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Fuels, Chemicals and Materialsfrom the Oceans andAquatic Sources

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Wiley Series in Renewable Resources

Series EditorChristian V. Stevens – Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium

Titles in the SeriesWood Modification – Chemical, Thermal and Other ProcessesCallum A. S. Hill

Renewables-Based Technology – Sustainability AssessmentJo Dewulf & Herman Van Langenhove

Introduction to Chemicals from BiomassJames H. Clark & Fabien E.I. Deswarte

BiofuelsWim Soetaert & Erick Vandamme

Handbook of Natural ColorantsThomas Bechtold & Rita Mussak

Surfactants from Renewable ResourcesMikael Kjellin & Ingegard Johansson

Industrial Application of Natural Fibres – Structure, Properties and Technical ApplicationsJorg Mussig

Thermochemical Processing of Biomass – Conversion into Fuels, Chemicals and PowerRobert C. Brown

Biorefinery Co-Products: Phytochemicals, Primary Metabolites and Value-Added BiomassProcessingChantal Bergeron, Danielle Julie Carrier & Shri Ramaswamy

Aqueous Pretreatment of Plant Biomass for Biological and Chemical Conversion to Fuelsand ChemicalsCharles E. Wyman

Bio-Based Plastics: Materials and ApplicationsStephan Kabasci

Introduction to Wood and Natural Fiber CompositesDouglas Stokke, Qinglin Wu & Guangping Han

Cellulosic Energy Cropping SystemsDouglas L. Karlen

Introduction to Chemicals from Biomass, Second EditionJames Clark & Fabien Deswarte

Lignin and Lignans as Renewable Raw Materials: Chemistry, Technology and ApplicationsFrancisco G. Calvo-Flores, Jose A. Dobado, Joaquin Isac-Garcia & Francisco J. Martin-Martinez

Cellulose Nanocrystals: Properties, Production and ApplicationsWadood Hamad

Forthcoming Titles

Biorefinery of Inorganics: Recovering Mineral Nutrients from Biomass and Organic WasteErik Meers & Gerard Velthof

Bio-Based SolventsFrancois Jerome & Rafael Luque

Nanoporous Catalysts for Biomass ConversionFeng-Shou Xiao & Liang Wang

The Chemical Biology of Plant BiostimulantsDanny Geelen

Biobased Packaging: Material, Environmental and Economic AspectsMohd Sapuan Salit & Muhammed Lamin Sanyang

Thermochemical Processing of Biomass: Conversion into Fuels, Chemicals and Power 2eRobert C. Brown

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Fuels, Chemicals andMaterials fromthe Oceans andAquatic Sources

Edited by

FRANCESCA M. KERTONDepartment of Chemistry, Memorial University of Newfoundland,

Canada

NING YANDepartment of Chemical and Biomolecular Engineering,

National University of Singapore, Singapore

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This edition first published 2017© 2017 John Wiley & Sons Ltd

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, ortransmitted, in any form or by any means, electronic, mechanical, photocopying, recording orotherwise, except as permitted by law. Advice on how to obtain permission to reuse material fromthis title is available at http://www.wiley.com/go/permissions.

The right of Francesca M. Kerton and Ning Yan to be identified as the authors of the editorialmaterial in this work has been asserted in accordance with law.

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Contents

List of Contributors xi

Series Preface xiii

Preface xv

1 Overview of Ocean and Aquatic Sources for the Production ofChemicals and Materials 1Francesca M. Kerton and Ning Yan1.1 Introduction 11.2 Shellfish-Based Biomass 3

1.2.1 Crustacean Shells 31.2.2 Mollusc Shells 7

1.3 Finfish-Based Biomass 91.4 Plant-Based Biomass 121.5 Summary and Outlook 13

References 14

2 Production and Conversion of Green Macroalgae (Ulva spp.) 19Shuntaro Tsubaki, Wenrong Zhu and Masanori Hiraoka2.1 Production of Ulva Biomass 19

2.1.1 Land-Based Tank Culture in Kochi 202.1.2 Improvement for More Intensive Culture 25

2.2 Conversion of Ulva Biomass 272.2.1 Microwave-Assisted Hydrothermal Reaction of Biomass 282.2.2 Microwave-Assisted Conversion of Ulva Biomass 29

2.3 Conclusions 36References 36

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3 A New Wave of Research Interest in Marine Macroalgae forChemicals and Fuels: Challenges and Potentials 43Ravi S. Baghel, Vaibhav A. Mantri and C.R.K. Reddy3.1 Introduction 433.2 Macroalgal Feedstock for Chemicals 443.3 Marine Macroalgae as a Biorefinery Feedstock 453.4 Marine Macroalgal Biomass as an Energy Feedstock 46

3.4.1 Bioethanol 473.4.2 Biodiesel 483.4.3 Biobutanol 483.4.4 Bio-oil 55

3.5 Advances in Cultivation Technology 553.6 Marine Algal Cultivation for CO2 Sequestration 563.7 Opportunities, Challenges and Conclusions 57

References 58

4 Kappaphycus alvarezii: A Potential Sustainable Resource forFertilizers and Fuels 65Dibyendu Mondal and Kamalesh Prasad4.1 Introduction 654.2 Composition and Processing of Kappaphycus alvarezii 664.3 Simultaneous Production of Liquid Fertilizer (κ-Sap) and

κ-Carrageenan from Fresh Kappaphycus alvarezii Seaweed 684.4 κ-Sap as Potential Plant Stimulant 694.5 Manipulation of κ-Sap for Sustainable Biomass Intensification

of Maize 714.6 Bioethanol Production from Kappaphycus alvarezii 72

4.6.1 Pretreatment of Freshly Harvested Biomass 744.6.2 Hydrolysis of the Dry Biomass to Obtain Fermentable

Sugars 744.6.3 Pretreatment of Hydrolysate to Reduce the

Concentration of Fermentation Inhibitory Components 744.6.4 Enzymatic Fermentation of the Hydrolysate to Yield

