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Figure 10 | Biotechnology for Biofuels

Figure 10

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

Figure 10

State of severe hydrogen inhibition as a function of hydrogen productivity, P H 2 and k l a H 2 . The straight lines show the combinations of H2 productivity, P H 2 and K l a H 2 , resulting in a state of severe H2 inhibition. The state of severe H2 inhibition is assumed to occur at a value of H2aq equal to 80% of H2aqcrit (corresponding to a reduction in the growth and H2 production rate of 37%). The further away from, and above, the lines the state of a fermentation experiment is, the lower the inhibition by H2. An increase in H2 productivity and a decrease in K l a H 2 move the state of the fermentation to the right and down, respectively, on the graph, while an increase in P H 2 increases the slope of the lines. These changes all increase the dissolved H2 concentration and move the state of a fermentation experiment closer to a state of H2 inhibition. The open squares show the state of each experiment at the time of maximum productivity. An additional point is included for experiment 1 (12 hours), showing the state four hours before maximum productivity occurred. The curved line shows the relation between the stripping rate and K l a H 2 (the relation given by equation 27). The experimental K l a H 2 values (calculated from experimental values of K l a C O 2 using equation 25) are also included (open circles).

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