Supported honeycomb monolith catalysts for high-temperature ammonia decomposition and H2S removal

High Catalytic Performance of Fine Particles of Metallic Iron Formed from Limonite in the Decomposition of a Low Concentration of Ammonia

“…The conversion to N 2 was 75-90% at 900°C over the former two materials [6], 15% at 500°C with the monolith catalyst [4], and 20% at 550°C for the char-supported Fe [13], the space velocity being smaller [4,6] than or the same [13] as that in the present work. Although the decomposition of a higher concentration of NH 3 of more than 5 vol.% with fused Fe catalysts with some promoters has been studied at 400-500°C in relation to the kinetics of NH 3 synthesis, the conversion to N 2 can be estimated to be very low under the high space velocity of 45,000 h )1 used in this study [15,16].…”

“…Thus, the limonite catalyst realized the almost complete decomposition of 2000 ppm NH 3 at a much lower temperature, compared with other Fe-containing materials studied earlier from the viewpoint of the hot gas cleaning, such as ferrous dolomite [6], sintered iron ore [6], Fe oxide on TiO 2 monolith support [4], and metallic Fe supported on coal char [13]. The conversion to N 2 was 75-90% at 900°C over the former two materials [6], 15% at 500°C with the monolith catalyst [4], and 20% at 550°C for the char-supported Fe [13], the space velocity being smaller [4,6] than or the same [13] as that in the present work.…”

“…Although it has been reported that Ni-, Mo-, and Ru-based catalysts show NH 3 conversions of ‡70% in the decomposition of several thousands ppm NH 3 at high temperatures of 700-960°C under total pressures of 0.1-2.0 MPa [1,3,[6][7][8][9], inexpensive Fe-containing materials may be promising as the catalyst sources. According to earlier studies under ambient pressure, ferrous dolomite and sintered iron ore catalyzed this reaction at 900°C [6], and Fe oxide on TiO 2 monolith support provided high NH 3 conversion of 95% at 800°C [4]. We have also shown that nanoscale metallic Fe supported on coal char, which can simply be produced by heating fine FeOOH particles precipitated on brown coal in inert gas [10,11], is capable of achieving the complete decomposition of 2000 ppm NH 3 to N 2 at 750°C [12,13].…”

“…A hot gas cleanup method to remove a small concentration of NH 3 , typically 1000-5000 ppm (in volume), from fuel gas produced in a high temperature gasification process for IGCC can improve the thermal efficiency and environmental performance [1,2]. Catalytic decomposition of NH 3 to N 2 and H 2 may be the most efficient method for this purpose [1] and has thus attracted increasing attention [3][4][5]. Although it has been reported that Ni-, Mo-, and Ru-based catalysts show NH 3 conversions of ‡70% in the decomposition of several thousands ppm NH 3 at high temperatures of 700-960°C under total pressures of 0.1-2.0 MPa [1,3,[6][7][8][9], inexpensive Fe-containing materials may be promising as the catalyst sources.…”

Preparation of a Novel Emulsion-Templated MIP Monolith and its Application for on Line Assay of Nifedipine in Human Plasma

“…Nowadays, polymeric monoliths hold an impressively strong position due to excellent properties in comparison with conventional chromatographic supports and extensive applications such as biological tissues caffolds [1], catalysis supports [2], ion-exchange resin [3] and separation media [4]. In recent years, emulsion templating polymerization technology has been introduced in the preparation of monolith due to well defined open porous material that has good mechanical strength and possess favorable stability.…”