ASTM D5228-92(2010)
(Test Method)Standard Test Method for Determination of Butane Working Capacity of Activated Carbon
Standard Test Method for Determination of Butane Working Capacity of Activated Carbon
SIGNIFICANCE AND USE
The BWC, as determined by this test method, is a measure of the ability of an activated carbon to adsorb and desorb butane from dry air under specified conditions. It is useful for quality control and evaluation of granular activated carbons that are used in applications where the adsorption of butane and desorption with dry air are of interest. The BWC can also provide a relative measure of the effectiveness of the tested activated carbons on other adsorbates.
The butane activity and retentivity can also be determined under the conditions of the test. The butane activity is an indication of the micropore volume of the activated carbon sample. The butane retentivity is an indication of the pore structure of the activated carbon sample.
SCOPE
1.1 This test method covers the determination of the butane working capacity (BWC) of new granular activated carbon. The BWC is defined as the difference between the butane adsorbed at saturation and the butane retained per unit volume of carbon after a specified purge. The test method also produces a butane activity value that is defined as the total amount of butane adsorbed on the carbon sample and is expressed as a mass of butane per unit weight or 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 standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific hazard statement, see 7.1.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D5228 − 92(Reapproved 2010)
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
adsorbed at saturation and the butane retained per unit volume 4. Summary of Test Method
of carbon after a specified purge. The test method also
4.1 An activated carbon bed of known volume and mass is
produces a butane activity value that is defined as the total
saturatedwithbutanevapor.Themassadsorbedatsaturationis
amount of butane adsorbed on the carbon sample and is
noted. The carbon bed is then purged under prescribed condi-
expressed as a mass of butane per unit weight or volume of
tions with dry hydrocarbon free air. The loss of mass is the
carbon.
BWC and is expressed as mass of butane per unit volume of
1.2 The values stated in SI units are to be regarded as carbon.
standard. No other units of measurement are included in this
standard.
5. Significance and Use
1.3 This standard does not purport to address all of the
5.1 The BWC, as determined by this test method, is a
safety concerns, if any, associated with its use. It is the
measure of the ability of an activated carbon to adsorb and
responsibility of the user of this standard to establish appro-
desorb butane from dry air under specified conditions. It is
priate safety and health practices and determine the applica-
useful for quality control and evaluation of granular activated
bility of regulatory limitations prior to use. For a specific
carbons that are used in applications where the adsorption of
hazard statement, see 7.1.
butane and desorption with dry air are of interest. The BWC
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-
D2652Terminology Relating to Activated Carbon
minedundertheconditionsofthetest.Thebutaneactivityisan
D2854Test Method for Apparent Density of Activated
indication of the micropore volume of the activated carbon
Carbon
sample. The butane retentivity is an indication of the pore
D2867Test Methods for Moisture in Activated Carbon
structure of the activated carbon sample.
D3195Practice for Rotameter Calibration
E177Practice for Use of the Terms Precision and Bias in
6. Apparatus
ASTM Test Methods
6.1 Water Bath, capable of maintaining a temperature of 25
E300Practice for Sampling Industrial Chemicals
6 0.2°C and of sufficient depth so the entire carbon bed in the
E691Practice for Conducting an Interlaboratory Study to
sampletubeisimmersedinthewater.A6-mmODcoppertube
Determine the Precision of a Test Method
with an immersed length of 1.9 m (Fig. 1) provides adequate
heat transfer for gas temperature control.
This test method is under the jurisdiction of ASTM Committee D28 on
6.2 Sample Tube, as shown in Fig. 2. The glass plate with
Activated Carbon and is the direct responsibility of Subcommittee D28.04 on Gas
holes is preferred to a fritted disk to support the carbon, since
Phase Evaluation Tests.
Current edition approved April 1, 2010. Published May 2010. Originally fritted disks can vary widely in pressure drop.
approved in 1992. Last previous edition approved in 2005 as D5228–92 (2005).
6.3 Flow Meters, one capable of delivering air at 0 to 500
DOI: 10.1520/D5228-92R10.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or mL/min, and one capable of delivering butane at 0 to 500
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
mL/min, both calibrated in accordance with Practice D3195.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 6.4 Balance, capable of weighing to within 60.01 g.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5228 − 92 (2010)
6.7 Apparatus Assembly shown in Fig. 1.
7. Reagents
7.1 n-Butane, C. P. Grade. (Warning—Butane is a flam-
mable gas with a flash point of −138°C and a boiling point of
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
FIG. 1 Butane Working Capacity Apparatus Schematic
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
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
1– Ground glass stopper, hollow, medium length, 14/20, from Kontes Catalog
No. K-89100 Schwartz adsorption tube, or equivalent.
D2867, Section 4.
2– 5-mm rod, brace.
3– 17-mm O.D. × 1.2 mm standard wall tubing.
11.2 DeterminetheapparentdensityinaccordancewithTest
4– Coor’s perforated porcelain disk or extra coarse fritted disk, or equivalent.
Method D2854 and record.
5– 10-mm O.D. × 1.0 mm standard wall tubing.
6– Right angle stopcock, Kontes Catalog No. K-84700, size 4, 10 mm O.D.
11.3 Accurately weigh the empty, dry sample tube and
stem, with Kontes Catalog No. K-89340 size B serrated hose connector, or
stoppers to the nearest 0.01 g and record.
equivalent.
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