The maximum methane yield was
obtained at F:I ratio of 2:1 for OPT, EFB and OPF was 277.47,
253.45 and 248.31 m3 CH4 ton1 VS, respectively (Fig. 2). Among
the four F:I ratios tested, the highest methane yield was obtained
at an F:I ratio of 2:1 for all the feedstocks (EFB, OPF and OPT).
The maximum methane production obtained at F:I ratio of 2:1
for OPT, EFB and OPF was 69.1, 58.77 and 58.47 m3 CH4 ton1 biomass,
respectively.