Charcoal - a value added biomass

One of the methods of value addition of biomass is the production of charcoal for fuel, soil conditioner, water purification and other purposes and at the same time,contributing to carbon sequestration or CO2 emission reductions. Charcoal is usually produced by slow pyrolysis and the resulting soft, brittle, lightweight, black, porous material resembles coal with 85% to 98% carbon and the remainder consisting of volatile chemicals and ash. Charcoal is cleaner, easier and less smoky and smelly than other biomass fuels. Charcoal is a very stable substance and the half-life of charcoal (carbonized in 1000 degree Celsius) is reported to be around one thousand years. Gross heating value is estimated to be within the range of 28-30 MJ/kg. Charcoal carbonized under lower temperature is more stable under the higher concentration of ozone in the air. Charcoal can hold pure carbon inside it for a long time and can be a carbon sink. In the carbonization process (pyrolysis), considerable amount of carbon goes to the air and CO2 emission from charcoal production must be minimized. Burying char, known as black carbon sequestration enhances soils, helping future crops and trees grow even faster, thus absorbing more carbon dioxide in the future. Researchers believe that the char, an inert and highly porous material, plays a key role in helping soil retain water and nutrients, and in sustaining microorganisms that maintain soil fertility. It has been estimated that as much as 9.5 billion tons of carbon which is more than what is currently emitted globally through the burning of fossil fuels could be sequestered annually by the end of this century through the sequestration of char.