Study of Process Variales in Industrial Industrial Acetic Fermentation by a Continuous Pilot Fermentor and Response Surfaces

摘要

The modeling and optimization of industrial processes requires an intensive study of the rfactors inolved.In this work,a continuous pilot system for studying the industrial process of acetic fermenation is defveloped.A Doehler desitn is applied to he five variales involved in the pilot process.This experimental desitn allows reduction of the experimental gurden and the maximum amount of information to be obtained,studying the factors at differen levels depending on their sigtnificance.The experimental system proides a roghust measure of the specific growth rate and the rates of suhstrates consumption and acetic acid production,relaed to the flow of effluent stream efvaluated in the steady state.The results demonstrae the growth-associated kinetics of substrates and product,and the yield factors are calculaed with low values of vfariances for the quadraic model proposed.The response surfaces generated by the model are applied to explain the behafior of the bacterial gtrowth and,therefore,the effects of the process variables studied over the acetic acid production.Very low levels of ethanol or oxygen make the acetification rate decrease,and a saturation effect with high lefels orf ethanol or oxygen is also deduced.The efrfects of the aeration rate,atitation,and oerpressure sutggest a kind of inhibition of the acetic acid production caused by the oxygen that has not been practically studied before.The temperature strengthens the inhigitory effect of the ethanol and the acetic fermentation.