Turning Tamarind Shells Into Energy Stores

No longer relegated to the trash bins, tamarind fruit shells can be converted into carbon nanosheets used in energy storage devices.

AsianScientist (Aug. 25, 2021) – While tamarind fruits are already a sweet source of energy for consumers, it turns out their shells can be fashioned into a viable material for energy storage devices. An international team transformed these shells into carbon nanosheets, reporting their work in Chemosphere.

Along the pipeline of food production, waste rapidly piles up, posing an environmental and economic threat. Every little bit counts as various sectors search for ways to reduce this output of waste and alleviate mounting garbage disposal issues around the globe.

For instance, the tamarind fruit is a consumer favorite worldwide, but the shells hold little known value and are typically discarded as agricultural waste. These shells are bulky, however, and end up taking a hefty amount of space in landfills.

To turn tamarind trash into treasure, researchers from Nanyang Technological University (NTU) in Singapore, Alagappa University in India and the Western Norway University of Applied Sciences realized they could tap into the shells’ rich deposits of carbon and manufacture ultrathin materials called nanosheets.

Similar to how batteries act as energy reserves, carbon nanosheets are excellent materials for energy storage applications, as their porous structure creates a large surface area for carrying electrical charges. Accordingly, such devices can be used in powering up electric cars and hybrid trains as well as extending the life of consumer electronics like laptops.

By drying then grinding the tamarind shells into powder, the researchers converted the waste material into the carbon components needed in the nanosheet. Driven by high heat, a series of chemical reactions deposited the powder into fine layers of interconnecting hexagons—forming a porous, honeycomb-like structure to store charges.

Besides emulating the structure of industrially produced nanosheets, the sheets made from tamarind had similar electrical properties, like the flow of current through the material. The tamarind shells also required only six hours of drying, a quarter of the length of heating time needed by hemp fibers typically used for nanosheet manufacturing.

Given these promising results, the team hopes that scaling up production of such biomass-derived nanosheets can make a dent towards sustainability. Not only would it cut down on food waste, but it could also be an environmentally-friendly alternative to current industrial production methods.

“We found that the performance of our tamarind shell-derived nanosheets was comparable to their industrially-made counterparts,” said corresponding author Dr. Cuong Dang, assistant professor at NTU.

The article can be found at: Thirumal et al. (2021) Cleaner Production of Tamarind Fruit Shell into Bio-mass Derived Porous 3D-activated Carbon Nanosheets by CVD Technique for Supercapacitor Applications.


Source: Nanyang Technological University; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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