scholarly journals Concentration-Dependent Solar Thermochemical CO2/H2O Splitting Performance by Vanadia–Ceria Multiphase Metal Oxide Systems

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Asim Riaz ◽  
Muhammad Umair Ali ◽  
T. Gabriel Enge ◽  
Takuya Tsuzuki ◽  
Adrian Lowe ◽  
...  
Keyword(s):  
Exchange Capacity ◽  
Gas Production ◽  
Oxygen Exchange ◽  
Production Performance ◽  
Methane Partial Oxidation ◽  
Carbide Formation ◽  
Oxygen Carriers ◽  
Oxidation Reactions ◽  
Oxide Systems ◽  
Syngas Production

The effects of V and Ce concentrations (each varying in the 0–100% range) in vanadia–ceria multiphase systems are investigated for synthesis gas production via thermochemical redox cycles of CO2 and H2O splitting coupled to methane partial oxidation reactions. The oxidation of prepared oxygen carriers is performed by separate and sequential CO2 and H2O splitting reactions. Structural and chemical analyses of the mixed-metal oxides revealed important information about the Ce and V interactions affecting their crystal phases and redox characteristics. Pure CeO2 and pure V2O5 are found to offer the lowest and highest oxygen exchange capacities and syngas production performance, respectively. The mixed-oxide systems provide a balanced performance: their oxygen exchange capacity is up to 5 times higher than that of pure CeO2 while decreasing the extent of methane cracking. The addition of 25% V to CeO2 results in an optimum mixture of CeO2 and CeVO4 for enhanced CO2 and H2O splitting. At higher V concentrations, cyclic carbide formation and oxidation result in a syngas yield higher than that for pure CeO2.

scholarly journals Cyclic oxygen exchange capacity of Ce-doped V2O5 materials for syngas production via high-temperature thermochemical-looping reforming of methane

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 23095-23104
Author(s):  
Asim Riaz ◽  
Wojciech Lipiński ◽  
Adrian Lowe
Keyword(s):  
High Temperature ◽  
Partial Oxidation ◽  
Exchange Capacity ◽  
Oxygen Exchange ◽  
High Oxygen ◽  
Methane Partial Oxidation ◽  
Syngas Production ◽  
Redox Pair ◽  
Cerium Doping ◽  
Fast Rates

Cerium doping into the V2O5 lattice forms a reversible V2O3/VO redox pair after sequential methane partial oxidation and CO2/H2O splitting reactions and produces syngas (H2, CO) with fast rates and high oxygen exchange capacity.

Enhanced oxygen exchange capacity in nano-structured vanadia–ceria multi-phase oxygen carriers for solar thermal fuel production

2019 ◽  
Vol 7 (48) ◽  
pp. 27347-27360 ◽  
Author(s):  
Asim Riaz ◽  
Muhammad Umair Ali ◽  
Wojciech Lipiński ◽  
Adrian Lowe
Keyword(s):  
Solar Energy ◽  
Hydrocarbon Fuel ◽  
Exchange Capacity ◽  
Oxygen Exchange ◽  
Solar Thermal ◽  
Oxygen Carriers ◽  
Fuel Production ◽  
Crucial Step ◽  
Redox Cycles ◽  
Multi Phase

Developing an efficient redox material is a fundamental and crucial step in sustainable hydrocarbon fuel production via solar energy-driven thermochemical redox cycles.

scholarly journals Near 100% CO selectivity in nanoscaled iron-based oxygen carriers for chemical looping methane partial oxidation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yan Liu ◽  
Lang Qin ◽  
Zhuo Cheng ◽  
Josh W. Goetze ◽  
Fanhe Kong ◽  
...  
Keyword(s):  
Partial Oxidation ◽  
Density Functional ◽  
Bond Cleavage ◽  
Oxygen Carrier ◽  
Value Added ◽  
Silica Matrix ◽  
Methane Partial Oxidation ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Oxidation Reactions

AbstractChemical looping methane partial oxidation provides an energy and cost effective route for methane utilization. However, there is considerable CO2 co-production in current chemical looping systems, rendering a decreased productivity in value-added fuels or chemicals. In this work, we demonstrate that the co-production of CO2 can be dramatically suppressed in methane partial oxidation reactions using iron oxide nanoparticles embedded in mesoporous silica matrix. We experimentally obtain near 100% CO selectivity in a cyclic redox system at 750–935 °C, which is a significantly lower temperature range than in conventional oxygen carrier systems. Density functional theory calculations elucidate the origins for such selectivity and show that low-coordinated lattice oxygen atoms on the surface of nanoparticles significantly promote Fe–O bond cleavage and CO formation. We envision that embedded nanostructured oxygen carriers have the potential to serve as a general materials platform for redox reactions with nanomaterials at high temperatures.

