Volatile Organic Compounds VOCs

1
Volatile Organic Compounds (VOCs)
2
VOC - Origins and Effects

• VOCs are organic substances which are volatile
  and are photochemically reactive
• includes a long list of individual substances,
  many of which are CEPA 99 toxic
• the definitions of VOC vary
• effects
• precursor to ground level ozone
• precursor to secondary fine particulate
• human health impacts
• nuisance effects, such as odours

NOx
VOC
O3 ( SMOG )
3
Definition of VOC - NERM / NPRI

• Definition based on list of excluded substances
• refers to Order Adding Toxic Substances to
  Schedule 1 to the Canadian Environmental
  Protection Act, 1999, published in the Canada
  Gazette, Part II (July 3, 2003).
• Volatile Organic Compounds that participate in
  atmospheric photochemical reactions, excluding
• methane, ethane, list of 44 substances or classes
  of substances, excluded on the basis of their
  negligible photochemical reactivity
• list appears in Gazette Notice, Appendix of CCPA
  Guideline, Appendix 3 of Supplementary Guide to
  Reporting Criteria Air Contaminants (CACs) to the
  NPRI 2003

NERM uses the NPRI definition
4
Definition of VOC - OMOE

• Any compound of carbon, excluding carbon
  monoxide, carbon dioxide, carbonic acid, metallic
  carbides or carbonates, and ammonium carbonate,
  which participates in atmospheric photochemical
  reactions and has a vapour pressure of 0.01 kPa
  or greater at 25C
• OMOE has a list of substances excluded from the
  definition of VOC
• OMOE also has a list of over 600 included
  substances, but does not call this an all
  inclusive list

5
Still More on the Definition of VOCs

• VOC is distinct from the following
• total hydrocarbons (THC),
• non-methane hydrocarbon (NMHC), and
• total organic compounds (TOC)
• caution some of the estimation methods result in
  estimates of the above - they are not necessarily
  equivalent to VOC

6
Key Issues

• reporting thresholds
• NERM/NPRI, OMOE Reg. 127, Alberta
• ATH - alternate thresholds NPRI Parts 2 3
• major stack criteria for VOCs NPRI Part 4
• Reporting of stack parameters required for NPRI
  if stacks ? 50m and emissions meet reporting
  thresholds
• speciation of VOCs NPRI Part 5
• data reconciliation between reported total VOCs
  and reportable individual compounds

7
VOC and Species Reporting

• From CCPA Guideline, Table 2-1

8
VOC Speciation - NPRI Part 5 Substances

• Additional speciation requirements for VOC to
  NPRI beginning with 2003 reporting year
• Applies to the substances listed in Schedule 1,
  Part 5 of the January 2003 Gazette notice
• 34 individual substances
• 20 isomer groups
• 6 other groups and mixtures

9
NPRI Part 5 Substances (contd)

• required to report part 5 substances to NPRI if
• facility has already triggered VOC reporting
  requirements (total VOC to air gt 10 tonnes/yr)
  and
• quantity of Part 5 substance released to air is
  greater than 1 tonne per year
• additional major stack reporting requirement
• total VOC released to air from a stack (height gt
  50m) is greater than 5 tonnes
• report the quantity of each Part 5 substance
  released from each stack (height gt 50m)

10
NPRI Flowchart for Part 5 Substances (draft)
11
VOC Reporting Requirements - NERM

• NERM matches NPRI definition of VOC
• emissions reported as total VOC are to air only
• releases of individual substances which are VOCs
  are to ALL media
• NERM has an additional substance group, VOC
  Mixtures
• for reporting VOC mixtures and individual VOCs
  that are not on the pick list (all media)
• individual VOCs (air) VOC mixtures (air)
  total VOCs (air)

