ETHANOL PRODUCTION FROM YAM (DIOSCOREA SPP) PEELS

Thesis Overview

INTRODUCTIONBackground of the studyYams (Dioscorea spp) of the family Dioscoreaceae are members of the flowering plant. They are monocots, related to palms, grasses and orchids. Most yam species grow in the tropics and subtropics area with fairly heavy total annual rainfall, but with a definite day season. During the rainy season, they produced one or more underground tubers to store food and water through the dry season the tubers are thickened stems. Most yam plant have small flower with one plant having only male or female flower (Kay, 1987).The tubers of most species of yam are poisonous to humans. The cultivation of most yams is very labour intensive. Cultivated yams generally do not produce seed and so tubers or pieces of tuber must be planted in prepared soil, most often in wounds to grow new plants.Yams are nutritious food, providing carbohydrate, some protein, and mineral like phosphorus and potassium besides the use as food, yams have been symbolically associated with culture and ritualism in some parts of Africa, Asia and Latin Americas.According to Ogbuka (2005) Ethanol can be produced from starch containing substances like maize, cassava and yam. Ethanol is a monohydric alcohol that is colourless and flammable, it is a 2 –carbon alcohol with molecular formula CH3 CH2 OH, its empirical formula is C2H6O. An alternative notation is CH3CH2 OH which indicates that the carbon of a methyl group (CH3) is attached to the carbon of an ethylene group (CH2-) which is attached to the oxygen of a hydroxyl group (OH). Ethanol is a colourless liquid that burns with a smokeless blue flame. It has a choking smell and a boiling point of 780c. They are characterized by the possessing of hydroxyl group (OH) as their functional group. Alcohols can be classified as primary, secondary and tertiary. The primary alcohols have only one or no alkyl group attached to the hydroxyl bonded carbon atom, the secondary alcohol contain two alkyl group attached to the hydroxyl bonded carbon atom while the tertiary alcohol contains three alkyl groups but no hydrogen attached to the hydroxyl- bonded carbon atom while the tertiary alcohol contains three alkyl groups but no hydrogen attached to the hydroxyl-bonded carbon atoms:According to West et.al (2007) ethanol is a principle fuel that can be used as petrol substitute for vehicles. It is a renewable energy source produced mainly by sugar fermentation process. It is used in preservation of specimen, food e.t.c and even as a raw material in the manufacturing of chemicals and pharmaceuticals like trichloromethaneStatement of the ProblemsAlcohol has been known to be produced from fossil like maize, cassava, even yam tuber but there is still need to search for other sources considering the usefulness of ethanol source, hence the need for this study. Furthermore, yam peel are regarded as waste after using the main yam tuber, therefore there is need to source for alcohol in this peel which either are throw away. This study will also reduce environmental pollution which is caused by the yam peel.

• Objectives of the Study

Objectives of this study include:

• To extract ethanol from yam peel
• To carry out qualitative test on the produced ethanol

Significant of the StudyThe knowledge from this study will help in creating awareness to the government as well as the society at large on the need to grow more yams. Finally this study will also help the society to know that ethanol is not just present in the yam tuber alone but also in the peels (yam peels)Scope of StudyThis study is concerned with the production of ethanol using yam peel which involves

• Collection and identification of the sample
• Preparation of the sample
• Production of ethanol from the sample
• Qualitative tests on the produced ethanol.