Development and Application of Waste- driven Carbon Electrode for Reuse of Oil Sands Process-affected Water = 오일샌드 공정수 재이용을 위한 폐자원 소재 기반 탄소전극의 개발 및 적용

다국어 초록 (Multilingual Abstract)

Oil sands, one of the major unconventional oil resources, are known to possess recoverable reserves more than twice those of conventional crude oil; however, their extraction requires extensive water use and is accompanied by substantial economic and environmental burdens. OSPW contains elevated concentrations of dissolved salts, organic matter, and residual oil, necessitating advanced treatment for reuse. Conventional thermal evaporation and membrane based desalination technologies face limitations due to high energy demand and membrane fouling.
In this study, a CDI process incorporating waste derived carbon materials specifically waste petroleum coke (WPC) and spent coffee grounds was developed for the reuse of OSPW. The thermally activated waste derived electrode materials were characterized using BET analysis, SEM, XRD, Raman spectroscopy, and FT-IR to evaluate their structural and chemical properties. To enhance desalination performance, fabrication parameters including binder content, electrode thickness, and slurry viscosity were optimized. In addition, response surface methodology (RSM) was applied by selecting voltage (1.0–1.5 V), flow rate (10–20 mL/min), and adsorption/desorption ratio (1:0.8–1:1.2) as key variables. The WPC-based electrode achieved a total dissolved solids (TDS) removal efficiency exceeding 85% under its optimal operating conditions (1.5 V, 15 mL/min, 1:0.8). Finally, a scaled up CDI system equipped with WPC-based electrode modules was constructed, and performance evaluation using synthetic OSPW confirmed desalination efficiency, durability, and practical applicability for deployment in oil sands facilities.

국문 초록 (Abstract)

오일샌드 생산 과정에서 다량의 물이 사용되어 수자원 고갈 등 환경오염 문제가 야기되고 있다. 이러한 오일샌드 공정수(OSPW)는 고농도의 염류, 유기물, 오일성분 등을 포함하고 있어 처리 난의도가 높으며 기존 처리 공정으로는 기술적 한계가 존재한다. 본 연구에서는 오일샌드 공정수 재이용을 위해 폐코크스, 커피박 등 폐자원 탄소소재를 전극으로 활용한 전기흡착식 탈염공정(CDI)을 개발하였다. 열처리를 통해 활성화된 폐자원 전극 소재는 BET, SEM, XRD, Raman, FT-IR 분석을 통해 구조적·화학적 특성을 평가하였으며, 전극의 탈염 성능을 극대화하기 위해 바인더 비율, 전극 두께 및 점도 등 제조조건을 최적화하였다. 또한, 반응표면분석법(RSM)을 적용하여 전압(1.0-1.5 V), 유량(10-20 mL/min), 흡착/탈착비(1:0.8-1:1.2)를 주요 인자로 설정한 결과, 폐코크스 활성탄(WPC) 기반 전극 최적조건(1.5 V, 15 mL/min, 1:0.8)에서 총용존고형물(TDS) 제거율 85% 이상의 탈염 성능을 확인하였다. 마지막으로 폐코스크 활성탄(WPC) 기반 전극 모듈 기반 스케일업 장치를 구축하여 OSPW 합성시료를 이용한 성능평가를 통해 성능 검증, 내구성 등 실제 오일샌드 플랜트에서의 적용가능성을 검토하였다.

목차 (Table of Contents)

