Ammonia Decomposition Catalyst with Resistance to Coexisting Sulfur Compounds

Abstract

A cheap and disposal catalyst will be required for the decomposition of ammonia in the presence of sulfur compounds. The possibility of iron ore and red mud as the ammonia decomposition catalyst was investigated using pure or diluted ammonia containing hydrogen sulfide as a reactant. Among the catalysts tested, red mud had the highest catalytic activity for the ammonia decomposition in the presence of hydrogen sulfide. On the other hand, a relatively low conversion of ammonia was observed using a nickel-based commercial catalyst for the ammonia decomposition. The deactivation behavior of an iron ore catalyst caused by sulfur poisoning depended on the pretreatment atmosphere before the reaction; namely, the deactivation was observed for the H 2 pretreatment, while the high level of ammonia conversion remained constant for the CO pretreatment. From the X-ray diffraction pattern of the catalysts, the used iron ore catalyst pretreated in the CO atmosphere included FeC x , which was also included in the red mud that was active for the ammonia decomposition. FeC x may be responsible to the sulfur poisoning resistance.

H2 Production via Ammonia Decomposition Using Non-Noble Metal Catalysts: A Review

“…Alternatively, research has also focused on the development of sustainable catalysts that are not prone to sulphur poisoning such as the red mud catalyst reported by Uemiya et al [30], which was believed to be resistant to sulphur poisoning due to the presence of FeC x .…”

“…Notably, since red mud is a waste product from the extraction of aluminium in the Bayer process and currently its disposal represents a problem for the mining industry, any potential uses of red mud represent not only a highly attractive economic advantage for the industry but also a sustainable solution. Additionally, red mud was reported to be resistant to poisoning by sulphur and exhibited good stability over 200 h of operation [30]. However, the composition of red mud varies depending on the bauxite source.…”

“…red mud [30] have been tested for ammonia decomposition. Unfortunately insufficient data was provided to enable to calculation of rate for comparison sake but nevertheless, considering the high iron content and high temperatures of the studies, it is clear that they are not exceptionally active catalysts.…”

Hydrodeoxygenation of pinyon-juniper catalytic pyrolysis oil using red mud-supported nickel catalysts

“…RM has been investigated as catalyst for various applications, including pyrolysis of biomass [24,25], hydrogenation and liquefaction [26][27][28][29][30][31], hydrodechlorination and desulfurization reactions [32][33][34], and exhaust gas clean-up [35,36]. RM has also been used as catalyst in other reactions such as degradation of polyvinyl chloride containing polymer mixtures into fuel oil [37,38], conversion of waste oil and waste plastic to fuel [39], heavy crude oil hydrotreating [40], ammonia decomposition in presence of sulfur compounds [41], and nitrile synthesis from A C C E P T E D M A N U S C R I P T aldehydes and hydroxylamine [42]. Furthermore, RM has recently been used as catalyst for removal of organics from water [43,44], biodiesel production [45], and methanogenesis reaction [46].…”

Catalytic Membrane Reactors

“…Methane [201, 227-233] Higher hydrocarbons [234][235][236][237][238] Methanol [234,237,[239][240][241][242][243][244][245][246][247][248] hydrogen transport rate through the membrane, despite its thickness of 200 µm, was high enough to remove the hydrogen faster than it was produced if a high sweep gas flow rate was applied. Compared to a packed-bed without hydrogen removal, for which the cyclohexane conversion was limited by the equilibrium to 18.7%, the membrane reactor reached close to 100% conversion under the same conditions.…”