12
Example of VOC reporting thresholds

• A facility releases a mixture which consists of
  14 tonnes of benzene and 2 tonnes of toluene, to
  all media
• the discharge to air is 75 of this amount, from
  a stack with a height of 55 metres above grade
• benzene and toluene are
• both VOCs
• both on NPRI Part 1 and NERM substances list
• both on NPRI Part 5

13
Example of VOC reporting thresholds

• Part 1, NPRI
• employee and concentration thresholds are met
• what does this facility report for Part 1, and to
  what media?
• 14 tonnes benzene, all media, to NERM and NPRI
• 2 tonnes toluene, all media to NERM, and also to
  NPRI if 10 tonnes MPO threshold is met

14
Example of VOC reporting thresholds

• Part 4, NPRI CACs
• what does this facility report for Part 4, and to
  what media?
• 12 tonnes total VOC to air (75 of 16 tonnes), to
  both NERM and NPRI

15
Example of VOC reporting thresholds

• Part 5, NPRI speciated VOCs
• what does this facility report for Part 5, and to
  what media?
• Benzene
• 14 tonnes, all media, to NERM
• 10.5 tonnes, air releases, to NPRI
• toluene
• 2 tonnes, all media, to NERM
• 1.5 tonnes, air releases, to NPRI

16
Example of VOC reporting thresholds

• what does this facility report to NPRI w.r.t.
  stack parameters
• stack height, diameter, velocity, temperature
• total VOCs - 12 tonnes to air (gt 5 tonnes)
• benzene - 10.5 tonnes to air (gt 1 tonne)
• toluene - 1.5 tonnes to air (gt 1 tonne)

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Irreconcilable differences?

• Balance the individual Part 1 Part 5 substances
  with total VOC and aggregate amounts for each
  program
• Check that the amounts are reasonable between
  programs

18
VOC Emission Sources

• process emissions (stacks)
• fugitive emissions (leaking process equipment)
• storage operations
• loading operations
• landfarms
• water effluents
• spills and accidental releases
• combustion processes
• others (e.g. batch operations)

19
General Quantification Methods

• total VOC emissions can be estimated using the
  general methodologies described earlier
• direct measurement (CEMs, PEMs, stack testing)
• emission factors
• mass balance
• emission models and correlations
• emissions of individual VOCs may be estimated by
• speciating total VOCs
• applying the same quantification methods for
  total VOCs to sources which are composed 100 of
  a single substance

20
VOC Emission Sources - Fugitive

• Valves
• Flanges/connectors
• Pump seals
• Compressor seals
• Pressure relief valves to atmosphere
• Open-ended lines and sampling connections

21
Fugitive Emissions - Info Sources

• CCPA Guideline for Quantifying Emissions from
  Chemical Facilities, Section 4 - Fugitives
• CCME, Environmental Code of Practice for the
  Measurement and Control of Fugitive VOC Emissions
  from Equipment Leaks
• CMA (now American Chemistry Council) - Improving
  Air Quality Guidance for Estimating Fugitive
  Emissions (from 1989)

22
Fugitive Emissions - Info Sources (contd)

• U.S. EPA - Protocol for Equipment Leak Emission
  Estimates
• API - Fugitive Emissions from Equipment Leaks II
  Calculation Procedures for Petroleum Industry
  Facilities
• NPI (Australia) - Emission Estimation Technique
  Manual for Fugitive Emissions

23
Fugitive VOC Emissions

• Defining VOC service
• CCME Code equipment streams with at least 10
  VOC by volume
• CCPA members are encouraged to consider streams
  with less than 10 VOC by volume where these may
  contribute to VOC emissions

24
Fugitive Emissions Estimation Requirements

• Develop a count of all component (valves,
  flanges, etc.)
• actual counts from process instrumentation
  diagrams
• model counts by predicting based on number of
  liquid pumps, valves (from CMA, 1989)
• Stream Assignment
• gas/vapour, light liquid, heavy liquid

