Ethanol Production From Yam Peels
Chapter One
PURPOSE OF THE STUDY
The purpose of the study is to produce ethanol from yam peel (yam waste).
CHAPTER TWO
LITERATURE REVIEW
This chapter is a review of literature on yam. Yam is the second largest source of carbohydrate for human consumption in the world with an estimated annual world production of what it is grown in a limited area of the tropics, particularly in the humid parts of Africa and the Caribbean. The plant required good well drained soil ample with well distributed rainfall; it produces 90 tons per year. Yams are highly prized food and current production fall short of demand, yam has a reasonable yield the plant grow tall, it rounds all the part of the wood been placed to hold it, the leaves varies in shape and size. The edible parts are the tuberous root. The leaves are green in colour, the tuber is somewhat dark brown in colour and it grows to two feet long. It is unlikely that, they may complete with yamfor fuel alcohol purpose. They require better soil and water. It is year round available, it is tolerate to extreme stress condition and it fits nicely within traditional farming system. Although production level about traditional farming system is round 10 tons per hectare research to improved cultural practical system is required. Yam is one of the fermentable substances for the production of ethanol.
YAM GROWTH
There are some environmental and agronomic constraint of yam, growing the crop have a high uptake of nutrient and especially a high demand for potassium and vitamin A and B6. This lack of adequate supply of potassium in the soil may limit the yield of yam yield considerably. Excessive nitrogen fertilization on the other hand may create a high level of poisonous glycoside in the tuber making, it less suitable for human consumption furthermore, weed competition can be very detrimental to yam growth during the initial three months. After planting yam is rather drought tolerate except in the first few weekis after planting when it require soil moisture root growth is poor and root is gravely or stony soil are unsuitable for the growing of yam because these soil tend to hinder root penetration. In each locality where the crop is grown, numerous yam leave exist with different leaves, size, plant height, colour, tuber shape timing of maturity overall yam grow leaves in all part of the branches grow very tall and a stick is placed closely to the place that has been dogged. The stem then grow round the stick that is been placed closed to the yam. It last up to 6-8 months before it is due for harvest.
HARVESTING
Harvest, once leaves start to die down or turn yellow in the antum or early winter yam are ready to harvest, many prefer to let a few frosts effect. The crop before harvesting. At the garden soil does not become water logged over winter you can leave the crop in the garden for a few mouth. Yam is being harvested by using a long wooden stick which have iron in the mouth, cutlass and hand. Yam can be harvested by cutting the stem down leaving a little of the stem on top before you start digging. After digging up to about 2-3 mins you shake the yam if it free from the ground, after shaking, if it not free you continue digging until it is free from the ground, then you lift the yam up then cut the stem which you left on top the yam and place it on the ground then cover it up with sand. In some country mechanical harvest has been developed and mechanical harvest are being tested out in other part of the world as well it grabs unto the stem and lift the roots up from the ground. During the harvesting process care must be taking to minimize damage to the roots.
STORAGE
The traditional method to keep yam in good condition is in two ways, some people dig the ground a little bit and pack the yam inside and cover it with sand, if they need it they can go there and take from it, they can sell it or eat it. Why others may pack it in yam barn is made with a bamboo stick and it is been placed in the ground. The bamboo is placed standing, then place the yam on it, then use rope to tire the yam to the bamboo you can leave it there for as long as you want. Most people placed their own in the farm while some at home. Fresh roots that have been harvested for man consumption can be sliced, then dried it up. It can be used in making pounded yam or amala, yam flour eating as pounded yam. Yam is the third largest source of carbohydrate for human consumption in the world. As is a major source of high cost of carbohydrate and a stable food for people in the humid tropic. The edible parts are the ferberious root. Yam starch is one of the best fermentable substance for the production of ethanol.
CHAPTER THREE
MATERIALS AND METHODS
SOURCES OF SAMPLES
Four hundred grams (400g) of yam peels were collected from mama T restaurant as she just finished peeling it. They were ascetically collected into a polythene bag and taken to splendid research laboratory for analysis. The enzymes used were X amylase, B amylase and yeast. These were collected from the stock of splendid laboratory.
