| 1. |
- Jing, Dazheng, 1986, et al.
(författare)
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Examination of oxygen uncoupling behaviour and reactivity towards methane for manganese silicate oxygen carriers in chemical-looping combustion
- 2014
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Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 29, s. 70-81
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Tidskriftsartikel (refereegranskat)abstract
- Cheap and environmental friendly Mn-Si oxygen carriers manufactured from Mn3O4 and SiO2 by spray-drying have been investigated with respect to properties for chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU). Fifteen oxygen carriers with SiO2 content varying from 2wt% to 75wt% were prepared and calcined at 1050°C and 1150°C. The ability of material to release O2 and their reactivity towards CH4 were examined in the temperature range 900-1100°C. Particles with a SiO2 content of more than 45wt% and calcined at 1150°C showed limited CLOU behaviour and poor reactivity towards CH4 at all temperatures investigated. The rest of the materials had significant CLOU properties and provided high conversion of CH4 under the experimental conditions chosen. Increasing the temperature of operation enhanced the CLOU behaviour and reactivity towards CH4. At temperatures above 950°C, the CH4 conversion was 90-100% for these materials. Crystalline phases identified by XRD in the oxidized samples with more than 45wt% SiO2 and calcined at 1150°C were mainly rhodonite MnSiO3. For materials with SiO2 content below 45wt%, braunite Mn7SiO12 was detected as the main phase in most of the samples after oxidation. This indicates that braunite Mn7SiO12 is the main active phase for oxygen transfer in CLC and CLOU, which is supported by thermodynamic calculations. The reactivity of all of the materials were also studied with syngas (50% CO and 50% H2), showing complete gas conversion at 950°C, except for materials with a SiO2 content of more than 45wt% and calcined at 1150°C. The mechanical integrity and attrition resistance of the oxygen carriers were examined in a jet-cup attrition rig, and although the attrition rates varied, some reactive material showed low rates of attrition, making them very promising oxygen carrier materials for applications related to CLC and CLOU. However, measures should probably be taken to improve the crushing strength to some extent. © 2014 Elsevier Ltd.
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| 2. |
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| 3. |
- Carlsson, Per-Anders, 1972, et al.
(författare)
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Controlling selectivity in direct conversion of methane into formaldehyde/methanol over iron molybdate via periodic operation conditions
- 2012
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 26:3, s. 1984-1987
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Tidskriftsartikel (refereegranskat)abstract
- The partial oxidation of methane over a Fe 2 (MoO 3 )4 powder catalyst was studied under transient inlet gas conditions. The preparation of the Fe 2 (MoO 4 ) 3 catalyst was performed using a hydrothermal synthesis route. Analytical-grade Fe(NO 3 ) 3 .9H 2 O and (NH 4 ) 6 Mo 7 O 24 .7H 2 O were dissolved separately in distilled water. The molybdate solution was then added dropwise to the iron nitrate solution under continuous stirring to form a homogeneous solution, which was pH-adjusted to 3 by adding NH 3 .H 2 O and HNO 3 . The solution was transferred to a Teflon lined autoclave, sealed, and kept at 140°C for 12 h. The formed precipitate was then washed several times with distilled water and ethanol. At the lowest temperature, only CO can be observed, while at the higher temperatures, also HCHO and CO 2 are formed.
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| 4. |
- Englund, Johanna, 1988, et al.
(författare)
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Deactivation of a Pd/Pt Bimetallic Oxidation Catalyst Used in a Biogas-Powered Euro VI Heavy-Duty Engine Installation
- 2019
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Ingår i: Catalysts. - : MDPI. - 2073-4344. ; 9:12
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Tidskriftsartikel (refereegranskat)abstract
- The reduction of anthropogenic greenhouse gas emissions is crucial to avoid further warming of the planet. We investigated how effluent gases from a biogas powered Euro VI heavy-duty engine impact the performance of a bimetallic (palladium and platinum) oxidation catalyst. Using synthetic gas mixtures, the oxidation of NO, CO, and CH4 before and after exposure to biogas exhaust for 900 h was studied. The catalyst lost most of its activity for methane oxidation, and the activity loss was most severe for the inlet part of the aged catalyst. Here, a clear sintering of Pt and Pd was observed, and higher concentrations of catalyst poisons such as sulfur and phosphorus were detected. The sintering and poisoning resulted in less available active sites and hence lower activity for methane oxidation.
