Using Low-Cost Iron-Based Materials as Oxygen Carriers for Chemical Looping Combustion

Jerndal, Erik; Leion, Henrik; Axelsson, Louise; Ekvall, Thomas; Hedberg, Marcus; Johansson, Kristoffer; Källén, Malin; Svensson, Robin; Mattisson, Tobias; Lyngfelt, Anders

doi:10.2516/ogst/2010030

Cited by 62 publications

(54 citation statements)

References 30 publications

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“…Hence the iron migration is believed to cause a loss in oxygen transfer capacity. On the other hand, Jerndal et al found that iron-based oxygen carriers generally have higher conversion rates of H 2 and CO than mineral ilmenite [20]. Thermodynamic equilibrium calculations show that the oxide system Fe 2 O 3 / Fe 3 O 4 allows for a complete conversion of syngas to CO 2 and H 2 O [13].…”

Section: Ilmenitementioning

confidence: 99%

Testing of minerals and industrial by-products as oxygen carriers for chemical-looping combustion in a circulating fluidized-bed 300W laboratory reactor

Moldenhauer

Rydén

Lyngfelt

2012

Fuel

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Chemical-looping combustion (CLC) is a promising technology for future energy production with inherent CO 2 separation. One approach is to use minerals or industrial by-products as oxygen carriers to reduce the costs of the process. This study focuses on the investigation of two iron-based oxygen carriers, which were examined under continuous operation in a 300 W laboratory reactor. Ilmenite is an iron-titanium oxide mineral, whereas iron oxide scale (IOS) is obtained as a by-product from the rolling of sheet steel. Syngas was used as a fuel -pure and with steam addition to suppress the formation of solid carbon.During the experiments the variables reactor temperature, fuel flow and air flow were changed. Furthermore the effect of steam addition to the fuel was investigated. Particle properties were compared over the span of 85 h of continuous operation for ilmenite and 37 h for IOS. The analysis is based on gas measurements from the actual CLC operation, but also on scanning electron microscopy, X-ray powder diffractometry and measurements of BET surface area and density.With ilmenite oxygen carrier it was possible to achieve full conversion of syngas up to about 190 W th fuel equivalent at 900°C. With design fuel flow of about 300 W th at 900°C the combustion efficiency was above 98 %. There was almost no visible difference in reactivity of fresh activated particles and those used for 85 h. Combustion efficiency up to 99 % was achieved with IOS oxygen carrier at 900°C and about 100 W th fuel equivalent. At 300 W th fuel equivalent and 900°C a combustion efficiency of only 90 % could be reached.Both oxygen carriers were operated for tens of hours, which allowed for a better understanding of lifetime behavior and other basic characteristics. Whereas ilmenite oxygen-carrier particles were mostly stable over the course of 85 h of experiments, a large fraction of IOS oxygen-carrier particles had disintegrated to fines after only 37 h of experiments. The gathered data indicates that both oxygen carriers could be an alternative to synthesized particles, though with more drawbacks for IOS than for ilmenite.

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Section: Ilmenitementioning

confidence: 99%

Testing of minerals and industrial by-products as oxygen carriers for chemical-looping combustion in a circulating fluidized-bed 300W laboratory reactor

Moldenhauer

Rydén

Lyngfelt

2012

Fuel

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“…Besides the common chemical and mechanical properties demanded for an oxygen-carrier, in CLC of coal it is especially interesting to find inexpensive oxygen-carriers, as there might be losses of material during ash separation. Lately, different Fe-based ores [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] and industrial by-products [19,26,35] have been evaluated as oxygen-carriers for iG-CLC. Among the different Fe-based oxygen-carriers tested, the use of the natural ore ilmenite has been extensively analyzed.…”

Section: Introductionmentioning

confidence: 99%

Performance of a bauxite waste as oxygen-carrier for chemical-looping combustion using coal as fuel

