A kinetic model for beer production under industrial operational conditions

A kinetic model for beer production is proposed. The model takes into accou nt five responses: biomass, sugar, ethanol, diacetyl and ethyl acetate. In contrast with previously published models, this model segregates biomass in to three components: lag, active and dead cells and considers the active ce lls as the only fermentation agent. Experiments were first performed at lab oratory scale and isothermal runs were carried out at five temperatures (8 degrees C, 12 degrees C, 16 degrees C, 20 degrees C and 24 degrees C). Fitt ing of experimental data was made by non-linear regression. Parameter value s calculated were similar to those given in the literature. The kinetic mod el was able to fit experimental data with a very good agreement. Afterwards , experiments were conducted at pilot plant scale and runs were now carried out changing temperature with time, in the industrial way. The kinetic mod el, with the parameter values calculated as a function of temperature, was able to predict with a very high accuracy the non-isothermal experimental d ata achieved. This model can be used for simulation of the industrial proce ss under different operational conditions and for faults detection. It can also be utilized for the optimization and even for the supervised control o f the process and its automatization. (C) 1998 IMACS/Elsevier Science B.V.