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| 5. |
- Hallberg, Peter, 1984, et al.
(författare)
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Chemical Looping Combustion and Chemical Looping with Oxygen Uncoupling Experiments in a Batch Reactor Using Spray-Dried CaMn1–xMxO3−δ (M = Ti, Fe, Mg) Particles as Oxygen Carriers
- 2013
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 27:3, s. 1473-1481
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Tidskriftsartikel (refereegranskat)abstract
- Chemical looping combustion and chemical looping with oxygen uncoupling (CLOU) with oxygen carrier particles consisting of CaMn1-xMxO3-delta (M = Ti, Fe, Mg) has been studied by consecutive oxidation and reduction experiments in a fluidized-bed batch reactor. The examined particles were produced by spray drying, and all did show a significant release of gas-phase oxygen to the inert atmosphere at 900 and 1000 degrees C. All particles also provided very high reactivity with syngas and methane. Some of the examined particles showed unfavorable fluidization characteristics, i.e., they formed dust during operation or showed agglomeration or defluidization tendencies. The crushing strength of the particles that formed dust was typically
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| 6. |
- Hallberg, Peter, 1984, et al.
(författare)
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Experimental investigation of CaMnO3-δ based oxygen carriers used in continuous Chemical-Looping Combustion
- 2014
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Ingår i: International Journal of Chemical Engineering. - : Hindawi Limited. - 1687-806X .- 1687-8078. ; 2014:412517
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Tidskriftsartikel (refereegranskat)abstract
- Three materials of perovskite structure, (M = Mg or Mg and Ti), have been examined as oxygen carriers in continuous operation of chemical-looping combustion (CLC) in a circulating fluidized bed system with the designed fuel power 300 W. Natural gas was used as fuel. All three materials were capable of completely converting the fuel to carbon dioxide and water at 900°C. All materials also showed the ability to release gas phase oxygen when fluidized by inert gas at elevated temperature (700–950°C); that is, they were suitable for chemical looping with oxygen uncoupling (CLOU). Both fuel conversion and oxygen release improved with temperature. All three materials also showed good mechanical integrity, as the fraction of fines collected during experiments was small. These results indicate that the materials are promising oxygen carriers for chemical-looping combustion.
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| 7. |
- Jing, Dazheng, 1986, et al.
(författare)
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Development of CaMn0.775Mg0.1Ti0.1Ti0.125O3-delta oxygen carriers produced from different Mn and Ti sources
- 2016
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Ingår i: Materials and Design. - : Elsevier BV. - 1873-4197 .- 0264-1275. ; 89, s. 527-542
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite CaMa(0.775)Mg(0.1)Ti(0.125)O(3-delta) has attracted great interest as an oxygen carrier. To apply this material to a commercial scale chemical-looping unit, one key challenge is to find raw materials which are cheap and available in large quantities for production. Considering the content and price, Mn- and Ti-oxides are likely the raw materials having the major effect. Twelve Mn-oxide sources and four different TiO2 powders were evaluated for production of CaMa(0.775)Mg(0.1)Ti(0.125)O(3-delta) in this work. Particles with perovskite structure were successfully spray dried. All oxygen carriers showed oxygen uncoupling characteristics and most of them had a high reactivity, i.e. over 90% methane conversion already at 950 degrees C with a bed mass corresponding to 57 kg/MW, when examined in a batch fluidized-bed system at 900-1050 degrees C. Furthermore bulk density, crushing strength and resistance against attrition were studied. Although the attrition index varied, materials with good attrition resistance were identified. The rates of reaction were analyzed using two pseudo-first order apparent rate constants. The rates varied in a wide range, and are generally lower than with optimized Ni-based materials, but higher than with ilmenite. Still, the added oxygen uncoupling likely has a large positive effect at high degrees of solid conversion, something not seen with Ni-based materials.
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| 8. |
- Jing, Dazheng, 1986, et al.
