Continental Carbon India Limited, is a ISO 9001:2000 certified Carbon Black Manufacturing Company pioneering the Carbon Black Industry in India since 1977.

Here we are emphazing on How we manufacture Carbon Black in our Manufacturing Plant in detail, which brings out to you the Processes we follow and Standards we mantain in manufacturing of Carbon Black.

CARBON BLACK - BASIC FACTS
What is Carbon Black?

Carbon black is a quasi-graphite form of elemental carbon fused together in a grape like ‘agglomerate’ structure.

What are the common forms of Carbon Black?

They are gas black, channel black and furnace black. However, modern day’s most commonly used blacks are furnace black, named after its basic manufacturing process.

What is the basic principle of manufacture of carbon black?

The basic principle involves the cracking or “paralysis” of natural gas or liquid hydrocarbon in a limited supply of air to form carbon black particles. These particles after a number of further stages of formation and treatment take the final pellet form.

Brief Description of Carbon Black Production Process

Carbon Black as is a product of incomplete combustion of Carbon Black Feed stock, which in the case of CCIL, come from the following sources.

• Creosote oil from coal coking operations
• Ethylene Bottom Oil from Ethylene Production.
• Residual oil from Fluid Catalytic Cracking operations.

In the process it is essential to produce an intensely hot zone. With a suitable fuel or even the feed stock itself depending on the availability and economy. The Reactor oil, oil to be converted to carbon black is injected in to the hot combustion gases at suitable locations depending on the grade of carbon black to be produced.

"Reactors" are the equipment where Carbon Black is actually produced by partial combustion and pyrolysis of oils. Most of the primary properties are also controlled here. It is constructed out of carbon steel and lined with special Refractory, capable of withstanding very high temperature.

Process Air in predetermined quantities from a "Process Air" header system is injected into this Reactor. Fuel oil and Carbon Black feedstock are introduced into the reactors previously brought-up to a desired temperature level.

Carbon Black formed in the reactor in the form of smoke is cut off at suitable points by direct quenching with water at predetermined locations with predetermined quantities. Sometimes some Potassium Salt is injected to control the physical property called "Structure" of the Carbon Black. The entire operation of flow, temperature measurements and control are done by Distributed Control System.

The effluent smoke from the reactors, after the pre-heaters pass into a common header called "Smoke Header". The Smoke Header leads the Carbon laden flue into the "Main Bag Filter".

The Main Bag Filter is a filter house and can be of any one of the following types.

1. Multiple modular types Pulse Jet
2. One single rectangular multi-compartment Bag-house Reverse flow or pulse

Carbon Black is filtered here and collected in the hoppers and the clean gases, which contain some combustibles pass out of the filter. The clean gas is conveyed to Carbon Black Pellet dryer and Boiler combustor.

Carbon Black is recovered from the Bag Filters by reverse flow of flue gases (or by pulse air in case of pulse-jet filters) into the Compartments/cylinders, performed in rotation one unit at a time. Carbon Black thus released from the bags accumulate in the hopper and is dropped into a pneumatic conveying line through "Air Lock/Rotary Valves" in Tread Line and Screw Conveyor in case of a Carcass line. The conveying is achieved by two "Pneumatic Conveying Fans", drawing Carbon Black from underneath the hopper. Carrier gas used is the flue gas from system drawn from the hopper.

Loose black and conveying gases are drawn through a "Mikro-Pulverizer" whose main function is to break up the lumps formed as also accidentally formed coke and other foreign materials, which can become contaminants in their original form, and transferred to the "Surge Tank" through a "Cyclone Separator". The purpose of this cyclone is to separate Carbon Black from conveying gas. The gas from cyclone is returned to the smoke header.

Carbon Black being fluffy it is difficult to handle, therefore it requires to be Pellitised. The Pelletiser or Wet mixer as they are known, mixes loose black with a near equal quantity of water and small quantities of Pellet Binders. Pellet Binders are normally Molasses. Sometimes Sulphonates of Lignin is also used as binder. Pellets thus formed are to be completely dried. For this purpose a "Rotary Drum Dryer" is used. Wet Pellets are transferred into this dryer.

The Rotary Drum dryer is a rotating drum and heated by indirect firing. Waste gases from the Bag Filter, more so from the Main Bag Filter is heated in a specially designed "Combustor". The Hot Gases are let into the rotating drum in an annular hot chamber. Water vapour from the dryer is drawn by an Exhaust Blower or also called Purge Blower. This gas consisting of water vapour, fine carbon black and part of the flue gas are passed through "Exhaust or Purge Gas Filter". The purpose is to filter and prevent the carried over carbon particles during the drying process into the atmosphere. The gases then exit the filter into the atmosphere, the filtered carbon black is recycled to the Cyclone Separator.

The entire operation of manufacture pelletising and drying is completely automatic achieved by sophisticated electronic Distributed Control System of Instrumentation.

The dry black is lifted by a "Bucket Elevator", and discharge into "Product Storage Tanks" by "Product Screw Conveyors".

The Black is then packed into 25 Kgs. multi-wall paper bags, or FIBC of 900 kg or 950kg for despatches to customers.

There are still some waste gases available after using in the drying operation. This is burned in a specially constructed Waste Gas Boiler for producing Steam to produce Electricity which is in excess of that required by the plant and some of it is proposed to be sold to the national grid.