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

Mwamlima, Petro ; Mayo, Aloyce W. ; Gabrielsson, Sara LU and Kimwaga, Richard (2023) In Hygiene and Environmental Health Advances 7.
Abstract

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... (More)

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.

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organization
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type
Contribution to journal
publication status
published
subject
keywords
and Unplanted sand drying beds, Cooking energy, Dar es Salaam, Faecal Sludge (FS), Faecal sludge char briquettes, Pyrolysis
in
Hygiene and Environmental Health Advances
volume
7
article number
100068
publisher
Elsevier
external identifiers
  • scopus:85174421132
ISSN
2773-0492
DOI
10.1016/j.heha.2023.100068
language
English
LU publication?
yes
id
a7fb4596-f8c6-4ca6-bb4f-20d296144003
date added to LUP
2023-12-11 14:17:14
date last changed
2023-12-14 16:17:12
@article{a7fb4596-f8c6-4ca6-bb4f-20d296144003,
  abstract     = {{<p>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.</p>}},
  author       = {{Mwamlima, Petro and Mayo, Aloyce W. and Gabrielsson, Sara and Kimwaga, Richard}},
  issn         = {{2773-0492}},
  keywords     = {{and Unplanted sand drying beds; Cooking energy; Dar es Salaam; Faecal Sludge (FS); Faecal sludge char briquettes; Pyrolysis}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Hygiene and Environmental Health Advances}},
  title        = {{Potential use of faecal sludge derived char briquettes as an alternative cooking energy source in Dar es Salaam, Tanzania}},
  url          = {{http://dx.doi.org/10.1016/j.heha.2023.100068}},
  doi          = {{10.1016/j.heha.2023.100068}},
  volume       = {{7}},
  year         = {{2023}},
}