Abstract:
Energy from waste is about taking waste and turning it into a useable form of energy. This can
include electricity, heat and methane from waste source. Waste to Energy Conversion (WEC)
technology provides an alternative source of renewable energy in a world with limited or
challenged fossil reserves. The most common conversion method is through biological treatment
method via anaerobic digestion. Anaerobic digestion is a waste-to-fuel application that waste can
be converted into purified biogas which can then be used to power and to create heat or
electricity.
Food wastes and kitchen wastes reduction is the first step to food waste management. As long as
proper food safety and handling practices are followed, reusing leftover food can save money
and reduce waste. Creatively repurpose leftovers and trimmings to efficiently use excess food for
other meals. Flexibility in menu planning to accommodate the use of excess food from previous
meals is a good way to extract energy from those wastes. Also, diverting wasted food to
anaerobic digestion can generate renewable energy (biogas) and create a valuable soil
amendment.
Jimma University, JiT, Kito Furdisa Campus currently generates approximately 33,902
Kg/month of food waste and kitchen waste by the on-campus dining halls. Production of dining
hall wastes is seasonal, as food preparation needs decrease significantly in mid of July and
August. While dining hall and kitchen wastes provides a significant potential source for
feedstock energy and in anaerobic digestion processes. These wastes should be an acceptable
feedstock for the anaerobic digestion process.
From food and kitchen wastes of Kito Furdisa Campus of Jimma Institute Technology about
33,902 kg of wastes is assessed within a month and biogas plant of 322m
3
volumes is designed
and also total biogas produced is calculated 113m
3
/ day. This gas produced using energy
conversion gives us 722kwh of power per day. Based on biogas produced it diverted to combined
heat and power (CHP) system to generate electricity and heat that recovered to produce hot water
using stove for cafeteria of Kito Furdisa and its kitchen itself. Energy consumption of this
anaerobic digestion of system in dining hall & kitchen wastes give us 41.03 kwhr and the net
energy used is 681 kWh which used for CHP. This means the production of electricity will be
75.42MWh/y and the production of heat will be 138.27MWh/y.
