Due to its high degree of microporosity, just one gram of activated carbon has a surface area in excess of 500 m2, as determined by adsorption isotherms of carbon dioxide gas at room or 0.0 °C temperature. An activation level sufficient for useful application may be attained solely from high surface area; however, further chemical treatment often enhances adsorption properties.
The adsorbing characteristic of activated charcoal is used for many purposes. When a compound passes near this charcoal, the latter adsorbs the substance by chemical attraction. It is considered as the most effective poison antidote till date. If administered early, activated charcoal can adsorb about 60 - 70 percent of the ingested poison. Due to its various benefits and multiple applications, it is produced on a large scale. Commercially, it is available in the form of dry powder, liquids and tablets.
Steps to Make Activated Charcoal at Home
Activated charcoal can be made at home by chemical activation procedure, provided you have the required materials and equipment. Though any organic material can be used as a precursor or raw material for producing activated charcoal, you should select a nontoxic carbon source with absorbent properties. The best choices are clean coconut shells and hardwood. Let's discuss in brief how to make activated charcoal by using coconut shells as the raw material.
First of all, keep all the required materials ready for making activated charcoal; you need:
- Coconut shells (without meat)
- Burning sink
- Oven25 percent concentrated solution of calcium chloride (CaCl2) or zinc chloride (ZnCl2)
- Sterilized water
- Plastic pail
- Draining tray
- Zipper bags
Hoping that the coconut shells are free of moisture, add them in the burning sink (or drum). Measure the temperature and make sure it is adjusted to about 600 - 900 degrees Fahrenheit. Maintain the recommended temperature range and burn continuously for about 4 ½ hours or until the coconut shells turn into ash. For safe handling, you can leave the ash until it cools down.
After the ash has cooled down, take it out carefully from the sink and transfer into a clean plastic pail. Then, pour the 25 percent concentrated solution of calcium chloride or zinc chloride into the plastic pail.
The amount of calcium chloride or zinc chloride solution should be such that the ash is soaked completely into the solution. Cover the pail with a lid and leave for 20 - 24 hours. During this process, the chemicals are impregnated into the ash and further treatment will transform the ash into activated charcoal. The next step is removing the charcoal from the chemical solution and transferring it into a draining tray. Allow the treated charcoal to drain for about 1 hour.
For removal of trace chemicals from the charcoal, you can wash and rinse it repeatedly with sterilized water. Thorough washing is essential in order to get rid of the chemical solution, which otherwise will remain in the charcoal. It is one of the most common problems in the making of activated charcoal by chemical activation procedure. After washing, keep the charcoal in the tray for draining water. Following this, transfer charcoal into an oven, setting the temperature to about 215 - 230 degrees Fahrenheit and bake for about 3 hours.
After baking for the stipulated time, remove the charcoal from the oven and crush it with the help of a blender. You can also grind the charcoal into powder form by using a hammer. For future use, store the powdered charcoal into zipper bags or airtight containers.
Though activated charcoal can be made at home if one has the required materials and equipment, it is readily available in many drugstores as well.
In the factory, activated carbon can be made from Coconut shell, Nut shell, Coal, Wood and other materials, Principles and the process is similar to it was made at home.