Ammonia measurements and metrology in the context of ... · PDF fileAmmonia measurements and...

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Ammonia measurements and metrology in the context of research and policy questions NH 3 concentrations orders of magnitude higher than “background” in many parts of the globe due to anthropogenic activities NH 3 not widely measured in compliance networks NH 3 being a sticky, reactive chemical is challenging to measure well Metrological standards and tools need development

Transcript of Ammonia measurements and metrology in the context of ... · PDF fileAmmonia measurements and...

Ammonia measurements and metrology in the

context of research and policy questions

• NH3 concentrations orders of magnitude higher than “background” in

many parts of the globe due to anthropogenic activities

• NH3 not widely measured in compliance networks

• NH3 being a sticky, reactive chemical is challenging to measure well

• Metrological standards and tools need development

The ammonia measurement challenge

Aim: quantitative, molecule specific measurements fit to the purpose of the research

or policy question

Gas-phase extraction followed by analytical chemical

Direct gas phase measurement

On-line Off-line

Open path/remote Closed path/gas sampling

Target data quality?

accuracy: ±5% reference traceable calibrations

Temporal resolution?

Policy • The UN and related UN ECE to abate Acidification,

Eutrophication and Ground-level Ozone: set limits and reduction goals for ammonia in

signatory countries (Annex IX, revised 2012).

• In parallel the EU (2001/81/EC) applies even lower emission ceilings for NH3.

A revision as part of the Clean Air Policy Package shall ensure:applicability until 2020, new

reduction commitments for ammonia from 2020 and 2030.

• national reports to use EMEP Emission Inventory Guidebook, emission .

• Real AQ measurement data (as for SO2, NOx, CO, Benzene

and PM)NFR SOURCE CATEGORY SO2 NH3 1.A.1 Public power, cogeneration and

district heating A

1.A.2 Industrial combustion A 1.A.3.b Road transport C E 1.A.3.a 1.A.3.c 1.A.3.d 1.A.3.e

Other mobile sources and machinery

C

1.A.4 Commercial, institutional and residential combustion

B

1.B Extraction and distribution of fossil fuels

C

2 Industrial processes B E 3 Solvent use 4 Agriculture activities D 6 Waste treatment B 6 Disposal activities C E - Nature D E D: 100 to 300 % E: order of magnitude

(EMEP-EEA air pollutant emission inventory guidebook – 2013, Part A,

Chapter 5, Table 3-3)

UK National Ammonia Monitoring Network

Protocols and standards

• CEN committee standards• Currently passive sampler review in progress

• No on-line NH3

• EMEP Handbook of methods

• ACTRIS/WMO-GAW protocol developmentBest Practice delivered through the existing

organisations however preparing draft documents to

include important as process is slow

Due to continuous development of technologies and

scientific understanding it is important to write

inclusive, general protocols

MetNH3 project 2015-2017www.metnh3.eu

Instrument surfaces, inlets (and filters)

f (t)

f (T, RH)

f (air mass)

Adsorption 316L/SN2000

Objectives:

� Produce and characterise improved gas mixture standards with

long term stability and lower uncertainty (~1% rel.)

� Develop improved gas mixture standard methods that are

traceable, mobile with uncertainty < 3 % rel.

Static gas mixture standards:

� levels: 10 and 100 µmol/mol

� 5 different treatments

� 2 mixtures per level,

treatment and partner

Realisation of gas standards and mixtures

Summary of validation of PSMs

Cylinder

number

Gravimetric

amount fraction/

µmol mol−1

Percentage deviation from gravimetric amount fraction when certified using:

NPL1657 NPL1659 NPL30718 NPL1844 NPL1769 NPL11269 NPL11268

NPL1657 100.05 − 0.42 + 0.10 + 0.15 − 0.60 − 0.82 − 0.07

NPL1659 100.00 + 0.42 + 0.53 + 0.57 − 0.18 − 0.40 + 0.36

NPL30718 99.95 −0.10 −0.52 + 0.05 − 0.70 − 0.92 − 0.17

NPL1844 100.29 −0.15 −0.57 −0.05 −0.75 −0.97 −0.22

NPL1769 101.16 + 0.60 + 0.18 + 0.70 + 0.75 − 0.22 + 0.54

NPL11269 100.01 + 0.83 + 0.40 + 0.93 + 0.98 + 0.22 + 0.76

NPL11268 100.02 + 0.07 − 0.36 + 0.17 + 0.22 − 0.53 − 0.75

• 7 mixtures analysed by NDIR analyser

• Validated using a “standard/unknown” routine

• Each mixture treated in turn as the “unknown” and certified against the

other six

Expanded (k = 2) uncertainty in the amount

fraction of ±2 %

Partners METAS and BAM work on 2 independent for

traceable mixtures (0.5 to 500 nmol/mol)

� Designs have been setup

� METAS investigated materials

and coated elements (MFCs, valves)

� Permeation devices have been

calibrated. New magnetic suspen-

sion balance (coated SS; p < 6 bar)

� METAS ReGaS1 is operational

Dynamic gas mixture standards

A CB

D

E

F G

HI

Field measurements…

• What type of measurement methods

• What concentrations

• For what purpose

Types of measurementQuestion: Answer: Responses:

1. What type of ammonia

analyser(s) do you use?

