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A 'molecular sieve' is a material containing tiny pores of a precise and uniform size that is used as an adsorbent for gases and liquids.
Molecules small enough to pass through the pores are adsorbed while larger molecules are not. It is different from a common filter in that it operates on a molecular level. For instance, a water molecule may be small enough to pass through while larger molecules are not. Because of this, they often function as a desiccant. A molecular sieve can adsorb water up to 22% of its own weight.
Often they consist of aluminosilicate minerals, clays, porous glasses, microporous charcoals, zeolites, active carbons, or synthetic compounds that have open structures through which small molecules, such as nitrogen and water can diffuse.
Molecular sieves are often utilized in the petroleum industry, especially for the purification of gas streams and in the chemistry laboratory for separating compounds and drying reaction starting materials. The mercury content of natural gas is extremely harmful to the aluminum piping and other parts of the liquefaction apparatus - silica gel is used in this case.
Methods for regeneration of molecular sieves include by pressure change as in oxygen concentrators or by heating and purging with a carrier gas as when used in ethanol dehydration.
★ 3A : Adsorbs NH3, H2O
★ 4A : H2O, CO2, SO2, H2S, C2H4, C2H6, C3H6
★ 5A : H2O, H2S, hydrocarbons to C22H46, alcohols to C4H9OH, mercaptans to C4H9SH.
Some of the many types of molecular sieves are:
★ Activated carbon
★ Desiccant
★ Lime (mineral)
★ Silica gel
★ Zeolite
★ Sieves put a lid on greenhouse gas
★ molecular sieve patents
★ Molecular sieve faq.
★ An Open Cycle Molecular Sieve Dehydration System.
★ Sigma-Aldrich
Molecules small enough to pass through the pores are adsorbed while larger molecules are not. It is different from a common filter in that it operates on a molecular level. For instance, a water molecule may be small enough to pass through while larger molecules are not. Because of this, they often function as a desiccant. A molecular sieve can adsorb water up to 22% of its own weight.
Often they consist of aluminosilicate minerals, clays, porous glasses, microporous charcoals, zeolites, active carbons, or synthetic compounds that have open structures through which small molecules, such as nitrogen and water can diffuse.
Molecular sieves are often utilized in the petroleum industry, especially for the purification of gas streams and in the chemistry laboratory for separating compounds and drying reaction starting materials. The mercury content of natural gas is extremely harmful to the aluminum piping and other parts of the liquefaction apparatus - silica gel is used in this case.
Methods for regeneration of molecular sieves include by pressure change as in oxygen concentrators or by heating and purging with a carrier gas as when used in ethanol dehydration.
| Contents |
| Adsorption capabilities |
| See also |
| External links |
Adsorption capabilities
★ 3A : Adsorbs NH3, H2O
★ 4A : H2O, CO2, SO2, H2S, C2H4, C2H6, C3H6
★ 5A : H2O, H2S, hydrocarbons to C22H46, alcohols to C4H9OH, mercaptans to C4H9SH.
See also
Some of the many types of molecular sieves are:
★ Activated carbon
★ Desiccant
★ Lime (mineral)
★ Silica gel
★ Zeolite
External links
★ Sieves put a lid on greenhouse gas
★ molecular sieve patents
★ Molecular sieve faq.
★ An Open Cycle Molecular Sieve Dehydration System.
★ Sigma-Aldrich
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