Activated carbon is derived from carbonaceous materials, particularly effective when produced from coconut shells due to their ideal pore structure. It serves various applications including purification, decolorization, and odor removal in industries such as food, pharmaceuticals, and water treatment. The production processes and characteristics of different types such as coal and wood activated carbon, along with treatment methodologies, are also discussed.

1. ACTIVATED
CARBON
PRODUCTION
-Dhulasi Vinothini K.S.

2. ACTIVATED CARBON
Activated carbon is a form of carbon which could be produced from
any carbonaceous material such as coal, rice husk, paddy husk, coconut shell,
wood etc. Due to their low ash content, high carbon content and natural pore
structure, coconut shells are ideal for producing high quality activated carbon.
Activated carbon manufactured from coconut shell is considered superior to those
obtained from other sources mainly because of small macro-pores structure which
renders it more effective for the adsorption of gas/vapor and for the removal of
color and odour of compounds and as pre-filters in water purification because of
the large internal surface area which makes it as a very good adsorbent for many
contaminants in drinking water.
1. Activated carbons are versatile adsorbents. Their adsorptive properties
are due to their high surface area, a microporous structure, and a high
degree of surface reactivity. They are, used, therefore, to purify,
decolorize, deodorize, dechlorinate, separate, and concentrate in order
reactivity. They are, used, therefore, to purify, decolorize, deodorize,
dechlorinate, separate, and concentrate in order to permit recovery and to
filter, remove, or modify the harmful constituents from gases and liquid
solutions. Consequently, activated carbon adsorption is of interest to
many economic sectors and concern areas as diverse as food,
pharmaceutical, chemical, petroleum, nuclear, automobile, and vacuum
industries as well as for the treatment of drinking water, industrial and
urban waste water, and industrial flue gases.
2. Activated carbons have a microcrystalline structure. But this
microcrystalline structure differs from that of graphite with respect to
interlayer spacing, which is 0.335 nm in the case of graphite and ranges
between 0.34 and 0.35 nm in activated carbons. The elemental 0.335 nm
in the case of graphite and ranges between 0.34 and 0.35 nm in activated
carbons. The elemental composition of a typical activated carbon has
been found to be 88% C, 0.5% H, 0.5% N, 1.0% S, and 6 to 7% O, with
the balance representing inorganic ash constituents. The oxygen content
of an activated carbon can vary, however, depending on the type of the
source raw material and the conditions of the activation process.

3. USES:
Activated Carbon is used in:
• In food and non-food industries.
• In processing of cooking oil, sugar, and chemical matter purification
• Used in drinking water and waste-water treatment.
• Refining and bleaching of vegetable oils.
• Recovery of solvents and other vapors & gold.
• In gas mask for protection against toxic gases etc

4. PRODUCTION:
 COCONUT SHELL ACTIVATED CARBON:
Like its name, coconut shell activated carbon comes from the coconut shell. To
create its activated carbon form, the coconut undergoes a steam activation process.
During activation, it creates millions of pores at the surface of the carbon thus
increasing the total surface area. Coconut shell carbon has mainly micro-pores to
meso-pores and due to its unique distribution of pore diameter, coconut shell
activated carbons are very popular in the gas phase purification and potable water
purification industries.
Activated carbons were prepared at 800°C in a small scale rotary kiln fed either
with fresh or precarbonized coconut shell, employing a mixture of steam and air,
flowing cocurrently. Typical product rates obtained were 0.2 and 0.6g/min for
fresh and precarbonized shell respectively. Product surface area increased with
increasing water input concentration from about 0.5 to 5 g H2O/g feed, resulting in
values up to about l,400m2
/g. The use of N2 instead of air during activation did not
significantly change product surface area. It was demonstrated that both
carbonization and activation of the coconut shell can be carried out together in a
single heating step, resulting in a higher overall yield than if carried out with the
usual two steps procedure. The morphology of the carbons produced consisted of
micropores <10 Å width which afforded most surface area, and of macropores,
some of them resembling the skeletal structure of the raw material.
 COAL ACTIVATED CARBON
Coal based activated carbon originates from coal that has undergone a steam
activation process.
During activation, millions of pores are created on the surface of the carbon,
increasing the total surface area. Coal based carbon has mainly meso-pores and

