Green Choice - Why Coconut Shell Activated Carbon
Many natural substances are used as base material to make activated carbon. The most common of these used in water purification are lignite, bituminous, peat and coconut shell.

Different base materials and the activation process results in unique pore size and pore distribution. The pore size grouping in carbon are commonly described by its pore diameter:

Macro pores (above 50 nm diameter), Meso pores (2-50 nm diameter) and Micro pores (under 2nm diameter).

Coconut Shell based activated carbon is predominately micro porous and is well suited for organic chemical adsorption. Coconut shell based carbon are least dusty and has the most hardness compared to other type of activated carbons which makes it the ideal carbon for water purification

In terms of base material, Coconut shell is renewable resources compared to Lignite and Bituminous. Coconut plantations with millions of acres of land continue to provide all the benefits of green trees to our environment in spite of using billions of coconut shell per year for activation.
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Current Pollution Process

Activated carbon is produced from coconut shells by a two-step process. The first step in activation is to carbonize the shells to drive out about two thirds of the volatiles out of the shells creating carbonaceous mass full of tiny pores. This carbonized base material in the second stage is activated at high temperature (1100 degree C) in steam.

The carbonization process involves converting the coconut shells to Char (charcoal). The charring process (making of charcoal) is known as the Pyrolysis, which is chemical decomposition of the shell by heating in the absence of oxygen. During the carbonization of coconut shells, volatiles amounting to 70% of the mass of coconut shells on dry weight basis are released to the atmosphere, yielding 30% of coconut shell mass of charcoal. The volatile released during the carbonization process is Methane, CO2 and wide range of organic vapors. Coconut shells are carbonized in an old-age process commonly known as open pit method. In this process earth is used as an insulator and to heat the shells in the absence of oxygen.

One ton of coconut shells releases about 12 to 15 Kg of Methane into the atmosphere. India, Philippines, Sri Lanka, and Indonesia are the primary countries that char coconut shells for activation to be used in water and air purification. Several countries in the ASEAN region in the recent years have also started charring coconut shells for activation process.

A conservative estimate is that in the four leading countries: India, Philippines, Sri Lanka and Indonesia about 350 Million MT/year of Methane is emitted to the atmosphere by these pits method of charring. This is equivalent to the CO2 emitted by 350,000 midsize cars (driven 20,000 miles/yr).
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Green Technology
Disruptive Technology to Prevent Green House Gas Emission in the Charring process.

In the pit method of charring coconut shells, the GHGs are emitted to the atmosphere with out any control and treatment of effluent gases. Global Ecocarb Pvt Ltd has developed a novel process to char the coconut shells in a reactor capturing the GHGs and using them under controlled conditions for the production of thermal energy. Since char is generated during the gasification process the entire operation is self-sustaining.

In this novel process the shells are fed from the top with twin air entry, re-burn process. This process consists of a fuel and ash handling system, gasification system - reactor, gas cooling and cleaning system. The process is unique to prevent the formation of tar during pyrolysis.

Global Ecocarb Pvt is in the process of having this as a registered CDM in Kyoto treaty protocol.
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