Characterisation Peal of Fruit and Leaf of Vegetable Waste with Cow Dung for Maximizing the Biogas Yield

Massreshaw Assnakew Abebe

doi:10.11648/j.ijepe.20170602.12

Abstract

The biogas production and methane (CH4) enrichment for anaerobic digestion (AD) of fruit and vegetable waste (FVW). The biogas production and methane content of fruit and vegetable wastes (FVW) degradation were evaluated against a treatment combination with a cow dung at a Ratio of FVW to Cow dung T1 (cow dung alone), T2 (1:3), T3 (1:1), T4 (3:1),and T5 (FVW alone). The digesters were operated for 80 days. The highest total methane yields about 78.35% was obtained from the cow dung digester (T1). The highest production of biogas yield (7552.67 ml) was observed in T1 and the lowest biogas production rate (2652.83ml) was from a reactor operated by FVW alone. Similar to the biogas yield, higher percentage of methane was produced in 1. Anaerobic digestion; vegetable and fruit wastes of high calorific contents can be transformed to a source of energy through the production of biogas in this day and age of energy insufficiencies. Role in maximizing the process of anaerobic digestion through speeding up hydrolysis and to compare production potentials of commonly available wastes in Addis Ababa for possible co-digestion in large scale production of biogas. Thermo-chemical pre-treatment was the most effective for speeding up hydrolysis with the co-digested substrates producing maximum biogas. The moisture content ranged between 67-83%. The pH reduced from 6.8-7.2 before digestion to 6.2-6.8 after digestion. The desired C: N ratio was between 18:1 to 32:1 for Anaerobic Digestion. The gas produced was found to contain 63.89% methane, 33.12% CO2 and 3% other gases.

Highlights

The maximum biogas was produced in a mixture of fruit and vegetables to cow dung at the ratio of 25:75(T4) which provided 7552.67ml in 80 days of retention time
The biogas produced from cow dung alone was 6872.3ml; best biogas production and the Minimum production of biogas was 2652.83ml of T5 and it was the study further revealed that those treatments (T1 and T5) that have carbon to nitrogen ratio (C/N) ratios within the range of 20-35 are found to perform better in biogas yield and methane production than those outside this range
The C/N ratio of T2 and T4 was beyond the optimum C/N value

Summary

Introduction

An anaerobic digestion of fruit and vegetable wastes were the rapid acidification due to the lower pH of wastes and the larger production of volatile fatty acids (VFA), which reduced the methanogenic activity of the reactor. The rate limiting step in fruit and vegetable wastes were methanogenesis rather than hydrolysis because methanogenic bacteria take long mass doubling time of 3-4 days in anaerobic reactors [8]. Fruit-processing wastes, especially banana waste is highly biodegradable because of their rich organic matter and high moisture content. The banana waste was a concentrated source of putrid organic waste, ideal for anaerobic digestion to produce energy while fermentation products can serve as fertilizer with high nutritional value, as well as a valuable energy source in form of biogas [4]

Methods

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Discussion

Conclusion