scholarly journals The Potential of Gas Switching Partial Oxidation Using Advanced Oxygen Carriers for Efficient H2 Production with Inherent CO2 Capture

2021 ◽  
Vol 11 (10) ◽  
pp. 4713
Author(s):  
Carlos Arnaiz del Pozo ◽  
Schalk Cloete ◽  
Ángel Jiménez Álvaro ◽  
Felix Donat ◽  
Shahriar Amini
Keyword(s):  
Partial Oxidation ◽  
Co2 Capture ◽  
Oxygen Carrier ◽  
H2 Production ◽  
Advanced Materials ◽  
Oxygen Carriers ◽  
Large Power ◽  
Steam Methane ◽  
Hydrogen Supply ◽  
Energy Penalty

The hydrogen economy has received resurging interest in recent years, as more countries commit to net-zero CO2 emissions around the mid-century. “Blue” hydrogen from natural gas with CO2 capture and storage (CCS) is one promising sustainable hydrogen supply option. Although conventional CO2 capture imposes a large energy penalty, advanced process concepts using the chemical looping principle can produce blue hydrogen at efficiencies even exceeding the conventional steam methane reforming (SMR) process without CCS. One such configuration is gas switching reforming (GSR), which uses a Ni-based oxygen carrier material to catalyze the SMR reaction and efficiently supply the required process heat by combusting an off-gas fuel with integrated CO2 capture. The present study investigates the potential of advanced La-Fe-based oxygen carrier materials to further increase this advantage using a gas switching partial oxidation (GSPOX) process. These materials can overcome the equilibrium limitations facing conventional catalytic SMR and achieve direct hydrogen production using a water-splitting reaction. Results showed that the GSPOX process can achieve mild efficiency improvements relative to GSR in the range of 0.6–4.1%-points, with the upper bound only achievable by large power and H2 co-production plants employing a highly efficient power cycle. These performance gains and the avoidance of toxicity challenges posed by Ni-based oxygen carriers create a solid case for the further development of these advanced materials. If successful, results from this work indicate that GSPOX blue hydrogen plants can outperform an SMR benchmark with conventional CO2 capture by more than 10%-points, both in terms of efficiency and CO2 avoidance.

Natural Gas Decarbonisation Technologies for Advanced Power Plants

2006 ◽  
Author(s):  
Marco Gambini ◽  
Michela Vellini
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Partial Oxidation ◽  
Power Plants ◽  
H2 Production ◽  
Combined Cycle ◽  
Methane Reforming ◽  
Steam Methane Reforming ◽  
Steam Methane ◽  
Percentage Points

In this paper two options for H2 production, by means of natural gas, are presented and their performances are evaluated when they are integrated with advanced H2/air cycles. In this investigation two different schemes have been analysed: an advanced combined cycle power plant (CC) and a new advanced mixed cycle power plant (AMC). The two methods for producing H2 are as follows: • steam methane reforming: it is the simplest and potentially the most economic method for producing hydrogen in the foreseeable future; • partial oxidation of methane: it could offer an energy advantage because this method reduces energy requirement of the reforming process. These hydrogen production plants require material and energetic integrations with power section and the best interconnections must be investigated in order to obtain good overall performance. With reference to thermodynamic and economic performance, significant comparisons have been made between the above introduced reference plants. An efficiency decrease and an increase in the cost of electricity has been obtained when power plants are equipped with a natural gas decarbonisation section. The main results of the performed investigation are quite variable among the different H2 production technologies here considered: the efficiency decreases in a range of 5.5 percentage points to nearly 10 for the partial oxidation of the natural gas and in a range of 8.8 percentage points to over 12 for the steam methane reforming. The electricity production cost increases in a range of about 41–42% for the first option and in a range of about 34–38% for the second one. The AMC, coupled with partial oxidation, stands out among the other power plant solutions here analysed because it exhibits the highest net efficiency and the lowest final specific CO2 emission. In addition to this, economic impact is favourable when AMC is equipped with systems for H2 production based on partial oxidation of natural gas.

scholarly journals Exergy Analysis of Gas Switching Chemical Looping IGCC Plants

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 544 ◽  
Author(s):  
Carlos Arnaiz del Pozo ◽  
Ángel Jiménez Álvaro ◽  
Jan Hendrik Cloete ◽  
Schalk Cloete ◽  
Shahriar Amini
Keyword(s):  
Co2 Capture ◽  
Exergy Analysis ◽  
High Efficiency ◽  
Oxygen Carrier ◽  
Scale Up ◽  
Air Separation ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Constant Flow Rate ◽  
Oxidation Reactor

