Applications adsorbent

Adsorbent Applications. One of the earliest uses for activated alumina was removal of water vapor from gases and this remains an... 

Mordenite and cHnoptiloHte are used in small volume in adsorbent applications including air separation and in drying and purification [24]. Natural zeolites have also found use in bulk applications as fillers in paper, in pozzolanic cements and concrete, in fertihzer and soil conditioners and as dietary supplements in animal husbandry. 

The price of zeolites varies considerably depending on the apphcation. The typical price of catalysts in the United States varies from about US 3 /kg for FCC to about US 20/kg for specialty catalysts, adsorbents from about US 5-9/ kg, up to tens of dollars per kilogram for specialty adsorbents and about US 2/ kg for detergents. Natural zeolites in bulk applications sell for US 0.04—0.25/kg and in industrial adsorbent applications for US 1.50-3.50/kg [22]. 

In the majority of impurity removal processes, the adsorbent functions both as a catalyst and as an adsorbent (catalyst/adsorbent). The impurity removal process often involves two steps. First, the impurities react with the catalyst/adsorbent under specified conditions. After the reaction, the reaction products are adsorbed by the catalyst/adsorbent. Because this is a chemical adsorption process, a severe regeneration condition, or desorption, of the adsorbed impurities from the catalyst/adsorbent is required. This can be done either by burning off the impurities at an elevated temperature or by using a very polar desorbent such as water to desorb the impurities from the catalyst/adsorbent. Applications to specific impurities are covered in the followings section. The majority of industrial applications involve the removal of species containing hetero atoms from bulk chemical products as purification steps. 

The adsorbent slurry may be applied to the TLC plates by means of several methods. For analytical work, the plates are best prepared with a special TLC adsorbent applicator which provides uniform layers and can be often adjusted to various thicknesses from 250 pm (normal) up to 500 or 1000 pm for preparative separations. The preparation of plates with a typical applicator is shown in Fig.3.1. These applicators are available from a number of suppliers of TLC equipment including most of those mentioned in Table 3.2. After the slurry has been applied, the plates are dried in air overnight or in a warm oven at 80-90°C for ca. 30 min. The dry plates are stored in a dust-free cupboard for further use. Portable cabinets for plate storage are available from a number of suppliers. 

Anderson, R. A., "Molecular Sieve Adsorbent Applications State of the Art," American Chemical Society Symposium Series 40, 1977. 

K. H. Nam and L. L. Tavlarides, Synthesis of a high-density phosphonic acid functional mesoporous adsorbent, application to Chromium(III) removal, Chem. Mater. 17, 1597-1604 (2005). 

Synthetic zeolites are used in a variety of catalyst and adsorbent applications. Most zeolites are synthesized in batch processes, but U.S. 6,773,694 (to UOP) describes a continuous crystallization process for zeolite formation. The resulting crystals can be dried and formulated into catalysts, adsorbents, and other products. Estimate the costs of producing zeolite X and Mordenite by this method. 

An adsorbent application of major commercial importance is the adsorption of potentially haze-forming proteins from beer. This process is called chillproofing because the haze forms when the beer is cooled after a period of aging subsequent to bottling. Silica hydrogels and intermediate-density xerogels are employed, because both have pores of sufficient size (>10-nm average diameter) to admit the proteins in question. 

Experimental interest lies in the value of q that depends on the applied concentration, that is, where q =/(c), which thus describes the isotherm-of the adsorbate. Application of protein solution to the column produced an effluent profile of the type shown in Figure 5. The amount of protein adsorbed may be calculated by integrating the area between the void volume and the actual effluent profile (lateral diffusion, DM, does not modify the integrated area). A series of runs using different cG values thus establishes a dynamic isotherm. 

Pramendra Kumar is an Assistant Professor in the Chemistry Department at M.J.P. Rohilkhand University, Bareilly. He obtained his Master of Science from C.C.S. University, Meerut and Master of Engineering from Delhi College of Engineering. His research interests include modification of polysaccharides, synthesis of multifunctional nano materials and synthesis of nano bio-composites for their various applications e.g. water remediation, enzyme immobilization and other adsorbent applications. 

Although tin is an important element in both adsorbent applications and catalysis science, procedures for the incorporation of Sn" into zeotype structures at framework positions were not readily evident (147). The postsynthesis modification of zeohtes using Snp4 or SnCl4 was attempted, but the crystalline structures of the zeohtes were damaged (4,148). However, Mai et al. (66a) incorporated Sn" into silicahte (MFI) and silicahte-2 (MEL) structures. Tin incorporation into the frameworks of MTW (66a, 149), beta (68), and MCM-41 (150) has also been accomplished. 

Adsorbent Applications (typical examples) Compacted density, kg/m Pore volume for pore size d < 20 nm, ml/g Pore volume for pore size d > 20 nm, ml/g Specific surface 2/ area, m /g Specific heat capacity, J/kgK... 

Hu J, Shao D, Chen C, Sheng G, Li J, Wang X, et al. Plasma-induced grafting of cyclodextrin onto multiwaU carbon nanotube/iron oxides for adsorbent application. J Phys Chem B 2010 114 6779-85. 

P. B6nard, R. Chahine. Modeling of High-Pressure Adsorption Isotherms above the Critical Temperature on Microporous Adsorbents Application to Methane. Langmuir. 13 (1997) 808-813. 

Trap Adsorbent Application Drying Drying Desorb Desorb Bake-out Bake-out Conditioning Remarks... 

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