Production of Biogas from Co-Digestion of Cow Dung, Saw Dust and Maize Husk

Abstract

The co-digestion of cow dung, with maize husk for biogas production at laboratory scale was investigated. The study was carried out at a temperature range of 24°C - 30°C and pH range of 5.5 - 6.5 for a period of 60 days with a total solid concentration of 7.4% in the digester sample (fermentation slurry). Water displacement method was used to collect the biogas produced which was subsequently measured. 444.8 mL was the cumulative biogas yield at the end of 60 days retention time in the digester 1, which comprised of cow dung, maize husk, and water. Digester 2, which is made up of sawdust, cow dung, and water produced negligible biogas at the end of 60 days of the experiment. X-RF analysis revealed high presence of elements like silica, aluminium oxides, and aluminium oxides in cow dung, maize husk, and sawdust respectively. The preponderance of alkanes and methyl group inmaize husk makes it to produce biogas compared to saw dust as shown by the Fourier transform infrared spectroscopy (FTIR) that was carried out to identify the various functional groups. The potential of maize husk to produced biogas was also established. The kinetic modeling shows that there was an increase in biogas yield as the retention time increases as depicted by the linear model.