ASTM D5228-92(2015)

5.1 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.

5.2 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.

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.