Utilization of industrial waste heat for the cultivation and harvesting of microalgae by Corey Alfred

165 Pages·2017·6.08 MB·English

by  J A Scott

Utilization of industrial waste heat for the cultivation and harvesting of microalgae

by

Corey Alfred Laamanen

A thesis submitted in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy (PhD) in Natural Resources Engineering

The Faculty of Graduate Studies
Laurentian University
Sudbury, Ontario, Canada

© Corey Laamanen, 2017
THESIS DEFENCE COMMITTEE/COMITÉ DE SOUTENANCE DE THÈSE
Laurentian Université/Université Laurentienne
Faculty of Graduate Studies/Faculté des études supérieures

Title of Thesis
Titre de la thèse Utilization of industrial waste heat for the cultivation and harvesting of microalgae

Name of Candidate
Nom du candidat Laamanen, Corey Alfred

Degree
Diplôme Doctor of Philosophy

Department/Program Date of Defence
Département/Programme PhD Natural Resources Engineering Date de la soutenance March 17, 2017

APPROVED/APPROUVÉ

Thesis Examiners/Examinateurs de thèse:

Dr. JA Scott
(Supervisor/Directeur(trice) de thèse)

Dr. Gregory Ross
(Committee member/Membre du comité)

Dr. Helen Shang
(Committee member/Membre du comité)
Approved for the Faculty of Graduate Studies
Dr. Markus Timusk Approuvé pour la Faculté des études supérieures
(Committee member/Membre du comité) Dr. David Lesbarrères
Monsieur David Lesbarrères
Dr. Baoqiang Liao Dean, Faculty of Graduate Studies
(External Examiner/Examinateur externe) Doyen, Faculté des études supérieures

Dr. Tom Kovala
(Internal Examiner/Examinateur interne)

ACCESSIBILITY CLAUSE AND PERMISSION TO USE

I, Corey Alfred Laamanen, hereby grant to Laurentian University and/or its agents the non-exclusive license to
archive and make accessible my thesis, dissertation, or project report in whole or in part in all forms of media, now
or for the duration of my copyright ownership. I retain all other ownership rights to the copyright of the thesis,
dissertation or project report. I also reserve the right to use in future works (such as articles or books) all or part of
this thesis, dissertation, or project report. I further agree that permission for copying of this thesis in any manner, in
whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis
work or, in their absence, by the Head of the Department in which my thesis work was done. It is understood that
any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my
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permitted by the copyright laws without written authority from the copyright owner.

