Page 20 - Advances in Eco-Fuels for a Sustainable Environment

Preface xix

Chapter 8 reviews the efficient ecofuel conversion approaches and techniques used
nowadays. The progress on technological advancement in the field of ecofuel conver-
sion is also critically reviewed and presented. The key parameters affecting the con-
version process were identified and discussed briefly in this chapter.
Chapter 9 discusses the advantages and drawbacks of catalytic and noncatalytic
technologies to convert inedible feedstocks such as rice bran, microalgae, and spent
coffee grounds into ecofuel. Research shows that for microalgae and spent coffee gro-
unds, in situ transesterification using a subcritical water-methanol mixture with an
acid catalyst and using supercritical methanol/ethanol, respectively, seem to be the
most promising methods. The purification processes are also discussed, particularly
the one that can isolate a small fraction of high-value bioactive compounds. The
utilization of these byproducts according to the biorefinery approach and its impact
on overall ecofuel production cost is also critically discussed.
Chapter 10 presents a detailed study on thermal depolymerization of biogas
digestate as a viable digestate processing and resource recovery strategy.
A comprehensive study on different biogas conversion technologies has been
evaluated with the economic assessment. It was revealed to have the potential of being
considerably lower than the unit digestate processing cost of traditional digestate
treatment and processing strategies.
Chapter 11 reveals in detail a study on ecofuel production from an ecofriendly and
nonedible aegle marmelos correa (AMC) oil. Nuclear magnetic resonance analysis
conducted for ester identification and gas chromatography analysis were done to iden-
tify the fatty acid methyl ester composition of the AMC ecofuel. The physicochemical
fuel properties of AMC fuel were tested, which met the ASTM and EN standards. The
tribological characteristics of pure ecofuel are reported; they were evaluated by using
a four-ball tribotester. This chapter deals with the investigation that AMC biodiesel
could be a promising alternative fuel for diesel engine application as it possesses
excellent physicochemical properties and tribological behavior.
Chapter 12 investigates the advanced ecofuel lubrication characteristics and their
compatibility with different automotive materials to assess diesel engine durability.
Tests conducted using the ecofuel extracted from Tamanu oil have been reported.
Tribological characteristics such as coefficient of friction, wear rate, and lubrication
stability were examined on a four-ball tribotester using the ASTM standard and
included in the chapter. Surface tropography using SEM/EDAX after a wear scar
study and its corrosive behavior have been discussed thoroughly. Tribological stud-
ies on diesel and ecofuels that are focused on the longevity of engines have been
discussed thoroughly.
Chapter 13 evaluated the diesel engine performance and emission parameters using
waste frying oil for ecofuel synthesis due to its availability and low cost. A study iden-
tified two main drawbacks–higher free fatty acid presence and higher viscosity–that
led to injector choking and decreased engine performance, respectively. In another
study reported in this chapter, the ecofuel was synthesised through the trans-
esterification process using a sodium methoxide catalyst. The fuel modification
was done by blending in different percentages with diesel fuel. More studies on engine
modification are reported that were adopted to increase the engine combustion and