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In the laboratory, molecular sieves are used to dry solvent. "Sieves" have proven to be superior to traditional drying techniques, which often employ aggressive desiccants. [7] Under the term zeolites, molecular sieves are used for a wide range of catalytic applications.
As a result, the pore entrance of LTA is an 8-ring (0.41 nm [3]) and belongs to the small pore zeolite, while the pore entrance of FAU is a 12-ring (0.74 nm [3]) and belongs to the large pore zeolite, respectively. Materials with a 10-ring are called medium pore zeolites, a typical example being ZSM-5 (MFI).
Pentasil-zeolites are defined by their structure type, and more specifically by their X-ray diffraction patterns. ZSM -5 is the trade name of a pentasil-zeolite. As early as 1967, Argauer and Landolt worked out parameters for the synthesis of pentasilzeolites, particularly those relating to the following molar ratios: OH − /SiO 2 = 0.07–10, SiO 2 /Al 2 O 3 = 5–100, H 2 O/SiO 2 = 1–240. [1]
DS-PSA can also be applied to increase the oxygen concentration. In this case, an aluminum silica based zeolite adsorbs nitrogen in the first stage reaching 95% oxygen in the outlet, and in the second stage a carbon-based molecular sieve adsorbs the residual nitrogen in a reverse cycle, concentrating oxygen up to 99%.
Clinoptilolite has many applications due to its effect as a molecular sieve, among others as an additive for building materials, as aggregate in horticulture, as an additive to cattle feed, as an additive in household products, as a desiccant, and in environmental technology.
Size-exclusion chromatography, also known as molecular sieve chromatography, [1] is a chromatographic method in which molecules in solution are separated by their shape, and in some cases size. [2] It is usually applied to large molecules or macromolecular complexes such as proteins and industrial polymers . [ 3 ]
SSZ-13 is a high-silica zeolite with the CHA topology. Materials with this topology are of industrial interest, as potential catalysts for application in the methanol to olefins (MTO) reaction. Recently SSZ-13 has attracted attention as the catalyst for selective catalytic reduction (SCR) of NOx. [8]
The presence of defects can make these membranes far less effective, and it is difficult to produce defect free zeolite membranes. [4] There are several mechanisms of transport that govern the separation of molecules by zeolite membranes. The main mechanisms for separation by zeolite membranes are molecular sieving, diffusion, and adsorption.