Bulk monolithic Ce–Zr–Fe–O/Al 2 O 3 oxygen carriers for a fixed bed scheme of the chemical looping combustion: Reactivity of oxygen carrier

2016 ◽  
Vol 163 ◽  
pp. 19-31 ◽  
Author(s):  
Zhenhua Gu ◽  
Kongzhai Li ◽  
Hua Wang ◽  
Shan Qing ◽  
Xing Zhu ◽  
...  
Keyword(s):  
Oxygen Carrier ◽  
Fixed Bed ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Combustion Reactivity

Effects of ZnO Addition on Fe2O3/Al2O3 Oxygen Carriers on CH4 Reduction for Chemical Looping Combustion

2016 ◽  
Vol 872 ◽  
pp. 196-200
Author(s):  
Sujinda Thongsermsuk ◽  
Benjapon Chalermsinsuwan ◽  
Prapan Kuchonthara ◽  
Pornpote Piumsomboon
Keyword(s):  
Oxygen Carrier ◽  
Synergetic Effect ◽  
Fixed Bed ◽  
Reduction Process ◽  
Fixed Bed Reactor ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Fuel Gas ◽  
Physical Mixing

Fe2O3/Al2O3/ZnO oxygen carriers with small content ZnO (5 wt% to 10 wt%) were prepared by physical mixing method and were evaluated its capability as an oxygen carrier in a chemical looping combustion. The combustion was conducted by using CH4 as a fuel gas. The reduction process of Fe2O3/Al2O3/ZnO oxygen carrier was carried out in a fixed bed reactor. The solid reduction products were characterized by X-ray diffraction (XRD) and Scanning Electron Microscope with EDS Attachment (SEM-EDS). The results show that the reactivity of Fe2O3/Al2O3/ZnO oxygen carriers is greater than that of Fe2O3/Al2O3 which is implied the synergetic effect between ZnO and Fe2O3. XRD results show that the iron oxide in the oxygen carriers is reduced to metallic iron. SEM-EDS also shows that the iron agglomeration is prevented. Consequently, the suitable content of ZnO in oxygen carriers is ranged from 5 wt% to 10 wt%.

Performance in a Fixed-Bed Reactor of Titania-Supported Nickel Oxide as Oxygen Carriers for the Chemical-Looping Combustion of Methane in Multicycle Tests

2006 ◽  
Vol 45 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Beatriz M. Corbella ◽  
Luis F. de Diego ◽  
Francisco García-Labiano ◽  
Juan Adánez ◽  
José M. Palacios
Keyword(s):  
Nickel Oxide ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers

Chemical-looping combustion of methane with CaSO4 oxygen carrier in a fixed bed reactor

2008 ◽  
Vol 49 (11) ◽  
pp. 3178-3187 ◽  
Author(s):  
Qilei Song ◽  
Rui Xiao ◽  
Zhongyi Deng ◽  
Huiyan Zhang ◽  
Laihong Shen ◽  
...  
Keyword(s):  
Oxygen Carrier ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Caso4 Oxygen Carrier

scholarly journals Computational Fluid Dynamics Modeling of the Fuel Reactor in NETL's 50 kWth Chemical Looping Facility

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Ronald W. Breault ◽  
Justin Weber ◽  
Doug Straub ◽  
Sam Bayham
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Oxygen Carrier ◽  
Fixed Bed ◽  
Nucleation And Growth ◽  
Chemical Looping ◽  
Gravimetric Analysis ◽  
Oxygen Carriers ◽  
Dynamics Modeling ◽  
Fuel Reactor

