NONLINEAR APPROACH FOR THE VFA REGULATION IN AN ANAEROBIC DIGESTER

This paper presents the design and the experimental validation of a nonlinear control approach for the regulation of volatile fatty acids (VFA) in an anaerobic digester. Such an approach is conformed by an output feedback control and an extended Luenberger observer which allows the estimation of the uncertain terms associated to the VFA dynamics (i.e., in∞uent composition and kinetic terms). The nonlinear approach is experimentally validated in a 0.528m 3 up-∞ow flxed-bed anaerobic digester used for the treatment of industrial wine distillery wastewater. The experimental results show that the VFA regulation is achieved in spite of uncertain kinetics, restrictions in the control input and unknown load disturbances. Copyright c ∞2007 IFAC

[1]  Derrick K. Rollins,et al.  Continuous-time Hammerstein and Wiener modeling under second-order static nonlinearity for periodic process signals , 2006, Comput. Chem. Eng..

[2]  Dale E. Seborg,et al.  Nonlinear Process Control , 1996 .

[3]  J Harmand,et al.  On-line measurements of COD, TOC, VFA, total and partial alkalinity in anaerobic digestion processes using infra-red ectrometry. , 2002, Water science and technology : a journal of the International Association on Water Pollution Research.

[4]  Arjan van der Schaft,et al.  Non-linear dynamical control systems , 1990 .

[5]  C. Pelayo-Ortiz,et al.  Robust interval-based SISO and SIMO regulation for a class of highly uncertain bioreactors: application to the anaerobic digestion , 2000, Proceedings of the 39th IEEE Conference on Decision and Control (Cat. No.00CH37187).

[6]  J P Steyer,et al.  Lessons learnt from 15 years of ICA in anaerobic digesters. , 2006, Water science and technology : a journal of the International Association on Water Pollution Research.

[7]  Ricardo Femat,et al.  Improving the performance on the chemical oxygen demand regulation in anaerobic digestion , 2004 .

[8]  A. Isidori.  Nonlinear Control Systems , 1985 .

[9]  David F. Ollis,et al.  Biochemical Engineering Fundamentals , 1976 .

[10]  Ricardo Femat,et al.  A robust feedforward/feedback control for an anaerobic digester , 2005, Comput. Chem. Eng..

[11]  D. T. Hill,et al.  Using volatile fatty acid relationships to predict anaerobic digester failure. , 1987 .

[12]  Mogens Henze,et al.  Wastewater Treatment: Biological and Chemical Processes , 1995 .

[13]  Gustaf Olsson,et al.  Instrumentation, Control and Automation in Wastewater Systems , 2015 .

[14]  Alessandro Astolfi,et al.  Set-point regulation of an anaerobic digestion process with bounded output feedback , 2003, IEEE Trans. Control. Syst. Technol..

[15]  A. Puñal,et al.  Automatic control of VFA in anaerobic digestion using a fuzzy logic based approach , 2002 .

[16]  A Genovesi,et al.  Dynamical model development and parameter identification for an anaerobic wastewater treatment process. , 2001, Biotechnology and bioengineering.