Synthesis Gas Production by Methane Partial Oxidation on Ni/Fe3O4-Ce0.75Zr0.25O2 Catalysts: Kinetic Study

2011 ◽  
Vol 14 (2) ◽  
pp. 133-139
Author(s):  
M. I. Sosa Vazquez ◽  
J. Salinas Gutierrez ◽  
D. Delgado Vigil ◽  
V. Collins-Martinez ◽  
A. Lopez Ortiz
Keyword(s):  
Kinetic Study ◽  
Partial Oxidation ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Oxygen Carrier ◽  
Nitrate Solution ◽  
Methane Partial Oxidation ◽  
Oxygen Carriers ◽  
Syngas Production ◽  
Global Reaction

Fe3O4-Ce0.75Zr0.25O2 (FeCZ) is an oxygen carrier material aimed to produce syngas through methane partial oxidation in absence of oxygen gas feed. The objective of the present research is to study the catalytic effect of Ni on FeCZ using an evaluation of the global kinetics (activation energy, reaction rate, order and constant) of its reaction with methane for syngas production. FeCZ and 0.05NiFeCZ (Ni/Fe = 0.05 molar ratio) were synthesized through co-precipitation of their precursor nitrate salts, while 2NiFeCZ was prepared by impregnation of FeCZ with a nickel nitrate solution to obtain a 2 %W Ni material. Samples were calcined at 950°C during 4 hours in air. Kinetic study of oxygen carriers (FeCZ, 0.05NiFeCZ and 2NiFeCZ) reduction with methane was followed through thermogravimetric analysis (TGA) at 5, 7.5 and 10% CH4/Ar and 600, 650 and 700°C. Initial reaction rate was obtained from the slope of the linear region of the weight change signal as a function of time. Results indicate a first order global reaction rate for all materials. Activation energies for samples FeCZ, 0.05NiFeCZ and 2NiFeCZ were 52.2, 39.5 and 28.3 Kcal/mol, respectively. Thus, reflecting the catalytic effect of Ni over the FeCZ global reaction rate.

scholarly journals Effect of specific surface area on syngas production performance of pure ceria in high-temperature thermochemical redox cycling coupled to methane partial oxidation

RSC Advances ◽  
2020 ◽  
Vol 10 (60) ◽  
pp. 36617-36626
Author(s):  
Manabu Heya ◽  
Xiang Gao ◽  
Antonio Tricoli ◽  
Wojciech Lipiński
Keyword(s):  
High Temperature ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Redox Reactions ◽  
Production Performance ◽  
Methane Partial Oxidation ◽  
Syngas Production ◽  
Pure Ceria ◽  
Key Parameter

Specific surface area is a key parameter determining the rates of thermochemical redox reactions in metal oxides.

Experimental Parameter Study on Synthesis Gas Production by Steam-Oxygen Fluidized Bed Gasification of Sewage Sludge

2021 ◽  
Vol 11 (2) ◽  
pp. 579
Author(s):  
Max Schmid ◽  
Selina Hafner ◽  
Günter Scheffknecht
Keyword(s):  
Sewage Sludge ◽  
Fluidized Bed ◽  
Experimental Parameter ◽  
Space Velocity ◽  
Phosphate Fertilizer ◽  
Gas Production ◽  
Raw Material ◽  
Parameter Study ◽  
Syngas Production ◽  
Fuels And Chemicals

The conversion of biogenic residues to fuels and chemicals via gasification and synthesis processes is a promising pathway to replace fossil carbon. In this study, the focus is set on sewage sludge gasification for syngas production. Experiments were carried out in a 20 kW fuel input bubbling fluidized bed facility with steam and oxygen as gasification agent. In-situ produced sewage sludge ash was used as bed material. The sensitivity of the key operation parameters gasifier temperature, oxygen ratio, steam to carbon ratio, and the space velocity on the syngas composition (H2, CO, CO2, CH4, CxHy, H2S, COS, NH3, and tars) was determined. The results show that the produced syngas has high H2 and CO concentrations of up to 0.37 m3 m−3 and 0.18 m3 m−3, respectively, and is thus suitable for synthesis of fuels and chemicals. By adjusting the steam to carbon ratio, the syngas’ H2 to CO ratio can be purposely tailored by the water gas shift reaction for various synthesis products, e.g., synthetic natural gas (H2/CO = 3) or Fischer–Tropsch products (H2/CO = 2). Also, the composition and yields of fly ash and bed ash are presented. Through the gasification process, the cadmium and mercury contents of the bed ash were drastically reduced. The ash is suitable as secondary raw material for phosphorous or phosphate fertilizer production. Overall, a broad database was generated that can be used for process simulation and process design.

Hydrogen-rich syngas production from chemical looping gasification of lignite by using NiFe2O4 and CuFe2O4 as oxygen carriers

Fuel ◽  
2021 ◽  
Vol 303 ◽  
pp. 121269
Author(s):  
Kun Zhao ◽  
Xiaojie Fang ◽  
Zhen Huang ◽  
Guoqiang Wei ◽  
Anqing Zheng ◽  
...  
Keyword(s):  
Chemical Looping ◽  
Oxygen Carriers ◽  
Syngas Production

Impact of the Cluster Spacing on Hydraulic Fracture Conductivity and Productivity of a Marcellus Shale Horizontal Well

