The improvement of hydrogen production was achieved by the addition of biochar (BC) and metal co-factor nanoparticle Ni-0 during the dark fermentation. A new hybrid approach by combing the artificial neural networks with the response surface methodology was applied to optimize the hydrogen production. The effects of operating conditions, ie, BC, metal cofactor Ni-0, pH, and dosage of microbes, upon the hydrogen production together with the concentrations of other metabolites such as the acetic acid, propionic acid, butyric acid, and ethanol were extensively investigated. From kinetic study of the major metabolites, the acetate pathway was found to be apparently enhanced by the addition of synergistic factors. The modified anaerobic digestion model with the consideration of inhabitation factor was found to best represent the kinetics of hydrogen production and the formation of major metabolites.