Faecal sludge (FS) management is a serious problem in developing countries which has caused environmental pollution and health risks. Hydrothermal carbonization (HTC) is an alternative technology that can be used to treat FS and convert it into a valuable solid product called hydrochar. This study evaluated the technical feasibility of hydrochar production from FS, determined the reaction kinetics of HTC of FS, and developed an empirical model which could estimate energy content of the produced hydrochar using the relevant parameters such as temperature (T), reaction time (t), moisture content (M), and volatile solid concentration (VS) in FS. The experiments were conducted with a 1-L high pressure reactor operated at the following conditions; T of 180–250 °C, t of 0.5–10.0 h, M of 70–95%wt, and VS of 40–340 g/L, which could produce at the energy content and hydrochar yield of 17–20 MJ/kg and 65%–80%, respectively. From these experimental data, an empirical model for determining energy content of the produced hydrochar was developed and validated satisfactorily with the literature data. Feasibility of applying the HTC process for FS treatment was discussed.
- energy content
- faecal sludge
- hydrothermal carbonization
- reaction kinetics
- regression model
- First received 2 February 2015.
- Accepted in revised form 20 April 2015.
- © IWA Publishing 2015