ABSTRACT
The work seeks to address environmental issue through the design and development of a carbonator for CO2 capture. A fixed bed carbonator with height 1.7 m and diameter 0.9 m for CO2 capture was successfully designed and fabricated at a flow rate 7.9g/hr of carbon dioxide using 2kV household electric generator as a source of flue gas. The flue gas was analyzed using NHA-506EN NANHUA Instrument gas analyzer and the average composition of the flue gas after allowing the generator to ranfor 30min was found to be 7.78% CO, 2.50% CO2, 46ppm NOx, and 392ppm HC. The material of construction used was mild steel and the fabrication was based on the specifications obtained from Aspes Plus version 11.1 software. Hydrated lime Ca(OH)2 powder was made into pellets of different sizes: 0.8, 1.2, 1.5 and 2cm and packed differently at a height of 0.4m in the carbonator. Flue gas at 150oC was passed through the bed of hydrated lime at 1atm. The average readings obtained from the outlet of the carbonator (top) were found to be 7.71%CO, 0.06% CO2, 46ppm NOx and 390ppm HC. These results showed that there was decrease in carbon dioxide concentration as time pass by. For the 0.8cm pellet size and packing height of 0.4 m, there was 97.6% carbon dioxide capture which compares favorably with literature values. The product (used lime) was taken for chemical analysis: XRF analysis gave 56.46%CaO, 1.52% SiO2, 3.44% Fe2O3; X-ray diffraction (XRD) showed that the used lime is crystalline and scanning electron microscopy (SEM) presented irregular, heterogeneous and coarse particles. It was found that fixed bed reactor with 0.8cm pelletized lime was more effective for CO2 capture.