Electricity generation from food wastes and spent animal beddings with nutrients recirculation in catalytic fuel cell

S O Dahunsi

doi:10.1038/s41598-020-67356-0

Abstract

A biochemical system was used for electricity generation from food waste (FW) and spent animal beddings (SAB). The wastes were blended and fermented anaerobically to produce fermentation liquids used as fuels for running a catalytic fuel cell. The fermentation liquids were analyzed for their components. The results show the organic contents i.e. volatile solids of both FW and SAB to be 23.4 and 20.9 g/L while the carbon contents were 6.5 and 6.1 g/L respectively. The media were however very rich in volatile fatty acids (VFAs). When used, the fermentation liquids from FW and SAB generated mean open-circuit voltages of 0.64 and 0.53 V and mean maximum power densities (Pmean) of 1.6 and 1.3 mW/cm2 respectively. The fuel cell showed very high efficiency in the conversion of all VFAs especially butyric acid with the highest been 97% for FW and 96% for SAB.

Highlights

A biochemical system was used for electricity generation from food waste (FW) and spent animal beddings (SAB)
Before the actual continuous experiment, the batch treatment was done by butyric fermentation with acetic acid as the major product based on the suggestion of Liu et al.[51] when a very high rate of acetic acid conversion was reported when the fermentation liquid from the FW treatment was used in a fuel cell
Since the rate of converting substrates to fermentation fluid during anaerobic fermentation depends on several factors among which are the organic loading rate (OLR) and p H43,61, these two factors were strictly regulated in this study in order to achieve higher working efficiency of the fuel cell

Summary

Introduction

A biochemical system was used for electricity generation from food waste (FW) and spent animal beddings (SAB). Even though fossil fuels form the bedrock of most economies in the world, a major factor that limits the reliability and investment into this sector is the constant sudden increase in the price of fuels and other allied products This has created an opportunity for renewable energies to favorably compete in the energy market and possess the potentials to solve the power outage problems usually experienced especially in remote areas. Several alternative energy devices have been developed and used These include biogas cookers and lightning systems, diesel generator, micro turbines, photovoltaic apparatus, wind turbine generators, electric storage devices and fuel cells which can be fired by either natural gas or biomass. AD is one of the most promising technologies for efficient energy recovery from food waste by utilizing functional microbes for the conversion of the organic portion of FW into biogas with about 50 to 70% methane c ontent[31,32,33]

Methods

Results

Conclusion