Comparative bioelectricity generation from waste citrus fruit using a galvanic cell, fuel cell and microbial fuel cell

This article demonstrates the new approaches for the generation of bioelectricity from waste citrus fruit using direct a galvanic cell (DGC), an indirect galvanic cell (IDGC), a conventional fuel cell (CFC) and a microbial fuel cell (MFC). The citrus fruit was used as whole for the preparation of DGC and their juices for the preparation of IDGC, CFC and MFC. The performance and bioelectrical parameters obtained were compared. The voltage found to be increased by increasing the number of cells in a series while, the current remains constant. Whereas the voltage remains constant and the current found to be increased with increasing the number of cells in parallel sequence. The power output of three units of citrus fruit connected together in a series found to be sufficient to turn on the LED light bulb in all cases. The result showed that lemons have the maximum power output by the DGC and MFC method, whereas grapefruit showed the maximum power output by IDGC, and thus considered as the best citrus fruit. Addition of NaCl solution in DGC and IDGC slightly increased the values of power output. The power output of citrus fruit was also determined by CFC and MFC before and after the inoculation of Escherichia coli. The detailed microscopic analysis of all the samples was carried out. It is found that all MFCs have higher power output as compared to their counterpart CFCs. However, maximum power output was displayed by DGCs. Moreover, a lemon fuel cell has the higher power output as compared to the fuel cells of other citrus fruit. This approach can be used to overcome the disadvantages of many non-renewable and conventional sources of energy including burning of fossil fuels to mitigate the major source of global warming and pollution by using such biodegradable and renewable sources.