5. macro-pores and is very popular in gas phase purification, potable water
purification, wastewater purification and aquarium/pond water purification
applications. Kalpaka Chemicals can perform water washing on different mesh
sizes as per the customer’s requirement.
Demand is typically high for this relatively low cost filter media for both gas and
liquid applications.
Carbon Activated stocks a large variety of granular and pelletized grades (3mm,
4mm & 5mm) in addition to powder carbon. We have excellent sourcing
capabilities for a number of specialized coal based activated carbons available for
direct shipment in container loads to worldwide customer destinations.
Coal base activated carbon has a high surface area characterized by both
mesopores and micropores.
• Consistent density
• Hard materials with minimal dust generation.
• Economical
Coal activated carbon is used in drinking water projects. Apart from that, there are
few other industrial applications like Effluent treatment and Waste water treatment.
This type of carbon can be best suited for odor removal and cost effective
applications.
 WATER WASHED ACTIVATED CARBON
Kalbon Aquapura is a water washed high purity high activity granular activated
carbon manufactured by steam activation from carefully selected coconut shells.
Water washing is primarily performed to remove ash content from the granular
activated carbon. Water wash is also used for regeneration of granular activated
carbon. Kalpaka Chemicals can perform water washing on different mesh sizes as
per the customer’s requirement.

6.  ACID WASHED ACTIVATED CARBON:
– A process whereby the activated carbon is washed by acid to remove the water-
soluble ash. This process will also lower the total ash content of the carbon as seen
on the detailed specification sheets. Acid washed activated carbon is desirable for
treating drinking water and food grade applications. Industries include municipal
water treatment plants, food processing companies, breweries and distilleries
among others.
Water Filtration is to collect or gather impurities from the incoming water flow.
When the pores of filters logged, it has to be cleaned by forcing out the
accumulated particles by reversing the flow and increasing the velocity of water
passing back through the filter. It is called backwashing. We can improve the
quality of water by doing it at regular intervals.
There is an initial backwash and then there are periodic backwashes. The initial
backwash can be used to remove the fines and dust created from handling the
activated carbon. To properly backwash your filter, start slowly and speed up the
flow. This allows the carbon to expand gently. Do not start quickly because this
will push the carbon up. Backwash for 15-20 minutes. Backwashes done
periodically will help remove particles of the application that can get stuck in the
activated carbon pores. For instance, one of our car wash customers has a lot of
soap that goes through the filter. Occasionally they backwash the filter to get rid of
the soap that could be blocking some of the activated carbon pores.
BACKWASHING PROCEDURE
First the filter is taken off line and the water is drained to a level that is above the
surface of the filter bed. Next, compressed air is pushed up through the filter
material causing the filter bed to expand, breaking up the compacted filter bed and
forcing the accumulated particles into suspension for 20-30 minutes.
After the air scour cycle, clean backwash water is forced upwards through the filter
bed, causing the filter bed to expand and carrying the particles in suspension into
backwash troughs suspended above the filter surface. In some applications, air and
water streams are simultaneously pushed upwards through the granular

