Development of a Starfish-Derived CaO/MgO Catalysts Doped with Transition Metals for Enhanced Biodiesel Production = 바이오매스 기반 이종 촉매를 이용한 지속 가능한 바이오디젤 생산 연구

다국어 초록 (Multilingual Abstract)

The depletion of fossil fuels and increasing environmental concerns have accelerated the demand for sustainable energy alternatives such as biodiesel. As a renewable and biodegradable fuel, biodiesel offers advantages such as reduced emissions and compatibility with existing diesel engines. However, the use of homogeneous catalysts is limited by issues of separation and recyclability. Heterogeneous catalysts, in contrast, provide easier recovery and reusability, making them more suitable for green biodiesel synthesis.
This study introduces a novel catalyst derived from marine biomass waste— specifically starfish (Asterias rubens), which is rich in calcium and magnesium carbonate. Utilizing invasive or discarded starfish not only adds value to an underused bioresource but also contributes to marine ecosystem management. In the first experiment, CaO/MgO catalysts doped with Zn, Ni, and Cu were synthesized via a hydrothermal method. The Zn-doped catalyst (ZDS) showed the highest basicity (3.04 mmol/g) and biodiesel yield (96.6%), attributed to the amphoteric nature of ZnO.
In the second experiment, Zn loading was optimized (5, 10, and 15 wt%), with 10 wt% showing the best performance. Reusability tests confirmed 86.5% activity retention after three cycles, and SEM-EDS analysis verified minimal Zn leaching. These findings demonstrate the feasibility of converting marine waste into high-performance, recyclable catalysts for biodiesel production, aligning with circular economy principles and offering a scalable pathway for sustainable fuel generation.

목차 (Table of Contents)

• Contents ⅰ
• Contents of Table ⅲ
• Contents of Figure ⅳ
• Abstract ⅵ
• 1. Introduction 1
• 1.1 Biodiesel as a Sustainable Alternative Fuel and the Role of Heterogeneous Catalysts 1
• 1.2 Utilizing Marine Biomass for Catalyst Development: Opportunities and Challenges 3
• 1.3 Metal Doping Strategies for Enhancing Catalyst Stability and Activity 4
• 2. Experimental, Characterization and Performance Analysis 5
• 2.1 Catalyst Preparation from Starfish Biomass 5
• 2.1.1 Raw Material Preparation 5
• 2.1.2 Calcination of Starfish Biomass 5
• 2.1.3 Metal Doping by Hydrothermal Synthesis 5
• 2.2 Material Characterization 7
• 2.2.1 Crystal Structure Analysis 7
• 2.2.2 Surface Morphology and Elemental Mapping 9
• 2.2.3 Surface Chemical States 9
• 2.2.4 Basicity Analysis 9
• 2.3 Transesterification Reaction Procedure 11
• 2.4 Catalytic Performance Analysis 12
• 2.4.1 Biodiesel Yield Analysis via HPLC 12
• 2.4.2 Reusability Test 12
• 3. Comparative Study of Metal-Doped CaO/MgO Catalysts Synthesized from Starfish Biomass for Biodiesel Production 13
• 3.1 Overview 13
• 3.2 Experimental 14
• 3.2.1 Catalyst Synthesis 14
• 3.2.2 Catalyst Characterization 14
• 3.2.3 Transesterification Reaction 15
• 3.2.4 HPLC Analysis 15
• 3.3 Result and Discussion 16
• 3.3.1 Surface Chemical Composition 16
• 3.3.2 Morphological and Element Analysis 20
• 3.3.3 Basicity Measurement 23
• 3.3.4 Catalytic Performance 23
• 3.4 Conclusion 26
• 4. Optimization of Zinc-Modified Biomass-Derived CaO/MgO Catalyst for High-Efficiency Biodiesel Production 27
• 4.1 Overview 27
• 4.2 Experiment 28
• 4.2.1 Catalyst Synthesis 28
• 4.2.2 Morphological Analysis 29
• 4.2.3 Surface Chemical Analysis 29
• 4.2.4 Catalytic Performance 30
• 4.3 Characterization 31
• 4.3.1 Crystalline Structure 31
• 4.3.2. Morphological and Surface Chemical Analysis 33
• 4.3.3 Basicity Analysis 37
• 4.3.4 Catalytic Activity of Zinc-Doped Catalysts 37
• 4.3.5 Effect of Zinc Loading on Catalytic Activity 40
• 4.3.6 Catalyst Reusability 42
• 4.4 Conclusion 43
• 5. Conclusion 45
• Reference 47
• Abstract in Korean 52