From tobacco to biochar: a review of production processes, properties, and applications

Tobacco waste presents notable environmental challenges, such as soil and water contamination from nicotine and other harmful chemicals, compounded by inefficiencies in conventional waste management. Converting tobacco waste into biochar offers a promising solution to address these issues. This study reviews the production, properties, and applications of biochar derived from tobacco, using feedstocks such as stems, seeds, leaves, and tobacco fines. It has been observed that tobacco stems are the most commonly used precursor and pyrolysis is the most frequently employed thermochemical conversion process, with biochar yields ranging from 5% to 85%, depending on operational variables. Tobacco-derived biochar exhibits surface areas typically between 2 and 50 m²/g, fixed carbon content of 4 to 63 wt%, and ash content ranging from 12% to 51%. Tobacco-derived biochar has been applied in agriculture, water treatment, composting, and energy production, demonstrating its efficiency. It also plays an important role in soil pollution remediation. Despite existing research on tobacco-based biochar, gaps remain in areas such as the gasification and torrefaction of tobacco biomass and the use of other tobacco-related wastes like leftover cigarettes and fines. The findings of this study depict the dual benefits of utilizing tobacco waste for biochar production – addressing waste disposal challenges while creating a valuable material with multiple environmental and economic advantages.