Difference between activated charcoal and regular charcoal?

[Gary_T]

I understand that charcoal is used as fuel, whereas activated charcoal is used for filtering or adsorbing certain impurities or toxins.

What I haven’t been able to find is a definition and/or description of activated charcoal, how it is made, and how it differs from everyday throw-it-on-the-grill charcoal.

I’m also curious about exactly what is meant by “activated.”

Anyone know, or got a link? Thanks.

[Enola_Straight]

Made porous by exposure to steam.

[cynic]

http://www.ilpi.com/msds/ref/activatedcharcoal.html

Charcoal becomes activated by heating it with steam to approximately 1000 [sup]o[/sup]C in the absence of oxygen (O2). This treatment removes residual non-carbon elements and produces a porous internal microstructure having an extremely high surface area. A single gram of such material can have 400 to 1,200 square meters of surface area

[stuyguy]

A single gram of such material can have 400 to 1,200 square meters of surface area.

Wow! This is a staggering fact if it is true.

[antechinus]

It is the high surface area that not only makes it a great adsorbent but also presents a risk of spontaneous heating and combustion.

Another way of putting the earlier posts is that it is clean carbon.

Also handy to have by for poisonings. I recall a story about some French fellah in the 1800’s eating some rat poison then following it with activated charcoal and living. Dont try this at home kiddies.

[Gary_T]

Thanks to all. That answers my questions.

[RiverRunner]

*Originally posted by antechinus *
**Also handy to have by for poisonings. I recall a story about some French fellah in the 1800’s eating some rat poison then following it with activated charcoal and living. Dont try this at home kiddies. **

This same trick was used by the protagonist in Tim Powers’ The Anubis Gates.
RR

[robby]

*Originally posted by stuyguy *
**Wow! This is a staggering fact if it is true. **

It’s true. I used activated carbon extensively for my master’s thesis in environmental engineering.

Here’s another cite:

http://www.cee.vt.edu/program_areas/environmental/teach/gwprimer/group23/accharacteristics.html

Activated carbon is often characterized by its extremely large surface area. In fact, the surface area per gram of material can range from 500 to 1400 square meters, and values as high as 2500 m[sup]2[/sup]/g have been reported.

(Of course, this quote would probably read better if they said that the surface area per gram of material typically ranges from 500 to 1400 square meters, and that values as high as 2500 m[sup]2[/sup]/g have been reported.)