Chemical Gas Generators Based on Mechanically Alloyed Al·Mg Powder

2015 ◽  
Vol 1758 ◽  
Author(s):  
Marco A. Machado ◽  
Daniel A. Rodriguez ◽  
Edward L. Dreizin ◽  
Evgeny Shafirovich
Keyword(s):  
Hydrogen Generation ◽  
Video Recording ◽  
Sodium Chlorate ◽  
Ammonia Borane ◽  
High Energy ◽  
High Energy Density ◽  
Hydrogen Yield ◽  
Mechanically Alloyed ◽  
Promising Alternative ◽  
Steady Propagation

ABSTRACTBecause of the high energy density, easy ignition, and good storability, mechanically alloyed Al·Mg powder has the potential to improve the performance characteristics of various energetic and gas-generating materials. Here, the use of this powder in combustible mixtures for generation of oxygen and hydrogen is explored. The mixtures for oxygen generation consisted of sodium chlorate, nanoscale cobalt oxide catalyst, and Al·Mg powder, while those for hydrogen generation included water, polyacrylamide as a gellant, and Al·Mg powder. To increase hydrogen yield, ammonia borane (NH3BH3) was also added to Al·Mg − water mixtures. Combustion experiments were conducted in an argon environment, using laser ignition. The thermal wave propagation over the oxygen-generating mixtures was studied using infrared video recording. It has been shown that mechanically alloyed Al·Mg material is a promising alternative to currently used iron because significantly smaller amounts of this additive are needed for a steady propagation of the combustion wave. The hydrogen generation experiments have shown that mixtures of mechanically alloyed Al·Mg powder with 10−60 wt% gelled water are combustible, with the front velocities exceeding the values obtained for the mixtures of water with nanoscale Al. Hydrogen yield was measured using mass-spectrometry. In the mixtures that included ammonia borane, D2O was used instead of H2O. Measurements of H2, D2, and HD concentrations in the product gas provided insight into the reaction mechanisms. The isotopic tests have shown that AB participates in two parallel processes − thermolysis and hydrolysis, thus increasing hydrogen yield.

Methanol Reforming Over PT Catalysts for Polymer Electrolyte Membrane Fuel Cells

2006 ◽  
Author(s):  
Taehee Lee ◽  
Joongmyeon Bae ◽  
Ju-Yong Kim
Keyword(s):  
Hydrogen Generation ◽  
Polymer Electrolyte Membrane ◽  
High Energy ◽  
High Energy Density ◽  
Pt Catalysts ◽  
Methanol Reforming ◽  
Electrolyte Membrane ◽  
Cerium Oxides ◽  
Lower Temperature ◽  
Very High

An experimental investigation on hydrogen generation from methanol using Pt catalysts is presented in this paper. Methanol has the advantages of high energy density, high reforming activity and low CO selectivity at low temperatures. At present Cu-based catalysts are widely used for methanol reforming. But they are pyrophoric and thermally unstable, which causes issues in operating a real system. Pt catalysts dispersed on cerium oxides were tested for methanol reforming to resolve the problems. Steam reforming over Pt/cerium oxides showed the low conversion ratio less than 90% and the high CO concentration of about 15% at 400 °C. Autothermal reforming by adding O2 rapidly promoted the conversion of methanol and reduced the concentration of CO at lower temperature. Increasing the amount of dispersed Pt, the range of 0.5–3.0 wt%, shifted the reforming trends towards lower temperature and decreased the concentration of CO. To achieve more production rate within a given catalyst bed, catalysts coated monolithic honeycomb is prepared. It showed very high conversion at space velocities of up to 60,000/h.

