
#REDIRECT: Activated carbon
Activated carbon (also called activated charcoal) is the more general term which includes carbon material mostly derived from charcoal. It denotes a material which has an exceptionally high surface area, typically determined by nitrogen adsorption, and includes a large amount of microporosity. Sufficient activation for useful applications may come solely from the high surface area, though often further chemical treatment is used to enhance the adsorbing properties of the material. Activated carbon is used in metal extraction (e.g. gold), water purification (especially in home aquariums), medicine, Sewage treatment, filters in gas mask and filter masks, automobile emissions control and many other applications. It can generally be produced in two different processes: #''Chemical activation'': Mostly acids are mixed with the source material in order to Cauterisation the fine pores. This technique can be problematic because, for example, zinc trace residues may remain in the endproduct. #''Steam activation'': The carbonised material is mixed with vapours and|or gases at high temperature to activate it. The source material can be several carbonic materials, e.g. nutshells, wood, coal. Activated carbon may have a surface area in excess of 500 metre²/gram, with 1000 m²/gram being readily achievable. A tennis court is about 260 m². Under an electron microscope, the structure of activated carbon looks something like ribbons of paper which have been crumpled together, with a few wood chips thrown in for good measure. There are lots and lots of nooks and crannies, and many areas where flat surfaces of graphite-like material run parallel to each other, separated by a few nanometers or so. These micropores provide superb conditions for adsorption to occur, since adsorbing material can interact with many surfaces simultaneously. Tests of adsorption behaviour are usually done with nitrogen gas at 77 kelvin under high vacuum, but in everyday terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °celsius and a pressure of 1/10,000 of an atmosphere. saturation (chemistry) active carbon can be regeneration by heating. == External links == * [http://www.tifac.org.in/offer/tsw/apctt27.htm Technology Information, Forecasting and Assessment Council (TIFAC) of India] Materials Filters
Carbon! :Old encyclopedias mention "bone black" on this topic...maybe that phrase should appear somewhere... :User:Polyparadigm ::It appears that bone black is slightly different than the processed activated carbon. ::Why do we have that second link on the page? It appears to have nothing to do with carbon, other than that the students applying for the internship/grant money might use it... ::-- ~ender 19:09:MST == Incomprehensible == "Tests of adsorption behaviour are usually done with nitrogen gas at 77 K under high vacuum, but in everyday terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °C and a pressure of 1/10,000 of an atmosphere." Seems unintelligible to me. Does it mean that adsorption tests are done with both nitrogen gas and activated carbon? If so, what is the role of liquid water in such a prosedure, and the meaning of pressure? Should the quoted content be simplified, explained, divided to multiple parts or what? User:193.166.173.23 13:55, 1 Jun 2005 (UTC) Ok, I think I got it. Adsorpion can be tested either with gas or steam. They way it's told is really tricky tho. User:193.166.173.23 16:53, 1 Jun 2005 (UTC)
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Words begining with Activated_carbon:
Activated_Carbon
Activated_carbon
Activated_carbon
Activated Carbon
#REDIRECT: Activated carbon
Activated carbon
Activated carbon (also called activated charcoal) is the more general term which includes carbon material mostly derived from charcoal. It denotes a material which has an exceptionally high surface area, typically determined by nitrogen adsorption, and includes a large amount of microporosity. Sufficient activation for useful applications may come solely from the high surface area, though often further chemical treatment is used to enhance the adsorbing properties of the material. Activated carbon is used in metal extraction (e.g. gold), water purification (especially in home aquariums), medicine, Sewage treatment, filters in gas mask and filter masks, automobile emissions control and many other applications. It can generally be produced in two different processes: #''Chemical activation'': Mostly acids are mixed with the source material in order to Cauterisation the fine pores. This technique can be problematic because, for example, zinc trace residues may remain in the endproduct. #''Steam activation'': The carbonised material is mixed with vapours and|or gases at high temperature to activate it. The source material can be several carbonic materials, e.g. nutshells, wood, coal. Activated carbon may have a surface area in excess of 500 metre²/gram, with 1000 m²/gram being readily achievable. A tennis court is about 260 m². Under an electron microscope, the structure of activated carbon looks something like ribbons of paper which have been crumpled together, with a few wood chips thrown in for good measure. There are lots and lots of nooks and crannies, and many areas where flat surfaces of graphite-like material run parallel to each other, separated by a few nanometers or so. These micropores provide superb conditions for adsorption to occur, since adsorbing material can interact with many surfaces simultaneously. Tests of adsorption behaviour are usually done with nitrogen gas at 77 kelvin under high vacuum, but in everyday terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °celsius and a pressure of 1/10,000 of an atmosphere. saturation (chemistry) active carbon can be regeneration by heating. == External links == * [http://www.tifac.org.in/offer/tsw/apctt27.htm Technology Information, Forecasting and Assessment Council (TIFAC) of India] Materials Filters
Activated carbon
Carbon! :Old encyclopedias mention "bone black" on this topic...maybe that phrase should appear somewhere... :User:Polyparadigm ::It appears that bone black is slightly different than the processed activated carbon. ::Why do we have that second link on the page? It appears to have nothing to do with carbon, other than that the students applying for the internship/grant money might use it... ::-- ~ender 19:09:MST == Incomprehensible == "Tests of adsorption behaviour are usually done with nitrogen gas at 77 K under high vacuum, but in everyday terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °C and a pressure of 1/10,000 of an atmosphere." Seems unintelligible to me. Does it mean that adsorption tests are done with both nitrogen gas and activated carbon? If so, what is the role of liquid water in such a prosedure, and the meaning of pressure? Should the quoted content be simplified, explained, divided to multiple parts or what? User:193.166.173.23 13:55, 1 Jun 2005 (UTC) Ok, I think I got it. Adsorpion can be tested either with gas or steam. They way it's told is really tricky tho. User:193.166.173.23 16:53, 1 Jun 2005 (UTC)
See other meanings of words starting from letter:
A
AB | AC | AD | AE | AF | AG | AH | AI | AJ | AK | AL | AM | AN | AO | AP | AR | AS | AT | AU | AW | AX | AY | AZ |Words begining with Activated_carbon:
Activated_Carbon
Activated_carbon
Activated_carbon
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