Ethanol 764.6.5 Purification of Ethanol from Fermentation Broth 77

4.7 Fuel Intermediates and Useful Chemical from Kappaphycusalvarezii 77

4.8 Environmental Impact of Fuel and Fertilizers Production fromKappaphycus alvarezii 79

4.9 Conclusion and Future Prospect 79Acknowledgement 79References 80

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Contents vii

5 Microalgae Bioproduction – Feeds, Foods, Nutraceuticals,and Polymers 83Clifford R. Merz and Kevan L. Main5.1 Introduction 835.2 Microalgae and Bioproduction Methods 85

5.2.1 Microalgae Groups Considered 855.2.2 Bioproduction of Microalgae – Methods 86

5.3 Microalgae Feedstock Products and Coproducts 945.3.1 Microalgae as Animal Feed 945.3.2 Microalgae as a Human Food Source 955.3.3 Microalgae in Nutraceuticals 965.3.4 Biopolymers from Microalgae 98

5.4 Conclusion – The Path Forward 102Acknowledgments 103References 103

6 Innovations in Crustacean Processing: Bioproduction of Chitinand Its Derivatives 113Heather Manuel6.1 Introduction 1136.2 Innovations in Crustacean Processing 115

6.2.1 Conventional Processing Technologies 1156.2.2 Innovations in Crustacean Processing 122

6.3 Utilization of Marine By-Products 1286.3.1 Processing Technologies for Crustacean By-Products 1296.3.2 A Biorefinery Approach for Value-Chain Optimization

of Crustacean Biomass Waste 1306.4 Bioproduction of Chitin and Its Derivatives 132

6.4.1 Background 1326.4.2 Isolation and Extraction of Chitin and Chitosan 1346.4.3 Non-chemical Structural Modifications of Chitin and

Chitosan 1396.5 Conclusions 141

References 143

7 Recent Progress in the Utilization of Chitin/Chitosan forChemicals and Materials 151Bin Li and Xindong Mu7.1 Structure, Source and Properties of Chitin/Chitosan 1517.2 Isolation and Purification of Chitin/Chitosan 1537.3 Derivatives of Chitin/Chitosan 1557.4 Utilization of Chitin/Chitosan for Chemicals and Materials 156

7.4.1 Utilization of Chitin/Chitosan for Chemicals 156

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viii Contents

7.4.2 Utilization of Chitin/Chitosan for Materials 1707.5 Closing Remark and Perspectives 179

References 180

8 Characterization and Utilization of Waste Streams from MolluscAquaculture and Fishing Industries 189Jennifer N. Murphy and Francesca M. Kerton8.1 Introduction 1898.2 Processing and Characterization of Mollusc Shells 192

8.2.1 Processing Technologies 1928.2.2 Characterization of Shells 195

8.3 Applications of Mollusc Shells 1998.3.1 Soil Amendment 2018.3.2 Treatment of Metal Contamination and Acid Mine

Drainage 2028.3.3 Phosphate Removal and Water Purification 2088.3.4 Building Materials 2128.3.5 Mollusc-Derived Calcium Oxide in Catalysis 219

8.4 Conclusions 224References 225

9 Fish Processing Waste Streams as a Feedstock for Fuels 229Kelly Hawboldt and Ibraheem Adeoti9.1 Introduction 2299.2 Fish Processing By-Product 2309.3 Chemical and Physical Properties of Crude Fish Oil 231

9.3.1 Chemical Composition of Crude Fish Oil 2339.4 Oil Recovery Processes and Parameters 236

9.4.1 Physical/Thermal Separation Processes 2369.4.2 Chemical Extraction Processes 2389.4.3 Biological/Chemical Hydrolysis and Fermentation 2449.4.4 Purification 2459.4.5 Preservation of Feedstock and the Recovered Oil 246

9.5 Fuel Properties of Crude and Refined Fish Oils 2479.5.1 Rheological Properties 2479.5.2 Chemical Properties Affecting Fuel Quality 2489.5.3 Thermal Properties 2499.5.4 Other Fuel Properties 250

9.6 Performance of Crude Fish Oil as a Fuel 2519.7 Upgrading Marine Crude Bio-Oil 251

9.7.1 Types of Refined Fish Oil Products 2529.7.2 Transesterification 2559.7.3 Pyrolysis 258

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Contents ix

9.7.4 Microemulsification 2589.7.5 Alternative Processes 259

9.8 Emission Comparison for Bio-Oils 2599.8.1 Crude Fish Oil 2619.8.2 Fish Biodiesel 2629.8.3 Biogas from Fish Waste 2639.8.4 Fish Biofuels from Other Processes 264

9.9 Comparison of Crude Oil and Refined Oil Performance as a Fuel 2659.10 Comparison of Fish Biofuels 2689.11 Summary 268

References 269

Index 277

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List of Contributors

Ibraheem Adeoti Department of Process Engineering, Memorial University ofNewfoundland, Canada

Ravi S. Baghel Marine Biotechnology and Ecology Division, CSIR – CentralSalt & Marine Chemicals Research Institute, India; Academy of Scientificand Innovative Research (AcSIR), Central Salt & Marine Chemicals ResearchInstitute, India

Kelly Hawboldt Department of Process Engineering, Memorial University ofNewfoundland, Canada

Masanori Hiraoka Usa Marine Biological Institute, Kochi University, Japan

Francesca M. Kerton Department of Chemistry, Memorial University of New-foundland, Canada

Bin Li CASKey Laboratory of Bio-BasedMaterial, Qingdao Institute of Bioen-ergy and Bioprocess Technology, Chinese Academy of Sciences, China

Kevan L. Main Marine & Freshwater Aquaculture Research Program, MoteMarine Laboratory, USA

Vaibhav A. Mantri Marine Biotechnology and Ecology Division, CSIR –Central Salt &Marine Chemicals Research Institute, India; Academy of Scientificand Innovative Research (AcSIR), Central Salt & Marine Chemicals ResearchInstitute, India

