Phosphoric Acid Activated Carbon

Phosphate Active Carbon is a chemical active carbon which is obtained by impregnating a carbon-containing feedstock – usually wood, sawdust, or lignocellulose – with phosphate (H), PO (CO), and then subjected to a controlled heat treatment at a temperature generally between 400oC and 800oC, during activation, the phosphate can be used as a desiccant and an activator, penetrating into the feedstock structure, suppressing the formation of the tar, and catalyzing the evolution of a highly porous inner structure. Subsequently, the active carbon is cleaned thoroughly to eliminate the remaining phosphate and its derivatives prior to drying, sizing and preparation for final use.

The process of chemical activation with phosphate is especially suitable for wood based raw materials, in which the active carbon has been continuously produced with extremely large BET surface area – usually more than 1500 meters per gram – and the pore diameter profile strongly weighted towards the middle hole. This mesopore-dominant structure is the defining property of PAC, which distinguishes it from steam activated or zinc chloride active alternatives. Rich mesopores allow fast absorption dynamics and high efficient trapping of medium-to-large-molecular-weight organic compounds, which makes phosphate active carbon a preferred material for applications in which high molecular pollution elimination, decoloring, and liquid phase cleaning are the main processing goals.