Page 141 - Advances in Eco-Fuels for a Sustainable Environment

112 Advances in Eco-Fuels for a Sustainable Environment

the lignocellulosic material. The lignocellulosic material contains 48wt% carbon (C),
6wt% hydrogen (H), 45wt% oxygen (o), and inorganic matter forming a minor com-
ponent. In hardwood, cellulose and hemicelluloses content are more when compared
to softwood but in softwood, the lignin content is more than hardwood [77].

4.4 Drawbacks and prospects of ecofuels

The biofuels of the first generation used food crops as feedstock, which in turn resulted
in higher food prices due to the competition with food crops, and the feedstocks
proved to be expensive [79]. The first-generation biofuel feedstock comes from crops,
which take up land for producing ecofuels instead of utilization of land for food. The
second-generation biofuels are more efficient than first-generation biofuels because
the second-generation biofuels used the vast majority of feedstock, including the
waste [80]. The other drawbacks in first- and second-generation biofuel feedstock
are the presence of high free fatty acids and the water content in some vegetable
oil and WCO, which increases the cost of biodiesel production. Though third-
generation biofuel production proves to be costly, the research is more focused. Even
though the first- and second-generation biofuels suffered serious setbacks, much
research was focused on the ways to make it sustainable. The research focused on
replacing the chemicals with biological molecules such as enzymes and new extrac-
tion technologies were introduced. In addition, many other possible oil seed feed-
stocks were introduced. Ecofuels are the future renewable fuel source that will
completely replace the current fuel only when it becomes cheaper than petroleum.
While considering algae as a source of ecofuel, much more research needs to be
stressed on implementing novel economical techniques for cultivation and harvesting
of algae in a pilot scale, and also developing genetically engineered algae with high
lipid content. In the case of biodiesel feedstocks, research must be focused on sustain-
able production using low-cost feedstocks and highly efficient biocatalysts for the sus-
tainable conversion of feedstock oils to biodiesel.

4.5 Conclusion

Various physical and chemical properties such as fatty acid composition, fatty acid
content, moisture, etc., influence the production of ecofuels such as biodiesel. Among
the various feedstocks discussed, rapeseed oil, soybean oil, sunflower oil, jatropha oil,
and pongamia oil are the feedstocks with better biodiesel yield. However, feedstocks
such as soybean prove to be costly. Moreover, WCO can be the cheapest feedstock but
it is necessary to remove free fatty acids for the production of biodiesel using chemical
catalysts. Even though there are many feedstocks available to produce ecofuel, there is
a need for sustainable conversion. Thus, there is a need to select the ideal feedstock
that is cheap, less polluting, consumes less water for production, or can rely on waste-
water and sustainable conversion methods of converting the feedstock to ecofuel.