Get A New Family Of Mesoporous Molecular Sieves Prepared With Liquid Crystal Templates Form

Molecular sieves are available in different shapes and sizes. However, spherical beads have advantages over other shapes because they offer low pressure drops, are resistant to wear and good strength because they have no sharp edges, so the crushing force required per unit area is higher.

There are two types of molecular sieves: natural zeolite and synthetic zeolite.

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.

Molecular sieving is the process that takes over from Knudsen flow when the pore diameter approaches the diameter of the molecules attempting to pass through a porous membrane (Figure 8.5).

Molecular sieve manufacturing process The manufacturing stages consist of the preparation of these materials, mixing, crystallization, filtering, washing and drying, obtaining zeolite 4A powder. The production process of synthetic zeolite powder 3A and 5A, is very similar to that of synthetic zeolite 4A.

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.

The characteristics of these molecular sieves include fast adsorption speed, frequent regeneration ability, good crushing resistance and pollution resistance. These features can improve both the efficiency and lifetime of the sieve.

The main sources of carbon molecular sieves for commercial applications are coal and coconut shell.