Effects of Different Binders on the Physical and Combustion Properties of Dried Leaves Briquettes
Effects of Different Binders on the Physical and Combustion Properties of Dried Leaves Briquettes.
ABSTRACT
Biomass Briquetting can address waste problems, reduce air pollution from direct open air burning and also reduce dependence on fossil fuels for heat generation.
Dry leaves have been shown to have high calorific values; therefore the purpose of this study is to determine the effects of some binders on the physical and combustion properties of dried leaves briquettes.
Dried leaves were mixed with binders such as clay, starch and Arabic gum separately at different ratios of 10%, 20%, 30% and 40%, and made into briquettes using a manual press with a hydraulic jack of 20 tons.
Physical and combustion properties of these briquettes were obtained using different methods prescribed by other researchers. From the results of the properties tested, briquettes made from dried leaves and gum at 40% of binder was most resistant to water.
Dried leaves and clay at 40% had the highest relative density of 0.7977g/cm3. Dried leaves and starch had a relative density at 40%, 0.4640g/cm3 while briquettes with gum binder had 30%, 0.4030g/cm3.
Dried leaves and gum at 40% had the highest volatile matter of 84.110% and the highest heating value of 30.5118MJ/kg at 10%. Briquettes at this ratio failed to hold, because of its low durability.
The high ash content of briquettes bonded with clay 16.353% to 34.487% made it difficult to ignite, due to the presence of non combustible matter.
Dried leaves bonded with starch at 20% had high heating value of 30.2189, and was able to withstand shattering with durability of 81.752% and high relaxation ratio of 1.7427. It can then be considered as the best binder in this study.
TABLE OF CONTENT
Title page – – – – – – i
Certification – – – – – – ii
Dedication – – – – – – – iii
Acknowledgement – – – – – – – iv
Table of contents – – – – – – – vi
List of tables – – – – – – ix
Abstract – – – – – – x
CHAPTER ONE INTRODUCTION
- Background of the study – – – – – – 1
- Historical background of the study Area – – – 2
- Statement of the problem – – – – – 3
- Objectives of the study – – – – – – 4
- Research questions – – – – – 4
- Research Hypotheses – – – – – – 5
- Significance of the study – – – – – – 5
- Scope of the study – – – – – – 6
- Limitations of the study – – – – – – 6
- Definition of Terms – – – – – 6
References – – – – – – – 8
CHAPTER TWO: REVIEW OF RELATED LITERATURE
- Briquetting Technology 17
- History of briquetting 17
- Biomass briquetting 18
Advantages of Biomass Briquetting: 20
- Techniques of briquetting 21
High Pressure Briquetting: 22
Piston Presses: 23
Screw Presses: 25
Pellet Presses: 26
Low Pressure Briquetting: 27
Manual Presses: 27
- Briquetting characteristics 28
- Process variables factors 30
Temperature: 30
Pressure: 31
Die Geometry: 31
Binder To Biomass Ratio: 31
- Feedstock variables factors 32
Particle Size Distribution: 32
Moisture Content: 32
- Binders For Briquetting 33
- Binder quality 33
- Types of binders 33
Inorganic Binders: 33
Organic Binders: 34
CHAPTER THREE
- MATERIALS AND METHODS 36
- Dried Leaves Collection And Preparation 36
- Binder Collection And Preparation 37
- The Briquetting Process 38
- Dried leaves and starch binder 38
- Dried leaves and gum arabic binder 39
- Dried leaves and clay binder 39
- Determination of the Physical and Combustion Properties 40
- Physical properties 40
Compaction Ratio : 40
Compressed Density: 40
Relaxed Density: 40
Relaxation Ratio: 41
Dimensional Stability: 41
Durability: 41
Water Resistance: 41
- Combustion properties 42
Flame Propagation Rate: 42
Afterglow Rate: 42
Proximate Analysis: 42
Heating Value: 43
CHAPTER FOUR
- RESULTS AND DISCUSSION 44
- Comparism of the Effects of Binders on the Briquettes, Based On Three Major Properties; Relative Density, Volatile Matter and Heating Value 54
CHAPTER FIVE
- CONCLUSION AND RECOMMENDATIONS 61
- Conclusion 61
- Recommendations 62
REFERENCES 63
APPENDIX 72
INTRODUCTION
1.1 Background Information
Energy generated from biomass is categorized as sustainable and renewable energy. During the plant life cycle, plant biomass materials derived from plant adsorb carbon dioxide (CO2) through photosynthesis at same rate as they release the gas in the combustion process, thus leading to no net increase in atmospheric CO2 quantity.
Due to the lower contents of sulfur and nitrogen in biomass, its application also creates less environmental pollution and health risk than fossil fuel combustion. This is the reason why utilization of biomass is eco-friendly.
Compared to fossil fuel, however, most of agricultural wastes have higher moisture content and lower density, thus making them technically unsuitable for direct use due to combustion and handling problems. Conversion of biomass wastes to briquettes is a solution for such problems.
It improves biomass handling characteristics, increases the volumetric calorific values, and reduces transportation, collection, and storage costs (Grover and Mishra,1996).
The potential agro residues which do not pose collection and drying problems, normally associated with biomass are dried leaves, rice husk, groundnut shells, coffee husk and coir waste (obtained by drying process: Sybil 1958).
If these agricultural waste products can be properly recycled, into useful products, more goods will be made available to our society, environmental pollution and other disease attack would be greatly reduced.
REFERENCES
Adapa, P.K., Schoenau, G.J. and Tabil, L.G. (2003). Aerodynamic separation and fractional drying of alfalfa leaves and stems – a review and new concept. Drying Technology Journal, Vol 21, Pages 1669-1898
Adegoke, C.O. and Mohammed, T.I. (2002). Investigation of sawdust briquettes as high grade fuel. West Ind. J. Engin. Vol 25(1) Chapters 1-8.
Aina, O.M, Adetogun, A.C. and Iyola, K.A. (2009). Heat energy from value added sawdust briquettes. Ethopian Journal of Environmental Studies and Management. Vol 2, No 1. Pages 42-56.
ASTM Annual Book of ASTM Standards (2004). Standard Test Method for Unconfined Compressive Strength of Cohesive Soil. ASTM D2166-85, 2004.
Bailey, R.T. and Blankenhorn, P.R. (1982). Charcoal production, improvement for rural development. First Edition, Vol 1. Page 61-70.
CENBIO, (2001). The Brazilian National Reference Center on Biomass. Private Communication, 2000.
