OPTIMIZATION OF METHANE GAS BY ANAEROBIC DIGESTION

ABSTRACT

This project work aimed at demonstrating the benefits of organic wastes in the production of Biogas using a bio-digester through the use of different substrates and methods in order to optimize the production of Methane Gas by anaerobic digestion. Five samples (substrates) were used in this research with their different seeding substances.

Organic wastes, particularly plants wastes and animal dung constitute a nuisance to our environment and also a threat to public health, there is therefore a need to search for the beneficial ways of minimizing them without any harm to our environment. In order to alleviate the problems of rural and urban energy requirements, this research provides reliable information about different techniques we can employ to obtain a large amount of methane gas at relatively shorter time than is expected. It also explores and exploits other energy sources for man’s economic benefits and how to optimize them; this is connected to the rapid depletion of fossil fuels. Biogas is suitable, standard, affordable and sustainable alternative source of renewable energy since the raw materials are termed wastes and are readily available in very large quantities.

From this research, it could be deduced that a biogas generating plant can easily be constructed at a minimum cost affordable.

Table of Contents

Definition of Terms -----------------------------------------------------------------------------------1

CHAPTER ONE

Introduction---------------------------------------------------------------------------------------------3

Background to the Study -----------------------------------------------------------------------------3

Aims and Objectives ----------------------------------------------------------------------------------4

CHAPTER TWO

Literature ----------------------------------------------------------------------------------------------5

Survey of Biogas Technology in Nigeria ----------------------------------------------------------5

Chemistry of Biogas Production --------------------------------------------------------------------6

Factors affecting Anaerobic Digestion -------------------------------------------------------------9

Environmental Factors -------------------------------------------------------------------------------9

Operational Factors -----------------------------------------------------------------------------------10

Loading Rate ------------------------------------------------------------------------------------------13

Origin of Waste ---------------------------------------------------------------------------------------14

Type of Bacteria Selected ---------------------------------------------------------------------------14

Volatile Solids (VS) ----------------------------------------------------------------------------------14

Additives -----------------------------------------------------------------------------------------------15

Types of Biogas Digester ----------------------------------------------------------------------------16

Types of Biogas Plants -------------------------------------------------------------------------------16

Modes of Biogas Digestion --------------------------------------------------------------------------25

Effect of Catalyst on treatment of plant waste to produce biogas-------------------------------26

CHAPTER THREE

Calculation of Volume of Digesters ----------------------------------------------------------------27

Methodology ------------------------------------------------------------------------------------------30

Materials used -----------------------------------------------------------------------------------------31

Equipment/Apparatus --------------------------------------------------------------------------------32

Preparation of Sample -------------------------------------------------------------------------------34

Addition of Catalyst ---------------------------------------------------------------------------------35

Measurement of Parameters Affecting Biogas Production -------------------------------------36

Flammability Test ------------------------------------------------------------------------------------36

CHAPTER FOUR

Data Presentation and Analysis --------------------------------------------------------------------37

Data Presentation ------------------------------------------------------------------------------------37

Operating Parameters of the Five Samples ------------------------------------------------------37

Data Analysis ----------------------------------------------------------------------------------------56

Characterization of Four Samples Using Micrograph ------------------------------------------58

Structural Characteristics --------------------------------------------------------------------------61

CHAPTER FIVE

Result of the Analysis ------------------------------------------------------------------------------63

Discussion -------------------------------------------------------------------------------------------63

Structural Characteristics --------------------------------------------------------------------------67

Conclusion -------------------------------------------------------------------------------------------67

Difficulties Encountered ---------------------------------------------------------------------------68

References -------------------------------------------------------------------------------------------68