Mg-based composites as effective materials for storage and generation of hydrogen for FC applications

2021 ◽  
pp. 53-80
Author(s):  
D. Korablev ◽  
◽  
A. Bezdorozhev ◽  
V. Yartys ◽  
J. Solonin ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Generation ◽  
High Energy ◽  
High Energy Density ◽  
Hydrolysis Reaction ◽  
Preparation Technique ◽  
Power Sources ◽  
Safety Issues ◽  
Renewable Power ◽  
Physical And Chemical

Today, hydrogen is considered as an ideal choice for storing and carrying energy produced by renewable power sources since it is renewable, eco-friendly and has a high energy density. However, due to the low hydrogen storage capacity, high cost and safety issues of the conventional storage methods, several challenges need to be resolved to effectively use hydrogen in mobile applications. Solid-state hydrogen storage in atomic form in hydrides is a promising method of storage for this purpose, particularly because a double amount of hydrogen can be produced via hydrolysis reaction of chemically active hydrides. Among the metal hydrides, magnesium hydride (MgH2) is considered to be one of the most attractive candidates. However, the hydrolysis reaction is rapidly hindered by the passivation layer formed on the surface of MgH2. In order to improve MgH2 hydrolysis efficiency various approaches have been applied. This paper reviews recent progress on the modifications of MgH2-based materials by adding different type of additives, including metals, oxides, hydroxides, halides and surfactants. The introduced additives possess different catalytic properties due to their intrinsic physical and chemical characteristics, and therefore can strongly influence the hydrolysis reaction of MgH2. The most promising results were obtained for various salt additives showing that the reaction rate depends mostly on the additive type rather than on concentration. The effect of preparation technique on the hydrolysis of MgH2 – MgCl2 composites was studied in detail. The obtained results indicate that efficient hydrolysis performance can be achieved by ball milling of the freshly synthesized MgH2 with 5 wt.% MgCl2 and 1 wt.% TiC–2TiB2 additives. The combination of the applied approaches exhibited a notable synergistic effect on the hydrogen generation.

scholarly journals Recent Progress on Zinc-Ion Rechargeable Batteries

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Wangwang Xu ◽  
Ying Wang
Keyword(s):  
Energy Storage ◽  
Alternative Energy ◽  
Storage Systems ◽  
High Energy ◽  
Zinc Ion ◽  
Rechargeable Batteries ◽  
High Energy Density ◽  
Energy Storage Systems ◽  
Promising Alternative ◽  
Storage Technologies

Abstract The increasing demands for environmentally friendly grid-scale electric energy storage devices with high energy density and low cost have stimulated the rapid development of various energy storage systems, due to the environmental pollution and energy crisis caused by traditional energy storage technologies. As one of the new and most promising alternative energy storage technologies, zinc-ion rechargeable batteries have recently received much attention owing to their high abundance of zinc in natural resources, intrinsic safety, and cost effectiveness, when compared with the popular, but unsafe and expensive lithium-ion batteries. In particular, the use of mild aqueous electrolytes in zinc-ion batteries (ZIBs) demonstrates high potential for portable electronic applications and large-scale energy storage systems. Moreover, the development of superior electrolyte operating at either high temperature or subzero condition is crucial for practical applications of ZIBs in harsh environments, such as aerospace, airplanes, or submarines. However, there are still many existing challenges that need to be resolved. This paper presents a timely review on recent progresses and challenges in various cathode materials and electrolytes (aqueous, organic, and solid-state electrolytes) in ZIBs. Design and synthesis of zinc-based anode materials and separators are also briefly discussed.

Fuel Cell-Based MEMS Power Source

2008 ◽  
Author(s):  
Saeed Moghaddam ◽  
Eakkachai Pengwang ◽  
Kevin Lin ◽  
Rich Masel ◽  
Mark Shannon
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Hydrogen Generation ◽  
Control Mechanism ◽  
Membrane Electrode Assembly ◽  
High Energy ◽  
High Energy Density ◽  
Membrane Electrode ◽  
Mems Devices ◽  
Power Sources

The increasing demand for high energy density power sources driven by advancements in portable electronics and MEMS devices has generated significant interest in development of micro fuel cells. One of the major challenges in development of hydrogen micro fuel cells is the fabrication and integration of auxiliary systems for generation and delivery of fuel to the membrane electrode assembly (MEA). In this paper, we report the development of a millimeter-scale (3×3×1 mm3) micro fuel cell with on-board fuel and control system. Hydrogen is generated in the device through reaction between water and a metal hydride. The device incorporates a new control mechanism for hydrogen generation that occupies only 50 nL volume (less than 0.5% of the total device volume). More importantly, the control mechanism is self-regulating and does not consume any power, enabling the micro fuel cell to operate passively, similar to a battery.

