Department Sanitation, Water and Solid Waste for Development

Carbonization of Urban Bio-waste

Slow pyrolysis refers to the thermal decomposition (breakdown under heat) of biomass into a carbon-rich solid residue (char), with gases and liquids as by-products. This process does not require highly complex engineered systems and has already been applied to transform agricultural waste into char. Our projects target urban bio-waste treatment by slow pyrolysis.

The project “Carbonization of Urban Bio-waste in Dar es Salaam” is a research collaboration with the University of Dar es Salaam (College of Engineering and Technology) in Tanzania. The overall objective is to explore the potential of slow pyrolysis as a treatment and valorisation method for organic solid waste.

Hydrothermal Carbonization (HTC) is a thermochemical reaction that occurs in a pressurized reactor when a mix of organic matter and water is heated for several hours. In contrast to dry pyrolysis, HTC can process substrate that has a high moisture content, making it suitable for the wet fraction of municipal organic solid waste.

For experimental purposes, a bench scale prototype reactor that can handle 20 litres has been conceived, constructed, and is presently being tested. Current objectives are: i) to define optimal operational parameters and ii) to explore measures to increase the energy efficiency and autonomy of the HTC process.