Indian Institute of Technology Guwahati (IIT Guwahati) researchers have developed innovative technologies for sustainable and efficient utilization of tea waste from the tea industry. In line with the scope of waste to wealth mission (W2W) of Principal Scientific Adviser (PSA), Government of India, this research leverages a key regional resource to promote a more sustainable and diversified economy in the North Eastern states of India. The research will also fulfil the purpose of “Act East Policy” of Govt of India, “Advantages Assam” and “Biotechnology” policy of Govt of Assam.
As per a recent study, tea is one of the most widely consumed beverages worldwide with world tea consumption reaching 6.3 million tonnes and is expected to rise to 7.4 million tonnes by 2025. This huge increase in tea consumption leads to an increase in industrial tea waste generation which leads to non-utilization of valuable agricultural resources and deterioration of environment. Because of its high lignin and low inorganic content, efficient utilization of tea industry wastes demands scientifically advanced techniques. Addressing these waste utilization and management issues becomes paramount as it aligns with sustainable practices and innovative solutions, ensuring both the industrial growth and ecological preservation.
Addressing these issues, the research team led by Prof. Mihir Kumar Purkait, Department of Chemical Engineering, IIT Guwahati, has carried out cutting age research on the diversified application of tea factory waste to various pharmaceutical and foods products as an output of Abdul Kalam Technology Innovation National Fellowships of Indian National Academy of Engineering (INAE). These carbonaceous pharmaceutical materials form the basis for a broad spectrum of application-based commodities.
The range of innovative value-added products developed in their laboratory at IIT Guwahati include
Low-cost antioxidant-rich supplements which are designed to provide an affordable healthier lifestyle option by harnessing green tea’s potential properties
Organic preservatives developed from the green tea have redefined food preservation by extending the shelf life of vegetable and fruit juices for up to one year, effectively reducing waste and ensuring long-lasting freshness
In the sustainability realm, pharmaceutical super-grade activated carbon is setting new standards with its exceptional surface area, making it an incredibly versatile product in pharmaceutical as well as in Fast-moving consumer goods (FMGC)
Biochar produced from the waste contributes significantly to waste reduction and environmental restoration including carbon sequestration in various contexts
For pharmaceutical applications, the liquefiable carbon source promises innovative solutions that embrace the future of medicine
Micro and nano-crystalline cellulose tailored for intelligent packaging brings intelligence to product packaging, satisfying the evolving demands of modern consumers and industries
The developed carbon quantum dots are currently being explored for their sensing potential in detecting harmful contaminants in water bodies
The research team has filed multiple patents on the basis of these developments. These include technologies related to:
Catechins from green tea leaves are used to create organic preservatives, extending the shelf life of fresh fruit juices
Spent tea leaves are processed into pharmaceutical-grade super-activated carbon
Catechin powder is formulated for capsule preparation, with lightweight carbonaceous material added for catechin stabilization
The findings of these studies have also been published in various international journals including International Journal of Biological Macromolecules, Chemosphere, Critical Reviews in Biotechnology etc. This research has been carried out by Somnath Chanda, Prangan Duarah, and Banhisikha Debnath as a part of their PhD thesis work in the Centre for The Environment of IIT Guwahati.
Elaborating on one such technology to harness the potential of tea waste, Prof. Mihir Kumar Purkait, Department of Chemical Engineering, IIT Guwahati, said, “The convenience and health benefits of catechin-based capsules open a promising avenue, offering users access to the advantages of catechins without the necessity of multiple cups of green tea. This caters to the increasing demand for antioxidant-rich supplements in our daily routines.”
Purkait further added, “The lignin-rich spent tea leaves are transformed into activated carbon through a specialized reactor. This involves a dual-step procedure: first, carbonization, which converts lingo-cellulosic biomass into a carbon-rich matrix; then, activation, which creates a porous structure, enhancing adsorption properties for wide range of applications that includes, i) Food grade activated carbon as an alternative to synthetic food colorant to impart blackish, hues ii) natural based mild abrasive material in toiletries such as tooth paste and body washes, iii)) low density and light weight pharma-grade and chemically inert carbon as a pharmaceutical ingredient in solid-dosage forms as diluents, iv) non-selective adsorptive properties of microporous carbon used in anti-pollution masks and as a deodorant in socks, v) used in packaging to prevent moisture assisted degradation or spoilages etc.”
The commercial potential of these products is substantial. For instance, the demand for catechin based health supplements and organic preservatives are on the rise among health-conscious consumers and food processing companies.
The immediate future plans for the project involve advancing towards advanced Pilot stage (TRL-7) leading to the imminent Transfer of Technology (ToT) phase to potential industry partners. These value-added products not only enhance the economic viability of tea cultivation but also encourages sustainable practices by reducing waste and promoting resource efficiency.