Resumen de Kinetic study on fermentation from CO2 and H2 using the acclimated-methanogen in batch culture
Takaaki Maekawa, Zhen Ya Zhang
Methane was produced from H2 and CO2 using the acclimated-mixed methanogens in a 3.71 fermentor in batch culture at pH 7.2 and 37°C. The Fermentation kinetics parameter for the growth of methanogens, overall mass transfer coefficient of the reactor, and the conversion rate of H2 and CO2 to CH4 by the acclimated-mixed culture were determined using the technique of Vega et al. The maximum specific growth rate (μmax) and H2 specific consumption rate (qmax) were found to be 0.064(h−1) and 104.8 (mmol h−1 g−1) respectively. Monod saturation constants for growth (Kp) and for inhibition (K′p) were found to be 3.54 (kPa) and 0.57 (kPa), respectively. These findings indicate that without very low dissolved H2 levels, the fermentations are carried out under μmax, and the specific uptake rate (q) was almost not affected at any dissolved H2 level in the range studied. The yield of CH4 (Yp/s) was calculated to be 0.245 (mol CH4 mol−1 H2), which is near the stoichiometric value of 0.25. DH2 was also measured using the Teflon tubing method and was in good agreement with those estimated by kinetic calculations.
