Combination of extremum-seeking algorithms with effective hydraulic handling of equalization tanks to control anaerobic digesters

摘要

The benefits of upgrading extremum-seeking controllers with an effective exploitation ofnthe buffer capacity of equalization tanks have been investigated and applied to anaerobicndigesters. In this respect, a Fuzzy-based supervisory module that monitors the state of thenequalization tank has been designed and built on top of an extremum-seeking algorithmnin charge of automatically regulating the wastewater fed into the anaerobic digester.nThe extremum-seeking controller guarantees good disturbance rejection and methanenproduction around an upper limit set-point. The on-top Fuzzy module optimizes the long-termnmethane production by modifying this upper limit set-point as a function of the state ofnthe equalization tank. A systematic simulation study has been carried out to evaluate thenperformance of the proposed control solution. Thus, on the basis of existing simulationnbenchmarks for assessment of control strategies in wastewater treatment plants,na dedicated simulation protocol for anaerobic digesters has been defined andnimplemented. Simulation results have shown that, compared with manual operation,neffluent quality and methane production improvements of 10–15% are achievednusing the proposed control approach.