Microalgae Chlorella as a Sustainable
Feedstock for Bioethanol Production
Rahmath Abdulla, Tan Kah King, Siti Azmah Jambo and Ainol Azifa Faik
Abstract Microlgae can serve as an excellent feedstock for bioethanol production.
The microalgae cells of Chlorella were cultivated and acid hydrolyzed to extract the
glucose content in the cells. Production of bioethanol was achieved by fermentation
process with the use of yeast Saccharomyces cerevisiae. The bioethanol content
was determined by gas chromatography–mass spectrometry (GC-MS). The effect
of different parameters such as sulphuric acid concentration, temperature and time
on acid hydrolysis was studied. The maximum glucose concentration of 5.382 ±
0.063 g/l was obtained with the conditions of 2.0 M sulphuric acid, 30 °C and 30 min
of incubation time. On the other hand, the highest ethanol concentration of 1.126 g/l
was obtained with 15% v/v yeast inoculum concentration. Meanwhile, the bioethanol
production reached its maximum after 24 h with ethanol concentration and yield of
1.020 g/l and 0.190 g/g glucose, respectively.
Keywords Bioethanol · Microalgae · Chlorella · Biofuel
1 Introduction
The rapid increase in world population led to the rise of global energy consumption significantly from time to time. Among the energy sources, fossil fuels are the
most popular one as it accounts for approximately 87% of the total utilization (BP
2014; ExxonMobil 2014). Furthermore, the continued dependence on fossil fuels is
somehow considered unsustainable due to its associated environmental issues and
non-renewable properties. Considering these facts, there is an urgent call to explore
the alternatives for fossil fuel resources to support the increasing energy demand in
R. Abdulla (B) · T. K. King · S. A. Jambo · A. A. Faik
Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota
Kinabalu, Sabah, Malaysia
e-mail: rahmahabdulla@gmail.com
R. Abdulla
Energy Research Unit, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah,
Malaysia
© Springer Nature Singapore Pte Ltd. 2020
A. Z. Yaser (ed.), Green Engineering for Campus Sustainability,
https://doi.org/10.1007/978-981-13-7260-5_7
81
Feedstock for Bioethanol Production
Rahmath Abdulla, Tan Kah King, Siti Azmah Jambo and Ainol Azifa Faik
Abstract Microlgae can serve as an excellent feedstock for bioethanol production.
The microalgae cells of Chlorella were cultivated and acid hydrolyzed to extract the
glucose content in the cells. Production of bioethanol was achieved by fermentation
process with the use of yeast Saccharomyces cerevisiae. The bioethanol content
was determined by gas chromatography–mass spectrometry (GC-MS). The effect
of different parameters such as sulphuric acid concentration, temperature and time
on acid hydrolysis was studied. The maximum glucose concentration of 5.382 ±
0.063 g/l was obtained with the conditions of 2.0 M sulphuric acid, 30 °C and 30 min
of incubation time. On the other hand, the highest ethanol concentration of 1.126 g/l
was obtained with 15% v/v yeast inoculum concentration. Meanwhile, the bioethanol
production reached its maximum after 24 h with ethanol concentration and yield of
1.020 g/l and 0.190 g/g glucose, respectively.
Keywords Bioethanol · Microalgae · Chlorella · Biofuel
1 Introduction
The rapid increase in world population led to the rise of global energy consumption significantly from time to time. Among the energy sources, fossil fuels are the
most popular one as it accounts for approximately 87% of the total utilization (BP
2014; ExxonMobil 2014). Furthermore, the continued dependence on fossil fuels is
somehow considered unsustainable due to its associated environmental issues and
non-renewable properties. Considering these facts, there is an urgent call to explore
the alternatives for fossil fuel resources to support the increasing energy demand in
R. Abdulla (B) · T. K. King · S. A. Jambo · A. A. Faik
Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota
Kinabalu, Sabah, Malaysia
e-mail: rahmahabdulla@gmail.com
R. Abdulla
Energy Research Unit, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah,
Malaysia
© Springer Nature Singapore Pte Ltd. 2020
A. Z. Yaser (ed.), Green Engineering for Campus Sustainability,
https://doi.org/10.1007/978-981-13-7260-5_7
81