(författare)
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Effect of Production Parameters on the Spray-Dried Calcium Manganite Oxygen Carriers for Chemical-Looping Combustion
- 2016
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 30:4, s. 3257-3268
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Tidskriftsartikel (refereegranskat)abstract
- The oxygen carrier CaMn0.9Mg0.1O3-delta was successfully tested in different chemical-looping units. High methane conversion and oxygen uncoupling properties have been found for this type of material. Most of the CaMn(0.9)Mg(0.1)O(3-delta)oxygen carrier particles tested so far have been produced' using the spray-drying method. In this work, the focus has been on studying the effects of production parameters on the properties of this important oxygen carrier. The effects of three production parameters, i.e., milling time, calcination temperature, and calcination time, were examined for the spray-dried particles. The time of ball milling for the slurry prepared for spray-drying was varied from 5 to 45 min, the calcination temperature from 1300 to 1350 degrees C, and the calcination time from 4 to 16 h. None of these parameters had any influence on the final crystalline phases of the oxygen carrier, yet some of the properties were clearly changed. The bulk density, crushing strength, and resistance against physical attrition can be enhanced by increasing the calcination temperature, calcination time, or milling time. Further, the BET specific surface area and porosity of the oxygen carrier particles decreased when the slurry was milled or particles were calcined for extended periods. The average methane conversion of the oxygen carrier varied in a wide range, from 99% to 55% at 950 degrees C, depending upon the production parameters used. However, no obvious influence of the examined production parameters was observed for the oxygen uncoupling property of the oxygen carrier, which may be due to the thermodynamic limitation during testing.
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| 9. |
- Jing, Dazheng, 1986, et al.
(författare)
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Examination of Perovskite Structure CaMnO 3-δ with MgO Addition as Oxygen Carrier for Chemical Looping with Oxygen Uncoupling Using Methane and Syngas
- 2013
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Ingår i: International Journal of Chemical Engineering. - : Hindawi Limited. - 1687-806X .- 1687-8078. ; 2013
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite structure oxygen carriers with the general formula CaMn x Mg 1-x O 3-δ were spray-dried and examined in a batch fluidized bed reactor. The CLOU behavior, reactivity towards methane, and syngas were investigated at temperature 900°C to 1050°C. All particles showed CLOU behavior at these temperatures. For experiments with methane, a bed mass corresponding to 57 kg/MW was used in the reactor, and the average CH 4 to CO 2 conversion was above 97% for most materials. Full syngas conversion was achieved for all materials utilizing a bed mass corresponding to 178 kg/MW. SEM/EDX and XRD confirmed the presence of MgO in the fresh and used samples, indicating that the Mg cation is not incorporated into the perovskite structure and the active compound is likely pure CaMnO 3-δ . The very high reactivity with fuel gases, comparable to that of baseline oxygen carriers of NiO, makes these perovskite particles highly interesting for commercial CLC application. Contrary to NiO, oxygen carriers based on CaMnO 3-δ have no thermodynamic limitations for methane oxidation to CO 2 and H 2 O, not to mention that the materials are environmentally friendly and can utilize much cheaper raw materials for production. The physical properties, crystalline phases, and morphology information were also determined in this work. © 2013 Dazheng Jing et al.
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| 10. |
- Jing, Dazheng, 1986, et al.
(författare)
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Innovative Oxygen Carrier Materials for Chemical-Looping Combustion
- 2013
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 37:2013, s. 645-653
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Konferensbidrag (refereegranskat)abstract
- In chemical-looping combustion, the oxygen needed for combustion of fuel is provided by metal oxides called oxygen carriers, and inherent separation of CO2 is achieved without energy penalty. For gaseous fuels, such as natural gas, Ni-based oxygen carriers have generally been shown to be the most reactive. But as Ni-based materials are burdened by high costs and environmental risks with respect to toxicity, it is of high importance to find viable non-Ni alternatives. In the EU-financed project INNOCUOUS, one of the key issues is to find novel non-Ni based oxygen carriers. In this paper results from reactivity investigations of three groups of oxygen carrier materials are reported. The materials were prepared by spray-drying, and are based on 1) CuO, 2) Ca-Mn-X-O where X = Cu, Fe, Ti and Mg, and 3) Mg-Mn-O. A number of materials showed a combination of sufficient mechanical strength, high release of gas phase oxygen and high reactivity with methane, and can thus be considered viable alternatives to Ni-based materials.