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Abstract
Microalgae sourced lipids that can be transesterified into biodiesel are a promising source
of biofuels that can be produced while mitigating industrial carbon dioxide (CO ) in off-
2
gasses. There are many advantages to microalgae compared to other bio-feedstocks,
including their rapid growth rate, their ability to accumulate significant amounts of lipid,
and the possibility of year-round production. However, there are significant limitations to
achieving wide spread and economic microalgae mass cultivation and two of these are
addressed in this research program.
Microalgae cultivation is currently generally limited to climatic zones where
temperatures remain above 15°C, which effectively restricts mass cultivation to tropical
or sub-tropical regions thereby eliminating the use of a number of worldwide industrial
CO sources. However, many of these sources also produce significant amounts of waste
2
heat. The capture and repurposing of waste heat to maintain culture temperature and
provide an alterative method for harvesting was explored. A dynamic model was
developed to determine the potential of waste streams from a nickel smelter to maintain
year-round growth in a cold climate. From this model, it was determined that there is
more than enough heat to maintain cultivation temperatures even when the ambient
temperature drops well below freezing.
Harvesting of microalgae prior to lipid extraction is, with current approaches, often cited
as an area where costs need to be significantly reduced. As a wholly novel approach, the
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capture of this waste heat was also explored for the use as a pretreatment for harvesting
by flotation. It was determined to be highly effective and crucially avoids the addition
and costs of chemical coagulants, which contaminate and restrict the use of the remaining
biomass after lipid extraction.
Keywords
Microalgae, Waste heat, Off-gas, Biodiesel, Cold climates, Harvesting, Flotation
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Acknowledgments
First and foremost, I want to express my deepest gratitude to my supervisor, mentor and
friend, Dr. Ashley Scott. Without him none of this would have been possible, and he has
taught me so much.
In fact, there is only one person in the world I owe this to more – my mother. To her, I
owe the world. Thank you mom – for always being there for me, for being a role model,
and for helping me with my math homework for all those years. On the same note, I
would like to thank my brother – for being the best big brother anyone could imagine.
I would also like to thank Dr. Helen Shang, Dr. Greg Ross and Dr. Markus Timusk for
their insight as my thesis committee.
Also this project would not have been possible without the support of Sudbury Integrated
Nickel Operations, the Natural Sciences and Engineering Research Council of Canada,
Mitacs, and AIS plc.
Last but not least, I thank the lab group, all of you – past and present. You have made
this experience so enjoyable and have helped me grow as a researcher and a person.
v
Table of Contents
Abstract(.....................................................................................................................................(iii!
Keywords(...........................................................................................................................................(iv!
Acknowledgments(...................................................................................................................(v!
List(of(Figures(........................................................................................................................(viii!
List(of(Tables(.............................................................................................................................(x!
Nomenclature(.........................................................................................................................(xi!
List(of(Publications(..............................................................................................................(xiv!
Chapter(1(...................................................................................................................................(1!
Introduction(........................................................................................................................................(1!
1.1!Background!...............................................................................................................................................!1!
1.2!Thesis!Objective!......................................................................................................................................!4!
Chapter(2(...................................................................................................................................(5!
A(model(for(utilizing(industrial(offGgas(to(support(microalgae(cultivation(for(
biodiesel(in(cold(climates(...............................................................................................................(5!
Abstract!..............................................................................................................................................................!6!
2.1!Introduction!..............................................................................................................................................!7!
2.2!Process!development!..........................................................................................................................!11!
2.3!Model!development!.............................................................................................................................!13!
2.4!Simulation!Results!................................................................................................................................!22!
2.5!Conclusion!...............................................................................................................................................!29!
2.6!Nomenclature!.........................................................................................................................................!30!
Chapter(3(.................................................................................................................................(32!
Smelter(offGgas(waste(heat(and(carbon(dioxide(sequestration(to(promote(
production(of(biodiesel(................................................................................................................(32!
Abstract!............................................................................................................................................................!33!
3.1!Introduction!............................................................................................................................................!34!
3.2!Waste!heat!in!nickel!smelter!offMgas!............................................................................................!38!
3.3!Heating!microalgae!ponds!using!waste!offMgas!heat!.............................................................!41!
3.4!Model!development!.............................................................................................................................!42!
3.5!Pond!sectioning!.....................................................................................................................................!45!
3.6!Heat!transfer!coefficient!for!pond!heat!exchanger!................................................................!46!
3.7!Pond!pumping!requirements!..........................................................................................................!48!
3.8!Roaster!heat!exchanger!......................................................................................................................!50!
3.9!Simulation!results!.................................................................................................................................!52!
3.10!Conclusion!.............................................................................................................................................!60!
3.11!Nomenclature!......................................................................................................................................!61!
(
(
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Chapter(4(.................................................................................................................................(63!
Flotation(harvesting(of(microalgae(..........................................................................................(63!
Abstract!............................................................................................................................................................!64!
4.1!Introduction!............................................................................................................................................!65!
4.2!Microalgae!harvesting!........................................................................................................................!67!
4.3!Flotation!....................................................................................................................................................!72!
4.4!Coagulants!...............................................................................................................................................!76!
4.5!Types!of!flotation!..................................................................................................................................!82!
4.6!Operational!Parameters!....................................................................................................................!90!
4.7!Economics!................................................................................................................................................!99!
4.8!Conclusions!..........................................................................................................................................!100!
Chapter(5(..............................................................................................................................(102!
HeatGaided(flocculation(for(flotation(harvesting(of(microalgae(..................................(102!
Abstract!.........................................................................................................................................................!103!
5.1!Introduction!.........................................................................................................................................!104!
5.2!Materials!and!Methods!....................................................................................................................!106!
5.3!Results!and!discussion!....................................................................................................................!110!
5.4!Conclusion!............................................................................................................................................!119!
Chapter(6(..............................................................................................................................(120!
Development(of(heatGaided(flocculation(for(flotation(harvesting(microalgae(.......(120!
Abstract!.........................................................................................................................................................!121!
6.1!Introduction!.........................................................................................................................................!122!
6.2!Materials!and!Methods!....................................................................................................................!123!
6.3!Results!and!discussion!....................................................................................................................!126!
6.4!Conclusion!............................................................................................................................................!133!
Conclusions(..........................................................................................................................(135!
Conclusion(.....................................................................................................................................(135!
Future(Work(.................................................................................................................................(136!
Bibliography(........................................................................................................................(138!

