Methanol Promoted Oxidation of Nitrogen Oxide (NOx) by Encapsulated Ionic Liquids (ENILs)

Ruben Santiago*, Susanne Mossin, Jorge Bedia, Rasmus Fehrmann, José Palomar

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The removal of nitrogen oxides (NOx) has been extensively studied due to their harmful effects to health and environment. In this work, Encapsulated Ionic Liquids (ENILs) are used as catalysts for the NO oxidation at humid conditions and low temperatures. Hollow carbon capsules (CCap) were first synthetized to contain different amounts of 1-butyl-3-methylimidazolium nitrate IL ([bmim][NO3]), responsible for the catalytic oxidation. Then, the materials were characterized using different techniques, by analyzing microstructure, porosity, elemental composition and thermal stability. The catalytic performance of ENIL materials was tested for NO conversion at different conditions. Thus, NO concentration was fixed at 2,000 ppm at dry and humid conditions. Then, the methanol promotion of the reaction was demonstrated, increasing the NO conversion values in all cases, and the alcohol/water ratio was optimized. The temperature effect was studied as well, using the optimal conditions based on the previous measurements. The results reflect that humid conditions do not have a negative effect in terms of NO conversion when using ENILs, opposite behavior as the observed for CCap and traditional catalysts studied before. Low amount of IL inside the material (40% in mass) was found to be the optimum for the task, reaching conversions of almost 45% in near industrial conditions of temperature and O2 and H2O concentrations in the flue gas with a GHSV = 10,000 h-1.
Original languageEnglish
JournalEnvironmental Science and Technology
Volume53
Issue number20
Pages (from-to)11969-11978
Number of pages10
ISSN0013-936X
DOIs
Publication statusPublished - 2019

Keywords

  • NO oxidation
  • Nox removal
  • Ionic liquids
  • ENIL
  • Flue gas

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