This document summarizes sources and control methods for nitrogen oxides (NOx). It discusses that NOx is primarily produced during high-temperature combustion processes from automobiles, boilers, and industrial operations. It has negative health and environmental effects. The document outlines various NOx control technologies including combustion modifications to reduce peak temperatures and residence times, as well as add-on controls like selective non-catalytic reduction, selective catalytic reduction, and dry sorption that chemically convert NOx to less harmful compounds. Wet scrubbers are deemed not suitable for NOx control since nitric oxide is insoluble in water.
PM is a complex mixture of air borne particles that differ in size, origin and chemical composition, all of which are <10 µm in size.
US EPA described PM pollution as ‘mixture of mixtures’.
PM is among the most harmful of all air pollutants.
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Atmospheric particulate matter, Sources Of Particulate Matter
Industrial Sources of Particulate Emissions
Types Of Particulate Matter
Important Terms Describing Atmospheric Particles
Particulate Matter And Health
General Methods For Control Of Particulate Emissions
Particulate Collection Mechanism
PHOTOCHEMICAL FORMATION OF SMOG
Photochemical Reactions in Atmosphere
What is Smog ?
Formation of Photochemical smog
Probable Mechanism for Smog formation
PM is a complex mixture of air borne particles that differ in size, origin and chemical composition, all of which are <10 µm in size.
US EPA described PM pollution as ‘mixture of mixtures’.
PM is among the most harmful of all air pollutants.
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Atmospheric particulate matter, Sources Of Particulate Matter
Industrial Sources of Particulate Emissions
Types Of Particulate Matter
Important Terms Describing Atmospheric Particles
Particulate Matter And Health
General Methods For Control Of Particulate Emissions
Particulate Collection Mechanism
PHOTOCHEMICAL FORMATION OF SMOG
Photochemical Reactions in Atmosphere
What is Smog ?
Formation of Photochemical smog
Probable Mechanism for Smog formation
The branch of chemistry which deals with chemicals and other pollutants in environment
This presentation includes atmospheric pollution, water pollution, waste water treatment method and green chemistry.
AIR POLLUTION CONTROL course material by Prof S S JAHAGIRDAR,NKOCET,SOLAPUR for BE (CIVIL ) students of Solapur university. Content will be also useful for SHIVAJI and PUNE university students
AIR POLLUTION CONTROL course material by Prof S S JAHAGIRDAR,NKOCET,SOLAPUR for BE (CIVIL ) students of Solapur university. Content will be also useful for SHIVAJI and PUNE university students
Pollution is a global topic on which many scientists are working day in day out to find newer techniques to reduce it. Major pollutants include dust, effluent, harmful gases, etc. which cause major problems to the Earth’s health. One such pollutant found in the surrounding is the VOC. - ( Uploaded by - Sangram Nandawaekar.)
AIR POLLUTION CONTROL course material by Prof S S JAHAGIRDAR,NKOCET,SOLAPUR for BE (CIVIL ) students of Solapur university. Content will be also useful for SHIVAJI and PUNE university students
The branch of chemistry which deals with chemicals and other pollutants in environment
This presentation includes atmospheric pollution, water pollution, waste water treatment method and green chemistry.
AIR POLLUTION CONTROL course material by Prof S S JAHAGIRDAR,NKOCET,SOLAPUR for BE (CIVIL ) students of Solapur university. Content will be also useful for SHIVAJI and PUNE university students
AIR POLLUTION CONTROL course material by Prof S S JAHAGIRDAR,NKOCET,SOLAPUR for BE (CIVIL ) students of Solapur university. Content will be also useful for SHIVAJI and PUNE university students
Pollution is a global topic on which many scientists are working day in day out to find newer techniques to reduce it. Major pollutants include dust, effluent, harmful gases, etc. which cause major problems to the Earth’s health. One such pollutant found in the surrounding is the VOC. - ( Uploaded by - Sangram Nandawaekar.)
AIR POLLUTION CONTROL course material by Prof S S JAHAGIRDAR,NKOCET,SOLAPUR for BE (CIVIL ) students of Solapur university. Content will be also useful for SHIVAJI and PUNE university students
NOx emissions refer to a group of nitrogen oxides the are commonly found in combustion gases. These harmful emissions are caused by fuel combustion processes occurring in cars and industrial applications. They can cause environmental issues like photochemical smog, acid rain, and ozone accumulations. NOx has also been linked to asthma complications, pulmonary complications, as well as coughing and wheezing.
Correctly quantifying these emissions in air pollution control equipment is necessary to maximize the control of NOx gases. This presentation focuses on quantifying thermal NOx. This type of NOx is usually formed in the hottest parts of the burner flame.
Selective Catalytic Reduction (SCR) is an advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF). The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide (CO2), natural components of the air we breathe, which is then expelled through the vehicle tailpipe.