Heather Manuel Centre for Aquaculture and Seafood Development, Fisheriesand Marine Institute of Memorial University of Newfoundland, Canada

Clifford R. Merz University of South Florida, College ofMarine Science, USA

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xii List of Contributors

Dibyendu Mondal Natural Products & Green Chemistry Division,CSIR – Central Salt and Marine Chemicals Research Institute, India; Departmentof Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro,Portugal

Xindong Mu CAS Key Laboratory of Bio-Based Material, Qingdao Instituteof Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China

Jennifer N. Murphy Department of Chemistry, Memorial University ofNewfoundland, Canada

Kamalesh Prasad Natural Products & Green Chemistry Division,CSIR – Central Salt and Marine Chemicals Research Institute, India;AcSIR – Central Salt & Marine Chemicals Research Institute, India

C.R.K. Reddy Marine Biotechnology and Ecology Division, CSIR – CentralSalt & Marine Chemicals Research Institute, India; Academy of Scientific andInnovative Research (AcSIR), Central Salt & Marine Chemicals Research Insti-tute, India

Shuntaro Tsubaki Department of Applied Chemistry, Graduate School ofScience and Engineering Tokyo Institute of Technology, Japan

Ning Yan Department of Chemical and Biomolecular Engineering, NationalUniversity of Singapore, Singapore

Wenrong Zhu Graduate School of Kuroshio Science, Kochi University, Japan

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Series Preface

Renewable resources, their use, and modification are involved in a multitude ofimportant processes with a major influence on our everyday lives. Applicationscan be found in the energy sector, paints and coatings, and the chemical, pharma-ceutical, and textile industry, to name but a few.The area interconnects several scientific disciplines (agriculture, biochemistry,

chemistry, technology, environmental sciences, forestry, etc.), which makes it verydifficult to have an expert view on the complicated interaction. Therefore, the ideato create a series of scientific books that will focus on specific topics concerningrenewable resources has been very opportune and can help to clarify some of theunderlying connections in this area.In a very fast-changing world, trends are not only characteristic for fashion and

political standpoints; science is also not free from hypes and buzzwords. The useof renewable resources is again more important nowadays; however, it is not partof a hype or a fashion. As the lively discussions among scientists continue abouthow many years we will still be able to use fossil fuels—opinions ranging from50 to 500 years—they do agree that the reserve is limited and that it is essentialnot only to search for new energy carriers but also for new material sources.In this respect, renewable resources are a crucial area in the search for alter-

natives for fossil-based raw materials and energy. In the field of energy supply,biomass and renewable-based resources will be part of the solution alongside otheralternatives such as solar energy, wind energy, hydraulic power, hydrogen technol-ogy, and nuclear energy.In the field of material sciences, the impact of renewable resources will probably

be even bigger. Integral utilization of crops and the use of waste streams in certainindustries will grow in importance, leading to a more sustainable way of producingmaterials.Although our society was much more (almost exclusively) based on renew-

able resources centuries ago, this disappeared in the Western world in the nine-teenth century. Now it is time to focus again on this field of research. However, it

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xiv Series Preface

should not mean a “retour á la nature,” but it should be a multidisciplinary efforton a highly technological level to perform research toward new opportunities, todevelop new crops and products from renewable resources. This will be essen-tial to guarantee a level of comfort for a growing number of people living on ourplanet. It is “the” challenge for the coming generations of scientists to developmore sustainable ways to create prosperity and to fight poverty and hunger in theworld. A global approach is certainly favored.This challenge can only be dealt with if scientists are attracted to this area and

are recognized for their efforts in this interdisciplinary field. It is, therefore, alsoessential that consumers recognize the fate of renewable resources in a number ofproducts.Furthermore, scientists do need to communicate and discuss the relevance of

their work. The use and modification of renewable resources may not follow thepath of the genetic engineering concept in view of consumer acceptance in Europe.Related to this aspect, the series will certainly help to increase the visibility of theimportance of renewable resources. Being convinced of the value of the renew-ables approach for the industrial world, as well as for developing countries, I wasmyself delighted to collaborate on this series of books focusing on different aspectsof renewable resources. I hope that readers become aware of the complexity, theinteraction and interconnections, and the challenges of this field and that they willhelp to communicate on the importance of renewable resources.I certainly want to thank the people of Wiley’s Chichester office, especially

David Hughes, Jenny Cossham, and Lyn Roberts, in seeing the need for such aseries of books on renewable resources, for initiating and supporting it, and forhelping to carry the project to the end.Last, but not least, I want to thank my family, especially my wife Hilde and

children Paulien and Pieter-Jan, for their patience and for giving me the time towork on the series when other activities seemed to be more inviting.

Christian V. StevensFaculty of Bioscience Engineering

Ghent University, BelgiumSeries Editor “Renewable Resources”

June 2005

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Preface

This book provides a holistic view on fuels, chemicals and materials fromrenewable sources in the oceans and other aquatic media. To our knowledge, it isthe first of its kind to cover water-based biomass—both plants and animals—forvalue-added applications beyond food, despite the fact that there are previouslypublished books focused on more specialized sources (such as algae).The concept of biorefinery, referring to processes that convert biomass into

fuels, chemicals and materials, has received wide awareness and acknowledge-ment in the new century. The first-generation biorefinery uses sugar- or starch-richcrops, associated with the issue of food security, while the second-generationbiorefinery is based on cellulosic materials. In both cases, however, land scarcitysometimes becomes a limiting factor. In this context, oceans and other aquaticmedia, which account for over 2.5 times more area than land on Earth, appear tobe a complementary source of feedstocks for biorefineries.We realized the underestimated potential of a great variety of water-based

biomass resources years back. Together with other researchers around the world,we have strived to extend the concept of biorefinery to include diversified biomassresources from the ocean. For instance, F. Kerton and coworkers proposedand practiced the concept of ‘Marine Biorefinery’, taking fishery by-productsand transforming them into a range of value-added products in Newfoundland,Canada, while N. Yan proposed and practiced the concept of ‘Shell Biorefinery’,in which waste crustacean shells are fractionated into three major componentsand further upgraded for a range of applications.To date, research and development toward this sort of biorefinery are still in

a nascent state, with most work only demonstrated in the lab while large-scalecommercial productions may be years ahead. However, there is a consensus beingreached around the globe that the valorization of ocean biomass could nicely com-plement the existing biorefinery, to help avoid the compromise of food security andland use for human beings. Ocean biomass also features unique components and

