A Kashmiri researcher has developed a technique for converting walnut shells into carbon that can be used in batteries.
The research done by Dr Wahid Malik at Indian Institute of Science Education, Pune, has found that the shells can produce high-quality carbon for the anode part of battery. According to Satishchandra Ogale, the supervisor of the research, the shells would first be cleansed then heated at 1,000 degrees Celsius temperature for about 4 to 5 hours.
This technique extracts carbon which is converted into paste form. At the lab testing stage, about 300 – 400 mg of battery grade carbon has been produced from one gram of powder from the shell. As per this estimate about 3600 kg of carbon can be produced from the state. This much of carbon can produce of tons of batteries, as small battery requires only a mili gram of carbon, he added.
“Wahid who is a brilliant student came up with the idea that waste of walnuts can be used for making carbon. At the beginning of his Phd, he said since walnuts is produced in abundance in Jammu and Kashmir, the waste which at present is mostly not used for any purpose, can be converted into carbon,” Ogle told Kashmir Reader.
“Since the idea was brilliant and innovative, we gave him a nod. At the end of this Phd, he came with the findings which was mind boggling,” he added.
Ogle said the essence of the research, which was done in intra-displinary subject-Physics and Chemistry, is that the waste was converted into a product that can fetch good value, commercially.
At present, as per the figures of horticulture department, 266280 metric tons of walnuts are produced every year. According to Bahadur Khan, President Dry Fruit Association Kashmir, the shells used mostly in woodstoves, fetch around Rs 8 a kg.
“If the research turns to be success, it will give boost to the walnut economy and can be an alternative source of income for walnut farmers,” he said.
Kashmir’s lofty mountains and majestic slopes, together with the temperate are ideally suited for walnut production, and it is no wonder that Kashmiri walnuts are famous worldwide for their superior taste.
Naturally, a lot of organic waste, by way of walnut shells, is also generated.
A team of scientists from the Indian Institute of Science, Education and Research (IISER), carried out a study and found that 63,000 hectares of land is used for walnut cultivation in Kashmir. Of the total 36,000 tonnes of organic waste generated from the farm produce, 15,000 tonnes is contributed by walnut shells alone.
On a visit to his home, one of the researchers, Wahid Malik, who is a native of Kashmir, came up with the idea of using the carbon-rich walnut shells to make batteries.
Batteries are vital and are needed for all renewable energy resource management and usage, including grid-based setups, electric vehicles and biomedical or handheld devices.
The team, led by Satischchandra Ogale, went to work processing the nutshell, to obtain high-quality carbon, usually used in the anode part of the sodium-ion battery. Although these batteries are similar to the standard lithium-ion batteries, they are much cheaper, because of the abundance of sodium over lithium in nature.
The Indian Express quotes Malik. He says, “It is one of the greatest issues for farmers back home, to deal with the hard and nutty shell of dry fruits, especially that of walnut. That is when, while thinking of his proposal for CSIR-800 mission as a doctoral student, it was ideated and worked upon.”
According to the researchers, walnut nutshells have an advantage due to their natural composition. Ogale says, “The foliage of the shell perfectly suits the requirements once it is treated chemically, giving an edge over other natural resource substances.”
Crushed walnut shells are first cleaned using acids, and subjected to pyrolysis process, heated at temperatures as high as 1,000 degrees Celsius for about 4 or 5 hours. Then, the carbon chunks are extracted within the created inert atmosphere, and then powdered or converted into a paste.
This breakthrough has multiple advantages. According to Malik, sodium-ion batteries are expected to be at least five times cheaper than lithium-ion batteries. Also, farmers in the valley can have an extra source of income. As of now, just 5% to 10% of the leftover organic waste is used to make packaging products; the rest is burned, causing air pollution.