Biogas Production using Geomembrane Plastic Digesters as Alternative Rural Energy Source and Soil Fertility Management

Biogas Production using Geomembrane Plastic Digesters

Master's Thesis , 2008 , 111 Pages , Grade: Very Good

Agrarian Studies

Abstract
The study was conducted in North Wollo, Mersa-Chekorsa village, Ethiopia in 2006/2007, where animal dung for biogas production is available. The overall objective of the study was to introduce economically feasible, technically acceptable and environmentally friendly biogas plant to the farming community and other potential users in Ethiopia. The research was carried on two types of biogas plants of 3m3 capacity (1) geo-membrane plastic (two single and two double layered) biogas plants constructed below and above the ground surface and (2) fixed-dome biogas plant. Each bio-digesters was fed with a mixture of 75Kg of cow-dung and 75Kg pure water at equal volume and proportion. Amount of gas and slurry were measured using calibrated biogas burner and weight balance respectively. The quality of the slurry (i.e. total-N and organic matter content) were analyzed in the laboratory using Kjeldahl and ash method respectively. The bio-digesters were compared after gas has completely produced at the end of 40 days of fermentation with respect to amount of gas and slurry produced, quality of slurry in terms of total-N and organic matter content. Economic analysis of the bio-digesters was carried out using cost-benefit analysis. The social aspect of using biomass and biogas technologies and environmental impact assessment of the new geo-membrane plastic biogas technology was also assessed. The emissions of CO2 and CH4 were computed by measuring the production of biogas in the two models of bio-digester. Fermented slurry contained larger nitrogen content than fresh cow dung in both models of bio-digester. The geo-membrane plastic biogas plant gave higher net benefit than fixed-dome biogas plant. So, from this, investment on geo-membrane plastic bio-digester is economically feasible. Environmental impact assessment of the technology was studied and found that 360.04 m3 of CO2 and 600.06 m3 CH4 was prevented from emitting in to the atmosphere and save 0.562 hectare of forest per year. Generally, it was found that, the geo-membrane cylindrical film bio-digester technology was found cheap and simple way to produce gas in the study area and it was recommended to introduce the technology into the rural areas having even and high temperature which is similar to the study area more preferably to an area having mean daily temperature greater than 20 OC.
Key words:Geo-membrane ,fixed-dome bio-digester, biogas, quality of fermented slurry,economical feasibility

Inhaltsverzeichnis (Table of Contents)

• Acknowledgements
• Table of Contents
• List of Tables
• List of Figures
• Acronyms
• Abstract
• 1 Introduction
• 1.1 Background
• 1.2 Problem Statement
• 1.3 Purpose of Study
• 1.4 Hypothesis
• 1.5 Objective of study
• 1.5.1 General objective
• 1.5.2 Specific objective
• 2 Literature Review
• 2.1 Fuel Consumption in Ethiopia
• 2.2 Biomass and Biogas Energy Technologies in Ethiopia
• 2.3 Theory of Biogas Technology
• 2.4 Benefits of low-cost Plastic Biodigester Technology
• 2.4.1 Environmental Benefites of Biogas Technology
• 2.4.2 Social Benefits of Biogas technology
• 2.4.3 Economic Advantages of Plastic Biogas Technology
• 2.4.4 Beneficiaries of Biogas Production
• 2.5 Input materials of Bio-Gas production
• 2.6 Biogas Production Process
• 2.7 Theory of Biogas Burner
• 2.8 The Slurry after Digestion
• 2.9 Measurement of Biogas Production
• 2.10 Designing of Digester
• 2.11 Working of Fixed-Dome Biogas plant
• 2.12 Selection and Layout of Pipeline and Biogas Accessories
• 2.13 Transfer of the plastic film Bio-digester Technology
• 2.14 Promotion of Fixed and Floating Dome Biogas Plant
• 2.15 Economic Evaluations of Biogas Plants
• 2.16 LDPE Geo-membrane Plastic
• 2.17 Theory of Environmental Impact Assessment (EIA)
• 3 Materials and Methods
• 3.1 Description of the Study area
• 3.1.1 Location
• 3.1.2 Socio-economic activity
• 3.1.3 Climate
• 3.1.4 Land Use
• 3.1.5 Livestock population
• 3.2 Experimental Design and Layout
• 3.3 Geo-membrane plastic construction and methodology
• 3.4 Data collection procedures
• 3.4.1 Input to the digester
• 3.4.2 Measurement of gas production
• 3.4.3 Temperature of the air and Slurry
• 3.4.4 Total-Solids(DM) content
• 3.4.5 The organic dry matter(ODM)
• 3.4.6 pH of the fresh Cow Dung and Digested Slurry
• 3.4.7 Quality of output Slurry
• 3.4.8 The efficiency of Bio-digester
• 3.4.9 Social aspect of biomass and biogas technologies
• 3.4.10 The economic Visibility of a plastic and fixed Dome biogas plant
• 3.4.11 The Environmental Impact of the plastic biogas plant
• 3.5 Statistical Analysis
• 4 Result and Discussion

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This thesis investigates the potential of biogas production using geomembrane plastic digesters as a means of providing an alternative rural energy source and improving soil fertility management in Ethiopia. The study aims to assess the technical feasibility, environmental impact, and economic viability of this technology.

• Biogas production using geomembrane plastic digesters as a sustainable energy source
• Evaluation of the environmental impact of biogas technology
• Economic assessment of biogas production and its contribution to rural livelihoods
• The role of biogas technology in improving soil fertility and agricultural practices
• Social implications and adoption of biogas technology in rural communities

Zusammenfassung der Kapitel (Chapter Summaries)

Chapter 1 provides an introduction to the study, outlining the background, problem statement, purpose, hypothesis, and objectives. It highlights the importance of biogas technology in addressing the energy and environmental challenges faced by rural communities in Ethiopia.

Chapter 2 presents a comprehensive literature review on biogas production and its applications. It discusses the theory of biogas technology, its benefits, the production process, and the design of digesters. The chapter also explores the use of geomembrane plastic in biogas digester construction and its implications for environmental impact assessment.

Chapter 3 details the materials and methods employed in the study. It describes the study area, experimental design, and data collection procedures. The chapter outlines the methods used to assess biogas production, slurry quality, and the economic and environmental impact of the technology.

Chapter 4 presents the results and discussion of the study, focusing on the performance of the geomembrane plastic digesters, the environmental impact of the technology, and its economic and social implications. It also explores the potential of biogas technology in improving soil fertility and agricultural practices.

Schlüsselwörter (Keywords)

The key focus areas of this research include biogas production, geomembrane plastic digesters, rural energy, soil fertility management, environmental impact assessment, economic viability, Ethiopia, and sustainable development. This research aims to contribute to the knowledge and understanding of biogas technology as a promising solution for rural development in Ethiopia.

• Course: Tropical Land Resources Management
• Grade: Very Good
• Author: Bezabih Yimer (Author)
• Publication Year: 2008
• Pages: 111
• Catalog Number: V211838
• ISBN (eBook): 9783656395416
• ISBN (Book): 9783656395577
• Language: English
• Tags: biogas, production, geomembrane, plastic, digesters, alternative, rural, energy, source, soil, fertility, management