dc.description.abstract |
In many countries around the world including Ethiopia, the egg is used for different sources
either for direct consumption or as a raw material for food processing. This leads to the
formation of eggshell solid waste. This possesses loss of calcium carbonate within the eggshell s ,
which is the best natural source of calcium carbonate. Also a serious of environmental problem
occur s from the waste eggshell s . Therefore, this project was aimed to extract calcium carbonate
from an available eggshell s . At the same time, the environment is protected from pollution caused
by eggshell waste generated from different sources. The reasons tha t push us to do this research
are the easy availability of eggshell raw material, the high composition of calcium carbonate in
an eggshell, the shortage of eggshell calcium carbonate usage in Ethiopia, calcium carbonates
are non renewable resources and it takes million years to recover it , the environmental effect
caused by the eggshell and the need of developing research wor k. In this final year project,
e xtract eggshell calcium carbonate from the dry eggshell was used. It was extracted from
eggshell by; w as hing, boiling, drying, grinding , sieving ,extracting and priciptating to produce
calcium carbonate procedures. In this study, the effect of time, the size of eggshell powder were
studied. The calcium carbonate was extracted with at constant temperatures of 100 0 C, Eggshell
powder size of 1mm, 710 μm and 350 μm . The boiling process for 20 minutes of eggshell kills
any microbial growth on the surface. The grinding, drying and separatin g process was takes
place for 20, 50 and 10 minutes respectively. The obtained results indicated that the addition of
time led to slightly increase calcium carbonate yie ld when the size of eggshell powder is 350
μm , the calcium carbonate yield increases highly until the time reaches to 20 minutes for 350μm
size of eggshell powder then declines and finally the calcium carbonate yield decreases as the
tim e increases . The maximum yield is 80.23 %, obtained at constant temperature of 100°C, size
of 350μm and at time 20 minutes . From the economic point of view, the rate of return on
investment provides 30.6 % and the payback period is 2.6 years this implies the project is
feasible. |
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