Self-Ignition Resistant Thermally-Activated Carbon
AssigneeAlbemarle Corporation
InventorsJonathan P. O'Dwyer, Qunhui Zhou, Gregory H. Lambeth, Yinzhi Zhang, Christopher J. Nalepa
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Abstract
Thermally-activated cellulosic-based carbon is rendered more thermally stable by exposure to a halogen and/or a halogen-containing compound. Such treated cellulosic-based carbon is suitable for use in mitigating the content of hazardous substances in flue gases, especially flue gases having a temperature within the range of from about 100° C. to about 420° C.
Claims8
A thermally-activated cellulosic-based carbon that has been exposed to a halogen and/or a halogen-containing compound, has an ash content of 10 to 15 wt % and that has at least one of the following:
- (i) a temperature of initial energy release that is greater than the temperature of initial energy release for the same thermally-activated cellulosic-based carbon without the halogen and/or halogen-containing compound exposure;
- (ii) a self-sustaining ignition temperature greater than the self-sustaining ignition temperature for the same thermally-activated cellulosic-based carbon without the halogen and/or halogen-containing compound exposure;
- and
- (iii) an early stage energy release value that is less than the early stage energy release value for the same thermally-activated cellulosic-based carbon without the halogen and/or halogen-containing compound exposure.
A process for enhancing the thermal stability of a thermally-activated cellulosic-based carbon, which process comprises exposing the thermally-activated cellulosic-based carbon to a halogen and/or a halogen-containing compound at a temperature and for a time sufficient so that thermally-activated cellulosic-based carbon that has been exposed to the halogen and/or the halogen-containing compound, has an ash content of 10 to 15 wt % and has at least one of the following:
- (i) a temperature of initial energy release greater than the temperature of initial energy release for the same thermally-activated cellulosic-based carbon prior to the halogen and/or halogen-containing compound exposure;
- (ii) a self-sustaining ignition temperature greater than the self-sustaining ignition temperature for the same thermally-activated cellulosic-based carbon prior to the halogen and/or halogen-containing compound exposure;
- and
- (iii) an early stage energy release value that is less than the early stage energy release value for the same thermally-activated cellulosic-based carbon prior to the halogen and/or halogen-containing compound exposure.
A halogen and/or halogen-containing compound exposed, thermally-activated cellulosic based carbon that contains from about 2 to about 20 wt % halogen, has an ash content of 10 to 15 wt % and has at least one of the following:
- (i) a temperature of initial energy release that is greater than the temperature of initial energy release for the same thermally-activated cellulosic based carbon prior to the halogen and/or halogen-containing compound exposure, (ii) a self-sustaining ignition temperature greater than the self-sustaining ignition temperature for the same thermally-activated cellulosic-based carbon prior to the halogen and/or halogen-containing compound exposure;
- and (iii) an early stage energy release value that is less than the early stage energy release value for the same thermally-activated cellulosic-based carbon prior to the halogen and/or halogen-containing compound exposure.
Dependencies are inferred from the claim text.