Studies on synthesis of lactic acid from molasses and cheese whey in semifluidised bed biofilm reactors

Abstract

Synthesis of lactic acid from cheese whey and molasses in semifluidised bed biofilm reactor has been studied. Both of these raw materials are effluents discharged from industry and do not have any manufacturing cost. Lactic acid is most important raw material for the manufacture of bioplastic, Polylaevolactic acid. The bioreactor is modelled as being equivalent to a plug-flow dispersion reactor and the performance equation is solved using modified form of fourth-order Runge-Kutta method. The developed software package is tested by comparing package results with experimental data compiled on pilot plant scale and satisfactory agreement observed between the two. The bioreactor provides large degree of bioconversion of sucrose and lactose within a low reactor volume, but at large capacities. Also, with increase in substrate flow rate, fractional substrate conversion is seen to increase. Bioreactor performance is also improved with increased microbial concentration in biofilm.