Page 86 - Energy from Toxic Organic Waste for Heat and Power Generation

72 Energy from Toxic Organic Waste for Heat and Power Generation

Table 6.2 Properties of selected plant oils (nonedible) [2]
Viscosity
2
Density Cetane Cloud Pour Flash (mm /s) @
3
Oil (kg/m ) number point (K) point (K) point (K) 313 K
Castor 886 53 28 247 43 12
Jatropha 880 51–52 0 279 3 4.8
Karanja 889 41.7 283 288.8 461 6.88
Karanja 850 42–48 279 – 491 9.2
Mahua 916 51 – 279 423 3.98
Neem 890 – 278 276 402 5.53
Rubber 892 66.2 279 265 423 5.81
Rice bran 872 51.6 277 269 403 4.81

the fuel. It shows the readiness of the fuel for autoignition [8]. As shown
in Table 6.2, certain number of nonedible plant oil are higher than that of
petroleum diesel, so these can be replaced by diesel fuel without any engine
modification.

6.2.1.3 Used Edible Oils
Biodiesel production from used edible oils (commonly known as waste
cooking oil, “WCO”) had more economic feasibility compared to fresh
plant oils. Moreover, large quantities of WCO are dumped into landfills
and rivers, causing pollution to the environment. However, in the frying
process, the oil undergoes several reactions which lead to the formation of
undesirable compounds such as polymers and free fatty acids, among others
[9]. Hence, the proper utilization of such oils is important because of their
disposal problems and negative impacts [10]. The biodiesel production from
WCO is suitable for combustion with the proper pretreatment process.

6.2.1.4 Microalgae
Microalgae are the photosynthetic microorganisms that convert water, sun-
light, and CO 2 to algal biomass and also the raw material for biodiesel pro-
duction. Because of their quick biomass production and high oil content,
they have been recognized as good raw material for biodiesel production.
Microalgae play an important role in solving problems like use of edible
oils for biodiesel production and utilization of large forming land and water
recourses [11]. Biodiesel from microalgae has certain limitations like it does
not burn completely because of their low volatility and high viscosity. The
photographic view of microalgae is shown in Fig. 6.1. The layout of energy
production from microalgae is shown in Fig. 6.2.