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List of Figures
Figure(2.1:!Schematic!of!a!smelter!offMgas!treatment!(adapted!from!Shang!et!al.,!
2007)!...............................................................................................................................................................!9!
Figure(2.2:!Schematic!of!a!smelter!coupled!microalgae!production!facility!................!12!
Figure(2.3:(Annual!temperature!profile!for!example!smelter!sites!.................................!23!
Figure(2.4:(Annual!solar!radiation!profile!for!example!smelter!sites!.............................!24!
Figure(2.5:(Impact!on!required!energy!from!the!roaster!offMgas!per!250!m3!tank!
from!removing!either!the!insulation!or!roof!covering!from!the!tanks!whilst!
maintaining!water!temperature!at!15°C!in!Sudbury!...............................................................!26!
Figure(2.6:!Impact!on!required!energy!from!the!roaster!offMgas!per!250!m3!tank!
from!removing!either!the!insulation!or!roof!covering!from!the!tanks!whilst!
maintaining!water!temperature!at!30°C!in!Sudbury!...............................................................!27!
Figure(3.1:(Climatic!data!for!Sudbury,!ON,!Canada,!showing!average!monthly!
temperatures!(black)!and!solar!insolation!(grey).!!The!dashed!lines!represent!the!
minimum!of!the!respective!measurements,!15˚C!and!11!W/m2!(Barbosa,!Janssen,!
Ham,!Tramper,!&!Wijffels,!2003),!respectively.!.........................................................................!37!
Figure(3.2:(Schematic!of!a!smelter!coupled!microalgae!production!facility!(adapted!
from!Laamanen!et!al.,!2014)!..............................................................................................................!40!
Figure(3.3:(Proposed!roaster!offMgas!cooling!heat!exchanger.!..........................................!41!
Figure(3.4:(Sectioning!of!pond!for!heat!exchanger!spacing!determination.!................!42!
Figure(3.5:(Energy!requirements!to!maintain!30°C!for!sections!of!the!pond!(n!=!5).!!
Dashed!line!represents!the!energy!requirement!for!the!end!sections!and!the!solid!
line!the!energy!requirement!for!the!middle!sections.!............................................................!56!
Figure(4.1:(Flow!sheet!of!algae!production!(TSS!=!total!suspended!solids)!(adapted!
from!Mata!et!al.!(2010)).!......................................................................................................................!66!
Figure(5.1:(Laboratory!flotation!column!design!...................................................................!107!
Figure(5.2:(Recovery!(bars)!and!concentration!factor!(solid!squares)!of!
Scenedesmus)dimorphus!(UTEX!#1237)!as!a!function!of!heating!temperature.!The!
initial!microalgae!concentration!was!0.13!g/L!and!the!error!bars!represent!the!
standard!error!of!the!mean!(n!=!3).!.............................................................................................!111!
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Figure(5.3:((A)!Scenedesmus)dimorphus!(UTEX!#1237)!before!and!(B)!after!heating!
to!95°C.!Clumping!may!be!attributed!to!cell!lysing,!for!which!mass!loss!in!the!
heating!stage!was!measured!(C).!Error!bars!represent!the!standard!error!of!the!
mean!(n!=!3).!..........................................................................................................................................!113!
Figure(5.4:(Recovered!biomass!(Scenedesmus)dimorphus!(UTEX!#1237))!as!a!
function!of!postMheating!cooling!temperature.!Error!bars!represent!the!standard!
error!of!the!mean!(n!=!3).!.................................................................................................................!114!
Figure(5.5:(Recovery!(bars)!and!concentration!factor!(solid!diamonds)!as!a!function!
of!microalgae!strain!(initial!concentration!=!0.20!g/L),!at!a!temperature!of!85°C.!SD!
is!Scenedesmus)dimorphus!(UTEX!#1237),!and!the!wild!strains!were!WS1!
(Chlorococcum!sp.),!WS2!(Coccomyxa)sp.),!WS3!and!WS4!(Scenedesmus)sp.),!and!
WS5!and!WS6!(Chlamydomonas!sp.),!Error!bars!represent!the!standard!error!of!the!
mean!(n!=!3).!..........................................................................................................................................!115!
Figure(5.6:!Total!lipid!content!throughout!the!separation!process!of!Scenedesmus)
dimorphus!(UTEX!#1237).!Error!bars!represent!the!standard!error!of!the!mean!(n!=!
3).!................................................................................................................................................................!117!
Figure(6.1:!Laboratory!flotation!column!design!...................................................................!125!
Figure(6.2:(Recovery!(bars)!and!concentration!factor!(diamonds)!as!a!function!of!
algae!biomass!concentration!(1x!=!0.545!g/L),!at!a!temperature!of!85°C.!Error!bars!
represent!the!standard!error!of!the!mean!(n!=!3).!................................................................!128!
Figure(6.3:(Recovery!(bars)!and!concentration!factor!(diamonds)!as!a!function!of!
pH!alteration!(Initial!concentration!=!0.12!g/L).!Error!bars!represent!the!standard!
error!of!the!mean!(n!=!3).!.................................................................................................................!129!
Figure(6.4:(Recovery!(bars)!and!concentration!factor!(diamonds)!as!a!function!of!
combined!pH!alteration!and!heating!(Initial!concentration!=!0.12!g/L).!Error!bars!
represent!the!standard!error!of!the!mean!(n!=!3).!................................................................!130!

