Chemical Transformation of Fe, Air & Water to Ammonia: Variation of Reaction Rate with Temperature, Pressure, Alkalinity and Iron

2018 ◽  
Author(s):  
Ping Peng ◽  
Fang-Fang Li ◽  
Xinye Liu ◽  
Jiawen Ren ◽  
jessica stuart ◽  
...  
Keyword(s):  
Particle Size ◽  
Reaction Rate ◽  
Electrolyte Concentration ◽  
Iron Concentration ◽  
Reaction Medium ◽  
Iron Particle ◽  
Intermediate Step ◽  
Ammonia Production ◽  
Pure Nitrogen ◽  
Alkaline Reaction

The rate of ammonia production by the <u>chemical </u>oxidation of iron, N<sub>2</sub>(from air or as pure nitrogen) and water is studied as a function of (1) iron particle size, (2) iron concentration, (3) temperature, (4) pressureand (5) concentration of the alkaline reaction medium. The reaction meduium consists of an aqueous solution of equal molal concentrations of NaOH and KOH (Na<sub>0.5</sub>K<sub>0.5</sub>OH). We had previously reported on the <u>chemical </u>reaction of iron and nitrogen in alkaline medium to ammonia as an intermediate step in the <u>electrochemical </u>synthesis of ammonia by a nano-sized iron oxide electrocatlyst. Here, the intermediate <u>chemical </u>reaction step is exclusively explored. The ammonia production rate increases with temperature (from 20 to 250°C), pressure (from 1 atm to 15 atm of air or N<sub>2</sub>), and exhibits a maximum rate at an electrolyte concentration of 8 molal Na<sub>0,5</sub>K<sub>0,5</sub>OH in a sealed N<sub>2</sub>reactor. 1-3 µm particle size Fe drive the highest observed ammonia production reaction rate. The Fe mass normalized rate of ammonia production increases with decreasing added mass of the Fe reactant reaching a maximum observed rate of 2.2x10<sup>-4</sup>mole of NH<sub>3</sub>h<sup>-1</sup>g<sup>-1</sup>for the reaction of 0.1 g of 1-3 µm Fe in 200°C 8 molal Na<sub>0.5</sub>K<sub>0.5</sub>OH at 15 atm. Under these conditions 5.1 wt% of the iron reacts to form NH<sub>3</sub>via the reaction N<sub>2</sub>+ 2Fe + 3H<sub>2</sub>O ®2NH<sub>3</sub>+ Fe<sub>2</sub>O<sub>3</sub>.

Chemical Transformation of Fe, Air & Water to Ammonia: Variation of Reaction Rate with Temperature, Pressure, Alkalinity and Iron

2018 ◽  
Author(s):  
Ping Peng ◽  
Fang-Fang Li ◽  
Xinye Liu ◽  
Jiawen Ren ◽  
jessica stuart ◽  
...  
Keyword(s):  
Particle Size ◽  
Reaction Rate ◽  
Electrolyte Concentration ◽  
Iron Concentration ◽  
Reaction Medium ◽  
Iron Particle ◽  
Intermediate Step ◽  
Ammonia Production ◽  
Pure Nitrogen ◽  
Alkaline Reaction

The rate of ammonia production by the <u>chemical </u>oxidation of iron, N<sub>2</sub>(from air or as pure nitrogen) and water is studied as a function of (1) iron particle size, (2) iron concentration, (3) temperature, (4) pressureand (5) concentration of the alkaline reaction medium. The reaction meduium consists of an aqueous solution of equal molal concentrations of NaOH and KOH (Na<sub>0.5</sub>K<sub>0.5</sub>OH). We had previously reported on the <u>chemical </u>reaction of iron and nitrogen in alkaline medium to ammonia as an intermediate step in the <u>electrochemical </u>synthesis of ammonia by a nano-sized iron oxide electrocatlyst. Here, the intermediate <u>chemical </u>reaction step is exclusively explored. The ammonia production rate increases with temperature (from 20 to 250°C), pressure (from 1 atm to 15 atm of air or N<sub>2</sub>), and exhibits a maximum rate at an electrolyte concentration of 8 molal Na<sub>0,5</sub>K<sub>0,5</sub>OH in a sealed N<sub>2</sub>reactor. 1-3 µm particle size Fe drive the highest observed ammonia production reaction rate. The Fe mass normalized rate of ammonia production increases with decreasing added mass of the Fe reactant reaching a maximum observed rate of 2.2x10<sup>-4</sup>mole of NH<sub>3</sub>h<sup>-1</sup>g<sup>-1</sup>for the reaction of 0.1 g of 1-3 µm Fe in 200°C 8 molal Na<sub>0.5</sub>K<sub>0.5</sub>OH at 15 atm. Under these conditions 5.1 wt% of the iron reacts to form NH<sub>3</sub>via the reaction N<sub>2</sub>+ 2Fe + 3H<sub>2</sub>O ®2NH<sub>3</sub>+ Fe<sub>2</sub>O<sub>3</sub>.

