scholarly journals Sustainable nitrate production out of thin air: The photocatalytic oxidation of molecular nitrogen

2021 ◽  
Author(s):  
Aneta Pashkova ◽  
Bastien Burek ◽  
Jonathan Bloh
Keyword(s):  
Climate Change ◽  
Nitric Acid ◽  
Nitrogen Dioxide ◽  
Gas Phase ◽  
Photocatalytic Oxidation ◽  
High Selectivity ◽  
Molecular Nitrogen ◽  
Ambient Conditions ◽  
Uva Light ◽  
Combat Climate Change

Novel processes for the sustainable production of fertilizers are highly sought after to combat climate change. Herein, we demonstrate that by irradiating with strong UVA-light, TiO2 is able to photocatalytically oxidize molecular nitrogen in the gas phase under ambient conditions to NOx and nitrate. The reaction produces predominantly nitrogen dioxide with a high selectivity of up to 93% which could be captured afterwards to produce nitric acid or nitrates and used as sustainable (solar) fertilizer.

Inhibiting Effect of Hydrofluoric Acid In Fuming Nitric Acid on Liquid and Gas Phase Corrosion of Several Metals

CORROSION ◽  
1957 ◽  
Vol 13 (12) ◽  
pp. 55-61 ◽  
Author(s):  
DAVID M. MASON ◽  
LOIS L. TAYLORS ◽  
JOHN B. RITTENHOUSE
Keyword(s):  
Nitric Acid ◽  
Liquid Phase ◽  
Nitrogen Dioxide ◽  
Gas Phase ◽  
Hydrofluoric Acid ◽  
Weight Percent ◽  
Chromium Alloy ◽  
Pure Lead ◽  
Inhibiting Effect ◽  
Fuming Nitric Acid

Abstract Measurements were made at 130 degrees F of the extent of corrosion of several metals exposed to the liquid and the gas phase of thermally stable nitric acid containing 11 to 13 weight percent nitrogen dioxide and 2 to 4 weight percent water with and without hydrofluoric acid added as a corrosion inhibitor. Liquid-phase corrosion of the following metals was readily inhibited by hydrofluoric acid in fuming nitric acid of this composition: aluminum alloys 2S-0 (1100), 14S-T6 (2014-T6), 17S-T4 (2017-T4), 24S-T4 (2024-T4), 61S-T6 (6061-T6), and 75S-T6 (7075-T6); aluminum 2S-0 welded to 356; and chromium-nickel steels 302, 303, 304, 321, 347, Armco 17-7PH, and Uniloy 19-9DL and 19-9DX. Carbon steel C1020 and chromium alloy steels 4130, 410, 430, and 446 having intact natural metal oxide films, which were formed in moist air, were inhibited by hydrofluoric acid. Corrosive attack of these steels without the oxide film, however, was aggravated by the presence of hydrofluoric acid in fuming nitric acid, the corrosion becoming more extensive the lower the chromium content of the steel. Commercially pure lead was inhibited by hydrofluoric acid, whereas pure chromium, Nickel-A, tantalum, and titanium alloys 75A and 130A were either only slightly inhibited or showed corrosion rates which actually were increased by presence of hydrofluoric acid in fuming nitric acid. Inhibition of gas-phase corrosion was found to occur readily in the case of the following metals tested: steels 303, 410, 430, and 446 and aluminum 61S-T6. Gas-phase corrosion of steels 4130 and 1020 was usually aggravated by hydrofluoric acid. Exposure of aluminum 61S-T6 and stainless steel 347 to fuming nitric acid with a repeated cycling of temperature between 70 and 160 degrees F was found not to impair the inhibiting effect of hydrofluoric acid on gas and liquid-phase corrosion of these metals. A few tests of the liquid and gas-phase corrosion of aluminum 61S-T6 and steels C1020 and 347 by nitrogen dioxide at 130 degrees F were also made, and this medium was found in general to be much less corrosive than fuming nitric acid. 4.3.2

scholarly journals The detection of nocturnal N<sub>2</sub>O<sub>5</sub> as HNO<sub>3</sub> by alkali- and aqueous-denuder techniques

