Syngas combustion in a chemical-looping combustion system using an impregnated Ni-based oxygen carrier

In this paper, Computational Fluid Dynamics (CFD) was used to simulate the magnetic device for the separation of Fe-base oxygen carrier in chemical-looping combustion system. The simulation was based on the Euler multiphase flow model and the k-ε turbulence model, which uses UDF programming to increase volume source phase. Here, commercial computational fluid dynamics software fluent platform was used to build the air reactor cold flow mathematical model, magnetic field under the conditions of different flow conditions were added for separating the Fe3O4 and Fe2O3. And the simulation results has an important understanding of the process of scientific significance, and will promote the fundamental understanding and applications of the Fe-base oxygen carrier.

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Investigation into the Reactivity Behavior of CaSO4 with Coal Chars in the Chemical Looping Combustion System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.724-725.1158 ◽

2013 ◽

Vol 724-725 ◽

pp. 1158-1162 ◽

Cited By ~ 1

Author(s):

Hong Jing Tian ◽

Jing Chang ◽

Qing Jie Guo

Keyword(s):

Calcium Sulfate ◽

Oxygen Carrier ◽

Promising Method ◽

Chemical Looping Combustion ◽

Chemical Looping ◽

Iron Ions ◽

Combustion System ◽

Nickel Ions ◽

Energy Penalty

Chemical-looping combustion is a promising method to realize the near zero emissions of CO2without any excessive energy penalty. In this paper the reactivity behavior of calcium sulfate (CaSO4) as oxygen carrier (OC) with coal chars are investigated. After the impregnation of nickel ions or iron ions, the reacting behaviors of the OC are remarkably promoted comparing with that before the impregnation. The high impregnation of nickel ions or iron ions is beneficial to the reactivity of the OC, especially in the first half of the reaction. After the reaction of fresh CaSO4with coal chars, the solid products are merely CaS. In addition, the solid products of Ni-impregnated OC consist mainly of CaS, CaO and Ni3S2while the solid products of Fe-impregnated OC are composed of Fe3O4and CaS.

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Temperature variations in the oxygen carrier particles during their reduction and oxidation in a chemical-looping combustion system

Chemical Engineering Science ◽

10.1016/j.ces.2004.09.049 ◽

2005 ◽

Vol 60 (3) ◽

pp. 851-862 ◽

Cited By ~ 111

Author(s):

Francisco García-Labiano ◽

Luis F. de Diego ◽

Juan Adánez ◽

Alberto Abad ◽

Pilar Gayán

Keyword(s):

Oxygen Carrier ◽

Chemical Looping Combustion ◽

Chemical Looping ◽

Combustion System ◽

Temperature Variations ◽

Reduction And Oxidation

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Simulation of a New Chemical-Looping Combustion Process without Sulfur Evolution Based on Ca-Based Oxygen Carrier

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2012-0039 ◽

2014 ◽

Vol 12 (1) ◽

pp. 13-24 ◽

Cited By ~ 2

Author(s):

Hongjing Tian ◽

Xiude Hu ◽

Jing Chang ◽

Mingdong Han ◽

Guanglin Sun ◽

...

Keyword(s):

Partial Pressure ◽

Oxygen Carrier ◽

Combustion Process ◽

Operating Regime ◽

Steam Gasification ◽

Chemical Looping Combustion ◽

Chemical Looping ◽

Oxygen Carriers ◽

Combustion System ◽

Reactor Temperature

Abstract Calcium sulfate (CaSO4) is a promising oxygen carrier for chemical-looping combustion system. The release of sulfurous gas in the circulating of Ca-based oxygen carrier is a crucial problem. In this paper, it is found that the released amount of sulfurous gas is greatly affected by the partial pressure of reductive gas. If the partial pressure of the mixed reductive gases, composed of H2 and CO, maintains higher than 40 kPa, the sulfurous gas can be completely eliminated even at the reacting temperature higher than 1,000°C. Therefore, a new chemical-looping combustion system based on CaSO4 and NiO oxygen carrier, without any sulfur evolution, is simulated using Aspen Plus software. In the system, the syngas is generated from the steam gasification of coal and reacts with CaSO4 and NiO consecutively. The sulfur release occurred in the circulating of Ca-based oxygen carriers can be prevented because the concentrations of CO and H2 keep higher than 45% in the presence of Ca-based oxygen carriers. The suitable operating regime, in which auto-thermally operating of the system, zero-sulfur release and easy sequestration of CO2 from the flue gas are realized, is proposed in this paper. The effects of fuel reactor temperature, air reactor temperature and the recycle rate of oxygen carrier on the released heat from the system and the concentration of CO2 and H2O are also studied in the paper.

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