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xvi Preface

structures enabling the production of high-value chemicals and materials that aredifficult to be obtained from other biomass resources or fossil fuels.These promising aspects made us come together and organize this book, cov-

ering various aspects of ocean-biomass-based biorefinery. The book is structuredin the following manner: Chapter 1 provides an overview of ocean and aquaticsources for chemicals and materials. Chapters 2–4 describe the production, har-vesting and conversion of marine macroalgae into fuels and other compounds.Chapter 5 switches to the topic of microalgae, reviewing its transformation intofeeds, foods, nutraceuticals and polymers. Chapters 6 and 7 are focused on crus-tacean shells, with the Chapter 6 providing recent developments in fractionationof shells into chitin, while Chapter 7 summarizes a broad range of applicationsof chitin in chemical production and materials science. The final two chapters(Chapters 8 and 9) describe the utilization of waste streams from mollusc andfinfish industries, respectively.This book should be able to serve as a valuable reference for academic and

industrial professionals in research and development sectors in renewable fuels,chemicals andmaterials.Most chapters are written at an introductory level but withsufficient details to serve both undergraduate and graduate students majoring inchemistry, chemical engineering, marine sciences and biotechnology and beyond.Finally, the editors would like to express their gratitude to all the chapter authors

for their invaluable time and contribution to the book and our colleagues, studentsand family for their patience while we worked on it.

Francesca M. KertonMemorial University of Newfoundland, St. John’s, Canada

Ning YanNational University of Singapore, Singapore

October 2016

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1

Overview of Ocean andAquatic Sources for the

Production of Chemicals andMaterials

Francesca M. Kerton1 and Ning Yan2

1Department of Chemistry, Memorial University of Newfoundland, Canada2Department of Chemical and Biomolecular Engineering, National University of Singapore,

Singapore

1.1 Introduction

The Earth is a watery planet—about 71% of its surface is covered by water [1].Among all liquid water resources, less than 1% is freshwater, and over 99% is saltyseawater. Freshwater in lakes and rivers, despite being in a very small percentage,has shaped our civilizations since the beginning of humankind. On the other hand,people’s perspective towards the ocean has been changing over time. In the olddays, the oceans served for trade, adventure and discovery, as it set different civi-lizations apart. At present, the oceans are widely regarded as one of Earth’s mostvaluable natural resources for food, various minerals, crude oil and natural gas.As there is an increasing concern regarding sustainability, human beings cur-

rently strive for a paradigm shift of obtaining resources from renewable feedstocks

Fuels, Chemicals and Materials from the Oceans and Aquatic Sources, First Edition.Edited by Francesca M. Kerton and Ning Yan.© 2017 John Wiley & Sons Ltd. Published 2017 by John Wiley & Sons Ltd.

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2 Fuels, Chemicals and Materials from the Oceans and Aquatic Sources

Figure 1.1 Overview of the animal and plant resources from the ocean and other aquaticsources: microalgae, macroalgae, fish, crustaceans and molluscs.

instead of non-renewable, depleting ones. More than 150,000 animals and 100,000plants can be found in the oceans, all of which are renewable organic species.Sea plants can be divided into microalgae and macroalgae, whereas sea animalscan be broadly categorized into three main types, namely fish, crustaceans andmolluscs (Figure 1.1). Unfortunately, the huge potential of the oceans and otheraquatic sources to provide renewable organic carbon, hydrogen, nitrogen and otherelements as starting materials for chemicals and materials appears to be underes-timated. Indeed, according to the data from Web of Science in 2015, of the totalrelevant papers on renewable feedstocks, only 2.3% were concerned with algae oroceanic biorefinery [2].In fact, compared to conventional land-based biomass, aquatic (in particular,

oceanic) biomass has several advantages [3]. First of all, a majority of seaweedsand fishery waste are not consumed as human food, and as such, there are noethical issues of compromised food supply due to chemical and material produc-tion. At the same time, the development of ocean-based biorefinery can release theland area constrains, which are a serious problem in some countries such as Japanand Singapore. Many areas in the world are short of fertile soil for the genera-tion of land-based biomass, and through the development of ocean-sourced feed-stocks, people in these regions would utilize renewable materials without costlyland-based agriculture. Last but not least, certain oceanic biomass species haveintrinsic advantages over land-based resources, such as faster growth rate, lessdemanding growth conditions, more enriching components and so on.People have achieved remarkable success in harnessing land-based

biomass—starch, woody biomass and vegetable oils—for fuels and chemi-cals. A landmark event was the opening of the world largest cellulose bioethanol

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Overview of Ocean and Aquatic Sources for the Production of Chemicals and Materials 3

refinery plant with an annual productivity of 30 million gallons by DuPont inNovember 2015 [4]. Woody biomass, consisting primarily of cellulose, hemicel-lulose and lignin, enters the biorefinery to be separated and further converted intoa wide scope of valuable products [5, 6]. We could anticipate similar conceptstowards valorization of aquatic-source-based biomass feedstocks. In the aquaticbiomass refinery, ‘wastes’ could be fractionated through an array of processesinto different components and further transformed into end products via physical,chemical and biological treatments. Once these objectives are met, new oppor-tunities for building waste industries from ocean-based feedstock will arise. Toachieve that, strong supports from research institutes, governments, organizations,companies and the public are integral. In particular, groundbreaking fundamentalresearch from researchers worldwide is crucially required to conquer the technicalbarriers for integrated, value-added applications of oceanic biomass.In this chapter, we aim to provide an overview of various feedstocks from

ocean and other aquatic sources, including sea-plant-based biomass, finfish-basedbiomass and shellfish-based biomass. The chemical component, current produc-tion scale, utilization and potential application and/or upgrading of each of theseare summarized in separate sections.

