Improving the Stability of Wastewater Derived Microalgae Carbon Materials: Products Characterization, and Kinetic Modelling

Microalgae-derived char contains low stability and heating values with relatively high nitrogen content than lignocellulosic char. This study showed that co-pyrolysis helped improve the overall properties of char than individual pyrolysis of these feedstocks. Two batches of experiments were conducted (a) single step pyrolysis and (b) two-step pyrolysis in the range of highest treatment temperature of 400 – 600 °C. Single step pyrolysed char showed, lower aromaticity, higher yield, ash content and heating values of the char than two-step pyrolysed char. Similarly, ignition temperature and activation energy were higher during combustion by single step pyrolysed char than two-step char. Hence, two-step pyrolysed char is suitable in the energy applications, and low-temperature processing (400 – 500 °C) will result in optimum properties in terms of yield and heating values.