ASTM D5228-92(2005)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D5228–92(Reapproved 2005)
Standard Test Method for
Determination of Butane Working Capacity of Activated
Carbon
This standard is issued under the fixed designation D5228; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method covers the determination of the butane 3.1 Definitions—For definitions of terms used in this test
working capacity (BWC) of new granular activated carbon. method, refer to Terminology D2652.
The BWC is defined as the difference between the butane
4. Summary of Test Method
adsorbed at saturation and the butane retained per unit volume
of carbon after a specified purge. The test method also 4.1 An activated carbon bed of known volume and mass is
saturatedwithbutanevapor.Themassadsorbedatsaturationis
produces a butane activity value that is defined as the total
amount of butane adsorbed on the carbon sample and is noted. The carbon bed is then purged under prescribed condi-
tions with dry hydrocarbon free air. The loss of mass is the
expressed as a mass of butane per unit weight or volume of
carbon. BWC and is expressed as mass of butane per unit volume of
carbon.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
5. Significance and Use
standard.
5.1 The BWC, as determined by this test method, is a
1.3 This standard does not purport to address all of the
measure of the ability of an activated carbon to adsorb and
safety concerns, if any, associated with its use. It is the
desorb butane from dry air under specified conditions. It is
responsibility of the user of this standard to establish appro-
useful for quality control and evaluation of granular activated
priate safety and health practices and determine the applica-
carbons that are used in applications where the adsorption of
bility of regulatory limitations prior to use. For a specific
butane and desorption with dry air are of interest. The BWC
hazard statement, see 7.1.
can also provide a relative measure of the effectiveness of the
2. Referenced Documents
tested activated carbons on other adsorbates.
2.1 ASTM Standards: 5.2 The butane activity and retentivity can also be deter-
minedundertheconditionsofthetest.Thebutaneactivityisan
D2652 Terminology Relating to Activated Carbon
D2854 Test Method for Apparent Density of Activated indication of the micropore volume of the activated carbon
sample. The butane retentivity is an indication of the pore
Carbon
D2867 Test Methods for Moisture in Activated Carbon structure of the activated carbon sample.
D3195 Practice for Rotameter Calibration
6. Apparatus
E177 Practice for Use of the Terms Precision and Bias in
6.1 Water Bath,capableofmaintainingatemperatureof25°
ASTM Test Methods
6 0.2°C and of sufficient depth so the entire carbon bed in the
E300 Practice for Sampling Industrial Chemicals
sampletubeisimmersedinthewater.A6-mmODcoppertube
E691 Practice for Conducting an Interlaboratory Study to
with an immersed length of 1.9 m (Fig. 1) provides adequate
Determine the Precision of a Test Method
heat transfer for gas temperature control.
6.2 Sample Tube, as shown in Fig. 2. The glass plate with
This test method is under the jurisdiction of ASTM Committee D28 on
holes is preferred to a fritted disk to support the carbon, since
Activated Carbon and is the direct responsibility of Subcommittee D28.04 on Gas
fritted disks can vary widely in pressure drop.
Phase Evaluation Tests.
6.3 Flow Meters, one capable of delivering air at 0 to 500
Current edition approved Oct. 1, 2005. Published October 2005. Originally
mL/min, and one capable of delivering butane at 0 to 500
approved in 1992. Last previous edition approved in 2000 as D5228–92 (2000).
DOI: 10.1520/D5228-92R05.
mL/min, both calibrated in accordance with Practice D3195.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.4 Balance, capable of weighing to within 6 0.01 g.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.5 Fill Device—The vibration feed device used in Test
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Method D2854, Figs. 1 through 4, is preferred.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5228–92 (2005)
0.5°C. Its specific gravity is 2.046 relative to air. Butane may
be narcotic in high concentrations and is considered a simple
asphyxiant.Iftheentireapparatusisnotsetupinafumehood,
provision must be made to vent the gas coming from the
discharge stem of the sample tube.)
7.2 Dry Air, free of organics, with a dew point no higher
than −32°C.
8. Sampling
8.1 For guidance in sampling granular activated carbon,
refer to Practice E300.
9. Calibration of a Sample Tube
9.1 Clean and dry the sample tube to prevent any water
droplets from adhering to the inner surface of the tube.
9.2 Using distilled water, carefully fill the sample tube
throughthenarrowsidestemtopreventtheintroductionofany
air bubbles.
9.2.1 Holdthesampletubeuprightwhileslowlyintroducing
thedistilledwater.Airbubbleshaveatendencytoformdirectly
below the retainer plate of the tube.
9.3 Clamp the filled sample tube in an upright position to a
FIG. 1 Butane Working Capacity Apparatus Schematic
ring stand and stopper the narrow side stem.
9.4 Using a pipet, carefully remove the water from the
sample tube to the top of the retainer plate. Caution must be
taken so no water is removed from below the retainer plate
creating air bubbles that would result in a spurious calibration
of the sample tube. If this occurs, the tube must be refilled by
repeating 9.1 through 9.3.
9.5 Using the buret, fill the sample tube with 16.7 6 0.05
mL of water, then etch the tube at the level of the meniscus.
10. Maintenance of Bath Water
10.1 In order to prevent mold formation, the bath water
should be changed periodically.
11. Procedure
11.1 Dry an adequate sample as prescribed in Test Methods
D2867, Section 4.
11.2 DeterminetheapparentdensityinaccordancewithTest
Method D2854 and record.
11.3 Accurately weigh the empty, dry sample tube and
stoppers to the nearest 0.01 g and record.
1– Ground glass stopper, hollow, medium length, 14/20, from Kontes Catalog
11.4 Filltheadsorptiontubewithcarbontotheetchmarkat
No. K-89100 Schwartz adsorption tube, or equivalent.
2– 5-mm rod, brace.
a rate of 0.35 to 1.0 mL/s using the vibrating feeder apparatus
3– 17-mm O.D. 3 1.2 mm standard wall tubing.
described in Test Method D2854 with a funnel modified to
4– Coor’s perforated porcelain disk or extra coarse fritted disk, or equivalent.
5– 10-mm O.D. 3 1.0 mm standard wall tubing. accommodatetheadsorptiontube.Largerparticleswillrequire
6–
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