Page 441 - Advances in Eco-Fuels for a Sustainable Environment

394 Advances in Eco-Fuels for a Sustainable Environment

researchers have proved that biodiesel is an alternate for diesel after the trans-
terfication of raw vegetable oil. It has been indicated that biodiesel cannot be
substituted as a sole fuel in a CI engine.
All the technical studies showed that a 20% proportion of biodiesel along with die-
sel will be a viable and feasible solution for substituting biodiesel in the CI engine. It
has been further reported that while using 20% biodiesel, the properties are almost
equal to diesel. Hence, most of the researchers have attempted to find the new biodie-
sel and study the suitability of the new biodiesel as fuel in a diesel engine.

14.2 Materials and methods

14.2.1 Selection of biodiesel
It has been seen from the review of literature that a number of biodiesels are com-
monly used, such as jatropha, pongamia, mahua, callophyllum inophyllum, nerium,
cotton seed oil, neem oil, etc. Though many plant varieties are available in India,
the custard apple plant, which can be grown for ornamental purposes in many houses
and forests, can be used for the production of biodiesel. The biodiesel derived from
custard apple is not edible and the seed is the waste product. It is seen that no exper-
imental work is conducted with annona methyl ester (AME). Therefore, in the present
investigation, the AME is used as fuel in the CI engine.

14.2.2 Transesterification
Transesterification is widely used to reduce the viscosity of biodiesel to make it suit-
able for a CI engine. In this method, the triglyceride reacts with three moles of meth-
anol in the presence of sodium hydroxide (NaOH) or potassium hydroxide (KOH) as a
catalyst to form a mixture of methyl ester, fatty acids, and glycerol. Esterification is a
method of removal of fatty acids and glycerol. The methyl ester finally obtained is
called biodiesel. The properties of methyl ester will be similar to diesel fuel.

14.2.3 Fuel properties

The properties of AME are tested according to American Standard of Testing Methods
(ASTM). The properties of A20, A40, A60, A80, A100, and diesel are shown in
Table 14.1. The AME is blended with diesel in the ratio of 20%, 40%, 60%, 80%,
and 100% with diesel.

14.2.4 Experimental details

The tests were carried out in a single-cylinder, water-cooled diesel engine and at con-
stant speed. The schematic diagram of the test engine is shown in Fig. 14.1. The test
engine is coupled with an eddy current dynamometer to provide the brake load. The
test engine was started initially with diesel and allowed to warm up for about 10min.