Center for Energy Technology

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Browsing Center for Energy Technology by Subject "an annual energy saving of 80"

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    Assessment of Energy Consumption in Brewery Industry: Case Study in Dashen Brewery
    (Addis Ababa University, 2022-10) Zewge Worku; Solomon TekleMariam (PhD)
    Dashen Brewery factory is one of the biggest energy consuming brewery factory in Ethiopia. There are many processes involved in the manufacture of beer and these processes involve the use of thermal energy generated with heavy fuel oil and also electricity to drive pumps, motors, compressors, lighting and others. The 2019 of the factory energy bill data showed that the total electricity consumption of factory was around 36.2GWh and a thermal energy (heavy fuel oil) consumption of 96346.5GJ. The specific energy consumption of the factory for both thermal and electricity has been analyzed and compared with the international best performed factories. This has been done by collecting the historical energy consumption and production data of the factory. The purpose of this assessment is to identify energy saving opportunities and to recommend possible measures with their technical and financial feasibilities. To conduct this assessment different similar studies on breweries were assessed and detail analysis were not observed in many of the researches especially on leakage testing on air compressors, saving calculations from heat loss on valves and flanges, and heat recovery system on flue gas. In this study, the above research gaps have been addressed and saving potentials also been estimated. According to the preliminary analysis, the average total specific energy consumption of the plant is 98.14kWh/HL which is higher than the recommended international bench mark by 42kWh/HL. This initiates the researcher to conduct a detail energy consumption assessment on selected on major energy consuming devices like compressor, boilers, electric motors, and lightings. To conduct the assessment, historical data of the factory were collected and measurement was also taken for detail assessment by using portable instruments. Energy conservation measures have been identified and their saving potentials have also been estimated. Optimizing the compressed air usages and arresting the leakage a total annual electric energy of around 337,104kWh can be saved. This is equivalent to a monetary annual saving of 404000Birr. The energy consumption assessment study on one of the boilers indicated that, reducing the excess air, insulating the valves and flanges, and installing economizer at the stack, an annual fuel and cost saving of around 235,200 litter and 838,764 birr can be achieved respectively. The envisaged annual energy saving potential by retrofitting inefficient lightings by light emitting diode, LED, is 221,000 kWh per year equivalent to a monetary saving of about Birr 265,849 per year. Finally, the efficiency reduction due to under loading of electric motor was analyzed and some of them were found to be a loading of 50% and below. This efficiency reduction can be improved by installing variable frequency drive,VFD or other means. Improving the loading on electric motors, an annual energy saving of 80,800kWh and equivalent cost saving of 96,900 Birr can be achieved. Generally the study on the selected areas of the factory indicates that a total of 639428kWh electricity and 235249 litter of heavy fuel oil can be saved if the recommended energy conservation measures in each area are implemented. Additional energy might be saved by conducting energy consumption assessment on other sections other than the selected focus areas such as detail studies on pumps, cooling sections, cooling tower, waste water treatment, and on other remaining areas. Additional benefits of implementing the energy saving opportunities come from decreasing environmental impacts, improving working conditions of the plant employees and higher energy security at the plant.