Adsorption of sulfur dioxide in flue gas by polyamine based composite absorbent

Polyaniline (PANI) as an absorbent can effectively absorb SO_2 in flue gas. Unlike other absorbents, polyaniline has high thermal stability. Because of polyaniline's aggregate structure, the particles can mutually fuse in the process of desulfurization, resulting in a decrease in the adsorption efficiency. This study uses polyaniline composite absorbents that are respectively made of attapulgite, diatomite, vermiculite, and aniline to absorb SO_2 in flue gas, which can effectively reduce the contact of polyaniline particles with each other and avoid the fusion of particles in the process of desulfurization. The experimental results show that the polyaniline composite absorbents can absorb SO_2 because of the presence of polyaniline in composite absorbents. The principle of adsorption is mainly chemical adsorption. When the temperature of adsorption is 100~180 ℃, the polyaniline had a better effect. The adsorbent can be recycled and maintain its good adsorbing capacity. The composites doped with attapulgite, vermiculite, and diatomite had better excellent adsorption effects for SO_2 than those of PANI modified with nothing.