EVALUATION OF ECO-EFFICIENCY OF NAPIER GRASS (ELEPHANT GRASS) AND MISSION GRASS (PENNISETUM POLYSTACHION) IN BIOGAS PRODUCTION.pptx

ecoefficiency of napier grass

1. EVALUATION OF ECO-EFFICIENCY OF NAPIER GRASS (ELEPHANT GRASS) AND MISSION GRASS (PENNISETUM POLYSTACHION) IN BIOGAS PRODUCTION

2. CHAPTER ONE INTRODUCTION Biogas is a mixture of methane, carbon dioxide, water and hydrogen sulphide produced during the anaerobic decomposition of organic matter ( Luostarinen et al., 2011). Biogas is a clean-burning methane-rich gas produced through anaerobic digestion (bacterial action in the absence of air) of organic feed stocks (crop residues or animal dung).

3. Introduction (Continued…) The process of producing biogas is anaerobic and is subdivided into: Hydrolysis Acidogenesis Acetogenesis Methanogenesis

4. 1.2 Statement of The Research Problem Production of biogas from Eco-efficient material (Napier and Mission) grass under anaerobic digestion as methane can be used to replace non-renewable energy resources. Napier and Mission grass which do not need to be cultivated and often neglected; if properly utilized will be a suitable alternative feedstock for biogas production hence, solving the problem of energy scarcity. The availability and accessibility of the material will save cost for the production of biogas.

5. 1.3 Aim and Objectives The aim of this research work is to produce biogas from Napier and mission grass as alternatives source for feedstock to conventional feedstocks and unveil the potentials of biogas from underutilized sources such as Napier grass and mission grass which are available in our environment. To achieve the aim stated above, the following objectives will be carried out: ( i )production of biogas from Napier and mission grass (ii)Evaluation of percentage of biogas produced (iv)Characterization of the biogas produced

6. 1.4 Scope and limitation of the study This research seeks to develop a low cost and Eco-efficient biogas from Napier and mission grass, a natural resources found in abundance. The study is limited to biogas production from Napier and mission grass, The feedstocks under investigation was chosen based on its high content of methane when decomposed

7. 1.5 Significance of the study This study seeks to research on the potential of Napier and mission grass as feedstocks for biogas production. The study will also provide inputs on how Napier and mission grass which is normally used as cattle feed can be put into a useful resource to solve scarcity of energy problem as well as enhance the capacity of academic community for further research.

8. CHAPTER TWO LITERATURE REVIEW Review of Related Work Narinthorn et al. (2018), For this, the authors applied combined alkaline and biological pretreatment methods as a strategy to enhance biomethane yields from Napier grass. Liu et al. (2013), investigated the potential of Napier grass for bioethanol production by using dilute-alkali and dilute-acid pretreatment methods.

9. CHAPTER THREE MATERIAL AND METHOD Materials Napier Grass Mission grass Deionized water NaOH

10. EXPERIMENTAL FLOW CHART

11. CHAPTER THREE (Continue...) Equipment Container (Digester), laboratory mill, plastic hose, funnel, Set of beakers (100, 250 and 500 cm3), Measuring cylinders (200 and 500 cm3), Glass rod stir, Volumetric flasks (1000 cm), Weighing Balance, Digital pH meter, Thermometer, Gas chromatography, Electric Oven.

12. Characteristic of the Feed-stocks Before starting the anaerobic digestion experiments, samples of grasses will be analyze for Total solids (TS), V olatile solids (VS), C arbon (C) to nitrogen (N) ratio. pH Level .

13. Determination of Biogas produced Determination of Biogas Yield Biogas yield (BY) will be calculated from biogas productivity (BP) and VSr by using Equation. (3.1):

14. CHAPTER FOUR RESULTS AND DISCUSSIONS From the table, it can be deduced that 90.1% of the total solids are volatile. The pH which was found to be too acidic for methanogenesis and was improved by adding NaOH to the substrates as wrong pH is suspected to inhibit production. The optimal environmental conditions for the thriving of these methanogens were found to be pH of 6.5 to 8.5. Substrate Total Solids(TS) (%) Volatile Solids(VS) (ml/g.vs) Carbon to Nitrogen ratio Yield (ml) Napier Grass 32.1 30.4 10 93 Mission Grass 29.3 31.6 11 87 Co-digester 28.7 21.9 9 115

15. CHAPTER FOUR RESULTS AND DISCUSSIONS (Continued…) The weight of Napier grass, mission grass and the co-digester after it was sliced were 1.750kg, 1.750kg and 3.500kg respectively. The volume of deionized water used for Napier, mission and co-digester were 6L, 6L and 10L respectively. The temperature range across the setups was recorded to be between ranges from 32 C to 36 C in the day, 25 C to 34 C at night. Production started 3 days after the pH improvement. Optimum production was achieved on the 18 th day.

16. CHAPTER FOUR RESULTS AND DISCUSSIONS (Continued…) The pressure values for Mission grass, Napier grass and Co-digester after 14 th days interval are listed respectively: 10.62atm, 15.97atm and 18.09atm; resulting to the final values after 29 days showing the values: 29.63atm, 32.57atm and 35.67atm respectively. The yield was calculated and found to be 93ml, 87ml and 115ml for the N apier grass, mission and co-digester respectively.

17. CHAPTER FOUR RESULTS AND DISCUSSIONS (Continued…) Substrate % of CH 4 % OF CO 2 % of H 2 S % of N 2 % of Water vapour Napier grass 52.76 19.86 0.19 1.92 2.76 Mission grass 49.76 21.02 0.16 1.97 2.48 Co-digester 66.07 13.75 0.26 1.89 2.09 Table showing the Characterization of the Biogas Yield

18. Conclusion The overall yield of the biogas was dependent on the pH and the number of days the substrates stayed in the reactor. The total percentage of methane gas produced from the co-digestion of Napier grass and mission grass is high ( i.e 66.07%), hence it can be concluded that the production of biogas from Napier grass and mission grass is a good substitute for non-renewable energy source.