In this study, the utilization of waste coffee residue for biodiesel production, its solid byproduct after oil extraction for bioethanol production, as well as the second byproduct after bioethanol production for solid fuel and compost production was investigated. For the study, waste coffee residue sample was collected from TOMOCA PLC, Addis Ababa, Ethiopia. The oil was then extracted using n-hexane and resulted in oil yield of 19.73 %w/w. The biodiesel was obtained by a two-step process, i.e. acid catalyzed esterification followed by base catalyzed transesterification using catalysts sulfuric acid and sodium hydroxide respectively. The conversion, after esterification of waste coffee residue oil in to biodiesel, was about 80.4%. Various parameters that are essential for biodiesel quality were evaluated using the American Standard for Testing Material (ASTM D 6751- 09). The results obtained for kinematic viscosity (5.3 mm²/s), carbon residue (0.033%), flash point (222°C), ash content (0.0123%), water and sediment (<0.01%), iodine value (73.41 gI2/100g), acid value (0.78), copper striping corrosion (1a) and calorific value (38.4 MJ/kg) revealed that all quality parameters are within the range specified except for acid value. The fatty acid composition of the biodiesel was also analyzed by Gas chromatography and the major fatty acids found were linoleic acid (39.8%), palmitic acid (37.6%), oleic (12.7%), and stearic acid (7.6%). In addition, the solid waste remaining after oil extraction was investigated for possible use as a feedstock for the production of bioethanol. Hydrolysis of the spent was carried out using dilute sulfuric acid followed by fermentation using S. cereviciae, and resulted in bioethanol yield of 8.3 %v/v. Furthermore, the solid waste remaining after bioethanol production was evaluated for compost and solid fuel applications. The result indicated that the processed coffee residues could still be used as compost (21.9:1 C/N) and solid fuel (20.8 MJ/Kg). Therefore, the results of this work may suggest a new insight to production of biofuel from waste materials.
Keywords: Waste coffee residue, Biodiesel, spent of WCR, Saccharomyces cereviciae, Bioethanol, solid fuel, compost
Table of Contents
- 1. INTRODUCTION
- 1.1. Background and justification
- 1.2. Problem of the statement
- 1.3. Objectives
- 1.3.1. General objective
- 1.3.2. Specific objectives
- 1.4. Significance of the study
- 2. LITERATURE REVIEW
- 2.1. Overview of Ethiopia's Energy Sector
- 2.2. Introduction to biodiesel
- 2.3. Biodiesel production
- 2.3.1. The Transesterification (alcoholysis) Process of Biodiesel
- 2.3.1.1. Catalytic transesterification
- 2.4. Variables Affecting the Transesterification Process
- 2.4.1. Effect of free fatty acids (FFA) and moisture
- 2.4.2. Effect of Alcohol/oil Molar Ratio and Alcohol Type
- 2.4.3. Type and Amount of Catalyst
- 2.4.4. Reaction Time and Temperature
- 2.5. Parameters which define the fuel quality of biodiesel
- 2.5.1. Density (15 °C)
- 2.5.2. Viscosity (40 °C)
- 2.5.3. Gross calorific value
- 2.5.4. Cloud point (CP)
- 2.5.5. Cetane Number
- 2.5.6. Iodine Value (IV)
- 2.5.7. Flash point
- 2.5.8. Water and sediment
- 2.5.9. Carbon Residue
- 2.5.10. Sulfated ash
- 2.5.11. Acid value
- 2.6. Coffee production and Waste coffee residues
- 2.6.1. Coffee production in Ethiopia
- 2.6.2. Waste Coffee Residues (WCRs)
- 2.6.2.1. Chemical composition of WCR
- 2.7. Advantages and Disadvantages of Biodiesel
- 3. MATERIALS AND METHODS
- 3.1. Materials and chemicals
- 3.2. Experimental
- 3.2.1. Waste coffee residue (WCR) Moisture content Determination
- 3.2.2. Waste coffee residue (WCR) oil extraction
- 3.2.3. Physicochemical parameters of WCRs oil
- 3.2.3.1. Determination of Saponification Value
Objectives and Key Themes
This thesis investigates the potential of waste coffee residue as a sustainable source for biofuel production. The study aims to determine the feasibility of converting waste coffee grounds into biodiesel, bioethanol, and solid fuel, thereby reducing waste and promoting a circular economy.
- Biodiesel production from waste coffee residue oil.
- Bioethanol production from the solid byproduct after oil extraction.
- Utilization of the remaining solid byproduct for solid fuel and compost applications.
- Assessment of the quality parameters of the produced biodiesel.
- Analysis of the economic and environmental implications of the proposed biofuel production process.