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| 11. |
- Jing, Dazheng, 1986
(författare)
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Innovative Oxygen Carriers for Chemical-looping Combustion
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) are combustion technologies where carbon dioxide is inherently obtained in pure form without any gas separation step. In the processes, fuel is introduced to the fuel reactor and combustion air is introduced to the air reactor. Circulating metal oxide particles transport oxygen from the air to the fuel reactor, and high purity CO2 can be obtained after steam condensation. Some metal oxides have the ability to release oxygen to the gas phase, or so-called uncoupling properties, which may facilitate fuel conversion. The metal oxide, named oxygen carrier, is the cornerstone of the CLC process. Prior to this work, NiO was the benchmark oxygen carrier for gaseous fuels, like natural gas. However, the high cost, toxicity and thermodynamic limitation of Ni would likely make it difficult to up-scale a process using this type of oxygen carrier. Thus, the focus in this work is on oxygen carriers based on cheaper and more environmentally benign materials, i.e. combined manganese oxides and CuO-based oxygen carriers. Both of these types of oxygen carriers have the propensity to release gas phase oxygen in the fuel reactor, something which was deemed highly beneficial. The main focus is on the combined materials, and this work presents the first major screening of these types of oxygen carriers. All oxygen carriers were manufactured by the commercial spray-drying method and examined in a batch fluidized reactor system with respect to parameters important for chemical-looping. Several combined manganese oxide systems were investigated in this work, with the main focus on three rather promising systems: i) calcium manganites, ii) manganese-silica and iii) manganese with magnesium. For the first system, Ca-Mn-X-O (X= Fe, Ti and Mg), all materials had perovskite structure and performed very well. Clear oxygen uncoupling ability and full conversion of CH4 were achieved in the batch testing. Adjusting the production parameters, i.e. calcination temperature, calcination time and milling time, the physical properties of the oxygen carrier can be enhanced. The oxygen carrier with molar composition CaMn0.775Mg0.1Ti0.125O3-δ was produced by a wide range of Mn- and Ti-sources available commercially at tonnage scales. All materials showed similar oxygen uncoupling behaviour and had the perovskite structure. This shows that this type of oxygen carrier not only can be produced with cheap raw materials, but is simple to produce independent of the material source. Although the oxygen carriers based on Mn-Si-O had limited oxygen release at lower temperatures, there was a remarkable increase in release at temperatures above 950C for particles with less than 45 wt% SiO2. Similarly, the ability to convert CH4 for these particles increased with temperature, and over 90% combustion could be achieved at temperatures at and above 950°C. The third promising system investigated was a combination of Mn and Mg oxides. In this system, the uncoupling reactions were more pronounced at 900°C for the material with a molar ratio of Mn/Mg of one. Also, the methane conversion for some samples studied was high, making this material yet another interesting alternative. CuO-based materials with different support materials have a seemingly fast release rate of oxygen, approaching equilibrium at 900°C. Most investigated materials had the ability to fully convert CH4 at 925°C at the experimental conditions. Some CuO-support combinations did not perform so well, for instance the Cu36FAl24 sample due to formation of Cu0.95Fe1.05AlO4. Several very promising oxygen carriers have been developed in this work. Some of them have been successfully tested in continuous operation at 120 kW scale. Further, the work has led to the development of calcium manganites ready to be up-scaled to large scale application. In addition to this, several other promising systems have been developed, which may not be ready for upscaling, but have great potential when optimized further.
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| 12. |
- Mattisson, Tobias, 1970, et al.
