Possibility of ceylon tea waste conversion to biochar –a short review

Abstract

A few countries fulfil global tea demand, and Sri Lanka, formerly known as Ceylon, is one of the top tea exporters. Tea is Sri Lanka's largest agricultural export, with an annual production of approximately 340 million kg. Consequently, the tea industry generates significant quantities of tea waste. Unfortunately, the Sri Lankan tea industry often ignores proper tea waste management, relying on open dumping and burning, which can harm the environment despite the biodegradable nature of the waste. Among a number of modern waste management methods, pyrolysis is gaining increasing attention as a sustainable waste treatment method as it transforms waste into carbonaceous materials, biofuel and syngas, leaving no waste behind at comparatively lower temperatures (400-600℃). Considering the nature of the Ceylon tea industry, which mainly uses conventional tea production processes, this short review article mainly focused on the effect of tea pyrolysis temperature, derived biochar activation methods, and their uses. Biochar derived from tea waste has demonstrated remarkable utility in various fields. By converting waste into stable carbonaceous materials, it not only mitigates local emissions but also serves as a reliable long-term carbon storage. Moreover, biochar and activated carbon derived from tea waste has proven efficient and cost-effective for removing water, soil, and air contaminants. Industry can obtain financial benefits by introducing derived activated carbon as an adsorbent. These facts highlight the suitability of adopting low-temperature pyrolysis of tea waste and biochar production to the Ceylon tea industry using simple techniques such as double-barrel systems that can be operated with the excess heat produced in boilers.