온실가스 감소와 바이오 에너지 생산을 위한 미세조류 배양의 새로운 전략 = Novel Strategies of Algal Cultivation to Reduce Greenhouse Gas & Produce Bio-energy

다국어 초록 (Multilingual Abstract)

Microalgae are photosynthetic microorganism being capable of harvesting solar energy while converting carbon dioxide and water to cellular components such as lipid, carbohydrate, and protein. They could recover carbon dioxide that has been emitted from flue gas, one of major causes of global warming. Conventional petroleum diesel could be replaced by renewable diesel, which could be produced from the lipid component of microalgae. Thus, the production of microalgal biofuels (especially biodiesel) using the generated flue gas from fossil fuel combustion could be one of the best solutions for reducing greenhouse gas emission, improving energy security and developing new green-industry.
However there several technical bottlenecks have still remained to be economically feasible even much efforts has been made to reduce CO2 and produce biofuel from microalgae. Major bottleneck for microalgae cultivation is high cost by supplying artificial light and carbon sources. For outdoor culture, sunlight and flue gas could be use as light and carbon source. As these advantages, to overcome high cost for microalgae cultivation, utilization of sunlight and flue gases for construction of low cost cultivation system were developed and investigated.
Korean climate condition cannot provide proper and excellent condition for outdoor culture of algal cell, even though utilization of sun light energy still has numerous benefits in aspect of economics. Therefore, it is necessary to investigate how to utilize and combine artificial light and solar radiation effectively. Artificial light was provided during night time and effect of intermittent light was investigated by changing the intermittent light time to 30, 60, and 150 minutes with light and dark ratio as 1:1. Also, for efficient sunlight utilization, tinting films were used as simultaneous controller light quality and quantity. Light quality could be adjusted by cutting off the harmful UV and IR radiation, light quantity could be controlled by reducing the high solar light.
After cell cultivation, cell was harvested for biodiesel production. Although lipid concentration was decreased by night biomass loss, fatty acid composition was not change compare to control. As influence of intermittent illumination, some individual fatty acids such as C18:1 (Oleic acid), C18:3 (Linolenic acid) tended to increase by the intermittent light time period extended.
These results would be suggested novel strategy of microalgal cultivation to reduce greenhouse gas and produce bio-energy.

목차 (Table of Contents)

• CONTENTS ⅱ
• LIST OF FIGURES ⅴ
• LIST OF TABLES ⅵ
• ABSTRACT ⅶ
• 1. INTRODUCTION 1
• 2. LITERATURE REVIEW 4
• 2.1 Potential of Algae 4
• 2.1.1 Microalgae 4
• 2.1.2 Advantage of Algae 6
• 2.1.3 Products from Algae 7
• 2.1.4 Economics of Microalgal Production 8
• 2.2 Reduction of Greenhouse Gas from Microalgae 9
• 2.2.1 Global Warming by Greenhouse Gases 9
• 2.2.2 Various Method of CO2 Fixation 11
• 2.2.3 CO2 Fixation from Microalgae 14 2.3 Biodiesel from Microalgae 16
• 2.3.1 Biodiesel 16
• 2.3.2 Fatty Acid Composition of Biodiesel 18
• 2.3.3 Potential of Microalgal Biodiesel 21
• 2.4 Novel Strategies of Algal Cultivation 22
• 2.4.1 The combined CO2 Bio-mitigation and Biofuel Production Strategy 22
• 3. MATERIALS AND METHODS 24
• 3.1 Strain and Culture Conditions 24
• 3.2 Seed Culture and Culture Condition 25
• 3.3 Bubble column photobioreactor 25
• 3.4 Light Sources and Light Intensity Measurement 26
• 3.5 Measurement of Culture 27
• 4. RESUNTS AND DISCUSSION 30
• 4.1 Construction of Low Cost Cultivation System 30
• 4.1.1 Outdoor Culture of Microalgae by Sunlight as Light Source 31 4.1.2 Utilization of Flue Gas as Carbon Source 34
• 4.2 Efficient Utilization of Sunlight 37
• 4.2.1 Cut-off Harmful UV & IR by Tinting Films 37
• 4.2.2 Utilization of Filtered Light by Cellophane Films 41
• 4.3 Combination of Sunlight and Artificial Light 43
• 4.3.1 Intermittent Light 43
• 4.4 Application of Microalgae 46
• 4.4.1 Production of Biodiesel by Microalgae 46
• 4.4.2 Improvement of Biodiesel Quality 48
• 5. CONCLUSION 49
• 6. REFERRECES 51