Page 19 - Advances in Eco-Fuels for a Sustainable Environment

xviii Preface

liquid, gaseous, and solid ecofuel feedstocks is examined and their usage in internal
combustion engines has been explored. Prospects, including the proposed use of
genetically modified microalgae as well as innovative process configurations and
novel bioreactor designs, are also part of this chapter.
Chapter 3 reviews the potential biodiesel feedstocks, oil extraction, and conversion
techniques as an important determinant of the success of ecofuel synthesis. This chap-
ter includes the supercritical fluid extraction method as one the most viable extraction
methods that can play a great role in obtaining oil from feedstocks. The chapter also
analyzes the associated challenges with accessibility to feedstock on a commercial
scale, such as extraction of oil from the feedstocks and production of ecofuels from
extracted oils.
Chapter 4 provides an overview of the present status and future scope of ecofuel
feedstocks. It includes studies on some ecofuels such as biodiesel, bioethanol, bio-
hydrogen, etc., that can replace nonrenewable fuels. It also identifies some challenges
of ecofuel production relating to the cost and food versus fuel debates, keeping in view
the utilization of land for growing crop solely for ecofuel production. Vegetable oils,
animal fats, algae, waste cooking oils, lignocellulosics, grease, etc., are some of the
feedstocks that can be used for ecofuel production, which is discussed in detail. The
chapter also focuses on genetically modified algae with a higher oil yield for ecofuel
production.
Chapter 5 deals with an interesting feedstock called waste engine oil (WEO), which
can be utilised to derive ecofuel. Advanced research in this area, including the com-
parison of different pyrolytic processes, are covered. Current experimental studies on
microwave-assisted pyrolysis (MAP) covering energy efficient and ecofriendly
aspects have also been included. A case has been discussed regarding ecofriendly
technology to obtain high saturated liquid ecofuel from WEO. The fatty acid com-
positions were analysed by GC-MS. The study also reveals the physicochemical prop-
erties that were characterized using ASTM standards.
Chapter 6 is based on investigations on methanol as a second-generation ecofuel
that can reduce emissions for a sustainable environment. In this research, domestic
waste such as food waste, kitchen waste, and wastewater sludge have been studied
as feedstocks to produce methanol in a floating drum digester by anaerobic digestion.
The studies identified three key factors for biogas conversion efficiency to methanol,
which depends upon the carbon to nitrogen ratio, the temperature, and the pH value.
Research that shows that digestive waste rich in nutrients can be used as soil fertilizer
is also part of this chapter.
Chapter 7 presents detailed information on advanced ecofuel production and
its sustainability, which has advantages over other sources due to its availability and
easy conversion strategies. It is also found in the research that algae have been signif-
icantly studied, owing to their lipid profile containing arachidonic, eicosapentaenoic,
and docosahexaenoic acids. The recent advances in upstream processing for the
generation of biomass to oil has a great extent in this chapter focusing on cost effective
extraction and purification methods. This chapter has encapsulated various extraction
techniques used and the challenges involved in the extraction of oil to produce sustain-
able energy in an ecofriendly manner.