Institute for Sanitary Engineering, Water Quality and Solid Waste ...

Institute for Sanitary Engineering, Water Quality and Solid Waste Management
Simulation and nonlinear control of anaerobic
digestion
Anaerobic digestion represents a valid option in the
treatment of organic waste, providing a solution for
its disposal and the simultaneous production of green
energy. However the process is considered problematic
and tends to instability due to acidication. Process
control can improve the stability of the system keeping
the acid concentration within safety limits, while permitting
a regular and sustained production of methane.
The scope of this work is the development and test
of a nonlinear control strategy for anaerobic digestion
using reliable virtual laboratories or \simulators“. The
work proceeded through two major steps:
Industrieverlag GmbH, 2009. (Stuttgarter Berichte
zur Abfallwirtschaft; Bd. 96), 85 S., 34 Abb., 24 Tab.,
ISBN 978-3-8356-3191-5
1. the implementation and calibration of a nonlinear
anaerobic digestion model to test the capability of
reproducing the dynamical behaviour of a real system;
the model chosen is the detailed ADM1 [13],
implemented in the software Matlab ® and calibrated
for the simulation of three real cases: a biowaste
reactor, a cofermentation reactor for sludge and
kitchen waste and a surplus sludge fermentation
process. In the latter case a detailed parameter estimation
procedure is implemented.
Simulation model of fermentation
2. the design, implementation and tuning of a nonlinear
adaptive control algorithm, using the feedback
linearisation method; the control system is tested
on simulated plants, a co-fermentation reactor for
corn silage and cow manure and the biowaste reactor
simulated in the previous section.
The results of the work are very encouraging: the control
system is able to reject the disturbances acting on
the feed of the process while maintaining a sustained
biogas production. The tests on the simulated systems
are a valid alternative to costly and time-consuming
experimental work, and can be considered reliable, if
the model has been properly calibrated to the real system.
Doctoral candidate: Carla Cimatoribus
Principal examiner:
Prof. Dr.-Ing. Martin Kranert
Secondary examiners:
Prof. Dr.-Ing. Eckhard Kraft
Prof. Dr.-Ing. Renatus Widmann
Carla Cimatoribus
Simulation and nonlinear control of anaerobic digestion
(2009), Forschungs- und Entwicklungssinstitut für
Industrie- und Siedlungswasserwirtschaft sowie Abfallwirtschaft
e.V. Stuttgart (FEI). München: Oldenbourg
Comparison between experimental and predicted variables
with the estimated parameters
The bacterial degradation of halogenated and
methylsubstituted aromatic mixtures and its application
in biological waste air treatment
Methyl- and halogen substituted aromatics are widely
used in industrial processes as educt for the production
of o-cresol, agro-chemicals, flame retardants, dyes,
varnish and pigments, textile additives, pharmaceuticals,
adhesives, polymers and resins, air fresheners,
drain cleaners and optical brighteners. Furthermore, it
is used as solvent for agro-chemicals, in heavy metal
industry, paint thinners, heat conductable oils as well
as condenser liquids and is used as additive for fuels.
Depending on the specific aromatic compound about
5- 15 % of the world production per year is set free
into the air or water. Especially in case of the waste
air high volumetric flows with low carbon freight occur.
Thus, biological treatment techniques are the first
choice as treatment procedure.
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