Table Of ContentAlgal Biofuel
SUSTAINABLE SOLUTION
Algal Biofuel
SUSTAINABLE SOLUTION
Editors
Richa Kothari • Vinayak V Pathak • V VT yagi
THE ENERGY AND RESOURCES INSTITUTE
Creating Innovative Solutions for a Sustainable Future
First published 2023
by CRC Press
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British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
ISBN: 9781032425450 (hbk)
ISBN: 9781032425467 (pbk)
ISBN: 9781003363231 (ebk)
DOI: 10.4324/9781003363231
Typeset in Times New Roman
by TERI Press, New Delhi – 110 003
Foreword
Application of microalgal biomass as a renewable source of energy has gained
the attention of researchers around the world. Biomass-based fuel generation
became more important after the 1990 oil crisis. Deterioration of air quality and
climate change appeared as a result of rapid consumption of fossil fuel. Hence,
it is extremely important to develop sources of energy that can not only replace
the conventional fuel but also have a positive impact on the environment.
Algal Biofuel: Sustainable Solution primarily focuses on the different aspects
of bioenergy production using algal biomass as microalgae are considered the
optimum feedstock for bioenergy production. The major aim is to thoroughly
review the available bioenergy options, challenges in bioenergy production,
availability of bioenergy feedstock, and biomass to bioenergy conversion
process. This book also highlights the feasibility of lignocellulosic biomass,
crop residues, and non-edible oil seeds for generation of different bioenergy
products. It will be helpful for researchers and other stakeholders working in
the area of bioenergy production for development of innovative concepts in
emerging areas of bioenergy. It is not possible for a single book to convey all
dimensions of the bioenergy technologies, so application of algal biomass for
other value-added products has not been included in this book.
Algal Biofuel: Sustainable Solution begins with an introduction of a
biorefinery approach and its importance in promoting bioeconomy (Chapter 1).
With a biorefinery approach, we can implement bioenergy in less economically
advanced countries and create new job opportunities in the bioenergy sector.
Microalgae are considered as potential bioenergy feedstock and this source of
energy is constantly being researched, so the recent advancements happening
with microalgae are presented in Chapter 2. In Chapter 3, potential of biogas as a
bioenergy option is discussed with support of recent updated trends in the fields.
Chapter 4 provides an overview on the potential of algal-based biohydrogen
as afuture bioenergy option. Crop residues, which are mainly composed of
lignocellulosic biomass, can be used for bioenergy production as a part of waste
management process. In this context, Chapters 5 and 6 review the comparative
vi Foreword
potential of lignocellulosic biomass and algae for bioethanol production and
the potential of crop residues for bioenergy production. The main downstream
process in algal biofuel production involves harvesting. Chapter 7 provides a
detailed analysis on magnetic harvesting of algal biomass for cost effective
biofuel production. The potential of non-edible oil for biodiesel production is
explained in Chapter 8. Chapter 9 not only reflects on the bioenergy application
of algal biomass but also its key role in climate change mitigation through
carbon sequestration. Environmental aspects of biomass-based bioenergy
generation is equally important to ensure the sustainability of bioenergy. Thus,
Chapter 10 describes the role of modern bioenergy applications for control of
particulate emissions. In Chapter 11, applicability of immobilized algal cells
for wastewater treatment is reviewed, which is extremely important to achieve
a cost-effective biofuel production process. The role of a biotechnological
approach for generation of various bioenergy products is explained in Chapter
12, while methods for enhancement of lipid content, which is one of the key
attractions for researchers, is reviewed in Chapter 13.
By providing this information in an easily accessible format, my hope is
that newer workers in this field will be able to produce more reliable research,
which will be significant to understanding newer dimensions of bioenergy
technologies based on sustainable feedstock.
Professor John Korstad
Oral Roberts University
Preface
Energy sustainability has become a very important concern among researchers
and policymakers. Present energy situation around the globe is unsustainable due
to unequal distribution of natural resources as well as different environmental,
geopolitical, and economical concerns. Rise in population with accelerated
increase in industrial sector has led to rapid increase in the consumption of
energy sources, which will make them extinct soon. Major developing countries
such as India are heavily dependent on fossil fuels (coal, oil, natural gas) to
meet their energy demand of the transportation and industrial sector. Further,
to combat environmental pollution and mitigate the effects of greenhouse gases,
it has become imperative that an alternative energy source is found which is
sustainable and renewable.