(författare)
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Experimental investigation of binary and ternary combined manganese oxides for chemical-looping with oxygen uncoupling (CLOU)
- 2016
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 164, s. 228-236
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Tidskriftsartikel (refereegranskat)abstract
- Some binary and ternary combined manganese oxides of Mn with one or two additional metals or metalloids of Fe, Si, Ca and Mg were investigated as oxygen carriers for chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU). More specifically the following systems were investigated: (1) MnyMgOx, (2) CaMnO3-(Fe0.25Mn0.75)2O3, (3) CaMnO3-(Fe0.67Mn0.33)2O3, (4) CaMnO3-MnMgOx, (5) MnMgOx-(Fe0.25Mn0.75)2O3 and (6) Mn2SiOx-Fe2SiOx. The general trend was that the binary systems, where two metals are used in the formulation showed the most promising results in terms of oxygen uncoupling and reactivity. However, there are several ternary combinations which show a combination of high oxygen uncoupling, reactivity with methane and reasonable strength. A pseudo first-order effective rate constant was evaluated for the investigated particles. The measured rates are lower than for benchmark nickel oxide and calcium manganites, but higher than for ilmenite. The ternary System 6, Mn2SiOx-Fe2SiOx was investigated in more depth, including solid fuel experiments to determine the rate of oxygen release. At 850 and 900 °C (Mn0.5Fe0.5)2SiOx had the highest average reactivity, with a maximum average yield of 91.5% at 850 °C. On the other hand, at higher temperatures, the particles with the highest Mn content showed best behavior, i.e. (Mn0.67Fe0.33)2SiOx. Reactivity experiments with char in the FB reactor with this OC showed that the oxygen capacity for CLOU was high, 3.5 wt% at 950 °C, with a maximum release rate of 0.2 g O2/kg OC,s. The low rate of uncoupling means that the experiments with gaseous fuel were likely dominated by the direct gas-solid reaction, and not CLOU. X-ray powder diffraction suggests that the main reaction path is via (MnxFe1- x)2O3 to (MnxFe1- x)3O4, although the reaction between Mn7SiO12 to MnSiO3 cannot be ruled out as a possible route of oxygen transfer. This was supported by thermodynamic calculations of this multi-component system.
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| 13. |
- Rydén, Magnus, 1975, et al.
(författare)
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CuO-Based Oxygen-Carrier Particles for Chemical-Looping with Oxygen Uncoupling - Experiments in Batch Reactor and in Continuous Operation
- 2014
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 53:15, s. 6255-6267
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Tidskriftsartikel (refereegranskat)abstract
- Chemical-looping with oxygen uncoupling (CLOU) is an innovative method to oxidize fuels with inherent CO2 sequestration, which utilizes a solid oxygen-carrier material to provide O-2 for fuel combustion. In this study, a range of CuO-based oxygen-carrier particles have been manufactured and examined. Out of 24 samples prepared, 10 were examined in a batch fluidized-bed reactor, of which three were selected for further examination by continuous operation in a small circulating fluidized-bed reactor system. Composite particles consisting of CuO as active phase and support material such as ZrO2, YSZ, CeO2, and MgAl2O4 were capable of providing full conversion of CH4 at 900 and 925 degrees C, and were also found to release gas phase O-2 into inert atmosphere when fluidized with N-2. Particles using semiactive support such as Fe2O3, Mn2O3, and Al2O3 formed combined spinel phases with CuO. Such materials were still capable of releasing gas phase O-2 but at different concentrations as compared to particles with inert support. Materials with semiactive support had less good reactivity with CH4. No formation of unexpected phases could be detected by X-ray diffractometry, and all chemical reactions were completely reversible. The three materials that were examined in continuous operation were readily capable of providing more or less full conversion of natural gas under the chosen conditions. However, they also suffered from quick attrition and turned into a flour-like substance after a few hours of continuous operation with fuel. Crushing strength analysis showed that particles used in continuous operation were physically much weaker than fresh. In total, 23 h of continuous operation with fuel addition was recorded.
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| 14. |
- Rydén, Magnus, 1975, et al.
(författare)
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(Fe1-xMnx)TiyO3 based oxygen carriers for chemical-looping combustion and chemical-looping with oxygen uncoupling
- 2014
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 51, s. 85-98
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Konferensbidrag (refereegranskat)abstract
- The manganese based ilmenite analogue pyrophanite (MnTiO3) and six other combined (Fe1-xMnx)TiyO3 oxides have been examined as oxygen-carrier materials for chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU). Particles with different compositions were manufactured by spray drying and studied by consecutive reduction and oxidation at 850-1050°C in a batch fluidized-bed reactor using CH4 as fuel. A fuel conversion of 80-99% could be achieved with most materials, with different formulations being favored at different temperature levels. The exception was pure MnTiO3 which had very limited reactivity with CH4. The oxygen uncoupling behavior was examined by exposing the oxygen-carrier particles to an inert atmosphere of N2. The apparent equilibrium concentration during fluidization with pure N 2 ranged from zero to 0.9% O2, depending on temperature and particle composition. One material (Fe0.50Mn0.50) TiO3 was selected and further examined by 12 h of experiments in a small continuously operating circulating fluidized-bed reactor. Up to 80% conversion of natural gas was achieved at 910°C , but defluidization occurred when the temperature was increased to 950°C .
