Material Processing and Device Fabrication

High-grade activated carbon from coconut shells and a novel method of recovering waste graphite attached to wall rocks

The material Processing and Device Fabrication project at NIFS has produced two patents leading to commercialization.

Patent 1. G. R. A. Kumara, “A method of producing electrically conducting and highly porous, high-grade activated carbon from coconut shells using a simple procedure” National Institute of Fundamental Studies, Hantana Road, Kandy, National Intellectual Property Office, Sri Lanka, (2021), Patent No. 19595.

This invention of producing highly electrically conducting, highly porous, high surface area, and high-quality activated carbon from coconut shells has many advantages over other methods developed to produce activated charcoal from coconut shells. This method is low-cost and does not involve any activating chemicals for the activation process. This procedure is simple and the required equipment are readily available among the equipment that is commonly used in households.

The use of renewable energy storage systems for transport, instead of fossil fuels greatly relive greenhouse emissions and other environmental burdens. Unfortunately, the currently available storage devices “the batteries” pose additional problems and their performance is inadequate for large-scale use.  Batteries use toxic materials, hard to dispose of safely or recycle. A promising alternative to the battery is the supercapacitor, which is a device extensively investigated currently, unlike a battery, a supercapacitor can undergo an almost indefinite number of charging cycles and discharging operations. Advantageously, supercapacitors are based on carbon - the best is the activated charcoal obtained from coconut shells. The lab-scale model of the supercapacitor was fabricated using our highly activated coconut shell charcoal, already tested for its high capacity and fast charging together with low cost.

Patent 2. G. R. A. Kumara, R. M. G. Rajapakse, H. M. T. G. A. Pitawala and N. M. Gunawardhana. “A method of recovering waste graphite attached to wall rocks in vain graphite mines” National Institute of Fundamental Studies, Hantana Road, Kandy, National Intellectual Property Office, Sri Lanka, (2021), Patent No. 19596.

This invention is based on a successful method developed to recover graphite from those attached to wall rock pieces in mined graphite chunks without any contamination from stone particles and chemical species leaching from stones. The graphite powder thus obtained throughout this process is converted to super expanded graphite simply by subjecting to a heat-treatment process that again is a one-step method. This super expanded graphite can be used to remove and recover oil spread on water due to leakages from oil tanks or for any other reason. Having a very high surface area super expanded graphite has a high potential for a number of novel advanced technological applications.