1.2 Shellfish-Based Biomass

1.2.1 Crustacean Shells

Global shellfish production, such as crabs, shrimps and lobsters, reached around12 million tons in 2014 [7]. With such massive production, and due to the sig-nificant shell content (e.g. the shell of a crab can account for 60% of its weight),tremendous amounts of waste are generated from these crustacean species everyyear. As an estimation, astonishing 6–8 million tons of waste from crustaceans areproduced annually [8].Long before the modern era, shells were used as currency and regarded as a

symbol of wealth. Later on, they were gradually substituted with other materialsand became useless. Nowadays, there has been essentially no satisfactory solu-tion to utilize the crustacean shells. Raw shells, such as dried shrimp shell or crabshell powder, have very low monetary value. Newport International, a seafoodcompany partnering with co-packing plants in many Southeast Asian countries,including Indonesia, Vietnam, Thailand and Philippines, sells the by-product ofdried shrimp shells at merely US$ 100–120 per ton. The price is commensurablewith wheat straws and corn stover, which are agricultural wastes typically sold atUS$ 50–90 per ton [9]. Due to the very low profitability, a vast majority of wasteshells are disposed or landfilled without use. In developing countries that lack reg-ulations, waste shells are often directly discarded, posing environmental concern.In developed countries, disposal can be costly—for instance, as high as US$ 150per ton can be charged in Australia and Canada.

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4 Fuels, Chemicals and Materials from the Oceans and Aquatic Sources

Crustacean shells constitute 15–40% chitin, 20–40% protein and 20–50% cal-cium carbonate [10]. With several million tons of shells generated worldwide eachyear, the huge potential value of such shells is currently wasted. It is crucial toreconsider how to utilize such an abundant and cheap renewable resource, ratherthan continue treating it as waste. Further details on the processing of crustaceanshells and utilization of chitin and chitosan can be found in Chapters 6 and 7 ofthis book.The protein in shells is a good nutrient for animal feed. For example, the protein

from Penaeus shrimp shell is a complete protein food as it contains all the essentialamino acids. The ratio of essential amino acids to total amino acids is 0.4; thenutrient value is comparable with that of soybean meals [11]. The market demandfor proteinmeal continues to increase due to the rapid growth in livestock breeding.If all the protein from crustacean waste shells from Southeast Asia is extracted asanimal feed, an annual market value of over US$ 100 million could be expectedeven based on the most conservative estimation [12].Calcium carbonate is widely applied in construction, pharmaceutical, agri-

cultural and paper industries. Current production of calcium carbonate mainlycomes from geological sources such as marble and chalk. Ground calciumcarbonate, being the major product, has a market price based on a particle size,which ranges from US$ 60–66 per ton for coarse particles to US$ 230–280per ton for fine particles [13]. Ultrafine particles can reach an astonishing US$14,000 per ton. Provided that the calcium carbonate from crustacean shellscan only be made into coarse particles, an annual market value of up to US$45 million could be estimated from Southeast Asian countries. Due to itsbio-origin, calcium carbonate from waste shells is superior to that from marbleand limestone for applications involving human consumption, such as calciumcarbonate tablets.The last major component, chitin, is a linear polymer of β(1→4)-linked

2-acetamido-2-deoxy-d-glucopyranose [14]. The structure of chitin is similar tothat of cellulose, but chitin has an amide or an amine group instead of a hydroxylgroup on the C2 carbon in the repeating unit. Aside from being one of the majorcomponents in crustacean shells, chitin is widely present in the exoskeleton ofinsects, fungi and plankton, making it the second most abundant biopolymeraround the world, with approximately 100 billion tons produced per year [15].Chitin and chitosan (the water-soluble derivative) have been identified as usefulfunctional polymers in several niche applications, including cosmetics, watertreatment and biomedicals [16]. However, the current utilization of chitin neithermatches its abundance nor fully harnesses its structural uniqueness.Chitin serves as a major renewable feedstock that simultaneously offers organic

carbon and organic nitrogen elements. While a consensus has been reached onthe importance of renewable organic carbon, not much has been emphasized onrenewable organic nitrogen resources. The necessity is not obvious—after all,nitrogen is the dominant fraction in the Earth’s atmosphere. However, nitrogen

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Overview of Ocean and Aquatic Sources for the Production of Chemicals and Materials 5

gas has to be converted into ammonia prior to application or further transforma-tions. Ammonia synthesis is undesirable for the low efficiency that this singleprocess accounts for 2–3% global energy consumption [17]. In addition, threemoles of hydrogen gas, which is currently produced from fossil fuels, are con-sumed for every mole of nitrogen gas. The chemical industry cannot claim tobe sustainable without addressing the sustainability issue of the nitrogen sourcein its products.Chitin appears to be more suitable for the production of some nitrogen-

containing compounds. The major elements required—organic carbon, nitrogenand oxygen—are already in place. Chitin is also enriched with functional groups,thus requiring fewer derivatization steps when used as a raw material comparedwith fossil fuels. Effective valorization of chitin into chemicals may representa ‘Game-Changing Innovation’ by bringing substantial benefits for both theeconomy and environment.Valorization of shells from crustacean species is not easy. First and foremost,

fractionation is needed for further physical, chemical or biochemical processing.However, the current commercialized route to fractionate crustacean shells is asso-ciated with serious environmental and economic issues. Two key steps in the pro-cess include the removal of protein from the shell by sodium hydroxide solutionand the digestion of calcium carbonate by hydrochloric acid. If chitosan is thefinal product, an additional step of treating chitin with 40% concentrated sodiumhydroxide solution is required.The entire process is destructive, wasteful and expensive—protein and calcium