Aerodyne QC-TILDAS

Thermo 17C

UV-DOAS

Piccaro G2103

Other CRD Spectrophotometer

Omnisens TGA-310

ABB Instruments NDIR URAS 26

CEH Delta Denuder

AiRRmonia

Innova 1412i Photoacoustic Analyser

Filter Pack

3

1

1

6

1

1

1

1

1

1

1

2. What inlet material(s) do

you use?

Teflon*

PTFE

PFA

SilcoNert2000 Stainless Steel

Stainless Steel

FEP

[*Stated only as Teflon, not which type]

5

9

3

2

4

1

Types of study I: Anerobic Digestor emission factor study

Types of study I: Auchencorth Moss hourly data

Twigg et al. in prep. 2016

NH3 concentrations during 2012 in relation to wind speed for the wind sectors: NE (10˚ to 130 ˚), NW (230 ˚ to 360 ˚ to 10 ˚) and S (130 ˚ to 230 ˚). (Data are medians of 50

hourly measurements sorted by ascending order of wind speed).

Types of study I Effects assessment from passive sampler (Critical loads/levels)

Concentrations N Deposition

not exceeded

<= 0.5

0.5 – 1.01.0 – 2.0> 2.0

keq ha-1 year-1

Assessment of

Critical Loads

Exceedance

Jane Hall, Bangor

Critical

Levels

Exceedance

CBED

model

MetNH3 assessments

• Passive sampler chamber intercomparison

• Facility intercomparison (UBA)

• Active sampler intercomparison at Easter Bush (15th August- 15th September 2016)

• Passive sampler intercomparison, Whim NH3 manipulation experiment

Off-line testing

• Passive and active denuder intercomparison at NPL, ongoing

(previously discussed)

• Passive sampler intercomparisons at Whim Bog?

• Active vs passive during active instrumentation

intercomparison at Easter Bush

• CEN standard published

• Interlaboratory/manufacturer protocol developed?

Diffusive and denuder sampler exposure tests

Radiello holder

and cartridge

Gradko DIFRAM-

400 and

diffusion tube

CEH ALPHA

sampler and

Passam

ammonia

sampler

CEH DELTA

denuder

Off-line Analytical analysis of passive samplers

Controlloed Atmosphere Testing Facility

Exposure results

20

Non-extractive sampling

Most commercial spectrometers are based on infrared spectroscopy, though UV

instruments also developing

Confirmed parties for the intercomparison

• 12 universities and institutes (both research and metrological) + 6 SMES

• Instruments include:• Differential Optical Absorption Spectroscopy• Infrared absorption Spectroscopy – quantum cascade lasers either

using cavity ring down or multipass cell (both closed and open path methods)

• Photoacoustic spectrometer• Chemiluminescence• Rotating wet denuders with online IC• Flow injection analysis

Vehicle

gate

access

Pedestria

n access

Pedestria

n access

Whim Bog: Off-line ammonia metrology intercomparison

Contact: Sim Tang ([email protected])

Ammonia transect

Aug – Sept 2016: Intercomparison periodsOct -Nov 2016: Chemical analysisNov 2016 – Feb 2017: Collation and report

Example NH3 concentration profile along

transect

Passive Samplers from participating laboratories will be exposed along transect, in parallel with continuous measurements.

NH3 line release source

Transect downwind (NE)

Upwind (SW)

0.1

1.0

10.0

100.0

-20 30 80

NH

3( µ

g m

-3)

Distance (m)

WHIM (July 2015)Transect

0.1 m

0 m

Wet N plots

Ammonia transect

Strategy for standards AND data access required

• Mitigation and abatement evidence

• measurement strategy fits evidence needs

• These can be many fold…a. Emission factors

b. Emission mitigation

c. Concentration limits and exposures

d. Deposition calculations/fluxes

e. Impacts on ecosystems/PM/Human health

Use of calibration centres and test facilities

• Learn from the model of VOCs and NOx etc.• Establish centres of excellence• On-going annual checks and improvement plans• Plan for access for SMEs, researchers to regularly

check standards• Incorporate metrological standards (or close to

them!)

• concentration and fluxes both important, but different requirements for each

UKEAP monitoring

measurements

Modelling and

mapping pollutant

concentrations and

deposition

Critical Loads and

exceedence

mapping

Local

Environmental

Impact

Assessments

and planning

Screening tools

e.g. SCAIL

Public

access

to data

Measurements and models into policy and management

http://uk-air.defra.gov.uk

http://www.ceh.ac.uk/sci_programmes/UKEAP-Project.html

http://cldm.defra.gov.uk/index.htm

http://uk-air.defra.gov.uk/research/air-quality-modelling

Databases

EMEP

OSPAR

UK-Air

Air pollution information service

APIS

National and international assessments

atmospheric pollution and deposition to

the environment e.g. RoTaP, UNECE

http://www.apis.ac.uk/

http://www..scail.ceh.ac.uk/

EU compliance

modelling (PCM)

Secondary Inorganic

Aerosol

Site data used by other UK networks:• ECN

• LTMN

Partners and REGs

MetNH3

Takachiho, Radiello

Passam

StakeholdersCollaborators

Current review of NH3 measurements

1980 1985 1990 1995 2000 2005 2010 20150

2

4

6

8

10

12

# IS

I pap

ers

mea

surin

g am

bien

t NH

3

• Work in progress, ISI papers n=85

�25 use “on-line” methods

�39 use “off-line” methods

�3 remote sensing

� Several use both

�Estimate I have got ~50%

papers, as often NH3 not

primary aim

Grey literature, unpublished data. Search on-going, please help!