Mendiara

Gayán

Abad

et al. 2013

Fuel Processing Technology

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In the recently developed Chemical-Looping Combustion (CLC) technology, the oxygen needed for the oxidation of the fuel is provided by an oxygen-carrier. Today, there is an increasing interest on CLC application to solid fuels, especially coal. One of the possibilities to process coal in a CLC system is the in situ gasification and subsequent combustion of the product gases (iG-CLC). Potential CLC oxygen-carriers should comply with some chemical and mechanical requirements but it would be interesting that the carrier is as inexpensive as possible, as some losses are expected accompanying the coal ashes. In the present work, a residue from alumina production mainly constituted by Fe 2 O 3 has been tested as oxygencarrier in CLC of coal. Batch experiments were carried out in a fluidized-bed reactor using a bituminous coal as fuel. The effect of operating conditions, such as temperature and gasification agent on the char conversion and combustion efficiency of gasification products were evaluated. Several H 2 O/CO 2 mixtures were tested as gasifying agents. After 50 hours of cycling operation in a batch fluidized bed, no defluidization or agglomeration problems were observed. A gain in the reactivity of the bauxite waste was observed with the number of redox cycles. The carrier showed high combustion efficiencies at all temperatures tested meaning that the bauxite waste was capable of burning the gases generated during the gasification of the char. The percentage of CO 2 in the feeding should be limited in order to maintain high gasification rates and combustion efficiencies. The present results indicate that this bauxite waste is a promising oxygen-carrier for the iG-CLC of coal.

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“…The numbers given in parenthesis express the significant figures. The three types of Cu-O bonding are present because the crystal structure has two types of cation-polyhedral double layers of SrO 7 and CuO 4 that alternately connect parallel to the direction of the b axis, and the stacking along the c axis is closely related to the NaCl-like TlI-type structure. The values of the bond lengths differ somewhat slightly from the values obtained from the literature.…”

Section: Resultsmentioning

confidence: 99%

“…As natural carriers that might be potential candidates for chemical looping, the various ores [5], minerals [6], steel industry wastes [7], sediments from deep water purification [8] and finally sewage sludge ashes [9] were considered, mainly because of their attractive cost contributing to the overall cost of CLC. Recently, synthetic mixed materials have also been investigated intensively due to their emerging CLC properties [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Examining SrCuO2 as an oxygen carrier for chemical looping combustion

Ksepko

2015

J Therm Anal Calorim

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This paper contains the results of research work on chemical looping combustion (CLC). CLC is one of the most promising combustion technologies and has the main advantage of producing a concentrated CO 2 stream, which is obtained after water condensation without any energy penalty for CO 2 separation. The objective of this work was to study the chemical looping reaction performance for a novel spinel-type oxygen carrier. The SrCuO 2 was tested for the purpose of CLC for power generation, and hydrogen was utilized as a syngas component. SrCuO 2 was prepared as a powder. Reactivity tests were performed under isothermal conditions for multiple redox cycles using a thermogravimetric (TG) analyzer (Netzsch STA 409 PG Luxx). For the reduction, 3 % H 2 was used, and for the oxidation cycle, air was used. The effect of both reaction temperature (600-800°C) and reducing/oxidizing cycles (five cycles at each temperature) on the reaction performance of the oxygen carrier samples developed in this study was evaluated. The stability, oxygen transport capacity and reaction rates were analyzed based on experimental TG data. The material was systematically investigated by scanning electron microscopy, X-ray diffraction measurements, N 2 porosimetry, particle size distribution and studying the melting behavior. Investigation of the oxidation/reduction behavior of SrCuO 2 showed stable chemical looping performance, with great recyclability after continuous multiple redox reactions maintaining the chemical properties. Moreover, excellent oxygen capacity was maintained within cycling combustion tests.Furthermore, the oxygen carrier sample attained a high melting temperature, which provides attractive thermal resistivity. For comparison purposes, another Cu-based oxygen carrier was prepared and analyzed in the same manner. The CuO/TiO 2 carrier transported similar amounts of oxygen to the fuel, but its stability to reaction was questionable. The promising results obtained from CLC allowed us to conclude that SrCuO 2 is possibly a capable and suitable candidate for CLC for power generation.

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Using Low-Cost Iron-Based Materials as Oxygen Carriers for Chemical Looping Combustion

Cited by 62 publications

References 30 publications

Testing of minerals and industrial by-products as oxygen carriers for chemical-looping combustion in a circulating fluidized-bed 300W laboratory reactor

Testing of minerals and industrial by-products as oxygen carriers for chemical-looping combustion in a circulating fluidized-bed 300W laboratory reactor

Performance of a bauxite waste as oxygen-carrier for chemical-looping combustion using coal as fuel

Examining SrCuO2 as an oxygen carrier for chemical looping combustion

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