25
Fugitive VOC Estimation Methods

• Select methodology
• is leak detection and repair (LDAR) program in
  place?
• Methods range from
• SOCMI average emission factors
• (no monitoring required)
• screening ranges
• stratified
• correlation method

increasing accuracy and resource intensity can
result in order of magnitude difference in
estimate
26
Screening Range Method

• Recommended as minimum method for CCPA members

formerly known as leak / no leak method
27
Correlation Method

• Supported by CCPA during review of CCME Code

28
Quantification Methods Fugitive Emissions

• Example
• A process unit at a chemical facility has 500
  valves, 50 compressor seals and 525 connectors
  which are in Gas/Vapour service where the total
  VOC composition exceeds 10 by volume. The unit
  operates for 8 hours per day.

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Fugitive Emissions (contd)
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Fugitive Emissions - Speciation

• May be needed to estimate individual substance
  emissions from total VOC
• use measured data where available
• U.S. EPA SPECIATE program has VOC speciation
  profiles for certain source types or streams

31
Fugitive Emissions - Other Considerations

• Open-ended lines that are capped or otherwise
  plugged or equipped with a 2nd valve
• exempt from CCME Code requirements BUT
• CCPA recommends that emissions from these
  components be included where data is available
• inaccessible components (those which cannot be
  monitored)
• CCPA recommends estimating emissions based on
  average measured leak rate for same components
  associated with the same process unit

32
Emissions from Storage Tanks

• Information Sources
• CCPA Guideline for Quantifying Emissions from
  Chemical Facilities, Section 5 - Storage Tanks
• CCME, Environmental Guidelines for Controlling
  Emissions of VOCs from Aboveground Storage Tanks
• U.S. EPA, AP-42 - Section 7.1 - Organic Liquid
  Storage Tanks
• NPI (Australia) - Emission Estimation Technique
  Manual for Fuel and Organic Liquid Storage
• U.S. EPA TANKS Emission Estimation Software

33
Emissions from Storage Tanks

• Requirements
• Emissions Methodology
• Temperature Data - storage and ambient
• Data on storage tank
• capacity, colour, roof type, seals, fittings,
• Data on material stored
• vapour pressure, composition,
• volume throughput or number of tank turnovers
• Vapour Recovery Systems and Other Emission
  Controls

34
Emissions from Storage Tanks

• Recommended Emissions Methodology
• U.S. EPA AP-42 Section 7.1, Sept 1997 or
• latest TANKS software, (www.epa.gov)
• Temperature Data is required
• average tank storage temperature, if known
• if not
• for non-heated tanks, use average ambient
  temperature for location
• data from Environment Canada weather office

35
Emissions from Storage Tanks

• tank throughput or number of turnovers is needed
• use actual volume throughput if known
• or if number of turnovers is known, calculate
• total annual no. turnovers X
  total tank working
• throughput volume capacity volume
• for surge tanks assume turnover 4 per year, if
  no other information available

36
Emissions from Storage Tanks Speciation

• May be needed to estimate individual substance
  emissions from total VOC
• composition of vapour phase is different from
  liquid phase
• Raoults Law Pi (P)(xi)
• TANKS will do the calculation for you if you
  input the liquid composition
• U.S. EPA SPECIATE program also has VOC speciation
  profiles for certain source types

37
Emissions from Storage Tanks

• Vapour Recovery and Other Emission Controls
• External Controls, e.g. vapour recovery, apply
  percent () control efficiency
• Fixed roof tanks with pressure/vacuum vents,
  TANKS has inputs - user can enter breather vent
  settings or use default values
• Atmospheric tanks blanketted with gas, EPA
  indicates that the gas blanket will not affect
  emissions if the tank is operated near
  atmospheric pressure

38
Emissions from Storage TanksOther Considerations

• Pressurized Tanks
• no appropriate correlations from U.S. EPA or
  Australias NPI
• recommended that members include components
  associated with pressurized tanks in their
  fugitive emissions inventory

