Wood Based Activated Carbon

Our wood based carbons are made by steam activation, or by chemical activation, usually using zinc chloride or phosphoric acid depending in the final desired product properties. Generally speaking, wood based carbons have a high proportion of meso- and macropores when compared with typical coal and especially coconut based carbons.

They exhibit different sorption and desorption properties and are often capable of adsorbing quite large molecules. Their properties make them particularly suitable in applications such as:

  • Decolorising for fruit juices, beverages, food stuffs, and pharmaceutical products
  • Purification of edible oils, sweeteners, starches etc
  • Solvent recovery
  • Use in vehicle Evaporative Loss Control Devices

In decolourising applications, the performance of the products tends to be measured by parameters such as:

  • Methylene Blue adsorption; giving an indication of the capacity for adsorption of medium sized molecules including dyes. It is higher for carbons which have a preponderance of mesopores (2-5 nm diameter)
  • Molasses index: the adsorption of molasses from solution can be used to give an indication of the capability to adsorb larger molecules and is again strongly dependent on the mesopore structure

In many applications the purity of the carbons, and surface chemistry is also important, and wood based carbons generally have better purity than coal based. This can be enhanced by washing as necessary and the pH can also be altered. The size distribution of the powders is also important as it affects the adsorption kinetics.