Ammonia Adsorption on Nanostructured Silica Materials for Hydrogen Storage and Other Applications

2008 ◽  
Vol 8 (11) ◽  
pp. 5993-6002 ◽  
Author(s):  
R. Roque-Malherbe ◽  
F. Marquez-Linares ◽  
W. Del Valle ◽  
M. Thommes
Keyword(s):  
Hydrogen Storage ◽  
Pollution Abatement ◽  
Ammonium Hydroxide ◽  
The United States ◽  
High Specific Surface Area ◽  
Department Of Energy ◽  
Ammonia Adsorption ◽  
Adsorption Study ◽  
Silica Materials ◽  
Nanostructured Silica

Our focus in the present study is to apply high specific surface area silica nanostructured porous materials (about 2,200 m2/g, as synthesized, and 600–700 m2/g, after stabilization) to adsorb ammonia (NH3) for hydrogen storage and other chemical and pollution abatement applications. We describe here the synthesis, and characterization of these silica materials, and the adsorption study of N2 and NH3. These materials were obtained with the help of a modification of the Stöber-Fink-Bohn (SFB) method. The main change, made here to the SFB method, was the use of amines, i.e., triethylamine as catalysts instead of ammonium hydroxide. The silica materials have been characterized with the help of SEM and FTIR Spectrometry. The N2 adsorption study was carried out with the help of the Quantachrome-Autosorb-1 and the NH3 adsorption with the Quantachrome-Autosorb-1-C. The amount of hydrogen adsorbed in the form of NH3 in the studied silica samples at: P = 760 [Torr] (1.01325×105 [Pa]), was 2 [wt.%] and the amount of hydrogen stored in the form of NH3 at about: P = 7500 [Torr] (10.0×105 [Pa]), in the studied stabilized silica samples was 11 wt.%, a magnitude higher than the goal figure of 6.5 [wt.%] established by the United States of America, Department of Energy.

Discovering the Mechanism of H2 Adsorption on Aromatic Carbon Nanostructures to Develop Adsorbents for Vehicular Applications

2004 ◽  
Vol 837 ◽  
Author(s):  
A. C. Dillon ◽  
J. L. Blackburn ◽  
P. A. Parilla ◽  
Y. Zhao ◽  
Y-H. Kim ◽  
...  
Keyword(s):  
Binding Energy ◽  
Hydrogen Storage ◽  
Carbon Nanostructures ◽  
Hydrogen Adsorption ◽  
Iron Catalyst ◽  
The United States ◽  
Department Of Energy ◽  
United States Department ◽  
Iron Particles ◽  
Aromatic Carbon

ABSTRACTHydrogen adsorption has been observed with a binding energy of ∼ 50 kJ /mol on as-synthesized carbon multi-wall nanotubes (MWNTs). The MWNTs are virtually free of non-nanotube carbon impurities but contain residual iron catalyst particles. The MWNTs are also highly graphitic. No hydrogen adsorption is observed at near ambient temperatures for purified MWNTs that are free of iron particles. However, hydrogen adsorption is also not observed on bare iron particles even following reduction in the presence of hydrogen at 775 K. These results imply that a special synergy occurs when small iron particles or atoms are in intimate contact with sp2-hybridized aromatic carbon. Interestingly, reducing the as-synthesized MWNTs in H2 at 573 K results in an increased hydrogen capacity. Understanding this hydrogen storage mechanism could facilitate the economical engineering of a hydrogen storage material that meets the United States Department of Energy targets for vehicular fuel cell applications. Recent theoretical studies have shown that an iron ad atom forms a complex with a C36 fullerene and shares charge with four carbon atoms of a bent five-membered ring. Three H2 ligands then coordinate with the iron forming a stable 18-electron organometallic complex. Here the binding energy of the molecular hydrogen ligands is ∼43 kJ /mol. These theoretical results could possibly explain the unique hydrogen storage properties of MWNTs that are grown with an iron catalyst.

Study of the Influence of the V in the Zr2Fe Alloy from Hydrogen Storage on Thermodynamic Properties

2019 ◽  
Vol 31 ◽  
pp. 22-29 ◽  
Author(s):  
Alejandro Martinez ◽  
Darío Peña ◽  
Daniela Bellon
Keyword(s):  
Solid State ◽  
Hydrogen Storage ◽  
Room Temperature ◽  
The United States ◽  
Department Of Energy ◽  
Synthesis Process ◽  
United States Department ◽  
Stoichiometric Ratio ◽  
Desorption Kinetic ◽  
Multi Phase

Hydrogen storage in its solid state is one of the main challenges for mobile and stationary applications. Some metal hydrides are potential candidates for energy storage. This is an experimental research, which represents a contribution to the study of Hydrogen storage in its solid state, by studying the influence of the proportional substitution of V for Zr in the stoichiometric ratio Zr2-XVXFe (X=0.0, 0.1 y 0.2). Results indicate that the synthesis process generates a multi-phase type microstructure, and the absorption and desorption kinetic is less than 5 minutes at room temperature, in line with the parameters established by the United States Department of Energy; however, it is clear that the desorption capacity decreases.