Integrated gasification combined cycles (IGCC) are promising power production systems from solid fuels due to their high efficiency and good environmental performance. Chemical looping combustion (CLC) is an effective route to reduce the energy penalty associated with CO2 capture. This concept comprises a metal oxygen carrier circulated between a reduction reactor, where syngas is combusted, and an oxidation reactor, where O2 is withdrawn from an air stream. Parallel to CLC, oxygen carriers that are capable of releasing free O2 in the reduction reactor, i.e., chemical looping oxygen production (CLOP), have been developed. This offers interesting integration opportunities in IGCC plants, replacing energy demanding air separation units (ASU) with CLOP. Gas switching (GS) reactor cluster technology consists of a set of reactors operating in reduction and oxidation stages alternatively, providing an averaged constant flow rate to the gas turbine and a CO2 stream readily available for purification and compression, and avoiding the transport of solids across reactors, which facilitates the scale up of this technology at pressurized conditions. In this work, exergy analyses of a gas switching combustion (GSC) IGCC plant and a GSOP–GSC IGCC plant are performed and consistently benchmarked against an unabated IGCC and a precombustion CO2 capture IGCC plant. Through the exergy analysis methodology, an accurate assessment of the irreversible loss distribution in the different power plant sections from a second-law perspective is provided, and new improvement pathways to utilize the exergy contained in the GSC reduction gases outlet are identified.

Reaction Characteristics of Ce-Based Oxygen Carrier for Two-Step Production Syngas and Hydrogen through Methane Conversion and Water Splitting

2013 ◽  
Vol 641-642 ◽  
pp. 123-127
Author(s):  
Yong Gang Wei ◽  
Xing Zhu ◽  
Kong Zhai Li ◽  
Ya Ne Zheng ◽  
Hua Wang
Keyword(s):  
Methane Conversion ◽  
Oxygen Carrier ◽  
Precipitation Method ◽  
Oxygen Carriers ◽  
Steam Methane Reforming ◽  
Syngas Production ◽  
Steam Methane ◽  
Reaction Characteristics ◽  
Temperature Programmed ◽  
Co Precipitation

The two-step steam methane reforming for production syngas and hydrogen was investigated by using Ce-based oxygen carriers (CeO2, CeO2-ZrO2，CeO2-Fe2O3) which were prepared by co-precipitation method and characterized by means of X-ray diffractometer and Raman spectroscopy. CH4 temperature programmed and isothermal reactions were adopted to test syngas production reactivity, and redox properties were evaluated by a successive redox cycle. The results showed that the incorporation of ZrO2 into CeO2 was found to be an effective approach for enhancing the reducibility of CeO2 in methane conversion reaction and redox performance, and the addition of Fe2O3 into CeO2 could obviously increase the amount of reactive oxygen species in CeO2-Fe2O3 and the yields of syngas and hydrogen reached maximum in the 3rd cycle, but the redox stability of CeO2-Fe2O3 needs to be enhanced.

scholarly journals Extremely Stable and Durable Mixed Fe–Mn Oxides Supported on ZrO2 for Practical Utilization in CLOU and CLC Processes

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1285
Author(s):  
Ewelina Ksepko ◽  
Rafal Lysowski
Keyword(s):  
Oxygen Carrier ◽  
Reaction Rates ◽  
Hard Coal ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Spinel Type ◽  
Practical Utilization ◽  
Thermogravimetric Analyzer ◽  
Energy Penalty ◽  
Combustion Technology

This paper contains the results of research on a promising combustion technology known as chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU). The remarkable advantages of CLC are, among others, that concentrated CO2 stream can be obtained after water condensation without any energy penalty for its separation or significant decrease of NOx emissions. The objective of this work was to prepare a novel bi-metallic Fe–Mn supported on ZrO2 oxygen carriers. Performance of these carriers for the CLOU and CLC process with nitrogen/air and hard coal/air was evaluated. One-cycle CLC tests were conducted with supported Fe–Mn oxygen carriers in thermogravimetric analyzer utilizing hard coal as a fuel. The effects of the oxygen carrier chemical composition and process temperature on the reaction rates were determined. Our study proved that for CLOU, properties formation of bixbyite and spinel forms are responsible. Among iron ferrites, we concluded that iron-rich compounds such as Fe2MnO4 over FeMn2O4 spinel type oxides are more effective for CLOU applications.

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.

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