Optimization of technology for hydrogen production by anaerobic fermentation of swine manures

In order to set up the mathematical model between fermentation process parameters and hydrogen production, obtain optimized parameters and higher hydrogen production, a hydrogen-producing technique using anaerobic fermentation method was researched on the basis of one-factor tests and the quadratic orthogonal regressive rotational combination design principle, and the method of response surface analysis with three factors and three levels was adopted. A quadratic equation for hydrogen yield was built. Response surface and contour were graphed with the hydrogen yield as the response value. Based on the analysis of the response surface plots and their corresponding contour plots, effects of pH value, hydraulic retention time and substrate concentration and their alternant effects were explored. By using the new method, the optimum hydrogen-producing conditions were obtained as follows: initial pH value of 5.98, hydraulic retention time of 4.123 d, substrate concentration of 51.98 g/L. Under the optimized conditions, the hydrogen production rate in the latter validatory experiment was 32.4 mL/g.