The effect of particle size on the reactivity of active sodium carbonate towards sulfur dioxide

1979 ◽  
Vol 44 (12) ◽  
pp. 3419-3424
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Dušan Husek ◽  
Emerich Erdös
Keyword(s):  
Particle Size ◽  
Sulfur Dioxide ◽  
Sodium Carbonate ◽  
Reaction Rate ◽  
Active Form ◽  
Controlling Factor ◽  
Active Sodium ◽  
Effect Of Particle Size ◽  
Integral Reactor

The effect of particle size (0.33-1.0 mm) of the sodium carbonate on the reactivity of the active sodium carbonate prepared therefrom towards the sulfur dioxide was studied in a fixedbed integral reactor at a temperature of 150 °C. The found dependence of the reaction rate on the particle size exhibits an unexpected course; at sizes of about 0.65 mm, a distinct minimum appears. The reaction rate decreases approximately ten times in the first branch of this dependence. The controlling factor of the reactivity of sodium carbonate, however, remains to be the method of preparing the active form.

Effects of Reaction Medium on the Phase Synthesis and Particle Size Evolution of BaTiO3

2010 ◽  
Vol 93 (10) ◽  
pp. 3443-3448 ◽  
Author(s):  
Tomasz M. Stawski ◽  
Sjoerd A. Veldhuis ◽  
Ole F. Göbel ◽  
Johan E. Ten Elshof ◽  
Dave H. A. Blank
Keyword(s):  
Particle Size ◽  
Reaction Medium ◽  
Phase Synthesis ◽  
Size Evolution

scholarly journals Perborate Oxidation of Substituted 5-Oxoacids in Aqueous Acetic Acid Medium: A Kinetic and Mechanistic Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. Shree Devi ◽  
B. Muthukumaran ◽  
P. Krishnamoorthy
Keyword(s):  
Acetic Acid ◽  
Acid Medium ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Mechanistic Study ◽  
Aqueous Acetic Acid ◽  
Sodium Perborate ◽  
Acetic Acid Medium

Kinetics and mechanism of oxidation of substituted 5-oxoacids by sodium perborate in aqueous acetic acid medium have been studied. The reaction exhibits first order both in [perborate] and [5-oxoacid] and second order in [H+]. Variation in ionic strength has no effect on the reaction rate, while the reaction rates are enhanced on lowering the dielectric constant of the reaction medium. Electron releasing substituents in the aromatic ring accelerate the reaction rate and electron withdrawing substituents retard the reaction. The order of reactivity among the studied 5-oxoacids is p-methoxy ≫ p-methyl > p-phenyl > –H > p-chloro > p-bromo > m-nitro. The oxidation is faster than H2O2 oxidation. The formation of H2BO3+ is the reactive species of perborate in the acid medium. Activation parameters have been evaluated using Arrhenius and Eyring’s plots. A mechanism consistent with the observed kinetic data has been proposed and discussed. Based on the mechanism a suitable rate law is derived.

Acceleration of Baylis-Hillman reaction using ionic liquid supported organocatalyst

2021 ◽  
Vol 08 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Catalyst Loading ◽  
Catalyst Recycling ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Highly Active ◽  
Low Catalyst Loading

Background: Baylis-Hillman reaction suffers from the requirement of cheap starting materials, easy reaction protocol, possibility to create the chiral center in the reaction product has increased the synthetic efficacy of this reaction, and high catalyst loading, low reaction rate, and poor yield. Objective: The extensive use of various functional or non-functional ionic liquids (ILs) with organocatalyst increases the reaction rate of various organic transformations as a reaction medium and as a support to anchor the catalysts. Methods: In this manuscript, we have demonstrated the synthesis of quinuclidine-supported trimethylamine-based functionalized ionic liquid as a catalyst for the Baylis-Hillman reaction. Results: We obtained the Baylis-Hillman adducts in good, isolated yield, low catalyst loading, short reaction time, broad substrate scope, accessible product, and catalyst recycling. N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide was also successfully synthesized using CATALYST-3 promoted Baylis-Hillman reaction. Conclusion: We successfully isolated the 25 types of Baylis-Hillman adducts using three different quinuclidine-supported ammonium-based ionic liquids such as Et3AmQ][BF4] (CATALYST-1), [Et3AmQ][PF6] (CATALYST-2), and [TMAAmEQ][NTf2](CATALYST-3) as new and efficient catalysts. Tedious and highly active N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide derivative was also synthesized using CATALYST-3 followed by Baylis-Hillman reaction. Generally, all the responses demonstrated higher activity and yielded high competition with various previously reported homogenous and heterogeneous Catalytic systems. Easy catalyst and product recovery followed by six catalysts recycling were the added advantages of the prosed catalytic system.

