Spent tea leaves and tea bags - Promising biofuels?

Lucie Jezerska, Veronika Sassmanova, Rostislav Prokes, Daniel Gelnar and Pavlina Peikertova

Renewable Energy, 2025, vol. 238, issue C

Abstract: The spent tea leaves used after the extraction of liquid from processed tea are insufficiently utilized waste, rich in essential amino acids, polyphenols, alkaloids, and minerals, produced in large quantities, e.g., in tea houses, hospitals, school canteens, etc. Therefore, this study is aimed at characterizing this waste, how it is processed into pellets and how it subsequently increases its energy potential by torrefaction. The influence of the method of tea packaging, i.e., loose tea leaves or tea bags, was also considered. Several types of tea waste were processed using a pilot plant pelletizing press and torrefaction stand. The prepared pellets were characterized by mechanical parameters, such as the pellet durability index, the wettability index, water resistance, hardness, or specific bulk density, and were integrated by FTIR measurements. Furthermore, pellet's energy parameters, such as higher heating value, lower heating value, and elemental analysis, were compared. The results show that non-torrefied pellets have an average combustion heat of 19 kJ kg−1, while torrefied pellets have a value of 9 kJ kg−1 higher. Overall, the study demonstrates that spent tea leaves can be converted into a sustainable source of bioenergy and presents a solution for the treatment of this waste, as well as a renewable energy option.

Keywords: Tea grounds; Tea bags; Pellets; Torrefaction; Biofuels; FTIR (search for similar items in EconPapers)
Date: 2025
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0960148124019098
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:renene:v:238:y:2025:i:c:s0960148124019098

DOI: 10.1016/j.renene.2024.121841

Access Statistics for this article

Renewable Energy is currently edited by Soteris A. Kalogirou and Paul Christodoulides

More articles in Renewable Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().