Page 274 - Advances in Eco-Fuels for a Sustainable Environment

Ecofuel conversion technology of 9

inedible lipid feedstocks to
renewable fuel

†
*
*
*
Siti Zullaikah , Adi Tjipto Utomo , Medina Yasmin , Lu Ki Ong , Yi Hsu Ju †
*Department of Chemical Engineering, Institut Teknologi Sepuluh Nopember (ITS),
†
Surabaya, Indonesia, Department of Chemical Engineering, National Taiwan
University of Science and Technology, Taipei, Taiwan

9.1 Introduction

Rising energy demand due to increasing world population, industrialization, and
demand for transportation has been identified as the main causes of recent climate
change [1–3]. Traditional energy sources such as fossil fuels emit carbon dioxide
and other greenhouse gases into the atmosphere. The increased demand for energy
will increase the price of fossil fuel, global warming, environmental pollution, and
the fast-diminishing supply of fossil fuels because they are nonrenewable.
The use of renewable fuels that can be considered carbon neutral can mitigate this
issue. Biodiesel (fatty acid methyl esters, FAME) is a renewable clean energy, as it can
be produced from renewable resources such as vegetable oils, animal fats, and micro-
algae oil. Biodiesel can be considered one of the promising renewable fuels currently
produced on an industrial scale [4]. Biodiesel can be blended with petrodiesel, and
therefore requires practically no changes in the fuel distribution infrastructure [5].
However, most biodiesel currently in use is produced from edible feedstocks such
as soy oil, rapeseed oil, and palm oil, making the cost of biodiesel production higher
than petrodiesel [4–8].
Ideally, biodiesel feedstock should be available in a large quantity as well as being
cheap and inedible, such as rice bran, microalgae, and spent coffee grounds. Rice bran,
microalgae, and spent coffee grounds have attracted wide attention as alternative ined-
ible feedstocks for biodiesel production. Rice bran is produced as a byproduct during
rice milling and is traditionally used as cattle feed despite its rich nutrient content.
Husked rice contains 8%–12% rice bran while the rice bran itself contains 10%–
26% oil [6, 9–11]. The potential of annual rice bran oil (RBO) production in China
is about 6 million tons [12] while in Indonesia, it is 0.79–2.06 million tons [13],if
all rice bran produced is harnessed for oil extraction. However, RBO is rather
unsuitable for human consumption due to its high free fatty acids (FFA), high
acetone-insoluble contents, and dark appearance [8, 12, 14]. Complicated refining
and stabilization processes are required to transform crude RBO into edible oil, mak-
ing it economically uncompetitive against other edible oils such as palm, soy, and
rapeseed [5].

Advances in Eco-Fuels for a Sustainable Environment. https://doi.org/10.1016/B978-0-08-102728-8.00009-7
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