Biofuel is one such renewable, sustainable, and affordable energy source
that has the potential to replace conventional energy sources. Biomass has been
directly combusted for a long time; however, it generates severe incontinence
cost and pollution cost. Therefore, modern applications that use advance
conversion processes can make biomass more efficient for energy production.
By employing specific conversion processes, bioenergy can be derived in solid,
liquid or gaseous forms. Liquid biofuels such as biodiesel and bio-alcohol
can replace fossil fuels. They can also be used in combination with fossil
fuels so that the amount of fossil fuel consumption can be reduced. Despite
such promising potential, biomass-based energy generation requires intensive
research and development to become sustainable and affordable.
Algal Biofuel: Sustainable Solution provides focused information on
progressive trends in research and development with conversion strategies under
the impactful stress conditions in bioenergy sector. The most-effective ways to
valorize the available biomass resources with the concept of biorefinery, where
each part of this biomass is utilized with generation of zero or near to zero-
waste, have also been included in this book.
Governments of many countries have constituted policy frameworks that
ensure the optimum consumption of fossil fuel and develop renewable energy
viii Preface
sources. The policy initiatives in various countries have set a target to blend
diesel with bio-alcohol and biodiesel so that dependency on fossil fuels can
be reduced. The book points out the governance of biofuel at global and
national level and explores the potential of biofuel in meeting the rising energy
demand.
Conventional feedstock of first-generation biofuel is associated with food-
feed and biofuel trilemma; hence, it has less impact as a fossil fuel alternative.
Similarly, second-generation biofuels are also involved with high water input
and fertilizer support for feedstock development. Researchers have explored
the potential of microalgae as a cleaner and greener alternative for fossil fuel
replacement. Various algal strains of marine and freshwater habitat have been
successfully investigated for high lipid accumulation, which is considered as
precursor of biodiesel. The availability of algal biomass can be ensured for
biofuel production process by employing effective cultivation and harvesting
techniques, which is also termed as upstream processing for biofuel production.
Algal biomass can be grown in open as well as close system and in this book
authors have investigated the optimum culture conditions for enhancement of
biomass. Researchers have found that culture conditions influence the lipid
synthesis in algal biomass to a greater extent. Nutrient starvation and other
stress conditions have been studied for the lipid induction in algal biomass. The
practicality of these investigations for large-scale biodiesel production is still
unexplored and plays crucial role in developing algal-based biofuel sector. The
other technical step towards biodiesel production involves the conversion of fatty
acid into fatty acid methyl esters. Conventional ways of transesterification have
been found with limited yield efficiency and direct environmental impact. The
approach of green transesterification process and other innovative conversion
process have been found with higher efficiency than the conventional process.
The feasibility of algal-based biofuel production depends on its yield efficiency
and should be compatible in demand and supply chain. The chapters in this
book focus towards the strategies to ensure the availability of algal biomass,
effective cultivation, and harvesting techniques.
The book explores a wide spectrum of bioenergy sources, including their
applications. It also covers the latest information in the field of bioenergy
technologies and their future prospect in relation to algal biomass. Bioenergy
scenario provides waste to energy generation potential of various energy wastes
including agriculture and solid waste. The book also gives impactful solutions
to practical challenges with bioenergy technologies such as microalgal lipid
for biodiesel extraction processes, different biotechnological approaches for
bioenergy production, biodiesel from non-edible seeds among others. This book
will be beneficial to both students and researches in the field of bioenergy
generation.
Contents
Foreword v
Preface vii
1. Biorefinery: A Future Approach for a Sustainable Bioeconomy 1
Introduction 1
Role of Government, Public, and Private Stakeholders 13
Conclusion 17
2. Algal Biomass Harvesting for Biofuel Production 23
Introduction 23
Harvesting Process 26
Future Prospects and Conclusions 48
3. Biogas as Bioenergy Option: Advances and Challenges 67
Introduction 67
Biochemical Processes of Anaerobic Digestion 69
Feedstock Materials 72
Microbial Community 74
Important Parameters 74
Properties of Biogas 78
Upgradation of Biogas 79
Types of Digesters
81
Applications of Biogas 81
Challenges/bottlenecks 85
Conclusion 87
4. Application of Algal Biomass as a Feedstock 93
for Fermentative Biohydrogen Production
Introduction 93
Microalgae 95
