Shell Charcoal is an important product obtained from coconut shell. Shell charcoal is used widely as domestic and industrial fuel. It is also used by blacksmiths and goldsmiths and in laundries. Shell Charcoal is also used to produce activated carbon. Activated Carbon produced from coconut shell has certain specific advantages as the raw material can absorb certain molecular species. Shell is carbonized by using methods like pit method, drum method, destructive distillation etc.
The shell charcoal is the raw material required for the manufacture of activated carbon with a view to offering our clients a range of biodegradable and eco-friendly products we are engaged in manufacturing a very efficient range of Shell Charcoal Machine that produces a very high quality of coconut charcoal. The Shell Charcoal Machine is renowned for highly competent performance, precision engineering, durability and wear and tear resistance. We offer this range in both standard and customized version.
Shell Charcoal is obtained by burning the shell of fully matured coconuts with a limitedsupply of air so that they do not burn away to ash but are only carbonized. The manufacture ofshell charcoal shows from the coconut shell has become a very important economic andcommercial activity. Furthermore, coconut shell charcoal, which was relatively minor product inthe past, has now developed into a general commercial commodity due to its intrinsic value as a raw material for the manufacture of activated carbon. Coconut shell charcoal shall be of the following two types:
Simple Mud Pits/ Brick Lined Pits
It is basically a simple process, consisting of burning the shells in a limited supply of air,so that the shells are only carbonized and not burnt to ash. The tricky part of this operation is to set the optimum conditions for carbonization to the correct degree. The charcoal manufactured by this method is of inferior quality, containing lot of impurities. Moreover emission of a lot of smoke and flue gases during the process causes atmospheric pollution.
Process (Drum Method)
A M.S. Drum kiln is used for carbonization of shells. The drum consists of three sets of six 1" dia holes provided at its bottom, middle and upper layers and a lid. A detachable chimney is provided which is installed on the lid after closing the drum. The manufacture of charcoal requires optimum carbonization of raw shells in a limited supply of air so that there is neither unburnt shell nor ash due to complete combustion. The steel drum is filled with raw shells after placing temporarily a four inch diameter wooden pole in the centre of the drum.
The wooden pole is then removed, leaving a hollow space in the centre which allows the flow of smoke during carbonization. To start carbonization, a piece of burning rag is dropped to the bottom of the drum through the hollow space in the centre. When the fire is well underway, the lid with the chimney is placed into position and the upper and the middle sets of holes are closed.
Carbonization which starts at the bottom progresses as it goes up as well as radially from the hollow space. When carbonization is complete in a particular zone, a persistent glow can be seen in all the six holes of a set. When the bottom most set of holes indicate this situation, the middle set of holes is opened and the bottom set closed. The stoppage of air flowing into the bottom region avoids over-carbonization in that region. The progressive carbonization results in reduction in volume of contents and therefore more shells are added from the top. When the middle region is carbonized well, the top set of holes is opened while the middle set is now closed. A further addition of raw shells is done to fill the volume reduction to maximise capacity for burning. When the top region is well carbonized, the top set of holes is also closed, resulting in complete stoppage of air inflow to the drum. The drum is then cooled for about eight hours after which the product is ready for discharge.
It is a new technology adopted by many of the companies for the production of shell charcoal. In this method the coconut shells are dumped into a gasifier and heated at a temperature of 800ºC or more than that. The heat generated during the production of shell charcoal is separated out with the help of a cyclone separator and is used for purposes wherever heat can be utilized which ultimately help the entrepreneur to earn more profit.
The charcoal prepared is then pulverized to form granules and the granules are then used for the processing of activated carbon.
Packaging and Marking
Unless otherwise specified, coconut shell charcoal shall be packed in sacks suitable for safe transportation. They shall be of uniform size containing 50kg of the material. Each container shall carry a tag/label clearly marked with all details.
The shell charcoal powder is the waste product obtained during the processing of charcoal. The powder is binded with the help of binding materials and moulded in the form of briquettes using moulding machine.
Process Flow Chart
Yield of the product
In India, the average output has been found to be 35 Kg of charcoal from 1000 whole shells or about 30,000 whole shells yield 1 tonne of charcoal.
Properties of Shell Charcoal
Good coconut shell charcoal is uniformly dark and snaps with a clean shining fracture and produces a metallic sound, when dropped on hard ground. Underburnt shells do not give a metallic sound and a clean fracture, while the overburnt ones are friable and the surface of the fracture sounds dull when dropped and easily crumbles. Coconut shell charcoal contains the highest percentage of fixed carbons of all the lignaceous charcoals. The average composition of good charcoal is moisture 6.24%, volatile 5.46 %, ash 0.54% and fixed carbon 87.76%. The quality standards for shell charcoal as per Asian and Pacific Coconut Community (APCC) are as follows:
Uses of Shell Charcoal
The charcoal has a high adsorption capacity for gases and colouring matter and can therefore be used as a refining agent both as a deodorizer and as a decolourizer. The shell charcoal also finds way to laundries, smitheries etc. Well powdered shell charcoal finds limited used as a dentifrice. The charcoal is used by goldsmiths in melting gold and silver and for other metal works. The commercial value of shell charcoal lies in its use as the primary raw material for the production of activated carbon. It also finds very good demand as an industrial fuel to substitute furnace oil.