Cyclic life of metal hydrides with impure hydrogen: Overview and engineering considerations

Sandrock, G.; Goodell, P.D.

doi:10.1016/0022-5088(84)90452-1

Cited by 153 publications

(67 citation statements)

References 19 publications

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“…Exposure of the unmodified alloy (Fig. 4(a)) in the gas mixture containing 10% CO 2 resulted in immediate deterioration of H 2 absorption properties, in agreement with the literature data http://repository.uwc.ac.za reporting about strong retardation of hydrogen absorption and decrease of H absorption capacity during cyclic operation of hydride-forming materials at a presence of CO 2 in a feedstock gas [18]. In contrast, the exposure of the surfacemodified material (Fig.…”

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confidence: 79%

“…At the same time, a challenging problem that hampers application of MH for hydrogen separation from the mixtures containing chemically-aggressive gases (O 2 , H 2 O, CO, sulphur-containing compounds, etc.) is the deterioration of MH performances as a result of the presence in hydrogen of gas impurities [3,18] able to easily react with MH surfaces resulting in the formation of surface compounds (oxides and hydroxides, carbonyls, sulphides) which seriously limit hydrogen absorption. Most probably, the impurities deactivate surface centres responsible for H 2 dissociation (e.g., Ni clusters for AB 5 -type alloys) resulting in the retardation of this process, which represents the rate-limiting step in hydrogen absorption [19,20].…”

Section: Introductionmentioning

confidence: 99%

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Poisoning-tolerant metal hydride materials and their application for hydrogen separation from CO2/CO containing gas mixtures

Modibane

Williams

Lototskyy

et al. 2013

International Journal of Hydrogen Energy

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Modibane, K.D. et al. (2013). Poisoning-tolerant metal hydride materials and their application for hydrogen separation from CO2/CO containing gas mixtures. AbstractMetal hydride materials offer attractive solutions in addressing problems associated with hydrogen separation and purification from waste flue gases. However, a challenging problem is the deterioration of hydrogen charging performances resulting from the surface chemical action of electrophilic gases. In this work, the feasibility study of poisoning tolerance of surface modified AB5-type hydride forming materials and their application for hydrogen separation from process gases containing carbon dioxide and monoxide was carried out. Target composition of La(Ni,Co,Mn,Al)5 substrate was chosen to provide maximum reversible hydrogen capacity at the process conditions. The selected substrate alloy has been shown to be effectively surface-modified by fluorination followed by electroless deposition of palladium. The surface-modified material exhibited good coating quality, high cycle stability and minimal deterioration of kinetics of selective hydrogen absorption at room temperature, from gas mixtures containing 10% CO2 and up to 100 ppm CO. The experimental prototype of a hydrogen separation unit, based on the surfacemodified metal hydride material, was tested and exhibited stable hydrogen separation and purification performances when exposed to feedstocks containing concentrations of CO21. Introduction Metal hydride (MH) materials have found a number of promising gas-phase applications in processes of considerable economic potential, such as hydrogen storage, separation and recovery, thermally-driven compressors and heat pumps, etc. [1e3]. These materials exhibit a favourable combination of their properties, including reversibility and selectivity of interaction with H 2 gas at mild conditions, high volumetric density of hydrogen in the solid, significant heat effects in the course of hydrogenation/dehydrogenation. Thus they are very flexible in the applications, and often allow to develop multifunctional facilities (e.g., for hydrogen storage, purification and controlled supply) which offer to an end-user safe, efficient and cost-saving solutions [4].

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confidence: 79%

Section: Introductionmentioning

confidence: 99%

Poisoning-tolerant metal hydride materials and their application for hydrogen separation from CO2/CO containing gas mixtures

Modibane

Williams

Lototskyy

et al. 2013

International Journal of Hydrogen Energy

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“…If the material is repeatedly exposed to impurities over subsequent refueling cycles, the effect to capacity and performance can be cumulative, as demonstrated in conventional metal hydrides. 145,146 In some cases (e.g. sorbent systems), impurities can be removed by exposure to high vacuum and/or heating.…”