2013 ◽  
Vol 6 (2) ◽  
pp. 231-237 ◽  
Author(s):  
G. J. Phillips ◽  
U. Makkonen ◽  
G. Schuster ◽  
N. Sobanski ◽  
H. Hakola ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Gas Phase ◽  
Significant Proportion ◽  
Sampling Location ◽  
Ambient Conditions ◽  
Phase Component ◽  
Dinitrogen Pentoxide ◽  
Annular Denuder ◽  
Process Studies ◽  
Measurement Campaigns

Abstract. The almost total anthropogenic control of the nitrogen cycle has led to wide ranging trans-national and national efforts to quantify the effects of reactive nitrogen on the environment. A number of monitoring techniques have been developed for the measurement of nitric acid and subsequent estimation of nitrogen deposition within large networks and for process studies on shorter measurement campaigns. We discuss the likelihood that many of these techniques are sensitive to another important gas-phase component of oxidized nitrogen: dinitrogen pentoxide (N2O5). We present measurements using a MARGA wet annular denuder device alongside measurements of N2O5 with a discussion of evidence from the laboratory and the field which suggests that alkali- and aqueous-denuder measurements are sensitive to the sum of HNO3 + 2N2O5. Nocturnal data from these denuder devices should be treated with care before using HNO3 concentrations derived from these data. This is a systematic error which is highly dependent on ambient conditions and is likely to cause systematic misinterpretation of datasets in periods where N2O5 is significant proportion of NOy. It is also likely that deposition estimates of HNO3 via data obtained with these methods is compromised to greater and lesser extents depending on the season and environment of the sampling location.

scholarly journals Ammonium nitrate evaporation and nitric acid condensation in DMT CCN counters

2014 ◽  
Vol 7 (5) ◽  
pp. 1377-1384 ◽  
Author(s):  
S. Romakkaniemi ◽  
A. Jaatinen ◽  
A. Laaksonen ◽  
A. Nenes ◽  
T. Raatikainen
Keyword(s):  
Nitric Acid ◽  
Ammonium Nitrate ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Condensation Nucleus ◽  
Cloud Condensation Nucleus ◽  
Ambient Conditions ◽  
Particle Activation ◽  
Maximum Water ◽  
Ccn Activity

Abstract. The effect of inorganic semivolatile aerosol compounds on the cloud condensation nucleus (CCN) activity of aerosol particles was studied by using a computational model for a DMT-CCN counter, a cloud parcel model for condensation kinetics and experiments to quantify the modelled results. Concentrations of water vapour and semivolatiles as well as aerosol trajectories in the CCN column were calculated by a computational fluid dynamics model. These trajectories and vapour concentrations were then used as an input for the cloud parcel model to simulate mass transfer kinetics of water and semivolatiles between aerosol particles and the gas phase. Two different questions were studied: (1) how big a fraction of semivolatiles is evaporated from particles after entering but before particle activation in the DMT-CCN counter? (2) How much can the CCN activity be increased due to condensation of semivolatiles prior to the maximum water supersaturation in the case of high semivolatile concentration in the gas phase? Both experimental and modelling results show that the evaporation of ammonia and nitric acid from ammonium nitrate particles causes a 10 to 15 nm decrease to the critical particle size in supersaturations between 0.1% and 0.7%. On the other hand, the modelling results also show that condensation of nitric acid or similar vapour can increase the CCN activity of nonvolatile aerosol particles, but a very high gas phase concentration (as compared to typical ambient conditions) would be needed. Overall, it is more likely that the CCN activity of semivolatile aerosol is underestimated than overestimated in the measurements conducted in ambient conditions.

scholarly journals Photocatalytic oxidation of TCE and MTBE in the Gas phase

2013 ◽  
Vol 10 (2) ◽  
pp. 237-240
Keyword(s):  
Gas Phase ◽  
Photocatalytic Oxidation ◽  
Methyl Tert Butyl Ether ◽  
Inlet Concentration ◽  
Ambient Conditions ◽  
Butyl Ether ◽  
Tert Butyl ◽  
The Impact ◽  
By Products ◽  
Mtbe Decomposition

