Page 356 - Advances in Eco-Fuels for a Sustainable Environment

Physicochemical fuel properties and tribological behavior of aegle marmelos correa biodiesel 311

So the requirement of good fuel is not only to provide energy but also to act as a lubri-
cant between engine parts. Many of the properties of biodiesel influence the tribolog-
ical behavior when it contacts engine parts at sliding conditions [24]. The excellent
lubricity fuel increases the engine life and minimizes the energy consumption byreduc-
ing the friction between sliding parts [25, 26]. Numerous studies have proven that
biodiesel possesses good lubricity compared to diesel fuel. The lubricity capacity
maybe differs with different biodiesel due to its different chemical composition. So,
assessing the physicochemical and tribological behavior of biodiesel is important
before utilizing it in a conventional diesel engine [15].
The aegle marmelos correa (AMC) tree belongs to the Rutaceae family and
Aurantioideae subfamily, and is commonly known as Vilvam (Tamil), bael (Hindi),
Matum (Thailand), and Wood apple (English). India, Nepal, and the Andaman Islands
are the native countries of the AMC tree, but it is now naturalized and found in Sri
Lanka, Thailand, Malaysia, and throughout the South Asian countries [27].AMC
is a slow growing and 10–12m medium-sized subtropical plant that can be grown
at a maximum altitude of 1200m from sea level. It can adapt and grow in a variety
of soils such as sandy, waterlogged, clay, unirrigated, and even in acidic or basic con-
ditions. The matured tree takes 10–11 months to ripen the fruits and produce
400–1000 fruits. The fruits can be harvested once the outer color changes from green
to yellowish green [28].
The present study aims to examine the physicochemical and tribological character-
istics of AMC biodiesel for the first time. The ultrasonic-assisted extraction method
was used to extract crude oil from the AMC seeds. The two-step transesterification
process was to convert oil into biodiesel by using potassium hydroxide as a catalyst.
The nuclear magnetic resonance technique was used to confirm the ester formation
and determine the conversion percentage. The gas chromatography analytical instru-
ment was employed to separate them and identify the chemical composition of AMC
methyl ester. Physicochemical properties of biodiesel were determined and detailed as
per the ASTM D6751 and EN 14214 standards.

11.2 Materials and methods

11.2.1 Materials
The AMC fruits were collected from Coimbatore and Anthiyur, Tamilnadu, India. All
other reagents such as acetone, heptane, ethanol 95%, methanol 99.9%, hydrochloric
acid (HCl) 37%, diethyl ether 99.9%, potassium hydroxide (KOH) 85%, sodium thio-
sulfate 99%, potassium iodide 99%, wiji’s iodine solution, and chloroform 99.5%
were purchased from the local supplier.

11.2.2 Oil extraction

The fruit has a hard woody outer shell that was broken to extract the pulp and seed.
After extraction, the seeds were separated from the pulp by soaking in water for an
hour. The cleaned seeds were dried in the sunlight for 24h and stored in airtight bags.