XC. I. Nwoye and J. T. Nwabanne
This paper presents a model development for predictive analysis of methane gas yield during bio-treatment of fruit wastes in the digester; aimed at producing biogas for heat and electricity generation. The overall validity of the derived model was established using the 4th Degree Model Validity Test Technique (4th DMVTT); computational, graphical, statistical and deviational analysis. Computational analysis of the model-predicted and experimental results indicates that methane gas yield per unit organic loading rate are - 0.0421 (VS)2 d-1 and - 0.0395 (VS)2 d-1 as obtained from experiment and derived model respectively. The graphical analysis, apart from showing very close alignment of curves from both experimental and model-predicted results, indicates 0.9923 and 1.0000 as the correlation between methane yield and organic loading rate as obtained from experiment and derived model are respectively. Statistical analysis of the results indicate that the variance and standard deviation as obtained from experiment and derived model are 9.1004 x 10-4 and 0.0302 as well as 8.0934 x10-4 and 0.0284 respectively, indicating proximate agreement. Deviational analysis indicates that the maximum deviation of the model-predicted methane yield from the corresponding experimental value is less than 6%. It was also found that the validity of the model is rooted on the expression (Log α)/N = Log (γ)-1 where both sides of the expression are correspondingly approximately equal