39
Emissions from Storage Tanks Other Considerations

• Inorganic Chemical storage
• U.S. EPA equations TANKS developed to estimate
  evaporative losses from organic liquids
• Can be used to model losses from inorganic liquid
  storage tanks, if liquid has a measurable vapor
  pressure

40
Emissions from Loading Operations

• loading losses
• tank trucks
• rail cars
• marine vessel
• drums
• vapour recovery, vapour balancing or other
  controls

41
Emissions from Loading Operations

• Loading Losses
• use site-specific measurements
• if unavailable, refer to
• EPA AP-42 (fifth edition, January 1995),Chapter
  5.2, Transportation and Marketing of Petroleum
  Liquids

42
Emissions from Loading Operations

• LL 124 S P M / T
• where
• LL loading loss, mg VOC/litre of liquid loaded
• M molecular weight of vapours, kg/kgmol
• P true vapour pressure of liquid loaded, kPa
  (absolute)
• T temperature of bulk liquid loaded, oK (oC
  273.15)
• S saturation factor, an experimentally
  determined dimensionless constant (see Table 6-1
  in CCPA Guideline, or AP-42)

43
Emissions from Loading Operations

• Saturation factor

44
Emissions from Loading Operations

• Consider site-specific situations
• loading of pressurized railcars
• tanks equipped with gas blanket
• Loading of drums can be approximated using tank
  truck calculations
• Vapour Recovery
• VOC removal or destruction as a efficiency
  applied to estimated emissions

45
Emissions from Loading Operations Speciation

• May be needed to estimate individual substance
  emissions from total VOC
• use measured data, or composition of liquid
  product, where available
• U.S. EPA SPECIATE program has VOC speciation
  profiles for certain source types

46
Sources and Quantification Methods - Combustion

• VOCs and individual substances from combustion
  sources (e.g. boilers and heaters)
• AP-42 emission factors available
• check if published factors are for TOC or VOC
• e.g. AP-42 Table 1.4-2

47
Sources and Quantification Methods - Combustion

• VOCs and individual substances from combustion
  sources (e.g. boilers and heaters)
• emission factors for specified organic compounds,
  trace elements and metals
• some are listed in AP-42 (e.g. PAHs, metals)
• others can be found in U.S. EPA Locating and
  Estimating series (e.g. dioxins and furans,
  mercury, lead, PAHs)

48
Sources and Quantification Methods - Combustion
Example

• Use of speciation profiles to speciate VOC
  emissions
• Profile Number 003, External Combustion Boiler
  Natural Gas, from the U.S. EPA SPECIATE
  program, of the TOC estimate.

49
Sources and Quantification Methods - Combustion
Example
50
Sources and Quantification Methods - Flares

• To estimate VOCs from flares
• the composition of the flared gas is needed
• a general assumption from U.S. EPA, in the
  absence of site-specific information, is that 0.5
  wt of hydrocarbons are not combusted
• this is based on a 98 destruction efficiency

51
Sources and Quantification Methods - Other
Sources of VOCs and Reportable Substances

• Wastewater
• Spills
• Landfarm, landtreatment
• Underground injection
• Batch Processes

Covered in Quantification of Other
Sources (Afternoon Session)
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CEPA 1999 Toxic Designation

• Section 64 of CEPA 1999
• substance enters/may enter the environment in a
  quantity/concentration or under conditions that
• have or may have an immediate or long-term
  harmful effect on the environment or its
  biological diversity
• constitute or may constitute a danger to the
  environment on which life depends or
• constitute or may constitute a danger in Canada
  to human life or health.

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NPRI VOC Speciation

• Remaining VOCs, not required to be reported as
  individual substances under Part 1 or Part 5
• Identify reactivity of the remaining VOCs, in
  aggregate, as
• high
• medium
• low
• unknown

This requirement was repealed in Amendment
published in the Canada Gazette Part I, Jan. 17,
2004