Two-dimensional Simulation of Diffusion and Advection Effects in Enzymatic Hydrolysis of Cellulose

Norazaliza Mohd Jamil, Qi Wang

Abstract


Enzymatic hydrolysis process to transform lignocellulosic cellulose into sugar in a bioreactor tank involves different controlling factors such as advection, diffusion and fragmentation of cellulose chains. Although it has been observed experimentally that enzymatic hydrolysis is strongly influenced by the environmental effects in a tank, these effects have not been adequately quantified. In this work, a current kinetic model for enzymatic hydrolysis of cellulose was extended by coupling the population balance equations (PBE) with advection and diffusion terms to model the spatial evolution of the system. The mathematical model was solved using the DAE-QMOM technique. The aim of this study was to simulate the effect of diffusion and advection on the fragmentation of cellulose chains during enzymatic hydrolysis in two-dimensional domain. This study demonstrated the applicability and usefulness of a commercial software (COMSOL Multiphysics) for finding the solution of PBE-advection-diffusion in cellulosic hydrolysis problem. The key implication of this work is that advection is a significant phenomenon which could increase the number of cellulose particles. Also, diffusion alone cannot increase hydrolysis rate, but the combination of advection and diffusion increases hydrolysis rate. 


Keywords


Enzymatic hydrolysis; Advection; Diffusion; Population balance equations

Full Text:

PDF

References


A.J. Griggs, J.J. Stickel and J.J. Lischeske, A mechanistic model for enzymatic sacchariffcation of cellulose using continuous distribution kinetics I: depolymerization by EGI and CBHI, Biotechnology and Bioengineering 109(3) (2012), 665 – 675.

W. Wang, Q. He, N. Chen and M. Xie, A simple moment model to study the effect of diffusion on the coagulation of nanoparticles due to Brownian motion in the free molecule regime, Thermal Science 16(5) (2012), 1331 – 1338.

L. Mazzei, D.L. Marchisio and P. Lettieri, Direct quadrature method of moments for the mixing of inert polydisperse fluidized powders and the role of numerical diffusion, Industrial & Engineering Chemistry Research 49(11) (2009), 5141 – 5152.

X.Y. Woo, R.B. Tan, P.S. Chow and R.D. Braatz, Simulation of mixing effects in antisolvent crystallization using a coupled CFD-PDF-PBE approach, Crystal Growth & Design 6(6) (2006), 1291 – 1303.

J. Gimbun, Z.K. Nagy and C.D. Rielly, Simultaneous quadrature method of moments for the solution of population balance equations, using a differential algebraic equation framework, Industrial & Engineering Chemistry Research 48(6) (2009), 7798 – 7812.

R. McGraw, Description of aerosol dynamics by the quadrature method of moments, Aerosol Science and Technology 27(2) (1997), 255 – 265.

N.M. Jamil and Q. Wang, The nondimensionalization of equations describing enzymatic cellulose hydrolysis, World Applied Sciences Journal 34(2) (2016), 158 – 163.




DOI: http://dx.doi.org/10.26713%2Fjims.v9i4.1028

eISSN 0975-5748; pISSN 0974-875X