Charcoal activation

Activated Carbon (Charcoal). Activated carbon is commonly used as an adsorbent. It has a micro-... 

For the transfer of LN2, a simple thick-walled rubber tube or a low-conductivity metallic tube which can be bent to the required shape may be used. In the latter case, a convenient covering, e.g. a flexible foamed neoprene, is needed. Less frequent is the use of double-walled metallic tubes. In this case, the vacuum enclosure must contain some charcoal active as a cryopump. 

See also Activated charcoal Activated coke Carbon entries adsorption isotherm for hydrocarbons on coconut-shell, 2 635t chemical properties of, 4 741-743 economic aspects, 4 748 environmental concerns, 4 750 forms of, 4 747... 

Adsorbate Bone charcoal Sugar charcoal activated ... 

Adsorption systems make use of the fact that VOCs are attracted to and will adsorb to (attach to the surface of) certain special materials, the most common of which is activated charcoal. Activated charcoal consists of finely divided particles of charcoal. Flue gases containing VOCs are passed through a chamber and over a bed of the adsorbent, where they collect on its surface. The system may be designed such that the VOCs can then be removed from the... 

Charcoal. Activated coconut charcoal has gained the status as the almost universal solid sorbent. Petroleum-based charcoal is less active, but is also widely used. Charcoal is a very effective sorbent and is generally used for collection of nonpolar organic solvent vapors. It also collects polar organics, but they frequently cannot be recovered. However, many organic substances that are reactive, polar, or oxygenated (e.g., chloroprene, acetic acid, and acetone) have been successfully collected and recovered from charcoal. Substances for which charcoal tube methods have been validated are listed in Table II. 

Activated Carbon (activated charcoal) Activated carbon or charcoal is commonly used in gas-adsorption. 

Activated Carbon orCharcoal. See Carbon (or Charcoal) Activated Activated Complex Theory. See Absolute Rate Theory... 

This typically consists of a 2-10 mm OD stainless steel tube of 1-2 m length wound into a single or double helix or shaped into a U-tube. Many different packings solid supports) are available (e.g. glass beads, activated charcoal, activated alumina, etc.) which are coated with a selected solvent stationary phase). There are many of the... 

Most published methods are for analysis of crops and soil residues of the intact acaricides. Extraction has been done by stripping, blender or soxhlet. Extraction solvents have included petroleum ether, benzene, carbon tetrachloride, acetonitrile, diethyl ether, methanol and hexane/acetone. Clean-up steps have em -ployed liquid/liquid partitioning and adsorption on activated charcoal, activated charcoal/Florisil, Florisil, alumina and silica gel. Burke (14) reported that CB is not completely recovered from Florisil. Horn and coworkers (7) found that no clean-up was necessary when analyzing dog urine for CB using a Schecter-Haller procedure. For detection of residues, the colorimetric and UV methods have been replaced by gas chromatographic methods employing microcoulometric or electron capture detectors. 

Defluoridation processes can be classified into four main groups Adsorption methods, in these methods sorbents such as bone charcoal, activated alumina and clay are used in column or batch systems. Ion-exchange methods, these methods require expensive commercial ion-exchange resins. Coprecipitation and... 

Figure 8.5. Accessible surface area versus pore width, from immersion microcslorimetry in the liquids listed in Table 8.1 (right-hand side) for a set of charcoals (activation increasing from Cl to C4) (Denoyel tlal, 1993).

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