What is molecular sieve dryer?
What is molecular sieve dryer?
Molecular sieves are in the family of desiccants, also known as adsorbents, used for hydrocarbon drying, described as the removal of dissolved water from hydrocarbon gases and liquids. Refineries use molecular sieves dryers for many dissolved water removal applications.
How much water can molecular sieves absorb?
Molecular sieve desiccants have a very strong affinity and a high adsorptive capacity for water in an environment of low water concentration. At 25°C/10%RH, molecular sieves can adsorb water to approximately 14% of their own weight.
How do molecular sieves absorb water?
Molecular sieves are crystalline metal aluminosilicates having a threedimensional interconnecting network of silica and alumina tetrahedra. Natural water of hydration is removed from this network by heating to produce uniform cavities which selectively adsorb molecules of a specific size.
What is the difference between molecular sieve and silica gel?
The key difference between molecular sieve and silica gel is that a molecular sieve is a material containing pores of similar size, whereas silica gel is a substance can be used to prepare a porous material with pores of different sizes.
How do you dry molecular sieve?
Air dry the molecular sieve from empty solvent bottles in a fume hood draft until they appear dry before heating at elevated temperatures. While the sieves bind much water, they also hold some solvent and you don’t want to heat the pellets very hot with a lot of solvent present. (Fire hazard.)
Is molecular sieve expensive?
Being synthetic rather than naturally occurring, molecular sieve is higher in cost per unit, but due to its extremely large range of adsorptive capabilities, it might often be the best value.
How do you activate molecular sieves at home?
If the sieves are fully active they will become too hot to hold, even through the glove. Dehydration means 3A or 4A molecular sieves are needed. They can be activated by passing hot dry gas through them.
How do you dry a 3A molecular sieve?
Heat the drying agent at 250C for about 2 hours in a shallow layer (not over a few cm deep) with a cover that lets water escape (but retains much heat). Use tongs to transfer the cup with hot sieves to an glass dessicator with a porcelain support to allow cooling without much atmospheric water uptake.
What does molecular sieve mean?
Molecular sieve. A molecular sieve is a material with very small holes of precise and uniform size. These holes are small enough to block large molecules and allow small molecules to pass. Many molecular sieves are used as desiccants.
How does molecular sieve work?
A molecular sieve works by adsorbing gas or liquid molecules that are smaller than the effective diameter of its pores, while excluding those molecules that are larger than the openings. A practical example of the function of molecular sieves is to dry ethanol.
How is a molecular sieve made?
Molecular sieve starts out as powder . The powder is then combined with a binding material. This allows the powder to be rolled into beads. These beads are partially dried at 600-700 degrees F, which turns them into a ceramic.