The absorption rate of CO2/SO2/NO2 into a blended aqueous AMP/ammonia solution

Abstract

The Inter-governmental Panel on Climate Change (IPCC) reported that human activities result in the pro- duction of greenhouse gases (CO2, CH4, N2O and CFCs), which significantly contribute to global warming, one of the most serious environmental problems. Under these circumstances, most nations have shown a willingness to suffer economic burdens by signing the Kyoto Protocol, which took effect from February 2005. Therefore, an innovative tech- nology for the simultaneously removal carbon dioxide (CO2) and nitrogen dioxide (NO2), which are discharged in great quantities from fossil fuel-fired power plants and incineration facilities, must be developed to reduce these economical burdens. In this study, a blend of AMP and NH3 was used to achieve high absorption rates for CO2, as suggested in several publications. The absorption rates of CO2, SO2 and NO2 into aqueous AMP and blended AMP+NH3 solutions were measured using a stirred-cell reactor at 293, 303 and 313 K. The reaction rate constants were determined from the measured absorption rates. The effect of adding NH3 to enhance the absorption characteristics of AMP was also studied. The performance of the reactions was evaluated under various operating conditions. From the results, the reac- tions with SO2 and NO2 into aqueous AMP and AMP+NH3 solutions were classified as instantaneous reactions. The absorption rates increased with increasing reaction temperature and NH3 concentration. The reaction rates of 1, 3 and 5w t% NH3 blended with 30 wt% AMP solution with respect to CO2/SO2/NO2 at 313 K were 6.05~8.49×10 −6 , 7.16- 10.41×10 −6 and 8.02~12.0×10 −6 kmol m −2 s −1 , respectively. These values were approximately 32.3-38.7% higher than with aqueous AMP solution alone. The rate of the simultaneous absorption of CO2/SO2/NO2 into aqueous AMP+NH3 solution was 3.83-4.87×10 −6 kmol m −2 s −1 at 15 kPa, which was an increase of 15.0-16.9% compared to 30 wt% AMP solution alone. This may have been caused by the NH3 solution acting as an alternative for CO2/SO2/NO2 controls from flue gas due to its high absorption capacity and fast absorption rate.