Activated carbon standard tests

In order to prevent auto-ignition of activated carbon adsorbers activated carbons are tested in standardized procedures for their tendency to self-heating. These tests deliver parameters, which include a number of properties of the tested material, but important properties like the permeability for gasflow, etc. are neglected. The field of velocities in the adsorber plays an important role too. The calculation results discussed show that it is necessary to take not only the parameters of the material but of the whole system into account. On the other hand the calculaton results show that REBOS is a efficient tool... 

Source references for frequentiy used test procedures for determining properties of activated carbon are shown in Table 4. A primary source is the Jinnual Book ofyimerican Societyfor Testing and Materials (ASTM) Standards (61). Other usehil sources of standards and test procedures include manufacturers of activated carbon products, the American Water Works Association (AWWA) (33,34), and the Department of Defense (54). 

Table 4. Source References for Activated Carbon Test Procedures and Standards...

A key parameter in the design of the fuel vapor control system is the volume of activated carbon required to meet the emission standards for the various regulatory tests. In the case of the three-day diurnal test sequence, the emission limits are 0.05 grams of HC per mile during the run loss portion of the test (maximum emission -0.85 grams), and a maximum release of 2.0 grams for the sum of the hot soak period and any one of the three 24-hour periods making up the diurnal test sequence. 

This technology has broad applicability. For instance, using the same carbon support, test results show that a new Pt/C catalyst with edge-metal location and low dispersion resulted in 36% more activity than ESCAT 20 in a standard nitrobenzene (SNB) test (Figure 6). Using the same technology with a different carbon support yielded a catalyst with 57% more activity than ESCAT 20 in SNB test (16,17). 

Some new materials perspective for advanced biomedical technologies, especially carbon nanoparticles like fullerenes, are potentially mutagenic, carcinogenic and immunogenic [16,65], Therefore, standard tests of the morphological transformation of Syrian hamster embryonic cells in cultures on these materials (described in detail by [68,69]) can be performed. Immune activation of bone and vascular cells on the materials can be estimated by increased concentration of immunoglobulin and selectin adhesion molecules (ICAM-1, VCAM-1, ELAM-1), which bind cells of the immune system [15,16,18,19,23], as well as by the production of cytokines, such as tumor necrosis factor alpha or interleukins beta [55],... 

Again, there are several choices of extractant, and the preferred one depends mainly on the type of soil under test. One of the most widely used procedures is the Olsen method (Olsen ef al., 1954), which was developed in the USA to correlate crop response to fertilizer on calcareous soils. The amount of P extracted will vary with temperature (increases by 0.43 mg P kg- per degree rise between 20°C and 30°C) and shaking speed, so conditions should be standardized. The extractant is 0.5 M sodium bicarbonate adjusted to pH 8.5. The bicarbonate competes with phosphate on the adsorption sites extracts, and removes most, but not all of it, together with some soluble calcium phosphate. Addition of phosphate-free activated carbon before shaking is necessary if coloured soil extracts are obtained, and then they will require filtration. 

In all the cases a commercial activated carbon of high activity called AC-ref (Activated Carbon- reference) was used as a standard of comparison an exception is the Fischer-Tropsch test, in which the reference was called CON (Conventional Activated Carbon) by its different characteristics with respect to AC-ref. 

Adsorptive Processes. The use of activated carbon, sprayed into a dry/semi dry scrubbing unit along with lime or less frequently packed in an adsorption unit positioned after the particulate removal device and prior to the stack, has become a standard component in gas cleaning trains as a means of PCDD/F control on all sizes of plant fed with MSW or clinical waste. Other adsorptive media such as zeolites are also being tested. The inclusion of an adsorptive device in combustion systems fired with wood and agricultural wastes is not normally contemplated, and as noted above, an interesting issue to be resolved is whether different waste types generate flyash of different activities relative to PCDD/F formation. 

All the binary Cu/ZnO catalysts were found highly selective toward methanol without DME, methane, or higher alcohols and hydrocarbons detected in the product by sensitive gas chromatographic methods (59). Several of the composites were also found to be very active when subjected to a standard test with synthesis gas C0/C02/H2 = 24/6/70 at gas hourly space velocity of 5000 hr- pressure 75 atm, and temperature 250°C. The activities, expressed as carbon conversions and yields, are summarized in Table VIII. The end members of the series, pure copper and pure zinc oxide, were inactive under these testing conditions, and maximum activity was obtained for the composition Cu/ZnO = 30/70. The yields per unit weight, per unit area of the catalyst or the individual components, turnover rates per site titratable by irreversible oxygen and by irreversible carbon monoxide, are graphically... 

Portions of this test are adapted from ASTM D 4607-94(1999)— Standard Test Method for Determination of Iodine Number of Activated Carbon. The original ASTM method is available in its entirety from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428 phone 610-832-9585 fax 610-832-9555 email service astm.org website . 

Activated carbons have been successfully manufactured from sawmill waste using a fluidized bed pyrolysis and activation reactor. The carbons produced have been evaluated by means of standard adsorption tests and on the basis of their adsorptive capacity for several micropollutants. They are shown to be of similar quality as most commercially available activated carbons. 

These differences make some authors negate the usability of static methods for the evaluation of granular carbons. On the over hand, methods of testing should be quick and effective. Therefore many standards propose to evaluate granular activated carbons in static conditions in spite of differences in work conditions and in grain size of carbons [25-29, 42, 43). Results obtained in static conditions (Tab. 3,4) cannot be used... 

The reaction was initially tested by the use of PdCliCPPhs) . Although 6 equiv of iodide 80 was required to complete the reaction, the desired product 65 was obtained in 80% yield (Table 11, Entry 1) [97]. The catalyst is, however, inadequate especially in terms of cost. Studies were undertaken to search for a better protocol. Nickel system was resorted in this connection. The use of inexpensive nickel(IT) acetylacetonate [Ni(acac)2] was tested to reduce the cost of raw material, which led to a moderate yield of 65 (78%, Table 11, Entry 2) [98]. Easily recoverable heterogeneous palladium on activated carbon (Pd/C) catalyst was then examined. While the use of the standard conditions using THF and toluene as the solvent resulted in a moderate yield (50%, Table 11, Entry 3), addition of DMF to the reaction mixture considerably improved the yield, providing 65 in 94% yield (Table 11, Entry 4) [99]. Much less pyrophoric Pearlman s catalyst [Pd(OH)2/C] was found to give 65 in an excellent yield with such a tiny catalyst loading as 0.65 mol% (Table 11, Entry 5) [100]. 

Figure 8.7 Comparison of effects of mass transfer limitations in the desorption of alachlor from activated carbon using supercritical carbon dioxide tests with several flow rates and carbon mesh size. SLPM = Standard liters per minute.

A committee of the American Society for Testing and Materials is now studying ways and means to prepare standard definitions of terms relating to the manufacture, testing, and methods of using activated carbon. 

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