CATALYST
Catalyst
The Iron-Molybdenum catalyst (MOC5) is used for the selective oxidation of methanol to formaldehyde in presence of an excess of air in fixed bed converters.
It can be used pure (MOC5O) or diluted with an inert (MOC5I) or in a bed with layers of pure and diluted catalyst.
MOC5 is tabletted in holed-rings having an outside diameter of 4,5-5,0 mm, an inner diameter of 2,0-2,2 mm and a height of 4,5-5,0 mm.
The MOC5 has the following main technical properties referred to the pure product (MOC5O):
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Chemical composition
|
Iron-molybdenum oxide (iron polymolybdate)
|
|---|---|
| Iron content (as Fe) | 12±0,5 %w |
| Molybdenum content (as Mo) | 55,0±0,5%w |
| Surface area | 5,5±0,5 m2/g |
| Pore volume | 0,25±0,05 ml/g |
| Appearance | Tabletted holed-rings |
| Smell | Odourless |
| Colour | Grey-green |
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Bulk density
(in a 22,1 mm internal diameter tube)
|
600-700 kg/m3 |
Packaging
The catalyst is delivered in plastic drums: 40 kg per drum for MOC5O or 20 kg per drum for MOC5I).
Applications
The catalyst may be employed in multi-tube fixed bed reactors of different designs, of different tube diameters and with different heat transfer fluids (HTF) such as molten salts or diathermic oil.
The catalyst can work with HTF temperatures from 250°C to 320 °C, with a hot spot temperature up to 430°C.
A higher temperature may reduce the catalyst life due to the catalyst sintering and to the molybdenum anhydride sublimation.
The catalyst can work with a methanol content of 7–9%v in the air feeding stream (below the lower ignition point of the methanol gas mixture).
At reactor outlet, oxygen concentration in the air stream must never be lower than 5 %v.
To be noticed that the following products or elements can act as poisons for the catalyst (their presence must be strictly avoided in the air stream to the catalyst itself): chlorides, sulfur, sodium, heavy metals and carbonyls.
MSDS
CAS number: 13769-81-8
EC number: 237-389-3
Catalyst MSDS is available at request to Alder website contacts.
No labelling of the product is required according to CLP.
Please check additional information available at: https://echa.europa.eu/