The National Energy Technology Laboratory (NETL) has explored chemical looping in its 50 kWth facility using a number of oxygen carriers. In this work, the results for methane conversion in the fuel reactor with a hematite iron ore as the oxygen carrier are analyzed. The experimental results are compared to predictions using CPFD's barracuda computational fluid dynamics (CFD) code with kinetics derived from the analysis of fixed bed data. It has been found through analytical techniques from thermal gravimetric analysis data as well as the same fixed bed data that the kinetics for the methane–hematite reaction follows a nucleation and growth or Johnson–Mehl–Avrami (JMA) reaction mechanism. barracuda does not accept nucleation and growth kinetics; however, there is enough sufficient variability of the solids dependence within the software such that the nucleation and growth behavior can be mimicked. This paper presents the method to develop the pseudo-JMA kinetics for barracuda extracted from the fixed bed data and then applies these values to the fuel reactor data to compare the computational results to experimental data obtained from 50 kWth unit for validation. Finally, a fuel reactor design for near complete conversion is proposed.

scholarly journals LaFe1-xNix as a Robust Catalytic Oxygen Carrier for Chemical Looping Conversion of Toluene

2021 ◽  
Vol 12 (1) ◽  
pp. 391
Author(s):  
Haiming Gu ◽  
Juan Yang ◽  
Guohui Song ◽  
Xiaobo Cui ◽  
Miaomiao Niu ◽  
...  
Keyword(s):  
Oxygen Carrier ◽  
Fixed Bed ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Carbon Gasification ◽  
Syngas Production ◽  
Toluene Conversion ◽  
Substituted Ferrite ◽  
Tar Model Compound ◽  
H2 Yield

Chemical looping biomass gasification is a novel technology converting biomass into syngas, and the selection of oxygen carrier is key for efficient tar conversion. The performance of LaFe1-xNix as a robust catalytic oxygen carrier was investigated in the chemical looping conversion of toluene (tar model compound) into syngas in a fixed bed. LaM (M = Fe, Ni, Mn, Co, and Cu) was initially compared to evaluate the effect of transition metal on toluene conversion. LaFe (partial oxidation) and LaNi (catalytic pyrolysis) exhibited better performance in promoting syngas production than other oxygen carriers. Therefore, Ni-substituted ferrite LaFe1-xNix (x = 0, 0.2, 0.4, 0.6, 0.8 and 1) was further developed. The effects of Ni-substitution, steam/carbon ratio (S/C), and temperature on toluene conversion into C1 and H2 were evaluated. Results showed that the synergistic effect of Fe and Ni promoted toluene conversion, improving H2 yield yet with serious carbon deposition. Steam addition promoted toluene steam reforming and carbon gasification. With S/C increasing from 0.8 to 2.0, the C1 and H2 yield increased from 73.9% to 97.5% and from 197.7% to 269.6%, respectively. The elevated temperature favored toluene conversion and C1 yield. LaFe0.6Ni0.4 exhibited strong reactivity stability during toluene conversion at S/C = 1.6 and 900 °C.

scholarly journals Chemical Looping Combustion of Methane: A Technology Development View

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Rutuja Bhoje ◽  
Ganesh R. Kale ◽  
Nitin Labhsetwar ◽  
Sonali Borkhade
Keyword(s):  
Technology Development ◽  
Oxygen Carrier ◽  
Clean Energy ◽  
Unit Weight ◽  
Chemical Looping Combustion ◽  
Process Conditions ◽  
Net Energy ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Byproduct Formation

Methane is a reliable and an abundantly available energy source occurring in nature as natural gas, biogas, landfill gas, and so forth. Clean energy generation using methane can be accomplished by using chemical looping combustion. This theoretical study for chemical looping combustion of methane was done to consider some key technology development points to help the process engineer choose the right oxygen carrier and process conditions. Combined maximum product (H2O + CO2) generation, weight of the oxygen carrier, net enthalpy of CLC process, byproduct formation, CO2emission from the air reactor, and net energy obtainable per unit weight (gram) of oxygen carrier in chemical looping combustion can be important parameters for CLC operation. Carbon formed in the fuel reactor was oxidised in the air reactor and that increased the net energy obtainable from the CLC process but resulted in CO2emission from the air reactor. Use of CaSO4as oxygen carrier generated maximum energy (−5.3657 kJ, 800°C) per gram of oxygen carrier used in the CLC process and was found to be the best oxygen carrier for methane CLC. Such a model study can be useful to identify the potential oxygen carriers for different fuel CLC systems.

Sign in / Sign up

Export Citation Format

Share Document