Bioethanol Production and Optimization Test from Agricultural Waste: The Case of Wet Coffee Processing Waste (Pulp)

Ayanie, Ayele Kefale (2011) Bioethanol Production and Optimization Test from Agricultural Waste: The Case of Wet Coffee Processing Waste (Pulp). Masters thesis, Addis Ababa University.

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Abstract

Biofuels are alternatives to fossil fuels to ensure energy security and mitigate climate change. Currently, most biofuel is in the form of bioethanol generated from starch or sugar. Conversion of cellulosic biomass, which is both abundant and renewable, to bioethanol is a promising alternative. The objective of this work was to evaluate the feasibility of ethanol production and optimization from coffee pulp by using commercial bakery yeast, i.e., S. cereviciae. To conduct this study, fermentation was held at temperature 30 °C and pH 5, and treated using different acid concentrations and residence times. Coffee pulp was hydrolyzed by refluxing, a solid to liquid ratio of 1:10, using dilute sulfuric acid (1, 2 and 4 %) and distilled water at hydrolysis time of 1, 2, 4, 6 and 10 hours keeping boiling temperature. 90 % maximum total sugar concentration was obtained at 4 h acid free hydrolysis. Based on these hydrolysis results, fermentation process was performed. In the process, it was observed that ethanol concentration decreased with an increase in acid concentration, hydrolysis time and fermentation time. The maximum result was obtained with distilled water hydrolysis for 4 h and 24 h fermentation. Under these conditions maximum ethanol concentration production was 7.398 g/L, a satisfactory result as compared with literature data. The result indicated that being available in plentiful amounts and non-edible material, coffee pulp will be potential feedstock for bioethanol production in Ethiopia.

Item Type: Thesis (Masters)
Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
Q Science > Q Science (General)
Q Science > QH Natural history > QH301 Biology
Q Science > QK Botany
S Agriculture > S Agriculture (General)
Divisions: Africana
Depositing User: Selom Ghislain
Date Deposited: 07 Sep 2018 13:26
Last Modified: 07 Sep 2018 13:26
URI: http://thesisbank.jhia.ac.ke/id/eprint/5057

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