SCR technology is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reductant within a catalyst system. The chemical reaction is known as "reduction" where the DEF is the reducing agent that reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of CO2. The DEF can be rapidly broken down to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions up to 90 percent
Presentation given by Richard T. J. Porter from ETII, University of Leeds, on "CO2QUEST Typical Impurities in Captured CO2 Streams" at the EC FP7 Projects: Leading the way in CCS implementation event, London, 14-15 April 2014
Callide oxyfuel research project, Part 1: Removal of SOx, NOx and mercury gas...Global CCS Institute
To highlight the research and achievements of Australian researchers, the Global CCS Institute with ANLEC R&D will hold a series of webinars throughout 2016. Each webinar will highlight a specific ANLEC R&D research project and the relevant report found on the Institute’s website. This was the second webinar of the series, which focused on experiments quantifying and optimising the removal of SOx, NOx and mercury gases using compressed gaseous slip streams from the CPU as part of the Callide Oxyfuel Project.
The Callide Oxyfuel Project in central Queensland, Australia, has demonstrated carbon capture using oxyfuel technology on a retrofitted 30 MWe boiler. The project comprised of 2 x 330 t/day air separation units, a 30 MWe oxy-fuel boiler and a 75 t/day CO2 capture plant. The plant was commissioned in 2012 and operated for three years achieving nominally 10,000 hours of industrial operation in oxy-combustion mode.
The project has been able to demonstrate CO2 capture rates from the Oxyfuel flue gas stream to the CO2 capture plant in excess of 85%, and producing a high quality CO2 product suitable for geological storage. In addition, other benefits observed from the oxy-firing and CO2 capture demonstration have included: (i) increased boiler combustion efficiency; (ii) greater than 50% reduction in stack NOx mass emission rates; and (iii) almost complete removal of all toxic gaseous emissions including SOx, NOx, particulates and trace elements from the flue gas stream in the CO2 capture plant (CPU).
This webinar provided a technical presentation of experiments quantifying and optimising the removal of SOx, NOx and mercury gases using compressed gaseous slip streams from the CPU, complemented by plant measurements by the University Of Newcastle, supported by Australian National Low Emission R&D. This webinar was presented by Professor Terry Wall and Dr Rohan Stanger from The University of Newcastle, Australia.
1)M.Amulya, AITS ,Rajampet.
2)contents:
Effects of NOX
Introduction to SCR
SCR chemistry
SCR catalysts
Working
Advantages
Limitations
Conclusion
3)Effects of NOX:
Inhalation of NOX causes respiratory diseases such as Bronchitis and Emphysema
Causes depletion of ozone layer
main reason for occurence of acid rains
reacts of organic chemicals to form harmful components that causes biological mutations.
4)Introduction to SCR:
SCR means Selective Catalytic Reduction
It is the means of converting oxides of Nitrogen to atomic Nitrogen and water.
It meets the standards of US 2010 and EURO VI
leading technology for reducing NOX.
5) SCR chemistry:
6)SCR reductants:
Anhydrous ammonia
Aqueous ammonia
urea
SCR catalysts:
Vanadium-based SCR catalyst
Zeolite SCR catalyst
Copper Zeolite(CuZ)
Fe-Zeolite(FeZ)
7)Vanadium based SCR catalyst:
consists of vanadium pentoxide and tungsten trioxide.At higher temp.toxic compounds may release from this and also performance is poor.
Zeolite catalysts:
CuZ and FeZ are preferred due to their outstanding deNOX activity,temperature durability.
8)Catalytic converter:
Reactions in catalytic converter
9)Installation of catalytic converter in vehicles
10)Working of SCR system
11)working
12)comparison of SCR with other technologies in the reduction of NOX
13)Difference in NOX levels before and after NOX
14)Advantages
Does not require any modification in the combustion unit.
Higher NOX reduction is possible.
15)Disadvantages:
Ammonia slip may occur.
Large amounts of reductant and catalyst are required.
16)Conclusion:
The SCR technology is the dominant technology to meet the current and future emission regulations. To meet the current US 2010 and EURO VI Zeolite catalysts are required.
With the increasing emission regulations, it is important to improve and implement SCR technologies
17).Any auestions
18)Thank you
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Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
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Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
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The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
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• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
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NOx
1. NOxNOxSources and Control Methods
Presented by
KOMAL AROOSHKOMAL AROOSH
(2010-2012)
CENTRE FOR COALCENTRE FOR COAL
TECHNOLOGYTECHNOLOGY
UNIVERSITY OF THEUNIVERSITY OF THE
PUNJABPUNJAB 1
2. CONTENTSCONTENTS
• Specific sources of NOx
• NOx Effects
• Characteristics of NOx compounds
• NOx Regulation
•NOx Formation
• Control Technologies & Techniques
• Combustion Modification
• Add-On Controls (Flue Gas Treatment )
2
6. It is one of the main ingredients involved in the
formation of ground-level ozone, which can
trigger serious respiratory problems
contributes to nutrient overload that deteriorates
water quality
contributes to atmospheric particles that cause
visibility impairment most noticeable in national
parks
reacts to form nitrate particles, acid aerosols, as
well as NO2
, which also cause respiratory
problems
contributes to formation of acid rain
reacts to form toxic chemicals
contributes to global warming
6
8. NO – Nitric oxide
• Colorless and odorless gas
• Insoluble in water (Remember this for later on!)
