Mathematical models of ethanol inhibition effects during alcohol fermentation

Structured Mathematical Modeling, Bifurcation, and Simulation for the Bioethanol Fermentation Process Using Zymomonas mobilis

“…There are many mathematical models on the oscillatory behavior of Z. mobiliz. Li (2009) 2 indicated that the oscillatory behavior of ethanol production is not attributed to ethanol concentration. In addition, he claimed that both the rate of ethanol change and the ethanol concentration history may lead to the oscillatory behavior.…”

Method for Regulating Oscillatory Dynamic Behavior in a Zymomonas mobiliz Continuous Fermentation Process

“…Compared with batch operation, continuous fermentation can improve productivity by saving labor and maintenance costs and reducing capital investment on production facilities, thus it has been practiced for large scale production of fuel ethanol in industry . However, continuous ethanol fermentation with Z. mobiliz tends to be rich in dynamic instability, in which sustainable or damped oscillations have routinely been observed. − The concentrations of product, biomass and substrate vary periodically in these oscillatory phenomena, especially at low growth rate and high ethanol concentrations, and these are characterized by long oscillatory periods and large oscillation amplitudes. Under certain operating conditions, the oscillation periods are sustained for 50 h for glucose, ethanol and biomass, and the amplitudes of oscillation are about 20–100 kg/m 3 for glucose and 50–90 kg/m 3 for ethanol, as reported for continuous ethanol fermentation with Z. mobiliz …”

“…Diehl et al analyzed the nonlinear dynamic behavior in a continuous ethanol fermentation process with Z. mobiliz , and presented a multivariable control strategy with a high yield solution branch inside the steady-state multiplicity region, that could maintain process stability. Li et al developed three models to study the inhibitory effects that cause oscillatory behavior in alcohol fermentation via Z. mobiliz . The results showed that ethanol concentration alone did not cause periodic behavior during ethanol production but computer simulations indicated that oscillations were caused under certain circumstances.…”

“…Diehl et al 22 analyzed the nonlinear dynamic behavior in a continuous ethanol fermentation process with Z. mobiliz, and presented a multivariable control strategy with a high yield solution branch inside the steady-state multiplicity region, that could maintain process stability. Li et al 23 developed three models to study the inhibitory effects that cause oscillatory behavior in alcohol fermentation via Z. mobiliz.…”

A New Biochemical Fermentation Process Design Method Considering Bifurcations and Oscillations

“…Li et al (1995) observed that although the ethanol concentration history did not alter the fermentation capacity of Z. mobilis, increasing ethanol concentrations exerted a strong inhibitory effect. Li (2009) developed three models for investigating the inhibitory effects leading to oscillatory behavior in Z. mobilis alcohol fermentation. According to Garhyan et al (Garhyan et al, 2003;Garhyan and Elnashaie, 2004a,b), the ethanol yield and production rate is favored by minimizing ethanol inhibition.…”