Co-pyrolysis characteristics of microalgae Chlorella vulgaris and coal through TGA

► Co-pyrolysis presented three stages. ► Interaction between solid phases inhibited the thermal decomposition. ► Kinetic triplets were obtained. To find out an alternative of coal saving, a kind of microalgae, Chlorella vulgaris (C. vulgaris) which is widespread in fresh water was introduced into coal pyrolysis process. In this work, the pyrolysis experiments of C. vulgaris and coal blend (CCB) were carried out by TGA, and those of C. vulgaris and coal were also taken respectively as control groups. It was found that: the TG and DTG profiles of CCB were similar to C. vulgaris, but different from coal under various blending ratios; DTG profiles of CCB were different at several heating rates; interaction was observed between the solid phases of CCB; kinetic triplets were determined by the Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and master-plots method, respectively. The results provide a reference for further study on co-pyrolysis of microalgae and coal to a certain extent.