Continuous production of bioethanol using microalgal sugars extracted from Nannochloropsis gaditana

다국어 초록 (Multilingual Abstract)

We developed a continuous production process of bioethanol from sugars extracted from Nannochloropsis gaditana. To improve algal sugar production, the reaction conditions of acid-thermal hydrolysis were investigated based on five different types of acid and their concentrations (1-4%), and the loading ratio of solid/liquid (S/L). As a result, the maximum hydrolysis efficiency (92.82%) was achieved under 2% hydrochloric acid with 100 g/L biomass loading at 121 oC for 15 min. The hydrolysates obtained from N. gaditana were applied to the main medium of Bretthanomyces custersii H1-603 for bioethanol production. The maximum bioethanol production and yield by the microalgal hydrolysate were found to be 4.84 g/L and 0.37 g/g, respectively. In addition, the cell immobilization of B. custersii was carried out using sodium alginate, and the effect of the volume ratio of cell/sodium alginate on bioethanol productivity was investigated in a batch system. The optimal ratio was determined as 2 (v/v), and the immobilized cell beads were applied in the continuous stirred tank reactor (CSTR). Continuous ethanol production was performed using both free cells and immobilized cells at 1 L CSTR. In both groups, the maximum bioethanol production and yield were achieved at dilution rate of 0.04 h1 (3.93 g/L and 0.3 g/g by free cell, and 3.68 g/L and 0.28 g/g by immobilized cell, respectively).

참고문헌 (Reference)

1 E. Neri, 171 : 1006-, 2018

2 H. G. Lim, 135 : 564-, 2013

3 Y. Kourkoutas, 21 : 377-, 2004

4 K. H. Lee, 102 : 8191-, 2011

5 J. H. Park, 108 : 83-, 2012

6 H. Wang, 172 : 169-, 2014

7 S. H. Ho, 135 : 191-, 2013

8 H. Y. Yoo, 10 : 1894-, 2015

9 X. Yang, 49 : 335-, 2015

10 J. H. Lee, 264 : 387-, 2018

11 J. Singh, 14 : 2596-, 2010

12 M. Daroch, 102 : 1371-, 2013

13 N. Zhou, 118 : 512-, 2012

14 F. Monlau, 32 : 934-, 2014

15 D. I. Sánchez-Machado, 85 : 439-, 2004

16 Z. S. Ahmad, 21 : 27-, 2018

17 H. M. Holden, 278 : 43885-, 2003

18 S. C. Rabelo, 153 : 139-, 2009

19 J. R. Miranda, 104 : 342-, 2012

20 J. H. Lee, 187 : 903-, 2018

21 S. Montipó, 249 : 1017-, 2018

22 Matthew J. Scholz, "Ultrastructure and Composition of the Nannochloropsis gaditana Cell Wall" American Society for Microbiology 13 (13): 1450-1464, 2014

23 Jun Cheng, "Improving the CO2 fixation rate by increasing flow rate of the flue gas from microalgae in a raceway pond" 한국화학공학회 35 (35): 498-502, 2018

24 Weldejewergis Gebrewahid Kidanu, "Hydrogen and Volatile Fatty Acids Production from Marine Macroalgae by Anaerobic Fermentation" 한국생물공학회 22 (22): 612-619, 2017

25 유하영, "Evaluation of the Overall Process on Bioethanol Production from Miscanthus Hydrolysates Obtained by Dilute Acid Pretreatment" 한국생물공학회 21 (21): 733-742, 2016

26 유하영, "Enhancement of glucose yield from canola agricultural residue by alkali pretreatment based on multi-regression models" 한국공업화학회 51 : 303-311, 2017

27 Neeranuch Phusunti, "Effects of torrefaction on physical properties, chemical composition and reactivity of microalgae" 한국화학공학회 35 (35): 503-510, 2018