Combined mercury removal and low-temperature NH3-SCR OF NO with MnOx/TiO2 sorbents/catalysts. Issue 8 (3rd August 2018)

• Record Type: Journal Article
• Authors: Cimino, S.; Mangone, C.; Scala, F.
• Is Part Of: Combustion science and technology. Volume 190:Issue 8(2018)
• Page Start: 1488
• Page End: 1499
• Publication Date: 2018-08-03
• Subjects: Hg -- Flue Gas Purification -- DeNOx -- Supported Catalysts -- Regenerable Sorbents; Combustion -- Periodicals; Combustion engineering -- Periodicals; 541.36105
• DOI: 10.1080/00102202.2018.1452131
• Languages: English
• ISSNs: 0010-2202

Abstract

ABSTRACT: MnO x /TiO2 catalysts/sorbents were investigated for flue gas purification via the simultaneous low-temperature NH3 -SCR of NO and elemental Hg capture, in the temperature range 25–300°C. In particular, the effects of the Mn precursor salt (acetate vs. nitrate) and of the TiO2 support textural properties (nanotubes vs. random mesopores) on both DeNO x and Hg capture efficiencies were addressed. The catalysts/sorbents were also characterized by means of ICP-MS, SEM-EDX, XRD, BET, H2 -TPR, NH3 adsorption, and temperature programmed desorption of both NH3 and Hg. Catalysts prepared by acetate precursor generally displayed a higher reducibility at low temperature which translated into a higher oxidation activity, enhancing mercury capture rate, but adversely affecting the selectivity of the selective catalytic reduction (SCR) process at temperatures above 150°C. Hg was effectively captured up to 250°C and stored on the sorbent in an oxidized form. The original sorption properties could be fully restored by a simple thermal treatment in air at temperatures ≤500°C, releasing elemental mercury. The textural properties of the support were found to have a limited impact on both the Hg capture and SCR performance.