Molecular sieve

Type

3A

Composition

0.6 K₂O: 0.40 Na₂O : 1 Al₂O₃ : 2.0 ± 0.1SiO₂ : x H₂O

Description

The 3A form is made by substituting potassium cations for the inherent sodium ions of the 4A structure, reducing the effective pore size to ~3Å, excluding diameter >3Å, e.g., ethane.

Major Applications

ü      Dehydration of unsaturated hydrocarbon streams, including cracked gas, propylene, butadiene, acetylene;

ü      Dehydration of polar liquids such as methanol and ethanol.

ü      Adsorption of molecules such as NH₃ and H₂O from a N₂/H₂ flow. Considered a general-purpose drying agent in polar and nonpolar media.

ü     Dehydration of natural gas, if COS minimization is essential, or a minimum co-adsorption of hydrocarbons is required.
Dehydration of liquid alcohol with Z3-01 / 1-2 mm beads
Static, (non-regenerative) dehydration of insulating glass units, whether air filled or gas-filled.
Dehydration of refrigerants (e.g. R22, R134a etc)

Type

4A

Composition

1 Na₂O: 1 Al₂O₃: 2.0 ± 0.1 SiO₂ : x H₂O

Description

This sodium form represents the type A family of molecular sieves. Effective pore opening is 4Å, thus excluding molecules of effective diameter >4Å, e.g., propane.

Major Applications

ü      Dehydration in closed liquid or gas systems, e.g., in packaging of drugs, electric components and perishable chemicals;

ü      water scavenging in printing and plastics systems and drying saturated hydrocarbon streams.

ü      Adsorbed species include SO₂, CO₂, H₂S, C₂H₄, C₂H₆, and C₃H₆.

ü      Generally considered a universal drying agent in polar and nonpolar media.

Type

5A

Composition

0.80 CaO : 0.20 Na₂O : 1 Al₂O₃: 2.0 ± 0.1 SiO₂: x H₂O

Description

Divalent calcium ions in place of sodium cations give apertures of ~5Å which exclude molecules of effective diameter >5Å, e.g., all 4-carbon rings, and iso-compounds.

Major Applications

ü      Separation of normal paraffin from ranched-chain and cyclic hydrocarbons;

ü      Molecules adsorbed include nC₄H₁₀, nC₄H₉OH, C₃H₈ to C₂₂H₄₆, and dichlorodifluoro-methane (Freon 12^®).

Ø     The strong ionic forces of the divalent calcium ion makes it an excellent adsorbent to remove water, CO2, H2S from sour natural gas streams, while minimizing COS formation.  Light mercaptan are also adsorbed.
Production of high purity N2, O2, H2 and inert gases from mixed gas streams.

Type

13X

Composition

1 Na₂O: 1 Al₂O₃ : 2.8 ± 0.2 SiO₂ : xH₂O

Description

The sodium form represents the basic structure of the type X family, with an effective pore opening in the 910¼ range. Will not adsorb(C₄F₉)₃N, for example.

Major Applications

ü     Removal of CO2 and moisture from air (air pre-purification) and other gases.

ü     Separation of enriched oxygen from air. 

ü     Removal of mercaptan and hydrogen sulphide from natural gas.

ü     Removal of mercaptan and hydrogen sulphide from hydrocarbon liquid streams (LPG, butane, propane etc.)

ü     Catalyst protection, removal of oxygenates from hydrocarbons (olefin streams).

ü     Removal of n-chained compositions from aromatics.

ü     Production of bulk oxygen in PSA units .

ü     Production of medical oxygen in small scale oxygen concentrators