Section: Puritymentioning

confidence: 99%

High capacity hydrogenstorage materials: attributes for automotive applications and techniques for materials discovery

et al. 2010

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Widespread adoption of hydrogen as a vehicular fuel depends critically upon the ability to store hydrogen on-board at high volumetric and gravimetric densities, as well as on the ability to extract/insert it at sufficiently rapid rates. As current storage methods based on physical means-high-pressure gas or (cryogenic) liquefaction-are unlikely to satisfy targets for performance and cost, a global research effort focusing on the development of chemical means for storing hydrogen in condensed phases has recently emerged. At present, no known material exhibits a combination of properties that would enable high-volume automotive applications. Thus new materials with improved performance, or new approaches to the synthesis and/or processing of existing materials, are highly desirable. In this critical review we provide a practical introduction to the field of hydrogen storage materials research, with an emphasis on (i) the properties necessary for a viable storage material, (ii) the computational and experimental techniques commonly employed in determining these attributes, and (iii) the classes of materials being pursued as candidate storage compounds. Starting from the general requirements of a fuel cell vehicle, we summarize how these requirements translate into desired characteristics for the hydrogen storage material. Key amongst these are: (a) high gravimetric and volumetric hydrogen density, (b) thermodynamics that allow for reversible hydrogen uptake/release under near-ambient conditions, and (c) fast reaction kinetics. To further illustrate these attributes, the four major classes of candidate storage materials-conventional metal hydrides, chemical hydrides, complex hydrides, and sorbent systems-are introduced and their respective performance and prospects for improvement in each of these areas is discussed. Finally, we review the most valuable experimental and computational techniques for determining these attributes, highlighting how an approach that couples computational modeling with experiments can significantly accelerate the discovery of novel storage materials (155 references).

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“…However, so far, this approach was successfully implemented only for hydrogen-rich feed gases (vent streams in the ammonia synthesis loop, H 2 > 50%) which contain relatively innocuous admixtures, mainly nitrogen and argon [3,4]. At the same time, the gases associated with processing of coal, petrol, natural gas and other carbonaceous/fossil fuels feedstock, in addition to hydrogen, may contain significant amounts of other components, mainly carbon dioxide and monoxide, which in most cases cause the deterioration of hydrogen sorption performances of metal hydrides (MHs) [5,6]. 2 Earlier the authors reported on the improvement of activation performances and poisoning tolerance of AB 5 -type hydride-forming materials surface-modified by fluorination and/or electroless deposition of metals (including Pd), possessing high catalytic activity towards the dissociative H 2 chemisorptive process [7].…”

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Application of surface-modified metal hydrides for hydrogen separation from gas mixtures containing carbon dioxide and monoxide

Lototskyy

Modibane

Williams

et al. 2013

Journal of Alloys and Compounds

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Lototskyy, M. et al. (2013). Application of surface-modified metal hydrides for hydrogen separation from gas mixtures containing carbon dioxide and monoxide. AbstractApplication of surface-modified MH material for H2 separation using temperature/pressure swing absorption-desorption was studied. The substrate alloy had the following composition LaNi3.55Co0.75Al0.4-Mn0.3, and the surface modification was carried out through fluorination followed by aminosilane functionalization and electroless deposition of Pd. The material was found to have good poisoning tolerance towards surface adsorbates, even for the large (rv1.5 kg) batches. Feasibility of its application for H2 separation from gas mixtures (up to 30% CO2 and 100 ppm CO) was demonstrated by testing of a prototype H2 separation system (rv280 g of MH in two reactors), and H2 separation reactor (0.75 kg of MH). The H2 separation was characterized by stable performances in the duration of 250 absorption/desorption cycles. However, the total process productivity was found to be limited by the sluggish H2 absorption (partial H2 pressure 62.5 bar, temperature below 100 °C). In the presence of CO2 and CO, additional deceleration of H2 absorption was observed at space velocities of the feed gas below 5000 h 1. Introduction Selectivity of reversible hydrogen interaction with hydride-forming materials allows for the development of simple and efficient pressure/temperature swing absorptiondesorption systems for hydrogen separation from complex gas mixtures and its fine purification [1,2]. However, so far, this approach was successfully implemented only for hydrogen-rich feed gases (vent streams in the ammonia synthesis loop, H 2 > 50%) which contain relatively innocuous admixtures, mainly nitrogen and argon [3,4]. At the same time, the gases associated with processing of coal, petrol, natural gas and other carbonaceous/fossil fuels feedstock, in addition to hydrogen, may contain significant amounts of other components, mainly carbon dioxide and monoxide, which in most cases cause the deterioration of hydrogen sorption performances of metal hydrides (MHs) [5,6].

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Cyclic life of metal hydrides with impure hydrogen: Overview and engineering considerations

Cited by 153 publications

References 19 publications

Poisoning-tolerant metal hydride materials and their application for hydrogen separation from CO2/CO containing gas mixtures

Poisoning-tolerant metal hydride materials and their application for hydrogen separation from CO2/CO containing gas mixtures

High capacity hydrogenstorage materials: attributes for automotive applications and techniques for materials discovery

Application of surface-modified metal hydrides for hydrogen separation from gas mixtures containing carbon dioxide and monoxide

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