
CARBON DIOXIDE
COMBUSTION
CALCIUM SULFATES
CALCIUM SULFIDES
AIR
REDUCTION
CARRIERS
FLUE GAS
PARTIAL PRESSURE
SIMULATION
COMBUSTION KINETICS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 1000-4000 K
Chemical looping combustion
CO2 capture