Removing carbon dioxide from a stationary source through co-generation of carbonate/bicarbonate: The case of Mugher cement factory
The cement industries alone emit 5% of the world’s total green house gases. In Ethiopia, the current CO2 emission from this sector is about five fold of the countries overall CO2 emission in 2002. Mugher cement factory (MCF), a case study plant in this paper, alone emits 463,844 tons of CO2/year on average based on emission test and mass balance performed. Yet it accounts for less than 3% of the current CO2 emission from this particular industry in the country. Of those technical approaches, separation of CO2 before it joins the immediate atmosphere is getting wide spread interest. In relation to this, experiment on absorption of CO2 is conducted to determine the effect of flow rate of the gas sample, concentration of the sodium hydroxide, flow rate of solvent and temperature of absorbent on absorption of CO2 using the “Armfield” gas absorption column followed by the titrimetric analysis. Except temperature of solvent, all study variables showed strong relation with the amount of carbon dioxide absorbed (with a P-value < 0.05). Uniquely, this study has evaluated the potential for sodium bicarbonate production from the CO2 absorbed using gravimetric analysis. It is also possible to recover over 28% crystal sodium bicarbonate.
Key words: Green house gas, CO2, absorption, caustic soda, sodium bicarbonate.