Ambient temperature kinetic assessment of biogas production from co-digestion of horse and cow dung

Abstract

Yusuf M.O.L., Debora A., Ogheneruona D.E., 2011. Ambient temperature kinetic assessment of biogas production from co-digestion of horse and cow dung. Res. Agr. Eng., 57: 97-104.Biogas production from 5 batch digesters containing varying ratio of mix of horse and cow dung was studied for a period of 30 days at ambient temperature. It was observed that biogas production was optimized when horse and cow dung were mixed in a ratio of 3:1. The modified Gompertz equation was used to adequately describe the cumulative biogas production from these digesters. In addition, a modified first order model was developed to assess the kinetics of the biodegradation process. It was observed that the rates of substrate biodegradability and of removal of the biodegradable fractions of the substrate could be obtained by plotting 1/t (ln(dyt/dt)) against the inverse of time of digestion. This modified first order model also showed that the digester containing horse dung and cow dung in the ratio of 3:1 had the highest short term anaerobic biodegradability index (STABI) of 3.96 at room temperature.

Effect of Hydraulic Retention Time on Biogas Production from Cow Dung in A Semi Continuous Anaerobic Digester

“…One of kinetic model that is suitable to describe this is modified Gompertz kinetic equation. This model describes a sigmoidal growth curve contained three unknown mathematical parameters (Syaichurrozi et al, 2013) and is recently used by many researchers to describe a cumulative biogas yield from a batch system as a function of digestion time, for example Budiyono et al (2010), Yusuf et al, 2011), andSyaichurrozi et al, 2013). For the case of our work (with a semi continuous digester), modified Gompertz kinetic equation is presented as:…”

“…Constants B, Rb and λ were determined using the nonlinear regression approach with the aid of the solver function of the MS Excel ToolPak (Yusuf et al, 2011). Table 3 shows mathematical parameters of modified Gompertz kinetic equation resulted from our work.…”

Mesophilic Anaerobic Co-Digestion of Cow Manure, Chicken Manure and Pig Manure at Different Feed Ratios

“…The C/N ratio for the mixture of cow manure, chicken manure, pig manure at ratios of 4:1:1, 1:4:1, 1:1:4 was found to be 17.07 %, 9.91 %, and 9.08 %, which is within the optimal range [8]. The biogas that is produced and the methane accumulated of the co-digestion of cow manure, chicken manure and pig manure mixtures with different ratios are shown in figure 4.…”

Kinetic Study of Agricultural Wastes Conversion to Biogas using Cow Dung/Poultry Droppings as Inoculums

“…This study assessed the substrate biodegradability by developing a mathematical model that was based on the first order kinetics for bio-digesters operating as batch systems (Yusuf et al, 2011). The entire kinetic is described by equations (3 -7) for a batch reactor system.…”

“…the feedstock, with Stiffen et al (2000) stating that, it comprises of methane, CH 4 (55 -75%) and carbon dioxide CO 2 (25 -45 %) with a reported calorific value of 20MJ/m 3 (Yusuf et al, 2011 ;Nuhu et al, 2013).…”