Mathematical modeling of an isothermal tubular bioreactor coupled with batch culture for ethanol production: a one-dimensional approach

Alcohol fermentation in batch culture was carried out to determine the behavior of biomass transport phenomena along the bioreactor. The applied methodology utilized both a one-dimensional theoretical modeling of biomass transfer in a tubular bioreactor associated with alcohol fermentation in batch culture and an experimental approach based on a triplicate run. The model’s predictions are validated against experimental data obtained from a real bioreactor system, demonstrating its accuracy and reliability for practical applications. Furthermore, the model solution demonstrated that the converging of biomass concentration in the 5-point nodal bioreactor depends on the values of the model parameters, namely the maximum specific growth rate (μ_max), the diffusivity coefficient (D), dimensionless coefficient (α) and reciprocal of doubling time (β). The experimental results show that distribution of biomass concentration along the reactor column is in the range between 3.40 and 3.62 g_DW L⁻¹ with an average value of about 3.52 g_DW L⁻¹. Furthermore, the average final ethanol concentration is about 58 g L⁻¹ after an average fermentation time of about 35 h and an average starting sugar concentration of about 65 g L⁻¹.