scholarly journals Exploring the Economic Potential of Sodium-Ion Batteries

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 10 ◽  
Author(s):  
Jens Peters ◽  
Alexandra Peña Cruz ◽  
Marcel Weil
Keyword(s):  
Energy Density ◽  
High Energy ◽  
Sodium Ion ◽  
Raw Material ◽  
High Energy Density ◽  
Carbon Anode ◽  
Sodium Ion Batteries ◽  
Hard Carbon ◽  
Promising Alternative ◽  
Material Costs

Sodium-ion batteries (SIBs) are a recent development being promoted repeatedly as an economically promising alternative to lithium-ion batteries (LIBs). However, only one detailed study about material costs has yet been published for this battery type. This paper presents the first detailed economic assessment of 18,650-type SIB cells with a layered oxide cathode and a hard carbon anode, based on existing datasheets for pre-commercial battery cells. The results are compared with those of competing LIB cells, that is, with lithium-nickel-manganese-cobalt-oxide cathodes (NMC) and with lithium-iron-phosphate cathodes (LFP). A sensitivity analysis further evaluates the influence of varying raw material prices on the results. For the SIB, a cell price of 223 €/kWh is obtained, compared to 229 €/kWh for the LFP and 168 €/kWh for the NMC batteries. The main contributor to the price of the SIB cells are the material costs, above all the cathode and anode active materials. For this reason, the amount of cathode active material (e.g., coating thickness) in addition to potential fluctuations in the raw material prices have a considerable effect on the price per kWh of storage capacity. Regarding the anode, the precursor material costs have a significant influence on the hard carbon cost, and thus on the final price of the SIB cell. Organic wastes and fossil coke precursor materials have the potential of yielding hard carbon at very competitive costs. In addition, cost reductions in comparison with LIBs are achieved for the current collectors, since SIBs also allow the use of aluminum instead of copper on the anode side. For the electrolyte, the substitution of lithium with sodium leads to only a marginal cost decrease from 16.1 to 15.8 €/L, hardly noticeable in the final cell price. On the other hand, the achievable energy density is fundamental. While it seems difficult to achieve the same price per kWh as high energy density NMC LIBs, the SIB could be a promising substitute for LFP cells in stationary applications, if it also becomes competitive with LFP cells in terms of safety and cycle life.

scholarly journals Layered Iron Vanadate as a High-Capacity Cathode Material for Nonaqueous Calcium-Ion Batteries

Batteries ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 54
Author(s):  
Munseok S. Chae ◽  
Dedy Setiawan ◽  
Hyojeong J. Kim ◽  
Seung-Tae Hong
Keyword(s):  
Cathode Material ◽  
Calcium Ion ◽  
High Capacity ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Precipitation Method ◽  
New Host ◽  
Promising Alternative ◽  
Host Materials

Calcium-ion batteries represent a promising alternative to the current lithium-ion batteries. Nevertheless, calcium-ion intercalating materials in nonaqueous electrolytes are scarce, probably due to the difficulties in finding suitable host materials. Considering that research into calcium-ion batteries is in its infancy, discovering and characterizing new host materials would be critical to further development. Here, we demonstrate FeV3O9∙1.2H2O as a high-performance calcium-ion battery cathode material that delivers a reversible discharge capacity of 303 mAh g−1 with a good cycling stability and an average discharge voltage of ~2.6 V (vs. Ca/Ca2+). The material was synthesized via a facile co-precipitation method. Its reversible capacity is the highest among calcium-ion battery materials, and it is the first example of a material with a capacity much larger than that of conventional lithium-ion battery cathode materials. Bulk intercalation of calcium into the host lattice contributed predominantly to the total capacity at a lower rate, but became comparable to that due to surface adsorption at a higher rate. This stimulating discovery will lead to the development of new strategies for obtaining high energy density calcium-ion batteries.

