A kinetic model for quantitative evaluation of the effect of hydrogen and osmolarity on hydrogen production by Caldicellulosiruptor saccharolyticus

Table 5 The measured dissolved hydrogen concentration under different fermentation conditions compared with the model^a

Experiment	5	6	7	8
H₂ concentration	3.0%	9.1%	7.5%	3.6%
H₂ productivity	8.4 mmol/L/hour	6.0 mmol/L/hour	6.2 mmol/L/hour	10.7 mmol/L/hour
H_2aq	0.28 ± 0.01 mmol/L	0.8 ± 0.5 mmol/L	0.34 ± 0.02 mmol/L	0.9 ± 0.5 mmol/L
H_2aq at equilibrium	0.022 mmol/L	0.069 mmol/L	0.056 mmol/L	0.027 mmol/L
Oversaturation	12.5 ± 0.3	12 ± 7	12.5 ± 0.4	34 ± 19
H_2aq (model)	0.96 mmol/L	1.50 mmol/L	1.36 mmol/L	1.22 mmol/L

^aHydrogen (H₂) concentration, H₂ productivity and H_2aq are the experimentally determined H₂ concentration in the gas phase, H₂ productivity and dissolved H₂ concentration, respectively. H_2aq at equilibrium is the corresponding theoretical H_2aq at equilibrium with the gas. Oversaturation is the experimentally determined degree of H₂ oversaturation in the liquid. H_2aq (model) is the dissolved H₂ concentration calculated by the model under the same conditions.

ISSN: 2731-3654