• CHAPTER 1. Introduction 1
• 1.1. RESEARCH BACKGROUND 2
• 1.2. TECHNICAL DISTINCTION OF THIS STUDY 6
• 1.3. RESEARCH OBJECTIVES AND SIGNIFICANCE 7
• 1.4. THESIS ORGANIZATION 8
• CHAPTER 2. Literature review 10
• 2.1. OIL SANDS PROCESS-AFFECTED WATER (OSPW) 11
• 2.1.1. Physicochemical Characteristics of OSPW 11
• 2.1.2. Environmental Regulations for OSPW in Canada 13
• 2.2. OSPW WATER TREATMENT PROCESS 15
• 2.2.1. Sand Filter 16
• 2.2.2. Flotation 18
• 2.2.3. Adsorption 22
• 2.2.4. Evaporation 25
• 2.2.5. Electrodialysis 29
• 2.2.6. Membrane 31
• 2.3. CANADIAN OIL SANDS PRODUCTION PLANTS 35
• 2.3.1. Overview 35
• 2.3.2. Case studies of major oil sands plants 37
• 2.3.3. Environmental Management and Water Treatment 40
• 2.4. CAPACITIVE DEIONIZATION 41
• 2.4.1. Overview of CDI Technology 41
• 2.4.2. Electrode materials for CDI process 42
• 2.4.3. CDI Process and Operation 43
• 2.4.4. Membrane Capacitive Deionization (MCDI) 44
• 2.4.5. Applications and Energy Efficiency 44
• 2.4.6. Recent Developments and Trends 45
• CHAPTER 3. Characterization of Materials and Electrode Fabrication 46
• 3.1. INTRODUCTION 47
• 3.2. EXPERIMENTAL METHODS 51
• 3.2.1. Selection of Electrode Materials for CDI 51
• 3.2.2. Preparation of Active Materials from CGC and WPC 53
• 3.2.3. Characterization Methods for Electrode Materials 53
• 3.2.4. Electrode Fabrication and Recipe Optimization 54
• 3.2.5. Setup of the Lab-scale CDI System and Experimental Procedures for Assessing Electrode Performance 56
• 3.3. RESULTS AND DISCUSSIONS 58
• 3.3.1. Results of Electrode Material Characterization 58
• 3.3.2. Optimization of Electrode Fabrication Techniques 69
• 3.3.2.1. Waste Petroleum Coke (WPC)-Based Electrode 70
• 3.3.2.2. Coffee Ground activated Carbon (CGC)-Based Electrode 76
• 3.3.3. Optimization and Performance Comparison of Electrodes by Material Type 82
• 3.4. CONCLUSIONS 85
• CHAPTER 4. Optimization of Operating Conditions for CDI Process Using Waste-Derived Electrodes via RSM 86
• 4.1. INTRODUCTION 87
• 4.2. MATERIALS AND METHODS 89
• 4.2.1. Principle of CDI 89
• 4.2.2. Experimental Set-up 90
• 4.2.3. Feed water and operation conditions 93
• 4.2.4. Application of Response Surface Methodology 94
• 4.3. RESULTS AND DISCUSSIONS 97
• 4.3.1. Effect of Operating Variables 97
• 4.3.1.1. Waste petroleum coke (WPC)-based electrode 97
• 4.3.1.1.1. Effect of a single voltage condition on CDI performance 97
• 4.3.1.1.2. Effect of a single flow rate condition on CDI performance 99
• 4.3.1.1.3. Effect of a single sorption time ratio condition on CDI performance 101
• 4.3.1.2. Coffee grounds (CGC)-based electrode 103
• 4.3.1.2.1. Effect of a single voltage condition on CDI performance 103
• 4.3.1.2.2. Effect of a single flow rate condition on CDI performance 105
• 4.3.1.2.3. Effect of a single sorption time ratio condition on CDI performance 107
• 4.3.2. Optimization of CDI in CCD under RSM 109
• 4.3.2.1. Waste petroleum coke (WPC)-based electrode 109
• 4.3.2.1.1. RSM analysis results – TDS removal efficiency 112
• 4.3.2.1.2. RSM analysis results – Water production 115
• 4.3.2.1.3. Graphical optimization 118
• 4.3.2.2. Coffee grounds (CGC)-based electrode 120
• 4.3.2.2.1. RSM analysis result – TDS removal efficiency 123
• 4.3.2.2.2. Water production 126
• 4.3.2.2.3. Graphical optimization 129
• 4.3.3. Comparison of Optimal CDI Operating Conditions by Electrode Type 131
• 4.3.3.1. Comparison of RSM analysis results for electrode type 131
• 4.3.3.2. Comparison of Electrode Performance Based on Overlay Plot Analysis 133
• 4.4. CONCLUSION 135
• CHAPTER 5. Wasted Derived Electrode-Based CDI Application for OSPW Reuse 136
• 5.1. INTRODUCTION 137
• 5.2. MATERIALS AND METHODS 139
• 5.2.1. Preparation of Synthetic OSPW 139
• 5.2.1.1. Ionic Substances 139
• 5.2.1.2. Oil Components 142
• 5.2.2. Experimental set-up 145
• 5.2.2.1. Lab-Scale CDI System 145
• 5.2.2.2. Oil removal performance evaluation system (RSSCT) 148
• 5.2.2.3. Pilot-Scale CDI System 151
• 5.3. RESULTS AND DISCUSSION 154
• 5.3.1. Effect of Feed Water Characteristics 154
• 5.3.1.1. Effect of Feed Temperature and Concentration 154
• 5.3.1.2. Effect of OSPW Concentration on Different Electrodes 156
• 5.3.1.3. Effect of Oil Presence in Feed Water 159
• 5.3.2. Oil Removal Capacity of Waste-Derived Activated Carbons 162
• 5.3.3. Long-Term Evaluation of the Pilot-Scale CDI System 171
• 5.4. CONCLUSION 177
• CHAPTER 6. Conclusion 179
• 6.1. CONCLUSION 180
• REFERENCES 184
• 국문 초록 203