activated carbon - applications

Great flexibility, several different types and grades available and a variety of applications: activated carbon is the most widely used filtration media for treatments of fluids, in both liquid and gaseosus phase. Thanks to its non-polar surface characteristic, activated carbon shows high affinity with most organics, while showing low affinity with water, in contrast with the polar desiccating adsorbents (such as molecular sieves).

Activated carbon is the ideal adsorption media for vapor phase solvent recovery systems.

activated carbon - adsorption and desorption

Adsorption is a physical (reversible) process where organic molecules are held at the carbon surface, by a mechanical attraction (Van Der Waals forces) resulting from intermolecular attraction (relatively weak, if compared to normal chemical bonds). Desorption is the reversal of the adsorption process. In the (in situ) regeneration process, the adsorbed solvent is stripped from the activated carbon, using two processes, alone or combined:

  • TSA (thermal swing adsorption);
  • PSA (pressure swing adsorption).
  • activated carbon: core structure

    activated carbon - production process

    Activated carbon is produced from carbonaceous raw materials such as bituminous and lignite coals, coconut shells, petroleum coke, and bark, sawdust, and other wood products. Depending on raw material (mineral or vegetal), method and degree of activation (thermal or chemical) and other factors, activated carbons can perform differently in various applications. Thanks to the activation process, the internal pore structure is developed, usually obtaining internal surface areas of 1500m²/g or greater.

    The production goes through the following steps:

  • Dehydration;
  • Carbonization;
  • Activation.
  • raw materialactivated carbon, available types

    activated carbon - the structure

    Porosity of activated carbon, as defined by IUPAC (International Union of Pure and Applied Chemistry), is divided in three families:

  • MACROPORES (> 250 Å);
  • MESOPORES (10 ÷ 250 Å);
  • MICROPORES (< 10 Å).
  • activated carbon: macropores, mesopores, micropores

    Despite activated carbon huge commercial importance in the purification of air and water, the precise atomic structure of this adsorbent is still unknown.

    Activated Carbon Services

    Adsorption efficiency decreases over time and eventually activated carbon will need to go through the following maintenance services, provided by DEC SERVICE:

  • adsorbent sieving;
  • adsorbent reactivation;
  • adsorbent replacement.