The Defence Research and Development Organisation (DRDO) has come up with ‘activated carbon spheres’, an adsorbent with desirable qualities such as a porous structure, large surface area, high micropore volume, controllable pore size distribution, high mechanical strength, high purity, smooth surface, high wear-resistance, excellent durability, good fluidity, low ash content and low moisture content.
Wat is activated carbon spheres?
- Activated carbon, also known as activated charcoal, is a crude form of graphite, the substance used for pencil leads.
- It differs from graphite by having a random, imperfect structure which is highly porous over a broad range of pore sizes from visible cracks and crevices to molecular dimensions.
- The graphite structure gives the carbon its very large surface area which allows the carbon to adsorb a wide range of compounds.
- Activated carbon has the strongest physical adsorption forces, or the highest volume of adsorbing porosity, of any material known to mankind.
- Activated carbon (activated charcoal) can have a surface of greater than 1000m²/g. This means 3g of activated carbon can have the surface area of a football field.
- ACS is commonly used in applications such as catalyst support, purification of blood, supercapacitors, protective suits against chemical warfare agents, and adsorptive removal of gaseous and liquid toxicants.
- Using polymeric precursors, specific surface area greater than 800 sq m per gram along with total pore volume greater than 0.8 cubic cm per gram have been used for removal of toxicants.
- The application of activated carbon as adsorbents relies on the pore size and its distribution as micropores (less than 2mm) and mesopores (2-50 nm) that are mostly used for the gas phase and liquid phase.
- ACS has been successfully used for developing individual protective equipment (IPE) such as NBC (nuclear, biological, chemical) suit, socks, haversack and boot, says a note from DRDO.
- Some other typical applications are: Removal of volatile organic compounds such as Benzene, TCE, and PCE. Hydrogen Sulfide (HS) and removal of waste gases, Impregnated activated carbon used as a bacteria inhibitor in drinking water filters, Removal of taste and odor causing compounds such as MIB and geosmin, Recovery of gold, Removal of chlorine and chloramine.
