Effect of MnSO₄ on the Removal of SO₂ by Manganese-Modified Activated Coke

Abstract

In this study, the effect of manganese sulfate (MnSO 4 ) on desulfurization capacity was investigated through carrying out consecutive desulfurization−regeneration cycles of MnO 2 -blended activated coke (Mn/AC). It was observed that MnSO 4 was produced on the surface of Mn/AC during the desulfurization process, and the amount of MnSO 4 accumulated on Mn/AC first increased significantly and then became relatively stable. In addition, the desulfurization results of MnSO 4 -impregnated Mn/AC indicate that Mn 2+ from MnSO 4 could form new liquid-phase catalysis, which existed with the solid-phase catalysis (blended MnO 2 ) simultaneously in the desulfurization system. However, an excessive amount of MnSO 4 over the surface of activated coke can block the access of SO 2 to the pore network, hampering the activity of the solid-phase catalyst and, consequently, resulting in a decrease of desulfurization capacity.

The effects of metal oxide blended activated coke on flue gas desulphurization

“…14,23 The results indicated that the natural minerals containing MnO 2 , such as pyrolusite, can be used as the additive to prepare modied activated coke for ue gas desulphurization with low cost and high desulphurization performance. 14,23 The results indicated that the natural minerals containing MnO 2 , such as pyrolusite, can be used as the additive to prepare modied activated coke for ue gas desulphurization with low cost and high desulphurization performance.…”

The study on continuous denitrification, desulfurization of pyrolusite/activated coke hybrid catalyst

“…The reduction of SSA, V tot and V mic in the rst few cycles is due to the formation of metal sulphates during the SO 2 removal; the removed SO 2 primarily transformed to form sulphate, and they could not decomposed at the regeneration temperature. 21 With the increasing number of regeneration cycles, there is a higher ratio of removed SO 2 stored in AC as sulphur acid. The sulphuric acid, reacting with carbon, played the role of further activation of ACP and improved its porosity.…”

“…19 The linearly reduced desulfurization performance of ACP-Rn was primarily due to its large content of metal sulphate dispersed on the surface, which limited the catalytic oxidation of SO 2 on the surface of catalystsorbent. 21 3.2.3 Surface metal chemistry. The X-ray powder diffraction (XRPD) of ACP and ACP-Rn was applied to clarify the metal chemistry.…”

“…75-0257/04-0326) and Fe 0 (JCPD 87-0722) on the surface of ACP imply that manganese and iron oxides in the pyrolusite were reduced in the strong reduction atmosphere under the high activation temperature (900 C). 21 Aer desulfurization and denitrication, however, MnO and Fe 0 diffraction peaks weakened or even disappeared (ACP-Rn). 4+ and Fe 2+ could accelerate the electron transfer, which promote the NH 3 activation on the surface of ACP and further accelerate NO removal.…”

“…Mn 4 /AC). 21 However, what the effects of the formed metal sulphates on NO removal of such hybrid carbon-based catalyst are still unknown. Therefore, it has as great theoretical signicance and practical value (in terms of industrial applications) to study the continous application of AC for denitrication and desulfurization.…”