Dissertation: Optimal design, operation and control of an anaerobic digestion reactor

200 Pages·2014·4.47 MB·English

PhD Dissertation:
Optimal Design, Operation and Control of an
Anaerobic Digestion Reactor
Finn Aakre Haugen
Telemark University College, Norway
PhD Dissertation no. 2014:4
ISBN 978-82-7206-376-3
February 24, 2014
ii Finn Aakre Haugen’s PhD Dissertation
Contents
Preface vii
Acknowledgements ix
Summary xi
Part I — INTRODUCTION 1
Background of the research project 3
Aims of the research project and the approach taken 11
Technical implementation 13
Foss Biolab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Process description . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Monitoring and control system . . . . . . . . . . . . . . . . . . . . 15
Laboratory analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Contributions by this dissertation 23
Conferences attended 25
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Future work 27
Abbreviations and nomenclature for Part I 29
Part II — SCIENTIFIC ARTICLES 33
List of articles 35
Article 1 — Adapting a Dynamic Mathematical Model to a Pilot
Anaerobic Digestion Reactor 37
Background and methods of the article . . . . . . . . . . . . . . . . 37
Supplementary material: Causal diagram . . . . . . . . . . . . . . 39
Article 2 — Temperature Control of a Pilot Anaerobic Digestion
Reactor 63
Background and methods of the article . . . . . . . . . . . . . . . . 63
Article 3 — On-off and PI Control of Methane Gas Production
of a Pilot Anaerobic Digestion Reactor 85
Background and methods of the article . . . . . . . . . . . . . . . . 85
Article4—StateEstimationandModel-basedControlofaPilot
Anaerobic Digestion Reactor 105
Background and methods of the article . . . . . . . . . . . . . . . . 105
Supplementary material: Implementation of the predictive controller108
Article 5 — Optimal Design and Operation of a UASB Reactor
for Dairy Cattle Manure 143
Background and methods of the article . . . . . . . . . . . . . . . . 143
Article 6 — Relaxed Ziegler-Nichols Closed Loop Tuning of PI
Finn Aakre Haugen’s PhD Dissertation v
Controllers 171
Background and methods of the article . . . . . . . . . . . . . . . . 171
vi Finn Aakre Haugen’s PhD Dissertation
Preface
This dissertation is submitted for the academic degree of Philosophiae
Doctor (PhD) in the PhD study programme Process, Energy and
Automation Engineering at Telemark University College (TUC), Norway.
The dissertation consists of two main parts. Part I gives an introduction to
the research project. Part II consists of a collection of scientific articles
which have been published or submitted for publication, including the
background and the methods of each article.
It is assumed that the reader of this dissertation has basic knowledge
about anaerobic digestion, mechanistic mathematical modeling, automatic
control, and state estimation.
I have accomplished the study as a Research Fellow in a 3/4 employment
in parallel with a 1/4 academic employment at Telemark University
College, starting Fall 2009.
The research project is focused on a real pilot anaerobic digestion reactor
at a specific, typical Norwegian dairy farm, namely Foss farm, and a
planned full-scale reactor at the farm. Although these are specific
applications, I hope that the results can be useful also for other similar
applications.
To make the results as easily available as possible, the scientific articles
produced, are published, or submitted for publication, only in scientific
journals providing Open Access publication, which means that the articles
are freely available on the Internet.
My background is mainly in the field of engineering cybernetics, which
includes mathematical modeling, estimation and control of dynamic
systems. The field of biological systems, more specifically: anaerobic
digestion, has been new to me. The research has been application oriented,
aiming at improving design, operation and control of anaerobic digestion
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processes using model-based methods from engineering cybernetics and
optimization, regarding the speci(cid:133)c application mentioned as an
application example.
I am grateful to have had the opportunity to accomplish this PhD study. I
have learnt a lot. Hopefully, I have given some contributions. And it has
been great fun!
Finn Aakre Haugen
Porsgrunn, Norway
February 24, 2014
Acknowledgements
I am thankful to many:
Thanks to professor Bernt Lie who has been my main supervisor. His vast
knowledge, good judgements, and critical questions have been of great
value. Also, I appreciate the freedom and flexibility allowed me in planning
my PhD study.
Thanks to professor Rune Bakke who has been my co-supervisor. Being the
head of the research activities in bioengineering at TUC, he has been a key
figure in my and others’ research in this field at TUC. I have learnt a lot
from his expertise. Thanks to him for always sharing time and knowledge.
Thanks to Knut Vasdal at Foss farm who has played an invaluable role in
my work. He has built the AD reactor at the farm on which my work is
based, and he has been maintaining and operating the reactor
continuously. I have learnt a lot from his practical and theoretical
knowledge about biological processes through our numerous discussions.
Thanks to Eivind Fjelddalen who has built and mounted the control
cabinets and most of the instruments. It is impressive to experience his
mastery in practical electronics and instrumentation.
Thanks to Jon Hovland at the Tel-Tek research institute in Porsgrunn,
Norway, who has always provided useful inputs using his deep insight in
bioengineering.
Thanks to Wenche Bergland who has organized and supervised the
laboratory analysis at TUC from which I have got essential data for the
mathematical modeling. Thanks to Mehrdad Torabzadegan who has
organized and accomplished much of the laboratory analysis. Thanks also
to Nora Cecilie I. Furuvik, Hildegunn Hegna Haugen, and Carlos
Dinamarca for maintaining the laboratory facilities, and to the many
students in the master study in Environmental Engineering at TUC who
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