Waste to Energy : Potential of using activated carbon and rice husk ash in primary cells

Abstract

Rapid growth of population has brought up some serious concerns, such as waste management and excessive use of fossil fuels causing pollution and negative impact on climate change. A large portion of the waste is organic waste, which can be turned into Activated Carbon (AC) and AC can be used to generate electricity by using it as a cathode catalyst in metal-air cell. Aluminum-air cell has the potential of becoming vital in energy-storage application in future because of its high theoretical energy density, even higher than commonly used lithium-ion batteries. However, it is not used widely because the cost of air cathode catalyst and metal anode is high. But if we replace the catalyst by activated carbon obtained from waste or a mixture of activated carbon with other waste (rice husk ash) and use recycled aluminum foil as anode then the production cost might be feasible for vast use of this type of cells. Our objective is to utilize some common and organic waste in the process of fabricating Al-air battery suitable for small and day-to-day usage reducing production cost and limitations. In this paper, we have focused on the feasibility of using activated carbon and rice husk mixture as air cathode catalyst of Al-air cell; and the observations were interesting. We prepared 11 samples of mixture of rice husk and AC in different ratios and initially found the best results to be from 0.68-0.72V, which increases by 8-20% measuring each sample after 3 days. In this study, graphite cathode of a dry cell is replaced too by mixture of AC and RHA. Voltage drop is quite negligible for the mixture of 10% RHA. And, voltage is similar to the new battery in case of 100% activated carbon as cathode. If considered the environmental effect, using recycled activated carbon and rice husk ash will decrease the pollution