Richard's Charcoal Supplemented Briquettes
Edit Blue cells only	C C Pemberton-Pigott  Jan 2010		
Briquettes
Outside Diameter	100	mm
Height	70	mm
Central hole diameter	35	mm
Volume	 0.48 	litres	
Density of the briquette	 0.40 	kg/litre
Mass, Dry	 0.19 	kg	
Contents, density assumed to be equal	Portion	Energy
 Leaf/Straw 	75%	 17.00 	MJ/kg
 Paper 	25%	 18.40 	MJ/kg
Energy content of the final product, per kg	 17.35 	MJ/kg
Energy content of the resulting briquette	 3.35 	MJ
Selling price	 $0.04 		
Number of briquettes used to cook 2.00 (per day, per meal etc)
Total energy used	 6.70 	 MJ (per day, per meal etc)
Total cost to cook	 $0.08 		
ADDITION OF CHARCOAL FINES
Density of char fines	 0.80
Energy content of the char fines	 29.48 	MJ/kg
Portion of char fines relative to the rest of the mix	20%	char, 80%
Leaf/Straw+Paper
Heat content of the resulting mix (dry), per kg	 19.78 	MJ/kg
Density of the briquette	 0.48
Mass, Dry	 0.23 	kg
Energy content of the resulting briquette	 4.58 	MJ
Selling price	 $0.06 		
Number of briquettes used to cook 1.50 (per day, per meal etc)
Total energy used	 6.87 	 MJ (per day, per meal etc)
Total cost to cook	 $0.09 		
Energy use, With Char/Without Char	103%	No energy saved!
Cost to cook, With Char/Without Char	113%	No money saved!
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