Page 136 - Biofuels Refining and Performance

Raw Materials to Produce Low-Cost Biodiesel 119

(rapeseed-oil methyl esters, animal methyl esters, and linseed oil
methyl esters) to fuel the engine. These three-component mixtures
reduced exhaust emissions significantly, with the exception of NO that
x
increased them up to 13% [105].

4.2.8 Mahua oil
Crop description. Madhuca indica—commonly known as madhuka, yappa,
mahuda, mahua, mauwa, mohwa, hippe, butter tree, mahwa, mahula, or
elupa—belongs to the family Sapotaceae and grows up to 21 m high. This
deciduous tree is distributed mainly in India (see Fig. 4.9). The kernels are
70% of seed by weight. Seeds content includes 35% oil and 16% protein. Main
fatty acids are palmitic acid (16–28.2%), stearic acid (20–25.1%), arachidic
acid (3.3%), oleic acid (41–51%), and linoleic acid (8.9–13.7%) [106].

Main uses. Traditionally, it has been used as a source of natural hard
fat in soap manufacture. The seed oil is used as an ointment in rheuma-
tism and to prevent dry, cracked skin in winter. It is used in foods, cos-
metics, and lighting. The cake presents toxic and bitter saponins that
preclude its use as animal feed. However, mahua cake can be used as
organic manure [106]. Several approaches to produce biodiesel can be
found. Ghadge and Raheman have proposed a two-step pretreatment to
reduce high FFAlevels. Transesterification was carried out adding 0.25 v/v
methanol and 0.7% KOH. Fuel properties were found comparable to those
of diesel fuel [107]. Some authors have proposed different successful

Figure 4.9 Madhuca indica. (Photo courtesy of Antonie van den Bos
[www.botanypictures.com/plantimages/].)