🌿 Total gaseous organic carbon (TVOC) in waste gases — FID method
In short
Continuous measurement of the mass concentration of volatile organic compounds in waste gases, expressed as total organic carbon (TVOC, mg C/m³), with an analyser with a flame ionisation detector fed through a heated (≥ 180 °C) probe, filter and sampling line; calibration with propane, range up to 1000 mg/m³. The test is performed according to PN-EN 12619:2013-05 (EN 12619:2013); Range: up to 1000 mg/m³ as C (under reference conditions, dry gas). The procedure comprises 6 steps; it is used for: Periodic and control measurements of TVOC emissions from waste incineration and co-incineration plants, Installations using organic solvents: paint shops, printing works, manufacture of paints and adhesives, surface treatment, drying plants, The reference method for the calibration and the control of permanently installed measuring systems (AMS) for TVOC in accordance with EN 14181.
At a glance
- Standard: PN-EN 12619:2013-05 (EN 12619:2013)
- Category: Environment
- Procedure steps: 6
- Range: up to 1000 mg/m³ as C (under reference conditions, dry gas)
- Temperature of the sampling system: ≥ 180 °C throughout (PTFE lines max. 200 °C); residence time < 60 s
- Gases: fuel: hydrogen, H₂/He or H₂/N₂; zero gas and combustion air: TVOC < 0.2 mg C/m³ or purity 99.998 %; span gas: propane in synthetic air (uncertainty ≤ 2 %), about ½ of the ELV or 50–90 % of the range
Overview
EN 12619:2013 specifies a method with a flame ionisation detector (FID) intended as the standard reference method for the measurement of the mass concentration of organic substances in the form of gases and vapours (expressed as TVOC) in emissions from stationary sources — e.g. waste incineration plants and processes using solvents, measurements of emissions under Directive 2010/75/EU — over the range of concentrations up to 1000 mg/m³. The standard gives the requirements for the FID instrument and the procedures for its operation; the result is expressed in mg/m³ as total carbon. It does not apply to permanently installed automated measuring systems (AMS). The 2013 edition replaced EN 12619:1999 and EN 13526:2001. In Poland the regulation of the Minister of Climate and Environment on the requirements for carrying out measurements of emissions indicates PN-EN 12619 as the reference method for organic substances in the form of gases and vapours expressed as total organic carbon.
The advantage of the FID is its response to compounds of organic carbon together with a negligible response to the inorganic components of flue gases (CO, CO₂, NO, H₂O). The ionisation current depends on the number of carbon atoms in the compounds burnt, on the kind of bonds (straight or branched chain) and on the partners of the bonds — hence the response factors determined with test gases; the range of the instrument is set with propane, for which the response factor has been taken as equal to 1.00.
Method principle
The flame ionisation detector ionises the organically bound carbon atoms in a hydrogen flame; the sample gas is introduced into the flame, to which a constant polarising voltage has been applied, and the resulting ionisation current — proportional to the number of carbon atoms — is measured and amplified. A partial stream of the waste gases, representative of the composition of the main stream, is fed directly to the analyser through a probe, a heated particulate filter (which protects the burner against clogging) and a heated sampling line — the whole heated to at least 180 °C in order to avoid condensation; the residence time of the sample in the system is below 60 s, and with long lines an external pump with a bypass is recommended. The sampling system is made of stainless steel, PTFE or fluorinated polypropylene (other materials only after their inertness has been demonstrated). In front of the filter, at the inlet of the probe, there is an inlet for zero gas and span gas for checking the whole system. The analyser and the sampling system must meet the requirements of EN 15267-3; the planning and the strategy of the measurements — in accordance with EN 15259.