Chapter Summaries
1. INTRODUCTION: This introductory chapter sets the stage for the research by establishing the context of Ethiopia's energy sector and highlighting the problem of waste coffee residue disposal. It clearly defines the research objectives, both general and specific, and emphasizes the significance of utilizing waste materials for biofuel production, contributing to sustainable development and environmental protection. The chapter effectively lays the groundwork for the subsequent chapters, outlining the research methodology and the anticipated outcomes. The justification for the study is strongly presented, emphasizing the potential environmental and economic benefits of converting waste into valuable resources.
2. LITERATURE REVIEW: This chapter provides a comprehensive overview of existing literature on biodiesel production, focusing on the transesterification process and the factors that influence its efficiency. It explores the physicochemical properties of biodiesel and the standards for quality assessment. Additionally, it details coffee production in Ethiopia and the characteristics of waste coffee residue as a potential feedstock for biofuel production. The chapter successfully integrates different aspects of biodiesel production and waste coffee residue, laying the theoretical foundation for the experimental work undertaken in the subsequent chapters. The discussion of the advantages and disadvantages of biodiesel provides a balanced perspective on its viability as a sustainable alternative fuel source.
3. MATERIALS AND METHODS: This chapter meticulously describes the materials, chemicals, and experimental procedures employed in the study. It provides a detailed account of the methods used for waste coffee residue collection, oil extraction, biodiesel production (including both esterification and transesterification steps), bioethanol production via hydrolysis and fermentation, and the analysis of the resultant solid residue for compost and solid fuel applications. Each step is clearly outlined, ensuring reproducibility of the research. The chapter adheres to a rigorous scientific approach, enhancing the credibility and transparency of the research findings.
Keywords
Waste coffee residue, Biodiesel, Bioethanol, Solid fuel, Compost, Saccharomyces cerevisiae, Sustainable biofuel production, Waste management, Circular economy, Ethiopia.
Frequently Asked Questions: Waste Coffee Residue as a Sustainable Biofuel Source
What is the main topic of this thesis?
This thesis investigates the potential of waste coffee residue (WCR) as a sustainable source for biofuel production. It explores the feasibility of converting WCR into biodiesel, bioethanol, and solid fuel, thereby reducing waste and promoting a circular economy.
What are the key objectives of the research?
The research aims to:
- Produce biodiesel from waste coffee residue oil.
- Produce bioethanol from the solid byproduct after oil extraction.
- Utilize the remaining solid byproduct for solid fuel and compost applications.
- Assess the quality parameters of the produced biodiesel.
- Analyze the economic and environmental implications of the proposed biofuel production process.
What are the main chapters covered in the thesis?
The thesis is structured into three main chapters:
- Chapter 1: Introduction: Provides background information on Ethiopia's energy sector, the problem of waste coffee residue disposal, research objectives, and the significance of the study.
- Chapter 2: Literature Review: Reviews existing literature on biodiesel production, focusing on the transesterification process, biodiesel quality parameters, coffee production in Ethiopia, and the characteristics of WCR.
- Chapter 3: Materials and Methods: Details the materials, chemicals, and experimental procedures used in the study, including WCR oil extraction, biodiesel and bioethanol production, and analysis of the solid residue.
What methods are used for biodiesel production?
The thesis details the methods used for waste coffee residue collection, oil extraction, biodiesel production (including both esterification and transesterification steps), bioethanol production via hydrolysis and fermentation, and the analysis of the resultant solid residue for compost and solid fuel applications.
What are the key quality parameters of biodiesel assessed in this study?
The study assesses several key quality parameters of the produced biodiesel, including density, viscosity, gross calorific value, cloud point, cetane number, iodine value, flash point, water and sediment content, carbon residue, sulfated ash, and acid value.
What is the significance of this research for Ethiopia?
The research is significant for Ethiopia because it addresses the problem of waste coffee residue disposal and explores the potential of utilizing this waste material for biofuel production, contributing to sustainable development and environmental protection within the context of Ethiopia's energy sector.
What are the potential environmental and economic benefits of this research?
The research aims to demonstrate the environmental benefits of reducing waste coffee residue and the economic benefits of producing valuable biofuels from a readily available waste stream. The analysis of economic and environmental implications is a key component of the study.
What are the key words associated with this research?
Key words include: Waste coffee residue, Biodiesel, Bioethanol, Solid fuel, Compost, Saccharomyces cerevisiae, Sustainable biofuel production, Waste management, Circular economy, Ethiopia.
- Quote paper
- Mebrahtu Haile (Author), 2014, Biofuels. Sequential volarization of waste coffee grounds to Biodiesel, Bioethanol, and solid fuel, Munich, GRIN Verlag, https://www.grin.com/document/274372