An Overview of the Direct Energy Conversion Proof of Principle Power Production Program

2004 ◽  
Author(s):  
D. King ◽  
G. Rochau ◽  
D. Oscar ◽  
C. Morrow ◽  
P. Tsvetkov ◽  
...  
Keyword(s):  
Energy Conversion ◽  
The United States ◽  
Department Of Energy ◽  
Future Research ◽  
United States Department ◽  
Commercial Development ◽  
Direct Energy Conversion ◽  
Project Description ◽  
Direct Energy ◽  
Proof Of Principle

The United States Department of Energy, Nuclear Energy Research Initiative (NERI) Direct Energy Conversion Proof of Principle (DECPOP) project has as its goal the development of a direct energy conversion process suitable for commercial development. We define direct energy conversion as any fission process that returns usable energy without an intermediate thermal process. A prior Direct Energy Conversion (DEC) project [1] has been completed and indicates that a viable direct energy device is possible if several technological issues can be overcome. The DECPOP program is focusing on two of the issues: charged particle steering and high voltage hold-off. This paper reports on the progress of the DECPOP project. Two prototype concepts are under development: a Fission Electric Cell using magnetic insulation and a Fission Fragment Magnetic Collimator using magnetic fields to direct fission fragments to collectors. Included in this paper are a short project description, an abbreviated summary of the work completed to date, a description of ongoing and future project activities, and a discussion of the potential for future research and development.

scholarly journals The National Earth System Prediction Capability: Coordinating the Giant

2017 ◽  
Vol 98 (2) ◽  
pp. 239-252 ◽  
Author(s):  
Jessie C. Carman ◽  
Daniel P. Eleuterio ◽  
Timothy C. Gallaudet ◽  
Gerald L. Geernaert ◽  
Patrick A. Harr ◽  
...  
Keyword(s):  
Numerical Weather Prediction ◽  
Weather Prediction ◽  
The United States ◽  
Department Of Energy ◽  
Earth System ◽  
Numerical Weather ◽  
Interagency Coordination ◽  
Research Technology ◽  
Prediction Capability ◽  
The U.S

Abstract The United States has had three operational numerical weather prediction centers since the Joint Numerical Weather Prediction Unit was closed in 1958. This led to separate paths for U.S. numerical weather prediction, research, technology, and operations, resulting in multiple community calls for better coordination. Since 2006, the three operational organizations—the U.S. Air Force, the U.S. Navy, and the National Weather Service—and, more recently, the Department of Energy, the National Aeronautics and Space Administration, the National Science Foundation, and the National Oceanic and Atmospheric Administration/Office of Oceanic and Atmospheric Research, have been working to increase coordination. This increasingly successful effort has resulted in the establishment of a National Earth System Prediction Capability (National ESPC) office with responsibility to further interagency coordination and collaboration. It has also resulted in sharing of data through an operational global ensemble, common software standards, and model components among the agencies. This article discusses the drivers, the progress, and the future of interagency collaboration.

Investigation of the Down-Scaling Effects on the Low Swirl Burner and its Application to Microturbines

2018 ◽  
Author(s):  
Alex Frank ◽  
Peter Therkelsen ◽  
Miguel Sierra Aznar ◽  
Vi H. Rapp ◽  
Robert K. Cheng ◽  
...  
Keyword(s):  
Power Systems ◽  
Power Plants ◽  
Energy Savings ◽  
The United States ◽  
Primary Energy ◽  
Department Of Energy ◽  
Small Scale ◽  
United States Department ◽  
Scaling Effects ◽  
Swirl Burner

About 75% of the electric power generated by centralized power plants feeds the energy needs from the residential and commercial sectors. These power plants waste about 67% of primary energy as heat emitting 2 billion tons of CO2 per year in the process (∼ 38% of total US CO2 generated per year) [1]. A study conducted by the United States Department of Energy indicated that developing small-scale combined heat and power systems to serve the commercial and residential sectors could have a significant impact on both energy savings and CO2 emissions. However, systems of this scale historically suffer from low efficiencies for a variety of reasons. From a combustion perspective, at these small scales, few systems can achieve the balance between low emissions and high efficiencies due in part to the increasing sensitivity of the system to hydrodynamic and heat transfer effects. Addressing the hydrodynamic impact, the effects of downscaling on the flowfield evolution were studied on the low swirl burner (LSB) to understand if it could be adapted to systems at smaller scales. Utilizing particle image velocimetry (PIV), three different swirlers were studied ranging from 12 mm to 25.4 mm representing an output range of less than 1 kW to over 23 kW. Results have shown that the small-scale burners tested exhibited similar flowfield characteristics to their larger-scale counterparts in the non-reacting cases studied. Utilizing this data, as a proof of concept, a 14 mm diameter LSB with an output of 3.33 kW was developed for use in microturbine operating on a recuperated Brayton cycle. Emissions results from this burner proved the feasibility of the system at sufficiently lean mixtures. Furthermore, integration of the newly developed LSB into a can style combustor for a microturbine application was successfully completed and comfortably meet the stringent emissions targets. While the analysis of the non-reacting cases was successful, the reacting cases were less conclusive and further investigation is required to gain an understanding of the flowfield evolution which is the subject of future work.