• Toxic
NO2 – Nitrogen dioxide
• Usually exists as a dimer compound (N2O4) at low
0
C
• Has distinct reddish-brown color
• Moderately soluble in aqueous liquids
• Toxic
• Contributes to brown haze that occurs with smog
8
10. NOx concentrations are relatively low
in the atmosphere, so why are they
regulated?
NO and NO2 react rapidly with other
compounds, creating ozone and other
undesirable compounds. The NO and NO2
may never reach high concentrations, but are
creating other air pollutants.
10
12. • Formed at elevated temperatures during
combustion of fuel in the presence of air.
• Approximately 90 to 95% of the nitrogen
oxides generated in combustion
processes are in the form of nitric oxide
(NO). (Remember this for later on!)
• Once in the atmosphere, the NO reacts
in a variety of photochemical and thermal
reactions to form NO2
.
12
13. • Thermal NOx:Thermal NOx: formed by reaction
betweenN2 and O2 in the air; sensitive to
temperature
• Fuel (or Prompt) NOx:Fuel (or Prompt) NOx: formed from
combustion of fuel containing organic
nitrogen; dependent on local combustion
conditions and nitrogen content in the fuel.
Not all of the fuel nitrogen compounds are
released during combustion. Unlike sulfur,
a significant fraction of the fuel nitrogen
remains in the bottom ash or in the fly ash.
13
17. 1. Modify combustion to suppress NOx formation
• Low excess air operation
• Off-stoichiometric combustion
• Flue gas recirculation
• Natural gas reburning
2. Reduce Nox to molecular nitrogen through
controls (also known as flue gas treatment)
• Selective Non-Catalytic Reduction (SNCR)
• Selective Catalytic Reduction (SCR)
• Dry Sorption
17
NOx control TechniquesNOx control Techniques
18. Strategies for Combustion ModificationStrategies for Combustion Modification
Reduce peak
temperatures
of the flame
zone
Reduce gas
residence time
in the flame
zone
18
19. Would wet scrubbers be a good control
technique for NOx
emissions?
Wet scrubbers would not be a good
control technique for NOx
emissions.
Reason
NO is mainly formed during the
combustion process and NO2 is
formed in the atmosphere.
Since NO is insoluble in water, wet
scrubbing would not work very well!
19
21. Low excess air operation: Involves a reduction in the
total quantity of air used in the combustion process. By
using less oxygen, the amount of NOx produced is not as
great.
21
22. Off-stoichiometric combustion: Involves the mixing of
the fuel and air in a way that reduces the peak
gas temperatures and peak oxygen concentrations.
Low NOx burners: Keeps temperatures
down and dissipates heat quickly
Overfire air (OFA): Keeps mixture fuel rich
and completes combustion process using air
injection nozzles
Burners out of service (BOOS): Operates
alternate burners in combustion zone as
fuel rich, air rich, and air only
22
26. Flue gas recirculationFlue gas recirculation
Involves the return of cooled
combustion gases to the burner area
of the boiler. Reduced temperatures
produce less NOx. The process
requires a recirculation fan and duct
system.
26
27. Involves the operation of the main burners in a
boiler at very low excess air (fuel rich
conditions).
A series of overfire air ports are used in this
upper region to provide all of the air needed for
complete combustion.
Fuel ReburningFuel Reburning
27
30. Selective non-catalytic reduction systems
(SNCR)
Involves the injection of ammonia (NH3
) or urea
into the hot gas zone where reactions leading to
reduction of nitrogen oxides can occur. The
reactions are completed within the boiler, and
no waste products are generated. There is a
risk of ammonia (NH3
) being emitted into the
atmosphere if temperatures are too low,
however. SCNR systems are capable of
reducing nitrogen oxides from 20 to 60%.
30
32. Example SNCR System for NoExample SNCR System for Noxx Control in a BoilerControl in a Boiler 32
33. Selective catalytic reduction (SCR)
Involves using beds containing ammonia or urea to
reduce nitrogen oxides to molecular nitrogen and water.
Two or three catalysts (usually tungsten and vanadium)
are arranged in honeycomb shapes in the beds so air
can flow through. NOx reduction efficiencies ranging
from 75 to 90% are possible when the amount of
catalyst is sufficient, the catalyst is in good condition,
the ammonia reagent flow is sufficient, and the
ammonia is adequately distributed across the gas
stream.
33
34. Selective Catalytic Reduction (SCR) Reactions
OHNONHNO
OHNONHNO
22
catalystsupportedOVorTiO
232
22
catalystsupportedOVorTiO
23
6342
6444
522
522
+ →++
+ →++
Temperature ~ 300 - 400 o
C
34
35. Exapmle SCR System for NoExapmle SCR System for Noxx Control in a BoilerControl in a Boiler 35
36. Dry SorptionDry Sorption
◦ Activated carbon (220 ~ 230 o
C)
◦ Shell Flue Gas Treating System (~ 400 o
C)
CuOOCu
OHSOCuHCuSO
OHNONHNO
CuSOSOOCuO
→+
++→+
+ →++
→++
2
2224
22
catalystsasCuSOorCuO
23
422
5.0
22
6444
5.0
4
36