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| 15. |
- Snijkers, Frans, et al.
(författare)
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Chemical looping combustion: An emerging carbon capture technology
- 2015
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Ingår i: SPE - Abu Dhabi International Petroleum Exhibition and Conference, ADIPEC 2015, Abu Dhabi, United Arab Emirates, 9-12 November 2015. - : SPE. - 9781613994245
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Konferensbidrag (refereegranskat)abstract
- Chemical looping combustion (CLC) is a promising technology for energy production with inherent capture of carbon dioxide at minimal energy penalty. In CLC, oxygen is transferred from an air reactor to a fuel reactor by means of a solid oxygen carrier. Direct contact between air and fuel is avoided, resulting in an undiluted CO2 exhaust stream. As such, CLC was picked up recently as a high potential carbon capture and storage (CCS) technology. While initial focus was on storage projects, CO2 is more and more considered as a valuable chemical substance for enhanced oil/gas recovery projects as well as for the production of chemicals, polymers or building materials. A critical aspect of the CLC technology is the oxygen carrier performance which has a very strong impact on the economic viability. Parameters such as particle size, density, porosity, strength, attrition resistance, reactivity, environmental aspects and cost, define the performance of the oxygen carrier. The first generation oxygen carriers was Ni-based. However, due to cost of nickel and toxicity, a search for Ni-free oxygen carriers was conducted with similar or superior performance in CLC. This lead to the development of Cu-, Fe and Mn-based oxygen carriers, that demonstrate the beneficial oxygen uncoupling effect, with complete fuel conversion as a result. In this contribution it is shown that the industrial spray-drying technique is a very versatile and scalable technique for the fabrication of oxygen carriers. New and promising oxygen carriers with varying compositions, good fluidisability, high sphericity, high attrition resistance, and homogeneity on the micro-scale have been synthesized. Different materials such as perovskite type materials based on calcium-manganate, magnesium manganates, copper based materials, and iron manganates have been investigated for their performance with promising results towards complete combustion and high attrition resistance.
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| 16. |
- Snijkers, Franz, et al.
(författare)
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Chemical-looping combustion: An emerging carbon-capture technology
- 2016
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Ingår i: JPT, Journal of Petroleum Technology. - 0149-2136. ; 68:7, s. 85-86
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Tidskriftsartikel (refereegranskat)abstract
- Chemical-looping combustion (CLC) has been identified recently as a high-potential carbon-capture- and-storage technology. In chemical-looping combustion (CLC) , oxygen is transferred from an air reactor to a fuel reactor by means of a solid oxygen carrier The CLC process can be configured as two coupled fluidized-bed boilers, but packed-bed configurations, with the possibility of pressurizing, are also being considered. To transfer oxygen from the combustion air to the fuel, oxygen carriers are used. This avoids direct contact between air and fuel, and, after condensation of water, relatively pure CO2 is obtained in a separate exhaust stream from the fuel reactor. Thus, energy-consuming flue-gas separation is avoided. A critical aspect of CLC processes is oxygen-carrier performance, which has a strong effect on the economic viability of the technology. Parameters such as particle size, density, porosity, strength, attrition resistance, reactivity, and conversion efficiency, along with environmental aspects and cost, define the performance of the oxygen carrier. Besides the conversion efficiency, the mechanical (crushing) strength of the particles is extremely important because it determines the resistance to attrition and hence the operational-use hours (lifetime) of the particles e relationship between attrition resistance and the crushing strength is not straightforward, yet a crushing strength greater than 1 N is considered to be a good indication for acceptable attrition resistance.
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