Potential use of faecal sludge derived char briquettes as an alternative cooking energy source in Dar es Salaam, Tanzania

• Coprophobia considers faecal sludge (FS) as an unpleasing raw or partially digested faecal waste with no recycling value. However, this so-called waste is claimed to have tremendous recycling values after being pyrolyzed. This study hypothesised that char briquettes made from FS might have the potential of replacing charcoal consumption in Dar es Salaam, Tanzania. Quantitative methods were used to examine the proximate, emissions and environmental benefits of faecal sludge char briquettes against wood charcoal from Dalbergia melanoxylon (locally known as Mpingo). Results revealed that FS collected during the dry season was thicker (26% total solids) than that during the rainy season (20% total solids), the difference is statistically significant with p= 6.12405E-14 at α=0.05. The dewatered and further dried FS to at least 90% total solids had an energy value of 11 - 12 MJ/kg which is less than that of uncarbonized wood (firewood) which is 19 MJ/kg. Production of FS char briquettes bonded by paper waste has a lower energy value (13 MJ/kg) than that bonded by cassava starch (14.6 MJ/kg). The average energy value of FS char briquettes is almost half that of wood charcoal (26 MJ/kg), meaning that to replace 1 kg of charcoal consumption, then 2 kg of FS char briquettes is required. Nevertheless, due to an ineffective collection of FS to be used in the production of char briquettes, only 8% of charcoal consumption in the city can be replaced. The produced briquettes are recommended to be used in open kitchens where there is plenty of oxygen circulation because they emit carbon monoxide that is higher than the allowable limits by the Tanzania Bureau of Standards.

Subject headings

LANTBRUKSVETENSKAPER  -- Annan lantbruksvetenskap -- Förnyelsebar bioenergi (hsv//swe)

AGRICULTURAL SCIENCES  -- Other Agricultural Sciences -- Renewable Bioenergy Research (hsv//eng)

Keyword

and Unplanted sand drying beds

Cooking energy

Dar es Salaam

Faecal Sludge (FS)

Faecal sludge char briquettes

Pyrolysis

Publication and Content Type

art (subject category)

ref (subject category)