Kollam: Along with coconut, the demand for coconut shells has risen. In the past, people who came to buy fresh produce from homes were given coconut shells for free, but now they are being sold for up to Rs 20 per kilo. Manalil Subair, who runs a coconut shell business in Kollam, said the husks he sells are bought by agents from Tamil Nadu at Rs 28 per kilo. Earlier, the price was Rs 32. In North Kerala, the price had risen to Rs 33. Now, he said, it has fallen slightly.

On average, 8 coconuts yield one kilo of shell. These are taken to Tuticorin in Tamil Nadu. From there, agents from Tamil Nadu say the coconut shell charcoal is exported to China. Vehicles calling out over loudspeakers asking whether households have coconut shells have also become a common sight in villages.

The demand for coconut shells has increased because they are widely used in the manufacture of activated carbon. Ordinary wood without air contact has a moisture content of 10 to 15 per cent, while matured coconut contains only 6 to 9 per cent moisture. For this reason, coconut shell charcoal is considered suitable for making activated carbon.

Coconut shell is burned in a controlled manner to produce charcoal. It is then activated with steam to create activated carbon, which is used to purify edible oil and drinking water, in automobile carbon filters, cigarette filters, and soft drink packaging. Activated carbon also removes oxidants such as chlorine and ozone. Coconut shells’ long burn time and low smoke output make it industrially favourable. Gold mining companies in Africa, Australia, the US, Canada, and Russia also import activated carbon.