2021 ◽  
Author(s):  
Mohamed El Sgher ◽  
Kashy Aminian ◽  
Ameri Samuel
Keyword(s):  
Hydraulic Fracture ◽  
Marcellus Shale ◽  
Technical Information ◽  
Gas Production ◽  
Production Performance ◽  
Valuable Insight ◽  
Fracture Conductivity ◽  
Fracture Properties ◽  
Gas Recovery ◽  
The Impact

Abstract The objective of this study was to investigate the impact of the hydraulic fracturing treatment design, including cluster spacing and fracturing fluid volume on the hydraulic fracture properties and consequently, the productivity of a horizontal Marcellus Shale well with multi-stage fractures. The availability of a significant amount of advanced technical information from the Marcellus Shale Energy and Environment Laboratory (MSEEL) provided an opportunity to perform an integrated analysis to gain valuable insight into optimizing fracturing treatment and the gas recovery from Marcellus shale. The available technical information from a horizontal well at MSEEL includes well logs, image logs (both vertical and lateral), diagnostic fracture injection test (DFIT), fracturing treatment data, microseismic recording during the fracturing treatment, production logging data, and production data. The analysis of core data, image logs, and DFIT provided the necessary data for accurate prediction of the hydraulic fracture properties and confirmed the presence and distribution of natural fractures (fissures) in the formation. Furthermore, the results of the microseismic interpretation were utilized to adjust the stress conditions in the adjacent layers. The predicted hydraulic fracture properties were then imported into a reservoir simulation model, developed based on the Marcellus Shale properties, to predict the production performance of the well. Marcellus Shale properties, including porosity, permeability, adsorption characteristics, were obtained from the measurements on the core plugs and the well log data. The Quanta Geo borehole image log from the lateral section of the well was utilized to estimate the fissure distribution s in the shale. The measured and published data were utilized to develop the geomechnical factors to account for the hydraulic fracture conductivity and the formation (matrix and fissure) permeability impairments caused by the reservoir pressure depletion during the production. Stress shadowing and the geomechanical factors were found to play major roles in production performance. Their inclusion in the reservoir model provided a close agreement with the actual production performance of the well. The impact of stress shadowing is significant for Marcellus shale because of the low in-situ stress contrast between the pay zone and the adjacent zones. Stress shadowing appears to have a significant impact on hydraulic fracture properties and as result on the production during the early stages. The geomechanical factors, caused by the net stress changes have a more significant impact on the production during later stages. The cumulative gas production was found to increase as the cluster spacing was decreased (larger number of clusters). At the same time, the stress shadowing caused by the closer cluster spacing resulted in a lower fracture conductivity which in turn diminished the increase in gas production. However, the total fracture volume has more of an impact than the fracture conductivity on gas recovery. The analysis provided valuable insight for optimizing the cluster spacing and the gas recovery from Marcellus shale.

Geomechanical Response Induced by Multiphase (Gas/Water) Flow in the Mallik Hydrate Reservoir of Canada

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Yingli Xia ◽  
Tianfu Xu ◽  
Yilong Yuan ◽  
Xin Xin ◽  
Huixing Zhu
Keyword(s):  
Shear Stress ◽  
Shear Failure ◽  
Energy Resource ◽  
Gas Production ◽  
Production Performance ◽  
Reservoir Model ◽  
Hydrate Reservoir ◽  
Maximum Subsidence ◽  
Permeability Anisotropy

Summary Natural gas hydrate (NGH) is regarded as an important alternative future energy resource. In recent years, a few short-term production tests have been successfully conducted with both permafrost and marine sediments. However, long-term hydrate production performance and the potential geomechanical problems are not very clear. According to the available geological data at the Mallik site, a more realistic hydrate reservoir model that considers the heterogeneity of porosity, permeability, and hydrate saturation was developed and validated by reproducing the field depressurization test. The coupled multiphase and heat flow and geomechanical response induced by depressurization were fully investigated for long-term gas production from the validated hydrate reservoir model. The results indicate that long-term gas production through depressurization from a vertically heterogeneous hydrate reservoir is technically feasible, but the production efficiency is generally modest, with the low average gas production rate of 4.93 × 103 ST m3/d (ST represents the standard conditions) over a 1-year period. The hydrate dissociation region is significantly affected by the reservoir heterogeneity and reveals a heterogeneous dissociation front in the reservoir. The depressurization production results in significant increase of shear stress and vertical compaction in the hydrate reservoir. The response of shear stress indicates that the potential region of sand migration is mainly in the sand-dominant layer during gas production from the hydraulically heterogeneous hydrate reservoir (e.g., sand layers interbedded with clay layers). The maximum subsidence is approximately 78 mm and occurred at the 72nd day, whereas the final subsidence is slowly dropped to 63 mm after 1-year of depressurization production. The vertical subsidence is greatly dependent on the elastic properties and the permeability anisotropy. In particular, the maximum subsidence increased by approximately 81% when the ratio of permeability anisotropy was set at 5:1. Furthermore, the potential shear failure in the hydrate reservoir is strongly correlated to the in-situ stress state. For the normal fault stress regime, the greater the initial horizontal stress is, the less likely the hydrate reservoir is to undergo shear failure during depressurization production.

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