White coal is a form of
fuel
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
produced by drying chopped wood over a fire. It differs from
charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, cal ...
which is carbonised wood. White coal was used in
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
to melt
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
ore from the mid-sixteenth to the late seventeenth centuries. It produces more heat than green wood but less than charcoal and thus prevents the lead evaporating. White coal could be used mixed with charcoal for other industrial uses than lead smelting.
[Muir, Richard (2008). ''Woods, Hedgerows and Leafy Lanes.'' Pub. Tempus, Stroud. . pp. 91 - 92.] White coal was produced in distinctive circular pits with a channel, known as
Q-pit
Q-pits are kiln sites which were dug for the production of white coal prior to the Industrial Revolution when white coal was largely superseded by the use of coke.
Purpose
The white coal produced in Q-pits was largely used in the smelting of le ...
s. They are frequently found in the woods of South
Yorkshire
Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...
.
Production
Although traditionally made by drying chopped wood, white coal can be made from numerous waste products, most of which are formed into briquettes. Raw materials which can be used include:
* Groundnut shells
* Cotton hulls and salks
* Castor seed shells
* Forest leaves; wood chips and shavings
* Sugarcane bagasse
* Rice husk and paddy straw
* Mustard waste
*
Coir
Coir (), also called coconut fibre, is a natural fibre extracted from the outer husk of coconut and used in products such as floor mats, doormats, brushes, and mattresses. Coir is the fibrous material found between the hard, internal shell ...
dust
* Coffee husk
* Sunflower waste
* Maize stalks
* Bajra (
pearl millet
Pearl millet (''Cenchrus americanus'', commonly known as the synonym ''Pennisetum glaucum''; also known as 'Bajra' in Hindi, 'Sajje' in Kannada, 'Kambu' in Tamil, 'Bajeer' in Kumaoni and 'Maiwa' in Hausa, 'Mexoeira' in Mozambique) is the most w ...
) cobs
* Sesame seeds oil cake
* Wheat straw
Benefits
Producers of white coal proclaim the following benefits from using the fuel:
* White coal is cheaper than coal and fire wood.
* There is no sulphur in the white coal, therefore no toxic gases.
* Moisture content is nil.
*
Biomass briquettes
Biomass briquettes are a biofuel substitute to coal and charcoal. Briquettes are mostly used in the developing world, where cooking fuels are not as easily available. There has been a move to the use of briquettes in the developed world, where ...
have a higher practical thermal value.
* Briquettes have consistent quality, have high burning efficiency, and are ideally sized for complete combustion.
* Combustion is more uniform compared to coal and boiler response to changes in steam requirements is faster, due to higher quantity of volatile matter in briquettes.
* Low ash contents.
* The calorific value of the finished briquettes is approximately 3500 to 4000
kcal
The calorie is a unit of energy. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of on ...
/
kg.
India is fast becoming a major manufacturer and consumer of white coal. A large number of companies have switched their boiler fuels to use white coal instead of fossil fuels. White coal manufacturing capacity is increasing in the state of Gujarat, Maharashtra, Tamil Nadu and Rajasthan.
The production of white coal (briquettes made of biomass) using agricultural and forest waste is more common in
North India
North India is a loosely defined region consisting of the northern part of India. The dominant geographical features of North India are the Indo-Gangetic Plain and the Himalayas, which demarcate the region from the Tibetan Plateau and Central ...
.
India-carbon outlook
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See also
Solid biofuels
References
External links
Jaipur Green Fuels
Green Fuels
{{DEFAULTSORT:White Coal
Fuels