Molecular Sieve 4A 2-5mm, 25kg pail

Molecular Sieve 4A is a synthetic zeolite-based desiccant with a uniform pore size of 4 angstroms (0.4 nm).

It adsorbs molecules up to 4 Å in diameter, including water, CO₂ and H₂S, while larger molecules are excluded. This makes 4A the preferred choice for drying air, natural gas and solvents where extremely low moisture levels are critical. Why choose Molecular Sieve over silica gel? Molecular Sieve 4A has a higher adsorption capacity at low relative humidity and can reduce moisture content to below 1 ppm. Where silica gel is ideal for general moisture control, molecular sieve is necessary when equipment requires near-zero humidity, such as in subsea equipment, the defense industry and the process industry. Properties:

• Pore diameter: 4 Å (0.4 nm)
• Form: Beads, 2-5 mm
• Chemical formula: Na₂O · Al₂O₃ · 2SiO₂ · nH₂O
• Bulk density: 0.60–0.65 g/ml
• Water absorption: 20–21 % (weight)
• Can be regenerated at 200–315 °C

Typical applications: Drying of air and gases, removal of CO₂ and hydrogen sulfide, dehydration of solvents, protection of sensitive components during long-term storage and transport. Often used in conjunction with VCI packaging and humidity indicators for a complete preservation solution.

Molecular Sieve 4A is approved for food contact according to FDA 21 CFR 182.2727. Contact us for advice on choosing the right desiccant for your application.