7. media. Backwashing continues for 30 minutes to one hour time, or until the
turbidity of the backwash water is below an established value. A filter bed should
have as much expansion as possible upto 30 to 50 percent of bed volume without
loosing media or displacing the support gravel. At the end of the backwash cycle,
the upward flow of water is terminated and the filter bed settles by gravity in its
initial configuration.
After allowing sufficient time for the filter bed to settle by gravity, rinsing can be
done with clear water for 30 minutes until the crystal clear water comes out as the
output. Then water to be filtered is passed through the filter and the service cycle
can be from 16hrs to 20hrs
 WOOD ACTIVATED CARBON:
KALBON JULIA WOOD ACTIVATED CARBON
wood activated carbon is an acid washed high purity high activity granular
activated carbon manufactured by steam activation from carefully selected coconut
shells.
Wood Charcoal:
Wood charcoal is formed when carbon-containing raw wood is carbonized in a
limited supply of air with no oxygen called Pyrolysis. The wood substance is
forced to decompose into Wood charcoal, a black porous solid consisting mainly of
elemental carbon.
Wood Activated Carbon:
Wood charcoal is an important raw material for Activated Carbon. It is not a very
active adsorption material for either liquids or vapors because its fine structure is
blocked by residues. To convert the charcoal to "Activated Mode" this structure
must be opened up by removing the tarry residues and volatiles. The most widely
used method today consists in heating the granulated wood charcoal in a rotary kiln
to low red heat in an atmosphere of superheated steam. The steam prevents the
charcoal from burning away by excluding oxygen. Meanwhile the volatile tars can

8. be distilled away and are carried off with the steam, leaving the pore structure
open. The treated charcoal is run off into closed containers and allowed to cool.
Properties of Wood Activated Carbon:
Surface Area - Generally, higher the internal surface area, the higher is the
adsorption capacity of carbon. The surface area of activated carbon is 500 to 1500
m2/g or even more; a spoonful of activated carbon easily equates the surface area
of a soccer field.
It is in the activation process that this vast surface area is created. The most
common process is steam activation; at around 900°C steam molecules selectively
burn holes into the carbonized raw material, thus creating a multitude of pores
inside the carbonaceous matrix.
Total Pore Volume - Refers to all pore spaces inside a particle of activated carbon .
It is expressed in milliliters per gram (ml/g), volume in relation to weight. In
general, the higher the pore volume, the higher the effectiveness. However, the
selection of carbon mainly depends upon matching the molecular size of impurities
to be adsorbed by the carbon with suitable pore diameter and pore volume.
Pore Volume Distribution - Wood Charcoal has its own unique distribution of
Mesopores r > 1-25nm .
.PROCESS TECHNOLOGY:
1. Their preparation involves two main steps: the carbonization of the
carbonaceous raw material at temperatures below 800°C and the activation
of the carbonized product. Thus, all carbonaceous materials can be
converted into activated carbon,materials can be converted into activated
carbon, although the properties of the final product will be different,
depending on the nature of the raw material used, the nature of the activating
agent, and the conditions of the carbonization and activation processes. But
only a good hard biomass used as activated charcoal such as coconut shell
and palm shell.
2. During the carbonization process, most of the noncarbon elements such as
oxygen, hydrogen, and nitrogen are eliminated as volatile gaseous species by

9. the pyrolytic decomposition of the starting material. The residual elementary
carbonstarting material. The residual elementary carbon atoms group
themselves into stacks of flat, aromatic sheets cross-linked in a random
manner. These aromatic sheets are irregularly arranged, which leaves free
interstices. These interstices give rise to pores, which make activated
carbons excellent adsorbents.
3. During carbonization these pores are filled with the tarry matter or the
products of decomposition or at least blocked partially by disorganized
carbon. This pore structure in carbonized char is further developed
andcarbon. This pore structure in carbonized char is further developed and
enhanced during the activation process, which converts the carbonized raw
material into a form that contains the greatest possible number of randomly
distributed pores of various sizes and shapes, giving rise to an extended and
extremely high surface area of the product. The activation of the char is
usually carried out in an atmosphere of air, CO2, or steam in the temperature
range of 800°C to 900°C. This results in the oxidation of some of the regions
within the char in preference to others, so that as combustion proceeds, a
preferential etching takes place. This results in the development of a large
internal surface, which in some cases may be as high as 2500 m2/g.
4. Our continuous pyrolysis technology with capacity 60 up to 200 ton/day
INPUT would very reliable in theup to 200 ton/day INPUT would very
reliable in the process of carbonization. Integration our continuous pyrolysis
technology in activated carbon plant would be very beneficial because the
most efficient processes (self sustaining process with syngas) and all
products can be drawn. Then following with activation process.
5. Carbonisation (Slow Pyrolysis Process) : Charcoal Production Primitive
Charring Tehniques :large quantities of CO2 and unburned methane directly
to the atmosphere Closed pit charcoal production Advanced charcoal
production : Charcoal as main product, bio-oil and syngas as sideproduct.
Syngas can be used in activation process.

