Vanadium storage

Blood cells of C. intestinalis showed low and variable levels of vanadium in morula cells (154). In this species the primary vanadium storage site was determined to be the granular amoebocyte. It was first concluded that significant vanadium is present in the morula cells of the species A. mentula and Ascidiella aspersa, but the various cell types were not distinguishable (155), When the same two species were reexamined with improved fixation methods it was concluded that sig-... 

Solids materials that are insoluble in hydrocarbon or water can be entrained in the crude. These are called bottom sediments and comprise fine particles of sand, drilling mud, rock such as feldspar and gypsum, metals in the form of minerals or in their free state such as iron, copper, lead, nickel, and vanadium. The latter can come from pipeline erosion, storage tanks, valves and piping systems, etc. whatever comes in contact with the crude oil. 

Selective catalytic reduction (SCR) is cmrently the most developed and widely applied FGT technology. In the SCR process, ammonia is used as a reducing agent to convert NO, to nitrogen in the presence of a catalyst in a converter upstream of the air heater. The catalyst is usually a mixture of titanium dioxide, vanadium pentoxide, and hmgsten trioxide. SCR can remove 60-90% of NO, from flue gases. Unfortunately, the process is very expensive (US 40- 80/kilowatt), and the associated ammonia injection results in an ammonia slip stream in the exhaust. In addition, there are safety and environmental concerns associated with anhydrous ammonia storage. 

The most important undesired metallic impurities are nickel and vanadium, present in porphyrinic structures that originate from plants and are predominantly found in the heavy residues. In addition, iron may be present due to corrosion in storage tanks. These metals deposit on catalysts and give rise to enhanced carbon deposition (nickel in particular). Vanadium has a deleterious effect on the lattice structure of zeolites used in fluid catalytic cracking. A host of other elements may also be present. Hydrodemetallization is strictly speaking not a catalytic process, because the metallic elements remain in the form of sulfides on the catalyst. Decomposition of the porphyrinic structures is a relatively rapid reaction and as a result it occurs mainly in the front end of the catalyst bed, and at the outside of the catalyst particles. 

X.P Song, P. Pei, PL. Zhang, G.L. Chen, The influence of alloy elements on the hydrogen storage properties in vanadium-based solid-solution alloys, J. Alloys Compd. 455 (2008) 392-397. 

Polyoxometalates are important catalysts but they are also finding application in optical, electrical, and magnetic devices. Mixed-metal polyoxometalates with vanadium(V) in the polyoxoanion core confers enhanced properties to such structures, principally in their ability to form essentially infinite networks that can be utilized as coatings or as other thin film materials. Additionally, these materials have tunable electromagnetic and photochromic properties. In combination with organic polymers, so-called hybrid polymers, special electrochemical properties are conferred, making possible such electrical storage devices such as capacitors and batteries that utilize the redox properties of the polyoxometalate [7],... 

Bergman, G.M., S.J. Ebel, E.S. Takeuchi, and P. Keister. 1987. Heat dissipation from lithium/silver vanadium oxide cells during storage and low-rate discharge. J. Power Sources. 20 179-185. 

The development of implanted medical defibrillators required a high-rate, long-life battery system. In defibrillators, the CFx is used in combination with silver vanadium oxide (SVO) cathode materials [17]. A binary mixture of CFx and SVO are combined to form the cathode, giving the best features of SVO and CFx. Compared to CFx, the SVO has superior pulse current capability, but lower energy storage capability. The cell reactions are given in Equations 10.7 and 10.8. 

Aqueous pentavalent vanadium is readily reduced to the tetravalent state by iron powder or by S02 gas. A stronger reducing agent, eg, zinc amalgam, is needed to yield divalent vanadium. Divalent and tfivalent vanadium compounds are reducing agents and require storage under an inert atmosphere to avoid oxidation by air. 

Only rare-earth system (AB5-type) and zirconium-titanium-vanadium system (AB2 Laves phase-type) hydrogen storage alloys have been used as negative electrode materials for the commercial production of Ni-MH batteries [3, 7, 8], However, these materials have a low hydrogen storage capacity resulting in a low electrode energy density. 

The presence of certain elements in fuel and gas oils may accelerate the oxidative deterioration of refined products or otherwise reduce their stability during storage. Vanadium, for example, in boiler firing oils may produce corrosion and toxic emissions. 

A new vanadium pentoxide battery produces more electrical energy per pound than the lead storage batteries in cars today. They are also likely to cause fewer environmental disposal problems. 

The relatively uniform profiles of nickel and vanadium arc desirable, because this pattern results in maximum metah storage capacity without pore mouth plugging. The strong rinding tendency of iron can be a problem in commercial usc because it can accelerate pore mouth plugging and lead to degradation of the catalyst support... 

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