Experimental Study of the Removal of Fine Particulate Matter and Moisture from Flue Gas

Liquid desiccant systems are promising methods to recover water and waste heat simultaneously from flue gas. Prior research found that the reduction of particulate matter could occur during the absorption processes. In the present paper, experiments were carried out to explore the effect of removing fine particulate matter (PM2.5) in a liquid desiccant dehumidifier. Aqueous calcium chloride (CaCl2) was used as the desiccant in the experiments. The discrepancies in mass and energy conservation were within +/- 10% and +/- 15%, respectively, which showed the good reliability of the experimental results. Additionally, 23.5%-46.0% of the PM2.5 and 23.9%-45.1% of the moisture in the flue gas were removed. By comparing the desiccant solution and water, it was found that they could minimally remove PM2.5 through washing the flue gas. Regardless of whether the flue gas was dehumidified by water or the solution, the removal fractions of PM2.5 of these two methods could be very close if they achieve the same fraction of moisture removal. From the results of a parameter analysis, it was found that the removal fraction of PM2.5 was nearly proportional to the removal fraction of moisture within the experimental range.