Bipolar Plates for PEMFCs

2014 ◽  
Vol 11 (4) ◽  
Author(s):  
C. A. C. Sequeira ◽  
L. Amaral
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Manufacturing Process ◽  
High Energy ◽  
Proton Exchange ◽  
High Energy Density ◽  
Bipolar Plates ◽  
Promising Alternative ◽  
Power Sources ◽  
Fuel Cell Stack

Proton exchange membrane fuel cells (PEMFCs) have many advantages among the various types of fuel cells, such as high energy density, low temperature operation, near-zero pollution, and quick starting. Thereby, PEMFCs have been considered as the most promising alternative power sources in the transportation and stationary fields. Among the components of PEMFCs, the bipolar plates are the most representative regarding cost and volume, however, they have relevant functions on the fuel cell stack. There are about 500 bipolar plates in a PEMFC for a typical passenger car and, thus, the commercialization of the fuel cell technology becomes quite challenging. Important key aspects for a successful fuel cell stack are the design and the manufacturing process of the bipolar plate. For efficient mass production, the cycle time of the process is even more important than the material costs. It is, therefore, very important that the used material is appropriate for a fast manufacturing process. Recent developments are overcoming these issues, leading to improvements on the overall fuel cell performance and durability.

Progress in Magnesium-Based Hydrogen Storage Materials

2012 ◽  
Vol 174-177 ◽  
pp. 1339-1343 ◽  
Author(s):  
Hong Min Kan ◽  
Ning Zhang ◽  
Xiao Yang Wang ◽  
Hong Sun
Keyword(s):  
Hydrogen Storage ◽  
Alternative Energy ◽  
Fossil Fuels ◽  
Clean Energy ◽  
High Energy ◽  
High Energy Density ◽  
Potential Candidate ◽  
Promising Alternative ◽  
Oxygen Contamination ◽  
Kinetics Of

Hydrogen is considered a promising alternative energy carrier that can potentially facilitate the transition from fossil fuels to sources of clean energy because of its prominent advantages such as high energy density, great variety of potential sources, light weight and low environmental impact (water is the sole combustion product). Due to low price and abundance magnesium should be considered as a potential candidate for hydrogen storage. Recent progress in the application of Magnesium-based nanostructured and composite materials in hydrogen storage is presented in this review. The main focus is on the synthesis of composite material, the design of nanocomposite material, the improvement of the thermodynamical properties and kinetics of hydrogenation/dehydrogenation and the improvement of resistance towards oxygen contamination.

scholarly journals Design of Porous Metal-Organic Frameworks for Adsorption Driven Thermal Batteries

MRS Advances ◽  
2017 ◽  
Vol 2 (9) ◽  
pp. 519-524 ◽  
Author(s):  
Daiane Damasceno Borges ◽  
Guillaume Maurin ◽  
Douglas S. Galvão
Keyword(s):  
Water Adsorption ◽  
Metal Organic Frameworks ◽  
High Energy ◽  
High Energy Density ◽  
Working Fluid ◽  
Large Variability ◽  
Promising Alternative ◽  
Topological Features ◽  
Thermal Batteries ◽  
Metal Organic

ABSTRACTThermal batteries based on a reversible adsorption/desorption of a working fluid (water, methanol, ammonia) rather than the conventional vapor compression is a promising alternative to exploit waste thermal energy for heat reallocation. In this context, there is an increasing interest to find novel porous solids able to adsorb a high energy density of working fluid under low relative vapor pressure condition combined with an easy ability of regeneration (desorption) at low temperature, which are the major requirements for adsorption driven heat pumps and chillers. The porous crystalline hybrid materials named Metal–Organic Frameworks (MOF) represent a great source of inspiration for sorption based-applications owing to their tunable chemical and topological features associated with a large variability of pore sizes. Recently, we have designed a new MOF named MIL-160 (MIL stands for Materials of Institut Lavoisier), isostructural to CAU-10, built from the assembly of corner sharing aluminum chains octahedra AlO4(OH)2 with the 2,5-furandicarboxylic linker substituting the pristine organic linker, 1,4-benzenedicarboxylate. This ligand replacement strategy proved to enhance both the hydrophilicity of the MOF and its amount of water adsorbed at low p/p0. This designed solid was synthesized and its chemical stability/adsorption performances verified. Here, we have extended this study by incorporating other polar heterocyclic linkers and a comparative computational study of the water adsorption performances of these novel structures has been performed. To that purpose, the cell and geometry optimizations of all hypothetical frameworks were first performed at the density functional theory level and their water adsorption isotherms were further predicted by using force-field based Grand-Canonical Monte Carlo simulations. This study reveals the ease tunable water affinity of MOF for the desired application.

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