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List of Tables
Table(2.1:(Worldwide!smelting!operations!(*!Platinum!group!metals)!........................!11!
Table(2.2:(Parameters!used!in!the!model!...................................................................................!22!
Table(2.3:(Indirect!heating!requirements!to!maintain!a!250!m3!tank!at!15˚C!or!30˚C!
(empty!cells!represent!no!need!to!supply!indirect!heat)!......................................................!28!
Table(3.1:!Model!parameters.!..........................................................................................................!53!
Table(3.2:(OffMgas!and!energy!requirements!for!microalgae!ponds!maintained!at!
30°C.!..............................................................................................................................................................!54!
Table(3.3:(Comparison!of!different!plastic!piping!materials,!with!an!inlet!
temperature!of!70°C!and!an!exit!temperature!of!40°C!(PVC!=!polyvinyl!chloride,!PP!
=!polypropylene,!PEL!=!low!density!polyethylene)!.................................................................!57!
Table(3.4:(Experimental!results!based!on!inlet!temperature!and!pipe!size.!...............!58!
Table(4.1:!Comparison!of!algae!separation!techniques!........................................................!71!
Table(4.2:!Results!from!algae!flotation!for!water!treatment!..............................................!74!
Table(4.3:!Results!from!algae!flotation!for!biofuels!...............................................................!91!
Table(5.1:!Lipid!composition!of!unheated!and!heated!Scenedesmus!dimorphus!
(UTEX!#1237),!average!and!the!standard!error!of!the!mean!(n!=!3).!...........................!118!
Table(6.1:!Media!concentrations!before!and!after!heating!(a)!with!microalgae!
(Scenedesmus!dimorphus)!and!(b)!Bold’s!Basal!media!alone.!........................................!132!

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