ASTM D3466-06

Activated carbons used in gas-phase adsorption may be subjected to heating, either from heat applied externally to the carbon bed, or heat generated by radioactive⁴ contaminants, or by the adsorption process itself. If the application of heat is sudden, or if no ample means to conduct the heat from the carbon bed exists, the carbon bed may ignite. This test method provides a controlled laboratory test to determine the temperatures at which such ignition occurs. As stated in 1.2, this does not necessarily give the temperature at which ignition will occur under a specific bed operating condition. This test method does, however, allow some ranking of carbons with regard to ignition temperature, and is a useful quality-control method for unused carbons.

1.1 This test method covers the determination of reference ignition temperature of granular activated carbon in flowing air. This test method provides a basis for comparing the ignition characteristics of different carbons, or the change in ignition characteristics of the same carbon after a period of service.

1.2 The ignition temperature as determined by this test method cannot be interpreted as the probable ignition temperature of the same carbon under the operating conditions of a specific application unless those conditions are essentially the same as those in this test method. If it is desired to determine the ignition temperature of the carbon under a specific set of operating conditions, the test may be modified to simulate such conditions, taking into consideration the following variables: (1) air flow rate; (2) moisture content of the carbon; (3) bed depth; ( 4) relative humidity of the air stream; (5) heating rate; (6) contaminants (for example, hydrocarbons, etc.) in the air stream; and (7) contaminants that may have been adsorbed by the carbon under prior service conditions.

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. Specific precautionary statements are given in Section .