Approximation of Scale-Up of Enzymatic Hydrolysis Process from Phenomenological-Based Semiphysical Model and Control Theory Tools

Abstract

This study highlights the scale-up of enzymatic hydrolysis of wheat starch from the phenomenological-based semiphysical model and control theory tools. The state variables involved were glucose concentration (L 1), maltodextrins (L 5), and temperature (L rL) for liquefaction and glucose concentration (S 1), maltodextrins (S 5), and temperature (L rS) for saccharification. The design variables included initial substrate concentration (S 0), reactor volume (V r), and initial enzyme concentrations for liquefaction (E 0L) and saccharification (E 0S). The hierarchy of low scale (LS) for the liquefaction and saccharification stage was L 1 > L 5 > T rL and S 1 > S 5 > T rS. The values of the design variables changed between LS and the high scale (HS) from 161 to 180 g/L, from 0.05 to 15.10 mL/L, and from 0.26 to 0.76 mL/L for S 0, E 0L, and E 0S, respectively. These values maintained the hierarchy in the saccharification stage but not in the liquefaction stage.

Modeling Based Identifiability and Parametric Estimation of an Enzymatic Hydrolysis Process of Amylaceous Materials

“…The mass balances associated with each oligosaccharide only depend on their concentration rates. 9 Meanwhile, the energy balances show a heat exchange using the thermal jacket Q c and the heat taken using concentrations rates .…”

“…Therefore, J ( p ) is a measurement of the integral quadratic error of the parameter identification adjusted to the standard deviation and mean of each sample for including all information on the measured data in comparison with previous works. 7 , 9 While J ( p ) takes a lower value, p̂ will be a local minimum nearer to the real value of p .…”

“…In the saccharification stage, the first numerical values of the boundaries are based on previous results shown in the literature. 9 Moreover, those values were iterated following expected values selected using the phenomenological knowledge of the system. The objective of that is to reduce the neighborhood and improve the solution obtained in p̂ .…”

“…The used methodology is based on the PBSM methodology, developed by Alvarez et al 15 and applied in ref ( 9 ), which can generate gray-box and lumped parameter models. In this work, steps 6–11 were added in order to consider the identifiability of parameters.…”

“…This process is the basis of a major research project in bioprocess estimation and control started by Acosta-Pavas and Ruiz-Colorado. 9 Additionally, a better model of the enzymatic hydrolysis process of amylaceous materials can contribute to understand better how to use agro-industrial wastes for production of value-added products.…”