Saturday 7 October 2017

VANADIUM(V) OXIDE (VANADIA) [V2O5]


≥98%
Synonym: Divanadium pentaoxide, Divanadium pentoxide, Pentaoxodivanadium, Vandia
·         CAS Number 1314-62-1

·         Linear Formula V2O5

·         Molecular Weight 181.88

·          EC Number 215-239-8
·          MDL number MFCD00011457

·          PubChem Substance ID 24853404

Properties

Related Categories
More...
InChI Key  
GNTDGMZSJNCJKK-UHFFFAOYSA-N
assay  
≥98%
mp  
690 °C(lit.)
density  
3.35 g/mL at 25 °C(lit.)

Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being principal precursor to alloys of vanadium and is a widely used industrial catalyst.
Detailed description
The mineral form of this compound, shcherbinaite, is extremely rare, almost always found among fumaroles. A mineral trihydrate, V2O5·3H2O, is also known under the name of navajoite.

Preparation

Technical grade V2O5 is produced as a black powder used for the production of vanadium metal and ferrovanadium.[6] A vanadium ore or vanadium-rich residue is treated with sodium carbonate to produce sodium metavanadate, NaVO3. This material is then acidified to pH 2–3 using H2SO4 to yield a precipitate of "red cake" (see above). The red cake is then melted at 690 °C to produce the crude V2O5.
Vanadium(V) oxide is produced when vanadium metal is heated with excess oxygen, but this product is contaminated with other, lower oxides. A more satisfactory laboratory preparation involves the decomposition of ammonium metavanadate at around 200 °C:
2 NH4VO3 → V2O5 + 2 NH3 + H2O

Uses

Ferrovanadium production

In terms of quantity, the dominant use for vanadium(V) oxide is in the production of ferrovanadium (see above). The oxide is heated with scrap iron and ferrosilicon, with lime added to form a calcium silicateslag. Aluminium may also be used, producing the iron-vanadium alloy along with alumina as a by-product.[6]

Sulfuric acid production

Another important use of vanadium(V) oxide is in the manufacture of sulfuric acid, an important industrial chemical with an annual worldwide production of 165 million metric tons in 2001, with an approximate value of US$8 billion. Vanadium(V) oxide serves the crucial purpose of catalysing the mildly exothermic oxidation of sulphur dioxide to sulphur trioxide by air in the contact process:
2 SO2 + O2  2 SO3
The discovery of this simple reaction, for which V2O5 is the most effective catalyst, allowed sulfuric acid to become the cheap commodity chemical it is today. The reaction is performed between 400 and 620 °C; below 400 °C the V2O5 is inactive as a catalyst, and above 620 °C it begins to break down. Since it is known that V2O5 can be reduced to VO2 by SO2, one likely catalytic cycle is as follows:
SO2 + V2O5 → SO3 + 2VO2
followed by
2VO2 +½O2 → V2O5
It is also used as catalyst in the selective catalytic reduction (SCR) of NOx emissions in some power plants. Due to its effectiveness in converting sulfur dioxide into sulfur trioxide, and thereby sulfuric acid, special care must be taken with the operating temperatures and placement of a power plant's SCR unit when firing sulfur-containing fuels.

Other oxidations

Maleic anhydride is produced by the V2O5-catalysed oxidation of butane with air:
C4H10 + 4 O2 → C2H2(CO)2O + 8 H2O
Maleic anhydride is used for the production of polyester resins and alkyd resins.[7]
Phthalic anhydride is produced similarly by V2O5-catalysed oxidation of ortho-xylene or naphthalene at 350–400 °C. The equation is for the xylene oxidation:
C6H4(CH3)2 + 3 O2 → C6H4(CO)2O + 3 H2O
Phthalic anhydride is a precursor to plasticisers, used for conferring pliability to polymers.
A variety of other industrial compounds are produced similarly, including adipic acid, acrylic acid, oxalic acid, and anthraquinone.[5]

Other applications

Due to its high coefficient of thermal resistance, vanadium(V) oxide finds use as a detector material in bolometers and microbolometer arrays for thermal imaging. It also finds application as an ethanol sensor in ppm levels (up to 0.1 ppm).
Vanadium redox batteries are a type of flow battery used for energy storage, including large power facilities such as wind farms.

Packaging

100, 500 g in glass bottle

PRICE

$511.66/KG OR $232.57/IB

For more information:

mobile: +2348039721941

contact person: emeaba uche

e-mail: emeabau@yahoo.com



No comments:

Post a Comment