carbonate fractions are currently destroyed and never recovered; sodium hydroxideand hydrochloric acid are highly corrosive and hazardous; production of 1 ton chi-tosan from crustacean shells needs more than 10 tons water. All these factors leadto negative environmental impacts and high capital costs. As a result, the price ofgood-quality chitin is as high as US$ 200 per kilogram, although the starting mate-rial is not costly. Due to the high price, global industrial use of chitin is estimated tobe only 10,000 tons annually [15]. The lack of competitive pricing of chitin in themarket, in turn, limits its production scale, forming a ‘high cost/low demand/lowproduction’ pattern. Economically and ecologically unfavourable, chitin produc-tion plants are absent in many developed countries and only exist on a small scalein countries such as Thailand and Indonesia.There are considerable challenges in the post-fractionation steps as well. While

the utilization of calcium carbonate and proteins is comparatively easier, thetransformation of chitin to value-added, nitrogen-containing chemicals is a criticalproblem. We envisage that the major obstacles in valorizing chitin to be similarto those in woody biomass valorization. Unlike fossil fuels, biomass feedstockssuch as chitin and cellulose are highly functionalized, oxygen-enriched polymers.Side reactions occur easily, leading to the formation of a variety of complicatedcompounds under severe reaction conditions. In addition, natural chitin is ahighly crystallized biomass that impedes accessibility of reagents to the polymer

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6 Fuels, Chemicals and Materials from the Oceans and Aquatic Sources

chains. Finally, it is often challenging to separate these bio-based products fromthe reaction system in a cost-effective way.To establish a new profitable industry with crustacean shell waste, creative solu-

tions have to be developed for both upstream and downstream sectors. In theupstream sector, the key issue is enabling manufacturing competitiveness to lessenproduction cost and environmental impact; in the downstream sector, the key issueis establishing economic sustainability via integrated, value-added applications ofeach component.A revolutionary fractionation method to separate chitin, calcium carbonate and

proteins is highly desirable (Figure 1.2). For an ideal protocol, the following char-acteristics should apply: (i) all three major components are processed into separatefractions; (ii) strongly corrosive or hazardous reagents are avoided; and (iii) wastegeneration is minimized. Fortunately, new technologies that partially satisfy thesecriteria are emerging. For example, lactic acid fermentation has been developedfor chitin production both on a lab scale and a pilot-plant scale [18]. The processadopts blended bacteria to simultaneously consume proteins and decompose cal-cium carbonate. Protein hydrolysate and calcium lactate can be recovered afterchitin separation.Another method is to utilize specific ionic liquids, which can remarkably dis-

solve carbohydrate polymers and thus extract chitin from waste shells [19]. Inthis way, the produced chitin has high molecular weight and is thus suitable forprocessing into fibres and films. In addition to these, we propose exploring the pos-sibility of shell fractionation via physical methods more intensively. Ball mill andsteam explosion may be effective in separating the major components in the shells.Finally, a process combining chemical force and mechanical force might prove to

CaCO3 Constructions PapermakingPharmaceuticals

Textiles

Food additives

Protein

Fra

ctio

natio

n

Chitin

Nitrogen-

containing

chemicals8

3 21

4 5

6

OO

7

O

n

HO

HN

OH

Shell waste

Fertilizers Animal feeds

Figure 1.2 The concept of “waste-shell refinery” for various useful chemicals and materials(diagram based on the concept presented in Ref. [8]). (Source: Data taken from Yan and Chen2015 [8].)

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Overview of Ocean and Aquatic Sources for the Production of Chemicals and Materials 7

be advantageous, since synergistic effectsmay lead to unprecedented performance.To exemplify a scenario, combined use of ball mill and a small amount of acidcatalyst leads to a complete degradation of wood without extra heating. A simi-lar strategy could be applicable to shells, enabling a highly effective, solvent-freeapproach for fractionation.In the downstream sector, diversified utilization of each component is essential.

While calcium carbonate and proteins can find direct applications, there isan untapped potential towards chitin utilization. The transformation of chitininto functional polymers and a series of value-added chemicals is a promis-ing direction. There have been decades of research on chitin conversion topolymer derivatives for distinct applications. Conversion of chitin into smallnitrogen-containing chemicals is also developing very fast, although it is still ata very early stage. A nitrogen-containing furan derivative was obtained directlyfrom chitin via boric-acid-catalyzed depolymerization and dehydration [20, 21].Recently, a number of other value-added chemicals have also been producedfrom chitin or chitin monomer on the lab scale [22–25]. Future investigationshould be focused on the following: (i) exploration of new routes from chitinto other potentially related chemicals; (ii) enhanced product yield via improvedcatalysis and/or chitin pretreatment; and (iii) facile separation of products, suchas membrane-based pervaporation technique.

1.2.2 Mollusc Shells

As described in Chapter 8 of this book, in 2013, over 18 million tons of molluscswere harvested, which amounted to 11% of the world’s fisheries, and they weremainly produced via aquaculture [7]. In addition to being a valuable source ofprotein in our diets, molluscs have the benefits of being able to reach maturity inonly 2–3 years and are filter feeders, so they do not need to be fed by the farmer.Waste materials, which could be valorized, are produced at a number of stagesduring harvesting and processing this food. For example, some molluscs will bedead when harvested, die during harvesting or are damaged during the harvestingprocess (e.g. cracked shells). These wastes can be used to supply biorenewablecalcium carbonate and possibly protein product streams (Figure 1.3). The proteincan be used in a similar way to that obtained from crustacean shells as describedearlier, that is, as a feed or fertilizer. More recently, there has been interest in theuse of mussel protein as a nutritional supplement because it contains componentsthat have the potential to treat obesity [26]. Therefore, we expect enhanced interestin mollusc production in the coming years, which could lead to more waste beingproduced. Furthermore, if themollusc is processed before beingmarketed as a food(e.g. canned)—the meat will be removed from the shell, but the shell will oftenstill contain residual protein (i.e. the adductor muscle of the mollusc). The wastestreams from mollusc production, if not handled correctly, can be a biohazard,and if the waste is not used, it must be disposed of at specialist landfill sites with

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8 Fuels, Chemicals and Materials from the Oceans and Aquatic Sources

