Development of new CaO based sorbent materials for CO2 removal at high temperature

Martavaltzi, Christina S.; Lemonidou, Angeliki A.

doi:10.1016/j.micromeso.2007.10.006

Cited by 221 publications

(162 citation statements)

References 28 publications

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“…limestone, dolomite), it makes sense to use the material over several cycles and to perform multiple regenerations before disposing of the used carbonate, so as to achieve genuine energy and CO 2 emissions reductions. Research efforts are taking place worldwide to understand the reasons for the loss of CO 2 capacity with repeated cycling and increase the durability of Ca-based CO 2 sorbent with this very aim [35][36][37][38][39][40][41][42][43]. Table 2 allows comparison of the minima of enthalpy changes of the urea-water system at 1 atm (and the temperatures at which they occur) with those of the urea-water-CaO system (with Ca:C=1), in kJ/mol of H 2 produced, alongside the H ratio, maxima of H 2 yield and of H 2 purity, also listed with their corresponding temperatures.…”

Section: Figurementioning

confidence: 99%

Thermodynamics of hydrogen production from urea by steam reforming with and without in situ carbon dioxide sorption

Dupont

Twigg²,

Rollinson

et al. 2013

International Journal of Hydrogen Energy

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The thermodynamic effects of molar steam to carbon ratio (S:C), of pressure, and of having CaO present on the H 2 yield and enthalpy balance of urea steam reforming were investigated.At a S:C of 3 the presence of CaO increased the H 2 yield from 2.6 mol H 2 /mol urea feed at 940 K to 2.9 at 890 K, and decreased the enthalpy of bringing the system to equilibrium. A minimum enthalpy of 180.4 kJ was required to produce 1 mole of H 2 at 880 K. This decreased to 94.0 kJ at 660 K with CaO-based CO 2 sorption and, when including a regeneration step of the CaCO 3 at 1170 K, to 173 kJ at 720 K. The presence of CaO allowed widening the range of viable operation at lower temperature and significantly inhibited carbon formation. The feasibility of producing H 2 from renewable urea in a low carbon future is discussed.

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Section: Figurementioning

confidence: 99%

Thermodynamics of hydrogen production from urea by steam reforming with and without in situ carbon dioxide sorption

Dupont

Twigg²,

Rollinson

et al. 2013

International Journal of Hydrogen Energy

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“…[66] Multiple cycles of CO 2 adsorption and desorption confirmed that the adsorption capacity of these mesoporous metal phosphonate adsorbents could be well retained. This is quite different from lime-based CO 2 adsorbents, [73,74] for which the adsorption capacity decreased continuously depending on the number of cycles, which was caused by an unavoidable decay in the carbonation conversion.…”

mentioning

confidence: 68%

Metal Phosphonate Hybrid Mesostructures: Environmentally Friendly Multifunctional Materials for Clean Energy and Other Applications

Yuan

2011

ChemSusChem

106

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The synthesis of porous hybrid materials has been extended to mesoporous non-silica-based organic-inorganic hybrid materials, in which mesoporous metal phosphonates represent an important family. By using organically bridged polyphosphonic acids as coupling molecules, the homogeneous incorporation of a considerable number of organic functional groups into the metal phosphonate hybrid framework has been realized. Small amounts of organic additives and the pH value of the reaction solution have a large impact on the morphology and textural properties of the resultant hybrid mesoporous metal phosphonate solids. Cationic and nonionic surfactants can be used as templates for the synthesis of ordered mesoporous metal phosphonates. The materials are used as efficient adsorbents for heavy metal ions, CO₂, and aldehydes, as well as in the separation of polycyclic aromatic hydrocarbons. They are also useful photocatalysts under UV and simulated solar light irradiation for organic dye degradation. Further functionalization of the synthesized mesoporous hybrids makes them oxidation and acid catalysts, both with impressive performances in the fields of sustainable energy and environment.

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“…It was also reported that a mixture of CaO and 20 wt % MgO can maintain 24 wt % CO 2 capacity even after 1250 cycles (Albrecht et al 2008 ). Recently, a new regenerable calcium-based sorbent, CaO/Ca 12 Al 14 O 33 , was tested at different conditions (Li et al , 2006 (Martavaltzi and Lemonidou 2008 ). Sorbents can maintain a high residual capacity after 1000 cycles no matter if they are in the form of pellet or powder.…”

Section: Precursor and Support Materials Selectionmentioning

confidence: 99%

Chemical looping processes — particle characterization, ionic diffusion-reaction mechanism and reactor engineering

Zeng

Luo

Sridhar

et al. 2012

Reviews in Chemical Engineering

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The chemical looping strategy for fossil energy applications promises to achieve an effi cient energy conversion system for electricity, liquid fuels, hydrogen, and/or chemical generation while economically separating CO 2 by looping reaction design in the process. Two types of chemical looping technologies have been developed based on two different reactions of chemical looping intermediates. Type I chemical looping systems utilize metal and metal oxide reductionoxidation properties to perform the looping reactions. Type II chemical looping systems utilize metal oxide and metal carbonate carbonation-calcination properties to perform the looping reactions. The type of metal or metal oxide along with their preparation methods for applications in both types of chemical looping systems plays signifi cant roles in the chemical looping technology performance. Understanding the reaction mechanism associated with looping intermediates in both types of reactions is important to the rate process of reactions, in turn affecting the design of the looping particles. Furthermore, as conversions of gaseous and solid reactants are closely associated with their contact modes, the intricate contact mode plays an important role in determining the reactant conversions and hence the solid reactant fl ux in the reactors. The purpose of this paper is thus to provide a perspective on the two key aspects of chemical looping technology, which are not well reported in the literature, namely, reaction mechanism and reactor engineering.

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Development of new CaO based sorbent materials for CO2 removal at high temperature

Cited by 221 publications

References 28 publications

Thermodynamics of hydrogen production from urea by steam reforming with and without in situ carbon dioxide sorption

Thermodynamics of hydrogen production from urea by steam reforming with and without in situ carbon dioxide sorption

Metal Phosphonate Hybrid Mesostructures: Environmentally Friendly Multifunctional Materials for Clean Energy and Other Applications

Chemical looping processes — particle characterization, ionic diffusion-reaction mechanism and reactor engineering

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