Influence of SO2 in incineration flue gas on the sequestration of CO2 by municipal solid waste incinerator fly ash

The influence of CO2 content and presence of SO2 on the sequestration of CO2 by municipal solid waste incinerator (MSWI) fly ash was studied by investigating the carbonation reaction of MSWI fly ash with different combinations of simulated flue gas. The reaction between fly ash and 100% CO2 was relatively fast; the uptake of CO2 reached 87 g CO2/kg ash, and the sequestered CO2 could be entirely released at high temperatures. When CO2 content was reduced to 12%, the reaction rate decreased; the uptake fell to 41 g CO2/kg ash, and 70.7% of the sequestered CO2 could be released. With 12% CO2 in the presence of SO2, the reaction rate significantly decreased; the uptake was just 17 g CO2/kg ash, and only 52.9% of the sequestered CO2 could be released. SO2 in the simulated gas restricted the ability of fly ash to sequester CO2 because it blocked the pores of the ash.