Photocatalysis is a promising method for eliminating the volatile organic compounds emitted from various industrial processes because mild or ambient conditions are used. Titanium dioxide is commonly used as photocatalyst and ultraviolet light is utilized for decomposing gas phase pollutants. In the present work, the photocatalytic oxidation of methyl tert butyl ether (MTBE) and trichloroethylene (TCE) in the gas phase was studied. The impact of residence time, TCE/MTBE concentration and oxygen concentration on TCE/MTBE conversion and byproduct formation was examined. Acetone and tert-butyl formate were detected at the reactor outlet from MTBE decomposition, whereas dichloroacetyl chloride (DCAC) and phosgene were found as by-products of TCE oxidation. The residence time affected dramatically both TCE and MTBE photo-oxidation as well as by-products existence and configuration. In contrast, the variation of oxygen inlet concentration affected significantly only MTBE conversion. Finally, the increase in MTBE and TCE inlet concentration had as a result decreased conversions observed.

scholarly journals The detection of nocturnal N<sub>2</sub>O<sub>5</sub> as HNO<sub>3</sub> by alkali- and aqueous-denuder techniques

2012 ◽  
Vol 5 (5) ◽  
pp. 7489-7505
Author(s):  
G. J. Phillips ◽  
U. Makkonen ◽  
G. Schuster ◽  
N. Sobanski ◽  
H. Hakola ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Gas Phase ◽  
Significant Proportion ◽  
Sampling Location ◽  
Ambient Conditions ◽  
Phase Component ◽  
Dinitrogen Pentoxide ◽  
Annular Denuder ◽  
Process Studies ◽  
Measurement Campaigns

Abstract. The almost total anthropogenic control of the nitrogen cycle has led to wide ranging trans-national and national efforts to quantify the effects of reactive nitrogen on the environment. A number of monitoring techniques have been developed for the measurement of nitric acid and subsequent estimation of nitrogen deposition within large networks and for process studies on shorter measurement campaigns. We discuss the likelihood that many of these techniques are sensitive to another important gas-phase component of oxidized nitrogen; dinitrogen pentoxide (N2O5). We present measurements using a MARGA wet annular denuder device alongside measurements of N2O5 with a discussion of evidence from the laboratory and the field which suggests that alkali- and aqueous-denuder measurements are sensitive to the sum of HNO3 + N2O5. Nocturnal data from these denuder devices should be treated with care before using HNO3 concentrations derived from these data. This is a systematic error which is highly dependent on ambient conditions and is likely to cause systematic misinterpretation of datasets in periods where N2O5 is significant proportion of NOy. It is also likely that deposition estimates of HNO3 via data obtained with these methods is compromised to greater or lesser extents depending on the season and environment of the sampling location.

Fluorescence of BODIPY Dyes in Gas Phase at near Ambient Conditions

2020 ◽  
Author(s):  
Kseniya A. Mariewskaya ◽  
Denis Larkin ◽  
Yuri Samoilichenko ◽  
Vladimir Korshun ◽  
Alex Ustinov
Keyword(s):  
Gas Phase ◽  
Molecular Interactions ◽  
Atmospheric Pressure ◽  
Fluorescence Spectra ◽  
Visible Range ◽  
Intrinsic Properties ◽  
Ambient Conditions ◽  
Ideal Model ◽  
Molecular Fluorescence ◽  
Tesla Coil

Molecular fluorescence is a phenomenon that is usually observed in condensed phase. It is strongly affected by molecular interactions. The study of fluorescence spectra in the gas phase can provide a nearly-ideal model for the evaluation of intrinsic properties of the fluorophores. Unfortunately, most conventional fluorophores are not volatile enough to allow study of their fluorescence in the gas phase. Here we report very bright gas phase fluorescence of simple BODIPY dyes that can be readily observed at atmospheric pressure using conventional fluorescence instrumentation. To our knowledge, this is the first example of visible range gas phase fluorescence at near ambient conditions. Evaporation of the dye in vacuum allowed us to demonstrate organic molecular electroluminescence in gas discharge excited by electric field produced by a Tesla coil.

Preferential synthesis of ethanol from syngas via dimethyl oxalate hydrogenation over an integrated catalyst

2019 ◽  
Vol 55 (39) ◽  
pp. 5555-5558 ◽  
Author(s):  
Xin Shang ◽  
Huijiang Huang ◽  
Qiao Han ◽  
Yan Xu ◽  
Yujun Zhao ◽  
...  
Keyword(s):  
Gas Phase ◽  
High Selectivity ◽  
Dimethyl Oxalate ◽  
Preferential Synthesis

A novel, simple and efficient integrated catalyst exhibits an extremely high selectivity of 98% to ethanol in gas-phase hydrogenation of dimethyl oxalate.

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