EXPERIMENTAL DESIGN
The yam peel obtain from the above source were sliced into cheep and dry under a sterilize condition (25-300c) for a duration of 72 hours and milled into yam mill flour.
CHAPTER FOUR
RESULTS/DISCUSSION OF RESULTS
The production of ethanol from yam peel was carried out. The ethanol yield was estimated at day 0 and at the end of fermentation as well as the biochemical and microbiological characteristics of the yam peel was also determined.
BIOCHEMICAL RESULT ANALYSIS
Results from below table one show that there was observable reducing in the percentage of reducing sugar during the process of enzymatic hydrolysis of yam peel flour from day 0 to day 3 with the highest percentage of reducing sugar of 53.38% recorded at day 0 and the lowest reducing sugar percentage of 20.62% recorded for day 3.
Table: Effect of X-amylase and B-amylase hydrolysis on the reducing sugar concentration of yam peel flour.
CHAPTER FIVE
SUMMARY
The study evaluate the suitability of yam peel in the production of ethanol. Yam peel was processed into flour by washing, drying, and milling. The yam flour was enzyme hydrolyzed by mixing 30g of flour with 500ml followed by treatment with a combination of alpha and beta amlylase and heating to 920c at PH of 6.30 the hydrolyzed slung was cooled at 220c and yeast was inoculated. The sluny was allowed to ferment for 3 days during which the PH, cyanide contents, reducing sugar content, bacterial, and fungi counts were respectively determined. The reducing sugar content reduced decreased from 53.38% (on day 0) to 20.62% (on day 0). While the cyanide content was sustaintial at day 0 with only 0.573mg/100g and decreased to 20.62 at day 3 of fermentation. The PH of the hydrolyzed slung reduced from 6.32 (slightly acidic) at day 0 to 3.46 (acidic) at the 3rd day. The microbiological count (colony forming unit) increased with respect to bacterial from 3.52 x 105cfu/ml at day 0 to 5.93 x 105cfu/ml at the 3rd day of fermentation while the fungi count decreased from 1.61 x 105cfu/ml at 0 day of fermentation to 0.57 x 105cfu/ml at day 3 of fermentation. The yield of ethanol from the 30g of yam peel flour was 3.14ml. This study revealed that ethanol can be produced from yam peel and can be explore industrially for optimal utility.
RECOMMENDATIONS
Based on the findings, the following recommendations are being made;
Yam waste can be used to produce substantial amount of ethanol for commercial purposes.
Yam peel wastes which are generated from homes, restaurant and market dump site should be employed as suitable raw materials that can be used for production of ethanol.
The source of raw materials production can be explored by both private and government agencies as a cheap effective and alternative means for ethanol production as Africa is known to take leading role in world production of yam (about 96%) with Nigeria alone with (41%) of the total indices.
CONCLUSION
In conclusion, with the increase demand for ethanol production this work has tried to study the use of yam peel for the production of ethanol with the view to explore carbohydrate food waste as a source of ethanol industrially.
REFERENCES
- Aderemi, F.A. and Nworgu, F.C., (2007). Nutritional status of yam peels and root sieviate biodegraded with Aspergillus Niger. American-Eurasia. J.Agric. and Environ. Sci., 2 (3) 308-311.
- Adewusi, S.R. Ojumu, T.V. and Falade, O.S. (1999). The effect of processing on total organic acids content and mineral availability of simulated cassava-vegetable diets. Plant Foods for Human Nutrition, 53 (4) 367-380.
- Adu-Amankwa, B. (2006). Profitability analysis of pilot plant utilizing waste yam peels and pulp as substitute for maize in animal feed formulation. J. Sci. and Technol., 26 (3) 90-97.
- Bates, RA. G. (1954). Electrometric pH determination.
- Lippincott Williams (2000) Bergey’s manual Ninth edition.
- Oboh, .G. (2003). Changes in yam product (flour & Saccharomyces Cerevisae solid media chemistry.
- Raimbault, M. (2001). General and microbiological aspects of solid substrate fermentation, electronic journal of biotechnology (online).
