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Abstract: The kinetic models were developed and applied for fermentative hydrogen production. They were used to describe the progress of a batch fermentative hydrogen production process, to investigate the effects of substrate concentration, inhibitor concentration, temperatures, pH, and dilution rates on the process of fermentative hydrogen production, and to establish the relationship among the substrate degradation rate, the hydrogen-producing bacteria growth rate and the product formation rate. This review showed that the modified Gompertz model was widely used to describe the progress of a batch fermentative hydrogen production process, while the Monod model was widely used to describe the effects of substrate concentration on the rates of substrate degradation, hydrogen-producing bacteria growth and hydrogen production. Arrhenius model was used a lot to describe the effects of temperature on fermentative hydrogen production, while modified Han–Levenspiel model was used to describe the effects of inhibitor concentration on fermentative hydrogen production. The Andrew model was used to describe the effects of H+ concentration on the specific hydrogen production rate, while the Luedeking–Piret model and its modified form were widely used to describe the relationship between the hydrogen-producing bacteria growth rate and the product formation rate. Finally, some suggestions for future work with these kinetic models were proposed. [Copyright &y& Elsevier]

Abstract: A fractional factorial design was carried out to investigate the effects of temperature, initial pH and glucose concentration on fermentative hydrogen production by mixed cultures in batch tests and then the experimental data of substrate degradation efficiency, hydrogen yield and average hydrogen production rate were described by a neural network, based on which the simultaneous optimization of the three responses was performed by the method of desirability function. The analysis showed that the neural network could successfully describe the effects of temperature, initial pH and glucose concentration on the substrate degradation efficiency, hydrogen yield and average hydrogen production rate of this study. The maximum substrate degradation efficiency of 95.3%, hydrogen yield of 305.3mL/g glucose and average hydrogen production rate of 23.9mL/h were all obtained at the optimal temperature of 39.0°C, initial pH of 7.0 and glucose concentration of 24.6g/L identified by the method of desirability function based on a neural network. In sum, the method of desirability function based on a neural network was a useful tool to optimize several responses for fermentative hydrogen production processes simultaneously. [Copyright &y& Elsevier]

Abstract: This review summarized several main factors influencing fermentative hydrogen production. The reviewed factors included inoculum, substrate, reactor type, nitrogen, phosphate, metal ion, temperature and pH. In this review, the effect of each factor on fermentative hydrogen production and the advance in the research of the effect were briefly introduced and discussed, followed by some suggestions for the future work of fermentative hydrogen production. This review showed that there usually existed some disagreements on the optimal condition of a given factor for fermentative hydrogen production, thus more researches in this respect are recommended. Furthermore, most of the studies on fermentative hydrogen production were conducted in batch mode using glucose and sucrose as substrate, thus more studies on fermentative hydrogen production in continuous mode using organic wastes as substrate are recommended. [Copyright &y& Elsevier]