AN INVESTIGATION INTO THE ENERGY POTENTIAL OF ABATTOIR WASTE AND PALM OIL MILL EFFLUENT

Abstract

A larger population of Nigeria relies solely on fossil fuels for energy generation, which are not renewable and constitute hazards to both human and ecology. Nigeria is blessed with a lot of natural resources, through which alternative forms of energy, which are renewable, could be generated. This research work investigates the energy potential from the co-digestion of Abattoir Effluent (AE) and Palm Oil Mill Effluent (POME). Three (3) anaerobic digesters were employed for this research work. Substrates were collected from various abattoir (Slaughterhouses) around Akure metropolis and a palm oil mill at Ibule near Akure. The substrates were mixed together and characterized before been fed into the digesters in the following proportion; digester A (67% AE + 33% POME), digester B (33% AE + 67% POME) and digester C (50% AE + 50% POME). Each digester was equipped with a thermometer for daily temperature monitoring while the pH of the substrates was monitored weekly using a handheld pH meter. The average minimum and maximum temperature for the digesters were recorded to be 26.3 oC and 31.5 oC. The pH values were also recorded to be between; 6.8 – 7.4, 6.4 -7.6, and 6.6 – 7.3 for digesters A, B and C respectively. A chromatography test was carried out on the biogas produced in order to determine its composition. The results showed that biogas produced by digester A, B and C, were 46% CH4, 36.39% CO2; 49% CH4, 32.24% CO2, and 48.32% CH4, 34.51%CO2 respectively. The energy value of the biogas produced by each digester was calculated to be 16.7 MJ/m3, 17.7 MJ/m3 and 17.4 MJ/m3 respectively for digesters A, B and C. The specific volume of biogas produced were calculated to be 0.0325 m3/kg, 0,0311m3/kg and 0.022m3/kg for digesters A, B and C respectively. Thus, substrate B (33% AE + 67% POME) is recommended as the best mix ratio for the co-digestion of Abattoir and Palm Oil Mill Effluents. Hence, co-digestion of Abattoir and Palm Oil Mill Effluent indicates a promising result in biogas production by anaerobic digestion under mesophilic temperature