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continued rewrite, moved on section to manure article
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== Densifying biomass ==
 
== Densifying biomass ==
{{Main|Densifying solid biomass}}
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=== Densifying solid biomass ===
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Several types of densification can be applied, depending on the source material. For example:
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* [[charcoal]] can be produced from wood in order to increase the energy density. See [[charcoal production]].
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* [[briquetting]] is the densification of loose biomass material. Many waste products, such as wood residues and sawdust from the timber industry, municipal waste, bagasse from sugar cane processing, or charcoal dust are briquetted to increase compactness and transportability. Briquetting is often a large scale commercial activity and often the raw material will be carbonised during the process to produce a usable gas and also a more user friendly briquette. Some improved stoves have been designed specifically to be used with briquettes (Karekezi 1997). Clean dung briquettes finally can be made from [[manure]]
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=== Charcoal ===
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===Densifying gaseous biomass===
Charcoal can be produced from wood in order to increase the energy density. See [[charcoal production]]
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[[Biogas]] and [[biohydrogen]] can be compressed in tanks. Also, [[methane]] can be extracted from biogas, which is even more combustible.  
 
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=== Briquetting ===
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Briquetting is the densification of loose biomass material. Many waste products, such as wood residues and sawdust from the timber industry, municipal waste, bagasse from sugar cane processing, or charcoal dust are briquetted to increase compactness and transportability. Briquetting is often a large scale commercial activity and often the raw material will be carbonised during the process to produce a usable gas and also a more user friendly briquette. Some improved stoves have been designed specifically to be used with briquettes (Karekezi 1997).
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===Clean Dung Briquettes ===
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Dung washing is a simple process whereby the dung is washed with water, organic matter, fermented paper, sawdust or other additives mixed into the slurry and then the liquid removed via compression.  The benefits of washed compressed dung as a fuel source are three fold. 
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*The chlorine and the silica present in the dung are water soluble and hence can be removed prior to burning.  These components contribute a serious health risk for users when burnt.
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*The water-soluble fraction of the dung also constitutes the “agriculturally nutritious” aspects of dung and thus can be retained for fertiliser.
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*Removal of the silica content, lowers the ash content which inturn allows for the proper flow of air which overall translates to a reduction in the formation of the harmful carbon monoxide.
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[[Image:Briquette press.jpg|thumb|Two stage press being used by villge women Rupendehi Nepal]]
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A briquette press is a tool that can be used to remove the liquid and bind the slurry into solid briquettes.  A two stage press has been designed with a hybrid lever and screw compression that produces briquettes fast and efficiently with the minimum of effort. Initially a lever is depressed to a comfortable operating level, then the lever  mechanism is locked in place and a secondary screw system further depresses a plunger and applies the additional force  necessary to to remove additional moisture.  The steel briquette press can be manufactured locally, is easily maintenaned and simple to use.  The Briquette chamber can produce four briquettes simultaneously. Having two briquette chambers and base stands allows for increased speed an efficiency as one chamber can be filled whilst the other is being compressed.
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Briquettes take on average 6 days to dry in dry temperate conditions.
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Source: EWB NAMUNA Clean Cooking Initiative Nepal (2011)
      
==Utilising biomass==
 
==Utilising biomass==
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===Utililising the biomass efficiently===
 
===Utililising the biomass efficiently===
 
{{Main|Waste plant parts and residues as fuel}}
 
{{Main|Waste plant parts and residues as fuel}}
For economic reasons, the processing of the biomass is first done according to a specific pattern in order to get the most out of the biomass.<ref>[http://en.wikipedia.org/wiki/Biobased_economy Biobased economy]</ref> This pattern, as well as the quantities, ... depend on the types of biomass used. In addition, within some types of biomass (ie living or dead plants), some crops can only be used for one or a few applications (ie some oil crops as Jatropha, Pongamia, ... can only be used as storable fuel and immediatelly consumable fuel, oil crops as [[rapeseed]] can only be used as [[food]] and storable fuel). The whole of finding the most suitable pattern is known as [[biorefining]]. A general list shows the products with high added value and lowest volume of biomass to the products with the lowest added value and highest volume of biomass<ref>Kijk magazine, number 8, 2011</ref>:
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For economic reasons, the processing of the biomass is first done according to a specific pattern in order to get the most out of the biomass.<ref>[http://en.wikipedia.org/wiki/Biobased_economy Biobased economy]</ref> This then yields several products which can be further utilised. This pattern, as well as the quantities, ... depend on the types of biomass used. In addition, within some types of biomass (ie living or dead plants), some crops can only be used for one or a few applications (ie some oil crops as Jatropha, Pongamia, ... can only be used as storable fuel and immediatelly consumable fuel, oil crops as [[rapeseed]] can only be used as [[food]] and storable fuel). The whole of finding the most suitable pattern is known as [[biorefining]]. A general list shows the products with high added value and lowest volume of biomass to the products with the lowest added value and highest volume of biomass<ref>Kijk magazine, number 8, 2011</ref>:
 
* fine chemicals/medicins
 
* fine chemicals/medicins
 
* food
 
* food
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* non-storable fuels (immediate burning for electricity and heat)
 
* non-storable fuels (immediate burning for electricity and heat)
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For using the biomass to fulfill in our own energy needs, there are several options. The most basic (and energy-inefficient option) is the open fire. The open fire fulfills in several needs: it provides [[light]], [[heat]], the option to [[cook]] something, scare wild animals, repel insects, [[Food preservation|smoke food]]. More sophisticated technologies exist for extracting this energy and converting it into useful heat or power in an efficient way.
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For using the biomass to fulfill in our own energy needs, there are several options. The most basic (and energy-inefficient option) is the open fire. The open fire fulfills in several needs: it provides [[light]], [[heat]], the option to [[cook]] something, scare wild animals, repel insects, [[Food preservation|smoke food]]. Although open fires and other [[outdoor cooking|outdoor cooking techniques]] still axist, more energy-efficient [[cooker|cooking technologies]] now exist.
    
===Biomass use in the developing world===  
 
===Biomass use in the developing world===  
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