The effect of cotton stalk concentration on morphology and fixing bromine content in char while on co-pyrolysis with non-metal fractions of PCB

Printed circuit boards (PCB) and cotton stalk (CS), a unique composition till now, were used for co-pyrolysis experiments, and the synergistic effect between them was evaluated. The purpose of this research was to determine the influence of co-pyrolysis process on the chemical composition and physical attributes of the produced char as well as the advantages and effects of different CS ratios on product yield. The sample was heated up to 500 ℃ in a fixed bed reactor at a heating rate of 10 ℃/min in an inert environment. The char degradation behaviour was evaluated using thermogravimetric analysis and derivative thermogravimetric analysis (TGA/DTG). The physicochemical properties and morphological aspects of char were determined using a variety of analytical techniques, including nitrogen physisorption using the BET method, FE-SEM coupled with an EDS, FTIR, XRF and XRD. All char samples had an average pore diameter in the range of 2–50 nm, suggesting that they are mesoporous materials, and surface area was found to be increased with co-pyrolysis in the range of 16.79 m²/g where 30% CS was added with PCB. Increased amount of C and decreased amount of O are indications of increased char’s surface hydrophobicity which could have an application for removing contaminants from aqueous matrices. The most essential aspect of char analysis was bromine content, which was found to be increased with co-pyrolysis, showing that the co-pyrolysis process assisted in reducing bromine content in oil and fixing it in char.