Potential Bio-oil Production from Smouldering Combustion of Faeces


This study examined the potential bio-oil production from the smouldering combustion of faeces mixed with sand, through a series of experiments. Surrogate faeces, with demonstrated equivalence to human faeces, were used in order to minimize variability in the composition. The yield of bio-oil was studied as a function of the following experimental parameters: original moisture content of the faeces, airflow rate and sand-to-faeces mass ratio. The amount of bio-oil collected was shown to be dependent on the airflow rate and the relative amount of sand used but independent on the moisture content. The bio-oil obtained was characterized by ultimate analysis, water content and calorific value. Under the experimental conditions studied, up to 70 g of bio-oil per kg of dry faeces (HHV = 27.6 kJ/g) can be produced. Finally, experiments demonstrated that sand can be reused after each experiment. The effect of the ash accumulation in the sand matrix on smouldering was investigated over five successive tests with the same batch of sand. The implementation of this technology to other type of organic waste would contribute to the development of an integrated waste treatment technology, in combination with bio-oil production.

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This work was supported by the Bill and Melinda Gates Foundation. We acknowledge Zachary Fishman and Harrison Wall for faeces characterization, Brett MacDonald and Tommy Kokas for ash content, and Kieran J. May and Dustin J. W. Brown for condensate measurements.

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Correspondence to L. Yermán.

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Yermán, L., Cormier, D., Fabris, I. et al. Potential Bio-oil Production from Smouldering Combustion of Faeces. Waste Biomass Valor 8, 329–338 (2017). https://doi.org/10.1007/s12649-016-9586-1

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  • Faeces valorization
  • Smouldering combustion
  • Bio-oil
  • Waste treatment