slide1
Download
Skip this Video
Download Presentation
Detailed chemical modelling based on the Master Chemical Mechanism (MCM)

Loading in 2 Seconds...

play fullscreen
1 / 26

Detailed chemical modelling based on the Master Chemical Mechanism (MCM) - PowerPoint PPT Presentation


  • 67 Views
  • Uploaded on

Detailed chemical modelling based on the Master Chemical Mechanism (MCM). Mike Jenkin EMMA Group Department of Environmental Science and Technology [email protected] ic . ac .uk. Master Chemical Mechanism. Developed by a consortium of groups Imperial College London Leeds Meteorological Office

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Detailed chemical modelling based on the Master Chemical Mechanism (MCM)' - vicky


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Detailed chemical modelling based on the Master Chemical Mechanism (MCM)

Mike Jenkin

EMMA Group

Department of Environmental Science and Technology

[email protected]

slide2

Master Chemical Mechanism

  • Developed by a consortium of groups
  • Imperial College London
  • Leeds
  • Meteorological Office
  • NETCEN (AEA Technology)
slide3

MCM: chemical processing of emissions

NOX

nitrate

VOC

CO2, H2O

CH4

SO2

sulphate

emissions

slide4

MCM: chemical processing of emissions

NOX

nitrate

CO2, H2O

VOC

Oxidant (O3, NO2, PAN)

Secondary Organic Aerosol (SOA)

emissions

slide5

Master Chemical Mechanism (MCM v3)

(http://chem.leeds.ac.uk)

  • Degradation of CH4 and 124 non-methane VOC
  • ca. 4,500 chemical species
  • ca. 12,500 chemical reactions
  • Non-methane VOC selected primarily on the basis of UK National Atmospheric Emissions Inventory (NAEI)
  • Provides a reasonable representation of major organic compounds emitted into the boundary layer in UK and other populated regions
slide6

VOC degraded in MCM v3

(http://chem.leeds.ac.uk)

  • 22 alkanes (C1-C12)
  • 16 alkenes (C2-C6)
  • 2 dienes (C4-C5)
  • 2 monoterpenes (C10)
  • 1 alkyne (C2)
  • 18 aromatics (C6-C11)
  • 6 aldehydes (C1-C5)
  • 10 ketones (C3-C6)
  • 17 alcohols (C1-C6)
  • 10 ethers (C2-C7)
  • 8 esters (C2-C6)
  • 3 carboxylic acids (C1-C3)
  • 2 other oxygenates (C3)
  • 8 chlorocarbons (C1-C2)

125 hydrocarbons, oxygenated and chlorinated VOC representative of a variety of important source sectors

e.g. road transport, solvent usage, biogenic

slide7

MCM scheme writing framework

Saunders et al., Atmos. Chem. Phys. 3, 161-180, 2003

Jenkin et al., Atmos. Chem. Phys. 3, 181-193, 2003

slide8

emission

VOC

OH, O3, NO3

first generation

products

OH, O3, NO3, hu

second generation

products

CO2

slide9

Applications of the MCM

Calculation of organic species distribution for comparison with and supplementation of field measurements

slide10

Emitted VOC

Products

alkanes

Majority of emitted VOC will be oxidised to:

aldehydes (C1- C?)

ketones (C3- C?)

nitrates (C1- C?)

PAN(s) (C2- C?)

hydroperoxides

alcohols

esters

carboxylic acids

percarboxylic acids

bi- and multi-functional products (esp. hydroxy-carbonyls and nitrates and dicarbonyls)

alkenes/dienes

alkynes

aromatics

carbonyls

ethers

esters

acids

chlorocarbons

slide14

Applications of the MCM

Assessment of comparative importance of:

Free radical sources:

O3 + hu

Speciated alkenes + O3

Speciated carbonyls + hu

HONO + hu

Free radical sinks:

OH + NO2 HNO3

HO2 + HO2  H2O2 + O2

RO2 + NO  RONO2

RO2 + HO2 ROOH + O2

Assessment of oxidant formation associated with different VOCs/VOC source sectors

slide15

Reduced mechanism

Common Representative Intermediates Mechanism (CRI v1)

CRI v1

121 VOC

250 species

570 reactions

Jenkin et al., Atmospheric Environment, 36, 4725-4734, 2002

slide16

Reduced mechanism

Common Representative Intermediates Mechanism (CRI v1)

CRI v1

121 VOC

250 species

570 reactions

Jenkin et al., Atmospheric Environment, 36, 4725-4734, 2002

VOC

CO2, H2O

slide17

Reduced mechanism

Common Representative Intermediates Mechanism (CRI v1)

CRI v1

121 VOC

250 species

570 reactions

Jenkin et al., Atmospheric Environment, 36, 4725-4734, 2002

O3

O3

O3

O3

VOC

CO2, H2O

slide19

Urban

Urban

dM dlogDa (gm-3)

Urban

Rural

Urban

Semi Rural

Aerodynamic Diameter (nm)

Importance of organics in aerosols (slide from Hugh Coe, UMIST)

slide20

emission

VOC

OH, O3, NO3

first generation

products

OH, O3, NO3, hu

second generation

products

CO2

slide21

gas phase

condensed

phase

emission

VOC

OH, O3, NO3

first generation

products

first generation

products

OH, O3, NO3, hu

second generation

products

second generation

products

CO2

slide22

gas phase

condensed

phase

emission

monoterpenes

OH, O3, NO3

first generation

products

OH, O3, NO3, hu

second generation

products

C5-C7 multi-oxygenated species

(probably WSOC)

CO2

slide23

gas phase

condensed

phase

emission

aromatics

OH, O3, NO3

first generation

products

OH, O3, NO3, hu

second generation

products

(probably WSOC)

CO2

slide24

Equilibrium

partitioning

gas phase

organic

aerosol, OA

kin

X (a)

X (g)

kout

[X](a)/[X](g) = kin[OA]/kout

= Kp [OA]

slide26

Photo-oxidation of a-pinene/NOX

EU OSOA campaign at EUPHORE

ad