10. PROPERTIES:
• Ash Content – Ash is an actual property of activated carbon. It decreases
the effectiveness of the activated carbon. You will find low ash content in all
activated carbon products. Water soluble ash is the ash content that can be
washed away by water. Often, activated carbon that is intended for food
grade applications will be acid washed to remove the water-soluble ash
content. No acid is left behind in this process.
• Carbon Tetrachloride Number – A measurement of the quality of the
activated carbon typically used for vapor phase carbons. It is a test to see
how much CTC the carbon will remove.
• Humidity – Humidity is a problem if it causes enough condensation that
blocks the pores of the activated carbon and stop the carbon from being able
to adsorb the contaminants. Condensation will form in a carbon bed if the
dew point of the air flow is greater than the temperature of the air outside.
Humidity and condensation is an issue if you have chlorinated solvents
because the chemical reaction will not work well. 50% humidity is fine and
70-80% is tolerable.
• Iodine – A measurement of the quality of the activated carbon typically used
for liquid phase carbons. It is a test to see how much iodine the carbon will
remove.
• Mesh Size – a measure of the size of the granules. It is a range. For instance,
8×30 means that the largest particles are 1/8” and the smallest are 1/30”. The
8×30 means a range that the granule sizes will be in between 1/8” and 1/30”.
Larger mesh size carbons are used for air treatment because there is less
pressure drop. The smaller the particle the greater the pressure drop. Water
applications require greater contact time and therefore use smaller particles
so that the contaminants are close to always in contact to the surface area of
the activated carbon.
• Moisture Content – typically measured as packaged, the measurement of
the amount of water in the activated carbon.

11. • Pelletized Activated Carbon – Uniform in shaped, cylindrical carbon
pellets. Typically mined into chunks of charcoal, pulverized and formed into
pellets with a coal tar binder or petroleum tar binder. Used for low flow and
low pressure drop applications.
• pH – Acidic (0) -> Neutral (7) -> Basic (14). pH Effects the solubility of a
chemical but only a drastic pH is a big concern, ie. 2 or 12. pH will rise in
liquid phase applications because of water soluble ash. Higher ash content,
higher pH. Since coal has more ash, it will have a higher initial spike in pH.
A rule of thumb is to increase the size of the carbon bed by twenty percent
for every pH unit above neutral (7.0).
• Pore
Micropore – upto 100A <1nm
Mesopore -100 to 5000A, 1-500nm
Macropore - Greater than 5000A >500nm
• Powdered Activated Carbon – Activated carbon in powder form. Used
predominantly in water phase applications. Sizes 100-325 mesh which are
smaller than 0.147 mm. Can be coal, coconut shell or wood based.
• Surface Area – Activated carbon has a deceivingly gigantic surface area.
During its’ manufacturing process, it is superheated to create a large internal
pore structure. Contaminants adsorb, or stick, to the surface of the activated
carbon. You cannot see the pore structure with your naked eye but they look
like a sponge.
• Temperature – Carbon begins to lose its effectiveness for removing
contaminants when the temperature reaches 90 F. At approximately 120 F,
carbon will not work effectively. When liquid reaches boiling carbon will
work at all