Experimental simulation and kinetic modeling of bioenergy potential of Eichornia crassipes biomass from the Volta River basin of Ghana under mesophilic conditions

Abstract

The study presents the results of the laboratory experiment performed on the anaerobic digestion of water hyacinth biomass harvested from the Volta River basin of Ghana and Fruit waste sludge as the inoculum. Batch mode of experiment was performed under mesophilic conditions (29 ± 3 °C) with a hydraulic retention time of 61 days. The experimental setup was made up of three (3) fermenter bottles of 5.0 L capacity namely F1, F2 and F3. F1 served as the control whiles F2 and F3 served as the test fermenter bottles. Each of the fermenter bottles was fitted with BlueSens methane sensor and BlueVcount flowmeter for the measurement of methane composition and biogas volumes, respectively. The Theoretical Biomethane Potential (BMP) of the water hyacinth biomass was estimated to be 422.23 ml/gVS. The experimental BMP was determined to be 402.62 ml CH4/gVS and 356.03 ml CH4/gVS for F2 and F3, respectively. Consequently, a biodegradability value of 95.36 and 84.32 % was obtained from F2 and F3, respectively. Moreover, the F2 fermenter bottle recorded a cumulative net methane and biogas volumes of 5576.3 ml and 12,014 ml, respectively. Likewise, a total net cumulative methane and biogas volumes of 4931.0 ml and 11,384 ml were produced from the F3 fermenter bottle. Using the First order kinetic model, an average value of hydrolysis constant for water hyacinth biomass was determined as 0.051 day−1. Furthermore, the modified Gompertz model, the logistic function model and Transference function models were used to fit the experimental cumulative biogas and methane production data. The outcome of the study shows that, the production of biogas from water hyacinth biomass harvested the Volta River basin of Ghana could offer sustainable control solutions to its invasion on water bodies whiles providing a cheap and reliable means of biofuel to the riparian communities.