Improvement of continuous calibration based on temperature oscillation andapplication to biochemical reaction calorimetry

This paper describes an improvement of a method for continuous calibration of the global heat transfer coefficient, recently described in literature [ A. Tietze, Moglichkeiten und Grenzen der Temperaturschwingungskalorimetrie, Doctoral Thesis, Technishe Universitat Berlin, 1998; Chem. Eng. Sci. 51 (1 996) 3131; Chem. Ing. Tech. 68 (1996) 97]. The continuous calibration metho d is based on induced sinusoidal jacket temperature oscillations, allowing the uncoupling of the chemical heat production from the heat transfer param eters during the reaction. A mathematical computation procedure based on tw o-anchors, before and after the reaction, has been developed which gives be tter results as compared to the one reported in literature, using one-ancho r only, either before or after the reaction. The applicability of this meth od to biotechnology has been explored with respect to different culture par ameters, which affect the global heat transfer coefficient, i.e. stirring s peed, reactive volume, and medium viscosity. This oscillating reaction calo rimetry method (ORC) has been successfully applied to a fed-batch culture o f Saccharomyces cerevisiae with a non-linear increase of reactive volume. ( C) 2001 Elsevier Science B.V. All rights reserved.