Suchergebnisse

2 tablas, 3 figuras ; This work presents a methodology which exploits the underlying biochemical structure of bioprocesses to estimate concentrations in aerobic fermenters from oxygen measurements. Although a number of estimators have been proposed over the years in the literature, the methodology proposed in this work is able to operate in transient conditions while does not require the knowledge of the growth kinetics. In addition, it can be also applied to fermenters where the spatial distribution of the concentrations is relevant. In this case, we propose a systematic approach to optimally locate the sensors based on the use of reduced order models. This method allows the reconstruction of the oxygen concentrations from a limited number of sensors. Finally, the methodology proposed will be illustrated on a horizontal tubular reactor for the production of gluconicacid by free-growth of Aspergillus niger. ; Financial support received from the Spanish Government (MCyT Projects PPQ2001-3643 and DPI2004-07444-C04-03) and Xunta de Galicia (PGIDIT02-PXIC40209PN). ; Peer reviewed

7 páginas, 6 figuras, 1 tabla ; In this work, the dissipative nature of spatially distributed bioprocess systems is exploited to develop efficient state observers based on a low dimensional dynamic representation of the original set of partial differential equations. The approach we suggest combines standard observer design techniques for bioreactors with efficient model reduction methodologies based on projection of the original concentration fields on low dimensional subspaces capturing the slow dynamics of the process. Aspects related with the location of sensors and their influence on the ability to reconstruct concentration fields will also be considered. Finally, the different aspects of the methodology, as well as the efficiency of the resulting observers will be illustrated on a case study of industrial interest, namely a tubular bioreactor producing gluconic acid by Aspergillus Niger ; This paper includes results of the joint research project that is supported by the bilateral agreements between Bulgarian academy of sciences and Process Engineering Group IIMCSIC. The authors acknowledge financial support received from the Spanish Government (MCyT Projects PPQ2001- 3643) and Xunta de Galicia (PGIDIT02-PXIC40209PN). ; Peer reviewed