Shell

Cosmetics

pharmaceuticals

Water/soil

treatment

acid mine drainage

Building materials

composites

catalyst support

Protein

Fish feed

Flavourings

food supplements

Amino acids

(chemical building

blocks)

Figure 1.3 Potential products and applications of materials from a mollusc-based waste utiliza-tion process.

associated tipping costs of approximately US$ 150 per ton. This leads to an addedincentive for farmers to explore alternative waste disposal/processing options asdescribed as follows.There are two main processes that have been explored for cleaning mollusc

shells in order to eliminate the biohazard risk and produce value-added materials.The first process involves burning off residual protein and organic matter by heat-ing the shells to 500 ∘C. This has been explored on a pilot-plant scale in the regionof Galicia, Spain [27]. Various challenges were encountered during this scale-up,for example, SO2 and NO2 emissions when oil was used in the heating process.Furthermore, in such a process, the protein stream is wasted. From a sustainabilityperspective, biocatalytic (enzymatic) cleaning processes are perhaps more promis-ing. Enzymatic proteolysis of finfish and crustacean by-products has been studiedextensively, but there are few examples of its application to mollusc and molluscshell processing. In most examples, only a small amount of the catalytic proteaseenzyme is needed, and temperatures are not much higher than room temperature(40–70 ∘C) [28]. As with most enzymatic processes, the pH of the process must bemonitored in order to prevent deactivation of the enzyme. The protein hydrolysatestream produced via such hydrolysis reactions has potential uses in flavourings orsupplements within the food industry. Further hydrolysis and separations couldyield amino acids, which could be used as chemical building blocks to build upmore complex structures such as bioactive compounds (pharmaceuticals).

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Overview of Ocean and Aquatic Sources for the Production of Chemicals and Materials 9

Although less extensively studied compared to crustacean waste streamsdescribed in Section 1.2.1, applications of mollusc shells in a range of areas havebeen proposed and investigated on a lab scale. The calcium-carbonate-rich shellsproduced by molluscs have the potential to become high-value, low-volumeproducts (e.g. cosmetics or medicine) or low-value, high-volume products (e.g.soil amendment or building materials). Applications of mollusc shells include thefollowing: feed additives for poultry, soil amendment, treatment for acid minedrainage, water purification, additive for building materials (e.g. concrete) andlime (calcium oxide) production. Additonally, it is worth noting that the structureof biogenic calcium carbonate [29, 30] is significantly different from that ofquarried calcium carbonate, and this may lead to additional value to end users.For example, in Thailand, a range of different shells were studied as cost-effectivereplacements for Portland cement in the production of plastering cement [31].It is also worth noting that molluscs can play an important role in integrated

multi-trophic aquaculture (IMTA) that is being explored worldwide as a methodof sustainable farming. In such approaches, different organisms are grown/farmedin close proximity in an attempt to mimic natural aquatic ecosystems andprevent pollution of the oceans nearby. For example, a pilot project has beenstudied in the Bay of Fundy, New Brunswick, Canada [32]. Seaweed (Kelp),mussels and Atlantic salmon were grown nearby, uneaten salmon feed and faecesprovided nutrients to the mussels and excess dissolved nitrogen and phosphorusproduced during the salmon farming were taken up by the seaweed. It is hopedthat such practices will prevent hypernutrification and eutrophication of coastalwaters around finfish farms. If IMTA becomes a well-established way to reduceenvironmental impacts of finfish farming, levels of mollusc production will likelyincrease as the aquaculture industry continues to grow to meet the needs of agrowing global population [7].

1.3 Finfish-Based Biomass

About 580 species of fish, including finfish and shellfish, are farmed worldwide,and production from wild capture and aquaculture exceeded 160 million tonsin 2013, with aquaculture contributing 70 million tons [7]. The most importantfarmed finfish species are carp, tilapia, catfish and salmon. The amount andtype of fish farmed often depend on the location and climate. For example, themajor producers of farmed salmon are Chile, Norway, Scotland and Canada.Finfish farming can occur in cages at sea or on land. Research is ongoing towardsdevelopment of farming sites further out at sea, as, at present, most of them arenormally situated in sheltered, coastal locations. However, there is interest indeveloping multi-platform sites where IMTA (described earlier) can be pursuedand monitored alongside off-shore wind-farm platforms so that food and powerwould be generated at a single site and costs of manpower and transport could beshared.

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10 Fuels, Chemicals and Materials from the Oceans and Aquatic Sources

Hatchery/

nursey

Feed

Grow-out

cages

Fish meal and

fish oil

Smolts

(young fish)

Primary

processingHarvest

Food

distributor

Secondary

processing

Biofuel

fertilizer

supplements

pet food

Bioprocessing

Figure 1.4 Stages in the production of farmed finfish and potential end products.

The typical stages in finfish farming are outlined in Figure 1.4. Upon harvesting,fish frequently undergo primary processing where they are decapitated and guttedand often fileted. The fish may then undergo secondary processing such as smok-ing or salting. During processing, significant quantities of waste are produced:heads, viscera (guts), belly flaps, frames (bones), skin, gills and blood water [33].Approximately 70 million tons of fish per year are processed worldwide by fillet-ing, freezing, canning or curing, and these activities generate 30–50% waste, thatis, 21–35 million tons of waste [7]. It should also be noted that biological wastematerial is also produced during the farming process, such as morts (dead fish) arefound in cages and must be removed in order to prevent disease. Furthermore, insome cases, disease outbreaks or severe weather (low or high temperatures) cancause spikes in fish deaths. In most cases, this waste (processing waste and morts)currently goes to landfill and, in some cases, is used to produce fertilizer. How-ever, a major problem with this waste stream is that it is a biohazard, and this riskis heightened if the material is stored without undergoing some form of pretreat-ment (e.g. pasteurization). In order for the valorization potential of the waste to bemaximized, it would be ideal for bioprocessing to occur as soon after harvestingand primary processing as possible. Some of the bioactive components within thefish waste stream are temperature and time sensitive (i.e. they decompose/degradewhen heated or stored). If bioprocessing of properly stored and preserved materialis performed, a broad range of high-value products could potentially be obtained,including amino acids, bioactive peptides, enzymes, [34] collagen, hydroxyap-atite, calcium carbonate and ω-3 fatty acids. However, if the material degrades,the by-products of fish processing will only have a relatively low value, such asfertilizer, animal feed, heating oil and biogas from silage.In many cases, lessons can be learnt from waste management strategies and

