Catalysis of aromatic nitration by the lower oxides of nitrogen

Biodiesel is a viable substitute for petroleum-based diesel fuel. Its advantages are improved lubricity, higher cetane number and cleaner emission. Biodiesel and its blends with petroleum-based diesel fuel can be used in diesel engines without any signifi cant modifi cations to the engines. Data from the numerous research reports and test programs showed that as the percent of biodiesel in blends increases, emission of hydrocarbons (HC), carbon monoxide (CO), and particulate matter (PM) all decrease, but the amount of oxides of nitrogen (NOx) and fuel consumption is tend to increase. The most signifi cant hurdle for broader commercialization of biodiesel is its cost. In current fuel price policy in Indonesia (especially fuel for transportation), the higher percent of biodiesel in blend will increase the price of blends fuel. The objective of this study is to assess the optimum blends of biodiesel with petroleum-based diesel fuel from the technically and economically consideration. The study result recommends that 20% biodiesel blend with 80% petroleum-based diesel fuel (B20) is the optimum blend for unmodifi ed diesel engine uses.Keywords: biodiesel, emission, optimum, blend

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Corrigendum to “Effect of antioxidant additives on oxides of nitrogen (NOx) emission reduction from Annona biodiesel operated diesel engine” [Renew. Energy 148 (2020) 1321–1326]

Renewable Energy ◽

10.1016/j.renene.2020.11.016 ◽

2021 ◽

Vol 168 ◽

pp. 1403

Author(s):

Silambarasan Rajendran

Keyword(s):

Diesel Engine ◽

Emission Reduction ◽

Nox Emission ◽

Oxides Of Nitrogen ◽

Antioxidant Additives

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ChemInform Abstract: Aromatic Nitration under Neutral Conditions Using N-Bromosuccinimide/Silver(I) Nitrate.

ChemInform ◽

10.1002/chin.201248031 ◽

2012 ◽

Vol 43 (48) ◽

pp. no-no

Author(s):

Najmeh Nowrouzi ◽

Abdol Mohammad Mehranpour ◽

Elham Bashiri ◽

Zohre Shayan

Keyword(s):

Neutral Conditions ◽

Aromatic Nitration

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Improvements in the profiles and distributions of nitric acid and nitrogen dioxide with the LIMS version 6 dataset

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-4741-2010 ◽

2010 ◽

Vol 10 (10) ◽

pp. 4741-4756 ◽

Cited By ~ 5

Author(s):

E. Remsberg ◽

M. Natarajan ◽

B. T. Marshall ◽

L. L. Gordley ◽

R. E. Thompson ◽

...

Keyword(s):

Nitric Acid ◽

Nitrogen Dioxide ◽

Theoretical Calculations ◽

Spin Splitting ◽

Oxides Of Nitrogen ◽

Polar Night ◽

Chemical Effects ◽

Satellite Sensors ◽

Precision And Accuracy

Abstract. The quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) nitric acid (HNO3) and nitrogen dioxide (NO2) profiles and distributions of 1978/1979 are described after their processing with an updated, Version 6 (V6) algorithm and subsequent archival in 2002. Estimates of the precision and accuracy of both of those species are developed and provided herein. The character of the V6 HNO3 profiles is relatively unchanged from that of the earlier LIMS Version 5 (V5) profiles, except in the upper stratosphere where the interfering effects of CO2 are accounted for better with V6. The accuracy of the retrieved V6 NO2 is also significantly better in the middle and upper stratosphere, due to improvements in its spectral line parameters and in the reduced biases for the accompanying V6 temperature and water vapor profiles. As a result of these important updates, there is better agreement with theoretical calculations for profiles of the HNO3/NO2 ratio, day-to-night NO2 ratio, and with estimates of the production of NO2 in the mesosphere and its descent to the upper stratosphere during polar night. In particular, the findings for middle and upper stratospheric NO2 should also be more compatible with those obtained from more recent satellite sensors because the effects of the spin-splitting of the NO2 lines are accounted for now with the LIMS V6 algorithm. The improved precisions and more frequent retrievals of the LIMS profiles along their orbit tracks provide for better continuity and detail in map analyses of these two species on pressure surfaces. It is judged that the chemical effects of the oxides of nitrogen on ozone can be studied quantitatively throughout the stratosphere with the LIMS V6 data.

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Effects of thermal treatments on characteristics and morphological variations in the deposits of urea-SCR systems

Environmental Science and Pollution Research ◽

10.1007/s11356-021-14057-4 ◽

2021 ◽

Author(s):

Sadashiva Prabhu S ◽

Kapilan Natesan ◽

Nagaraj Shivappa Nayak

Keyword(s):

Cyanuric Acid ◽

Catalytic Reduction ◽

Morphological Changes ◽

Water Solution ◽

Slight Variation ◽

Gravimetric Analysis ◽

Oxides Of Nitrogen ◽

Deposit Formation ◽

X Ray ◽

Exhaust Gases

AbstractSelective catalytic reduction (SCR) systems are employed by automobile manufacturers for the abatement of environmental pollutants like oxides of nitrogen (NOx) emitted from exhaust gases of diesel engines. In SCR, the urea-water solution (UWS) is injected to exhaust gases in the form of a spray to generate the reducing agent NH3. Deposit formation at lower temperatures is a major concern with this technology. The deposits not only create backpressure but also leak NH3 to the environment as they deplete. It is very important to know the depletion characteristics of deposits formed at lower temperatures in order to assess the NH3 leakage to the environment when the engine exhaust gases attain higher temperatures. In the present work, deposits formed at a low-temperature range of 150–200°C for continuous run along with UWS injection were investigated. Additionally, they were aged at 300°C in the absence of UWS to check the variation in characteristics with the rise of temperature. By gravimetric analysis, it is inferred that the deposits formed at higher pre-age temperatures are less prone to depletion as the temperature increases. The elemental analysis using energy-dispersive X-ray spectroscopy (EDX) indicates slight variation in carbon, nitrogen and oxygen compositions for all the pre-age conditions. As an extended study, the byproducts at pre-age and post-age conditions were investigated through X-ray diffraction (XRD). The compounds like cyanuric acid (CYA) and biuret were not observed when pre-age samples were aged at 300°C. Instead, the compounds like ammelide, ammeline, triuret and melamine were observed. Scanning electron microscope (SEM) study revealed morphological changes in both pre-age and post-age samples. Further, the crystallinity variations were also observed for the changes in the heating cycles during deposit formation. The gravimetric analysis of deposits in pre-age and post-age conditions helps in predicting the amount of deposits for transient load cycles.

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