Potential for Bioethanol Production from Wet Coffee Pulp Waste in Karatina Nyeri County

Kenya is one of Eastern African countries that produce coffee both in large scale and in small
scale. Small-scale farmers produce about 70 percent of Kenyan coffee. One of the small-scale
coffee production centers in Nyeri County is Karatina. Now there is a substantial amount of
coffee pulp waste generated from the coffee milling process that is used as compost, and cattle
feed and the rest damped in pits. Solid coffee pulp waste has not been used optimally, generally
stacked around the processing mills for several months causing odors and pollution to the
environment. There is need to develop alternative sources of energy from these wastes and
reduce dependence on coal and petroleum to meet the energy needs of farmers and the
community around Karatina which projects to other small scale holdings around Kenya. Bio
ethanol is an innovative solution that is environmentally friendly and able to reduce pollution by
agricultural wastes. Bioethanol is easily obtained through fermentation of these organic wastes
with the help of commercial yeast. It has high oxygen content and burns more completely than
gasoline. The aim of the study was to evaluate the potential for bioethanol production at probable

optimum conditions using bakery yeast. Coffee pulp was hydrolyzed with distilled water and
fermented with bakery yeast. It produced a maximum of 6.12 g/L of ethanol at 5 hours, 24 hours
hydrolysis time, and fermentation times respectively. This was compared to other literature and it
was realized that there is a potential for bioethanol production. In substantial amounts therefore,
coffee pulp can be utilized as a potential raw material in ethanol production in Karatina and
Kenya as a whole. However, a cost benefit analysis should be conducted to determine the
economic viability of producing bioethanol from wet coffee pulp waste.