scholarly journals Reaction Rate of Hydrothermal Ammonia Production from Chicken Manure

ACS Omega ◽  
2021 ◽  
Author(s):  
Yukihiko Matsumura ◽  
Yuito Suganuma ◽  
Takayuki Ichikawa ◽  
Wookyung Kim ◽  
Yutaka Nakashimada ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Chicken Manure ◽  
Ammonia Production

Effect of Iron Substitution on Structure and Optical Properties of Nanocrystalline CaTiO3

2008 ◽  
Vol 3 ◽  
pp. 123-128 ◽  
Author(s):  
A. Bandyopadhyay ◽  
S. Mondal ◽  
M. Pal ◽  
Umapada Pal ◽  
M. Pal
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Iron Concentration ◽  
Rietveld Analysis ◽  
Exothermic Peak ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Soft Chemical Route

Nanocrystalline CaTiO3 powders doped with Fe2O3 have been prepared using a soft chemical route. Precipitation of CaTiO3 nanocrystals has been studied by monitoring the exothermic peak in their DSC spectra. The crystal growth temperature of the samples depends on the concentration of iron. Surface morphology, crystal structure, optical and electrical properties of the nanostructures are investigated. X-ray diffraction study shows that the as-prepared powders are amorphous in nature and CaTiO3 phase formation starts at around 500 0C. Rietveld analysis revealed that the particle size of iron substituted CaTiO3 is in nanometer range. Optical bandgap of the nanostructures varies from 4.3 to 3.7 eV for the variation of iron concentration from 0.05 to 0.2 mole %.

Influence of Different Gradation Carbonyl Iron Particles on the Properties of Magneto-Rheological Fluids

2012 ◽  
Vol 452-453 ◽  
pp. 623-627
Author(s):  
Cheng Bin Du ◽  
Guo Jun Yu ◽  
Zhi Wei Gong
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Shear Stress ◽  
Single Particle ◽  
Carbonyl Iron ◽  
Iron Particle ◽  
Iron Particles ◽  
Carbonyl Iron Particle ◽  
Magneto Rheological ◽  
Multiple Particle

The influence of carbonyl iron particles sizes on the properties of magneto-rheological fluids (MRFs) were studied. Different-sized carbonyl iron magnetic particles were prepared by ball milling with different milling times. On this basis, different particle MRF were prepared The off-state viscosity and the shear stress of the above MRFs were characterised and studied by an advanced rotational rheometer system. The test results show that the off-state viscosity and the shear stress of single-particle MRFs were enhanced with increasing average carbonyl iron particle size at a constant magnetic field. The shear stresses of MRFs containing two or three different particle sizes were significantly improved compared with the MRFs containing only a single particle size. At a reasonable level of medium and small size carbonyl iron particle spread throughout the structure of the multiple-particle MRFs, the defects in the chain structure were remedied when a chain reaction occurred, and the mechanical properties of MRFs were enhanced. Meanwhile, increased mass fractions of the small size carbonyl iron particle resulted in a reduction in overall average particle size of MRFs, and the mechanical properties of MRFs were also reduced. The mechanical properties of multiple-particle MRFs were observed to be strongly dependent on the size and mass fraction of the medium and small carbonyl iron particles.

Effects of HMX Particle Size on the Shock Initiation of PBXC03 Explosive

2012 ◽  
Vol 13 (2) ◽  
Author(s):  
Li-Jing Wen ◽  
Zhuo-Ping Duan ◽  
Lian-Sheng Zhang ◽  
Zhen-Yu Zhang ◽  
Zhuo-Cheng Ou ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Reaction Rate ◽  
Pressure Gauge ◽  
Rate Model ◽  
Shock Initiation ◽  
Gauge Data ◽  
Medium Formulation ◽  
Good Agreement

AbstractA series of shock initiation experiments are performed on the PBXC03 explosives in different formulations to understand the influence of the explosive particle size on the shock initiation, and the in-situ pressure gauge data are obtained which show that shock sensitivity decreases with the explosive particle size under the test condition used in this paper. Moreover, a mesoscopic reaction rate model which is calibrated by the experimental data on a medium formulation PBXC03 explosive is adopted and then applied to predict numerically the shock initiation of other PBXC03 explosives in different formulations. The numerical results are in good agreement with the experimental data.

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