Activated carbon types
What is coal based activated carbon?
Coal based activated carbon is most widely used type of activated carbon used in industrial and municipal applications today. It can be divided into four major categories: bitominous, sub-bitominous, anthracite and lignite, which vary in their characteristics due to pore size. Coal based activated carbon has an inherit benefit in its large degree of type and performance variation, making it easy to find a suitable type for both difficult and standard filtration processes. It is available in both pelletized and granular forms including powder.
Any type of coal based activated carbon from Mellifiq
Coal based activated carbon is extremely versatile for almost any application within Mellifiq’s expertize business areas. It includes drinking water, dechlorination, removal of active pharmaceutical ingredients (API), PFOS and PFAS, VOC air filtration and industrial wastewater. Mellifiq can offer and tailor any granule or extruded (pelletized) size as well as fine granules in powder form. Our standard portfolio of activated carbon stretches the entire range of recommended and suitable types which can satisfy any customer filtration need. Our standard available mesh sizes cover 4×8 to 80×325. and 0.80 to 9 mm pellets.
Coal based activated carbon manufacturing process
Both coal and coconut shell based activated carbon are primarily produced by steam activation following heating to produce char. Production includes a superheating process called pyrolysis where shells are transformed into char followed by a fluidization processes in a FBR (fluidized bed reactor) where the carbon is steam activated. The FBR consists of a rotary kiln, 20 meters long and 2.4 m in diameter in which carbon is activated at temperatures in excess of 1000 degrees Celsius (1800 F).
Various types, sizes and performance characteristics can be targeted by carefully selected raw material, activation temperature, activation time and by varying the concentration of the oxidation gases. Following steam activation, the carbon can be sorted into different granular sizes using different mesh sizes. Production of carbon can also generate valuable bi-products such as syngas and bio-oil.
Coal based activated carbon can be produced in both granular and pelletized form via differently sized mesh sized and extruder machines respectively. Pelletized carbon is used mostly for air treatment applications due its larger sizes which are less dust prone at high air flows.
Coal based carbon can be manufactured as agglomerated carbon, a process in which different coals are produced as powder (less than 40 micrometers) and undergo a pressing procedure to produce briquettes. Final product is then broken to desirable granular or pelletized particle size followed by further processing and activation.
Performance and recommended use
Just like for coconut based activated carbon, CTC (Carbon Tetrachloride, CCl4) is a key performance indicator based on pore size. Coal based carbon is an economical alternative to coconut based activated carbon but can be produced with high degree of flexibility and is normally used for odor control in our Nodora air treatment systems using pelletized types, unwanted taste removal, decolorization and purification of drinking water. Coal based activated carbon has slightly higher ash content than coconut based carbon due its raw material source.
Coal based carbon is excellent due to its common use for both air and water depending on granule or pellet size, where particle sizes up to around 2 mm are used for water and 2 to 5 mm particles are recommended for air treatment applications.