scholarly journals LEVELIZED COST OF ENERGY (LCOE) ANALYSIS OF HEXCRETE WIND TOWERS

2018 ◽  
Author(s):  
Ali Nahvi
Keyword(s):  
Power Generation ◽  
Wind Energy ◽  
Wind Power ◽  
The United States ◽  
Wind Power Generation ◽  
Department Of Energy ◽  
Energy Output ◽  
Gis Mapping ◽  
Levelized Cost ◽  
Cost Of Energy

Wind power generation has witnessed a dramatic growth in the 21st century. The Department of Energy (DOE) had a vision for wind energy that it would change into an extensively greater part of overall power generation in the U.S. by 2050. As specified by the DOE, wind power generation has grown by trifold from 2008 to 2013. This study presents a constructible, financially feasible alternative wind tower design to the 80 m steel tower platform which has the potential to decrease the overall Levelized cost of energy (LCOE). A hexagonal concrete wind tower solution is evaluated to facilitate the fabrication of a taller wind turbine generator to harvest more powerful, stable, and frequent wind resources for elevating wind energy production to cut down the overall LCOE. Subject matter experts from the industry were benefitted from to develop a process and estimate the cost and schedule of development and assembly of this process. To mitigate uncertainties and quantify risks, a sensitivity analysis was carried out on cost and schedule estimates. Also, estimating LCOE of wind towers is a primary requirement for efficient assimilation of wind power generation in the electricity market. In the state of Iowa, wind power is rapidly becoming a significant electricity generator. Unpredictable outputs and different options for deploying wind towers are one of the major problems of power system operators. Good estimation tools are important and will be needed to integrate wind energy into the economic power plant. The other objective of this research is to propose a GIS-based map to visualize LCOE of different wind tower construction options in various locations. Therefore, wind speed GIS mapping by using weather information will be crucial. Calculation of energy output by applying wind gradient formula to wind speeds energy are performed. The research concludes of Hexcrete towers can be achieved by use of the 120m and 140 m Hexcrete tower platform on certain wind sites in the United States.

scholarly journals Mechanical bending effects on hydrogen storage of Ni decorated (8, 0) boron nitride nanotube : DFT study

2019 ◽  
Vol 16 (1) ◽  
pp. 299-325
Author(s):  
Atef Elmahdy ◽  
Hayam Taha ◽  
Mohamed Kamel ◽  
Menna Tarek
Keyword(s):  
Boron Nitride ◽  
Hydrogen Storage ◽  
Density Functional ◽  
Boron Nitride Nanotubes ◽  
Department Of Energy ◽  
Functional Theory ◽  
Activation Barriers ◽  
The Us ◽  
Adsorption Energies ◽  
Mechanical Bending

The influence of mechanical bending to tuning the hydrogen storage of Ni-functionalized of zigzag type of boron nitride nanotubes (BNNTs) has been investigated using density functional theory (DFT) with reference to the ultimate targets of the US Department of Energy (DOE). Single Ni atoms prefer to bind strongly at the axial bridge site of BN nanotube, and each Ni atom bound on BNNT may adsorb up to five, H2 molecules, with average adsorption energies per hydrogen molecule of )-1.622,-0.527 eV( for the undeformed B40N40-? = 0 , ) -1.62 , 0-0.308 eV( for the deformed B40N40-? = 15, ) -1.589,  -0.310 eV( for the deformed B40N40-? = 30, and ) -1.368-  -0.323 eV( for the deformed B40N40-? = 45 nanotubes respectively. with the H-H bonds between H2 molecules significantly elongated. The curvature attributed to the bending angle has effect on average adsorption energies per H2 molecule. With no metal clustering, the system gravimetric capacities are expected to be as large as 5.691 wt % for 5H2 Ni B40N40-? = 0, 15, 30, 45. While the desorption activation barriers of the complexes nH2 + Ni B40N40-? = 0 (n = 1-4) are outside the (DOE) domain (-0.2 to -0.6 eV), the complexes nH2 + Ni- B40N40-? = 0 (n = 5) is inside this domain. For nH2 + Ni- B40N40-? = 15, 30, 45 with (n = 1-2) are outside the (DOE) domain, the complexes nH2 + Ni- B40N40-? = 15, 30, 45 with (n = 3-5) are inside this domain. The hydrogen storage of the irreversible 4H2+ Ni- B40N40-? = 0, 2H2+ Ni- B40N40-? = 15, 30, 45 and reversible 5H2+ Ni- B40N40-? = 0, 3H2+ Ni- B40N40-? = 15, 30, 45 interactions are characterized in terms of density of states, pairwise and non-pairwise additivity, infrared, Raman, electrophilicity and molecular electrostatic potentials. Our calculations expect that 5H2- Ni- B40N40-j = 0, 15, 30, 45 complexes are promising hydrogen storage candidates.

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