Richard's Charcoal Supplemented Briquettes

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!