Authors : Ekele Dinneya-Onuoha and Kechinyere B. Oyoh
Abstract: The aim of this work is to predict the effect of temperature, pH and retention time on biogas production using some regression models while investigating other parameters such as the chemical oxygen demand and total viable count. A slurry mixture of cassava peels and cow-dung was co-digested in a metallic fixed-dome anaerobic digester in a ratio of 1:1 and then monitored for a 30-day period. The experiment was carried out at ambient temperatures which also fall into the mesophilic temperature range, (25-40°C). Daily physicochemical data demonstrated that the pH and slurry temperature ranged from 5.8-7 and 25.8-34.7°C, respectively. Biogas production began on the second day with a peak production of 6.2-L on the 15th day. The work recorded a cumulative volume of 103.3-L for the 30-day span. Kinetic studies reveal significant biogas production with Modified Gompertz Model giving the better prediction with an R2 value of 0.9949 as compared to the Logistic Growth Model used. The explicit polynomial regression model was clearly seen to be the best predictor with R2 = 0.79, showing retention time as a primary factor while pH and temperature are secondary factors. This tool is thus, useful in the optimization of biogas production as it considers the interactions of these core factors affecting biogas production. There is further need for improvement and refinement.
Ekele Dinneya-Onuoha and Kechinyere B. Oyoh, 2021. Production, Kinetics and Purification of Biogas from Cow-Dung and Cassava Peels. International Journal of Electrical and Power Engineering, 15: 1-10.