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Applied Biochemistry and Biotechnology

, Volume 28, Issue 1, pp 527–538 | Cite as

Enzymatic hydrolysis of starch in a fixed-bed pulsed-flow reactor

  • A. Sanromán
  • R. Chamy
  • M. J. Núñez
  • J. M. Lema
Session 4 Bioengineering Research

Abstract

One of the most important problems in the design and operation of fixed-bed biological reactors is the control of the process rate by mass-transfer limitations. In order to overcome this problem, a new technology, based on the use of pulsed reactors, was developed. A new type of pulsing device, giving a see-saw-type of disturbance, was assayed. To quantify the possible improvement obtained, we have chosen as an example the hydrolysis of concentrated starch solutions by glucoamylase (fromAspergillus niger) immobilized on chitin slabs. The reactor has an internal diameter of 50 mm and a bed height of 200 mm. Temperature was controlled at 25°C, and the working hydraulic retention times were from 0.29 to 1.8 h. The results revealed that pulsation helps to lessen the diffusional difficulties, since the maximum reaction velocity increased 10%. Additional improvements, up to 20% in some cases, are achieved by recycling a part of partially converted feed.

Index Entries

Pulsed flow packed-bed starch hydrolysis immobilized glucoamylase chitin 

Nomenclature

τ

mean residence time h

So, S

initial and final substrate concentration g/L

r=V

hydrolysis rate g/L.min

Vmax

maximum reaction rate g/L-min

Ks

Michaelis constant g/L

R

recirculation rate = return flow/out flow

t

time h

θ

normalized time

D

axial dispersion coefficient m2/s

N

number of tanks in series

Cθ

normalized tracer response to a pulse input

µa

apparent viscosity kg/m.s

- dv/dr

velocity gradient s-1

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Copyright information

© Humana Press Inc. 1991

Authors and Affiliations

  • A. Sanromán
    • 1
  • R. Chamy
    • 1
  • M. J. Núñez
    • 1
  • J. M. Lema
    • 1
  1. 1.Department of Chemical Engineering, Avda, Ciencias s/nUniversity of Santiago de CompostelaSpain

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