Page 118 - Advances in Eco-Fuels for a Sustainable Environment

Prospective ecofuel feedstocks for sustainable production 91

The low-cost feedstock can help in the production of low cost and profitable ecofuel
[11]. The feedstocks used for the production of ecofuels include edible oils, nonedible
oils, waste oils and fats, microalgae oil, lignocellulosics, etc. Throughout the world,
edible oils such as soybean, sunflower, rapeseed, and palm are used as primary
biodiesel feedstocks. In developing countries where edible oils are in short supply,
nonedible oils such as Jatropha, Pongamia, neem, etc., are used as promising feed-
stocks for the production of biodiesel [12]. The other ecofuels such as biohydrogen
and biogas exploit microorganisms and waste biomass.

4.2.1 Vegetable oils as feedstock

The triglyceride that has been extracted from the plant source is referred to as vege-
table oil and various vegetable oils have been used as feedstock for the production of
biodiesel. The vegetable oils used as feedstock have been categorized as edible oils,
nonedible oils, potential edible oils, and potential nonedible oils [12]. The fatty acid
profiles (wt%) of various vegetable oil feedstocks are presented in Table 4.1 and the
oil content of feedstocks is presented in Table 4.2.

4.2.1.1 Edible oils
The following are the commonly used edible oils that have been used for the produc-
tion of biodiesel.

Rapeseed oil (Brassica napus)
The most significant feedstock used in the production of biodiesel in Canada and the
European Union (EU) is rapeseed (Brassica napus) oil or canola oil. The two largest
producers of rapeseed are Germany and France in the EU, followed by the United
Kingdom, Poland, and the Czech Republic. The main demand for rapeseed oil is in
the biodiesel industry. Rapeseed produces more oil per unit of land when compared
to other oil sources. Thus, rapeseed oil is the preferred oil stock for biodiesel produc-
tion [13]. The total oil content in rapeseed is around 38–46wt%. The rapeseed oil is
characterized by saturated fatty acids such as palmitic acid (4.9wt%) and stearic acid
(1.6wt%) as well as unsaturated fatty acids such as oleic acid (33wt%), linolenic
acid (<1.5wt%), and linoleic acid (20.4wt%) [12]. As per the work carried out by
Rashid and Anwar [14], around 95%–96% of biodiesel yield has been obtained
using 1% (wt of oil) KOH as a catalyst for ethanol to oil molar ratio 6:1 at a reaction
temperature of 65°C and a reaction time of 2h from 500g of rapeseed oil. Some of
the properties of rapeseed oil methyl esters include a kinematic viscosity of
2
4.15–4.76mm /s, calorific value of 44.8MJ/kg, a cloud point of 3°Cto 1°C,
and a pour point of 9°Cto 7°C [14].

Soybean oil (Glycine max)
The main raw material used for biodiesel production in Brazil is soybean (Glycine max),
which accounts for approximately 80% of national production. Brazil has great potential
for the production of cheaper raw material because the country has a vast territory and
climatic diversity [15]. The United States and Argentina are the other major producers