biosecurity containment approaches from other locations around the world. For

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Overview of Ocean and Aquatic Sources for the Production of Chemicals and Materials 11

example, in the field of salmon aquaculture, Canadians are exploring strategiespreviously used successfully in Norway and Scotland. From 2015 onwards, theNewfoundland Aquaculture Industry Association (NAIA), in cooperation withtheir member salmon-farming companies, has been investigating the industrialapplication and biosecurity benefits of ensiling waste from fish farms [35].Appropriate on-farm salmon silage systems from Norway and Scotland werestudied. Fish silage is ‘a liquid product made from whole fish or parts of fish thatare liquefied by the action of enzymes in the fish in the presence of an addedacid. The enzymes break down fish proteins into smaller soluble units, and theacid helps to speed up their activity while preventing bacterial spoilage’ [36]. Inthe NAIA systems, formic acid is being used, and the resulting silage is beingshipped to a dairy farm to be used as a feedstock in an anaerobic digester, whichis used to provide power on the farm. We think that there are many opportunitiesto enhance waste management strategies by combining efforts across severalindustries: in this case, agriculture (a dairy farm) and aquaculture (salmon farmsin the region), but such efforts could involve other areas with biological wastestreams such as food processing industries, forestry and municipal organic wastestreams.Fish silage can be used as a fuel in an anaerobic digester to produce energy

in the form of biogas. However, as described in Chapter 9 of this book, there issignificant potential in isolating oils and generating liquid fuels from fish wastestreams [37]. Some fish species are naturally oilier than others, with those fish withdarker flesh pigments generally having a higher lipid content (e.g. salmon, troutand Arctic char). A number of processes have been used to obtain fish oil fromfishery waste including the fishmeal process, supercritical carbon dioxide extrac-tion and fermentation processes [37–39]. Innovations in this area have included theuse of mobile fishmeal process plants that can travel around a region with fishingactivities (wild capture or aquaculture) and perform the processing on-site with-out the need to build a dedicated fishmeal plant at each site. Once the fish oil isisolated, it can be purified or upgraded in a number of ways. Many of these meth-ods have become well-established in the field of processing vegetable/land-basedbiomass and include transesterification to produce biodiesel and pyrolysis to pro-duce bio-oil [40]. Studies to apply such methods to ocean or aquatic sourcedbiomass are still ongoing. There is significant room for progress and improve-ments, given the different chemical nature of the feedstocks. Furthermore, in manycases, it is not economically viable to process fishery waste on-site immediately,and this leads to by-product decomposition. In the case of lipids, this involvesoxidation of the unsaturated bonds and means that they are no longer suitable inhigh-value products (e.g. ω-3 fatty acid food supplements). Therefore, the use ofthe oil component of the waste stream will often involve transformation into a fuelif the fish by-product stream is to be fully utilized.

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12 Fuels, Chemicals and Materials from the Oceans and Aquatic Sources

1.4 Plant-Based Biomass

Plants in our oceans can be divided into two categories: microalgae and macroal-gae.Microalgae typically contain a greater proportion of natural oils for potentiallyproducing fuels compared to macroalgae. Therefore, they have been extensivelystudied as a potential way of producing renewable fuels [41–43]. The US Depart-ment of Energy identified a number of attractive properties that microalgae possessthat make them a preferred feedstock for producing biofuels. They are highlyproductive and can offer large biomass yields per area cultivated. They can begrown using a range of different sources of water and are not limited to beinggrown using freshwater, which is in limited supplies in many areas. Furthermore,microalgae can be used to recycle carbon from processes that produce CO2-richemissions such as power-generating stations that combust fossil fuels. If microal-gae are used to produce oil for fuel, a by-product stream (rich in protein andcarbohydrate) will also be obtained. Researchers are now studying the potentialof whole utilization of microalgae (e.g. production of β-chitin, pigment and otherby-products in addition to oil) [44] and new methods of growing microalgae effi-ciently in order to bring an algae-based biorefinery to fruition [45]. Further detailson microalgae bioproduction and potential products are described in Chapter 5 ofthis book.Macroalgae or seaweed can also be used as a feedstock for chemicals, fuels and

materials. They are generally subdivided into three types based on pigments—red,brown and green algae. In various locations around the world, due to eutrophicocean conditions with enriched nitrogen and other nutrient levels, blooms of algae,known as green or golden tides, have occurred [46]. In addition to cultivating andharvesting seaweed for either food or other uses, it is important that the over-grown seaweed in these blooms can be processed and dealt with in a sustainableand productive manner. It is worth noting that algae have already been exploitedindustrially as they are the only sources of certain sulfated polysaccharides, whichpossess valuable gelation properties, for example, agar, carrageenan and alginicacid [47]. However, they contain secondary metabolites as well, which may be ofhigh economic value as a secondary commercial product if the algae are processedin the correct way in order to maintain the metabolite’s structure and function. TheUnited Nations’ Food and Agriculture Organization noted that commercial har-vesting of macroalgae has now reached 25 million tons per annum and is valuedat US$ 7.4 billion [7]. Furthermore, many have highlighted, as with microalgae,the potential of marine algae to act as a carbon sink and sequester carbon dioxidefrom the atmosphere.In order to make a marine biorefinery economically viable, it is important

to produce several low-volume, high-value materials in addition to lower costbiopolymers, fuels and food stuffs. In this regard, macroalgae seem ideal feed-stocks for biorefineries. In a recent case study, the red seaweed Kappaphycusalvarezii was studied in detail [48]. This seaweed is already cultivated in Asia