Renovation of Waste Chrysanthemum morifolium (Marigold) into Valuable Biochar: A Study on the Utilization of Solid Waste by Pyrolysis

Flowers have become a part of our daily life, and wind up joining the waste stream, after little use and almost practically no reuse. Disposal of the flowers despite playing an eloquent role in religious faith, rituals, wedding ceremony, etc., finishes up mostly at open dumping or in water bodies. An endeavor has been made to valorize the flower waste generated from the flower market in Puducherry. White Marigold Chrysanthemum morifolium was retrieved in bulk from the market waste stream and was thermally treated into valuable low-cost biochar. The products were synthesized by pyrolysis in slow thermal carbonization conditions at 350 °C and 500 °C. Before treating thermally, the collected waste marigold flowers were analyzed for decomposition behavior via TGA. The biochar products were further characterized, analyzed, and compared, for various physiochemical parameters, namely pH, conductivity, moisture content, ash content, and bulk density. Specific physical and chemical properties and the effect of slow pyrolysis at two different temperatures were further investigated by performing FTIR, SEM, XRD, and BET. Biochar pyrolyzed at 500 °C possessed better characteristics for environmental applications than biochar derived at 350 °C.