A. Nishiwaki et Ij. Dunn, PERFORMANCE OF A MULTISTAGE FERMENTER WITH CELL RECYCLE FOR CONTINUOUS ETHANOL-PRODUCTION, Chemical engineering communications, 162, 1997, pp. 179-198
The unsteady and steady-state performance of a multistage fermenter wi
th cell recycle is investigated numerically for continuous production
of ethanol. The tanks-in-series model is employed to describe the how
behaviour of culture in multiple tanks. In establishing mass balances,
the cell volume fraction and the equilibrium partition coefficient fo
r intracellular and extracellular ethanol concentrations are taken int
o account. Kinetic expressions are taken from the literature. Compared
to a single tank fermenter with recycle, multi-staging and cell recyc
le are shown to bring high cell and product concentrations and low sub
strate concentration in the final tank during unsteady-state operation
. Solutions to the steady state model are presented graphically, showi
ng concentrations as a function of dilution rate for different numbers
of tanks. Results are given for the maximum ethanol productivity as a
function of the optimal dilution rate, with parameters of tank number
, bleed ratio and recycle ratio. Also, the effects of the fractional t
ank volume and the saturation constant on the productivity and the sub
strate conversion are examined.