Applications
- Periodic and control measurements of TVOC emissions from waste incineration and co-incineration plants
- Installations using organic solvents: paint shops, printing works, manufacture of paints and adhesives, surface treatment, drying plants
- The reference method for the calibration and the control of permanently installed measuring systems (AMS) for TVOC in accordance with EN 14181
- Measurements of emissions for integrated permits and for reporting under Directive 2010/75/EU
- Testing of the effectiveness of thermal and catalytic afterburners and of adsorbers
Key parameters
| Parameter | Value |
|---|---|
| Range | up to 1000 mg/m³ as C (under reference conditions, dry gas) |
| Temperature of the sampling system | ≥ 180 °C throughout (PTFE lines max. 200 °C); residence time < 60 s |
| Gases | fuel: hydrogen, H₂/He or H₂/N₂; zero gas and combustion air: TVOC < 0.2 mg C/m³ or purity 99.998 %; span gas: propane in synthetic air (uncertainty ≤ 2 %), about ½ of the ELV or 50–90 % of the range |
| Checks (table 1 of the standard) | response time ≤ 200 s (every series); repeatability at zero and at span ≤ 2 % (once a year); linearity ≤ 2 %; influence of oxygen ≤ 2 %; zero and span drift < 5 % (at the beginning and at the end of the period, at least once a day); leak-tightness and check of the sampling system — every series |
| Response factor | propane = 1.00; for other compounds determined in accordance with annexes A and B |
| Limit of detection | twice the standard deviation at zero (definition 3.2) |
Standard
- Standard number
- PN-EN 12619:2013-05 (EN 12619:2013)
- Title (PL)
- Emisja ze źródeł stacjonarnych — Oznaczanie stężenia masowego ogólnego gazowego węgla organicznego — Metoda ciągłego pomiaru z detekcją płomieniowo-jonizacyjną
- Title (EN)
- Stationary source emissions — Determination of the mass concentration of total gaseous organic carbon — Continuous flame ionisation detector method
Step-by-step procedure
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Planning
Establish the objective of the measurement, the measurement section and the place of measurement and the plan in accordance with EN 15259; establish the expected concentrations, the oxygen content and the humidity of the gases, in order to choose the range of the analyser and the span gas.
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Assembly and heating up of the system
Install the probe, the heated filter and the sampling line; heat the whole system up to at least 180 °C and start the FID according to the instructions of the manufacturer (ignition of the flame, stabilisation).
-
Adjustment of the analyser
At the beginning of the measurement period feed zero gas and span gas directly to the analyser (bypassing the sampling system): set the zero, set the span, check the zero again — the deviation of the zero not greater than twice the repeatability at zero; repeat if necessary.
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Check of the sampling system
In every series of measurements carry out a leak test and a check of the sampling system — feed zero gas and span gas through the inlet at the tip of the probe (in front of the filter) and compare the response with that of direct feeding; determine the response time (≤ 200 s).
-
Measurement
Carry out a continuous recording of the concentration of TVOC over the required averaging time, checking the temperature of the line and the flow; record in parallel the parameters of the gases needed for the conversion to reference conditions (O₂, humidity, temperature, pressure).
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Drift check and calculations
At the end of the measurement period (and at least once a day) check the zero and span drift (< 5 %). Convert the results to mg C/m³ under reference conditions for dry gas and, if required, to the reference oxygen content; estimate the uncertainty (annex C).
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| FID analyser complying with the requirements of EN 15267-3 | with a system for the collection and the evaluation of the data; fuel gas according to the certification in accordance with EN 15267-1, -2, -3 | — |
| Heated sampling probe of stainless steel or PTFE | with an inlet for zero gas and span gas at the tip of the probe, in front of the filter | — |
| Heated particulate filter | in front of the sampling line; cleaned or replaced in every series depending on the dust load | — |
| Heated sampling line (≥ 180 °C) with regulation and control of the temperature | PTFE up to 200 °C or stainless steel; optionally a heated external pump with a bypass | — |
| Cylinders with gases: fuel (H₂ or a mixture), zero gas, span gas propane | with analytical certificates; the fuel lines of steel, copper or PTFE | — |
| Equipment for checking the response time, the leak-tightness and the drift | in accordance with annex A of the standard | — |
Health and safety (OHS)
- Hydrogen as the fuel gas — a leak-tight installation, the cylinders secured, no open flames; ignition of the FID according to the instructions (annex D of the standard)
- The heated parts of the sampling system (≥ 180 °C) are liable to cause burns; insert the probe into the port wearing heat-resistant gloves
- Work on the measurement platform of the stack: protection against falling, protection of the respiratory tract where the port is not leak-tight
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN 12619:2013-05 (EN 12619:2013) — “Stationary source emissions — Determination of the mass concentration of total gaseous organic carbon — Continuous flame ionisation detector method”.
How does this method work?
The flame ionisation detector ionises the organically bound carbon atoms in a hydrogen flame; the sample gas is introduced into the flame, to which a constant polarising voltage has been applied, and the resulting ionisation current — proportional to the number of carbon atoms — is measured and amplified. A partial stream of the waste gases, representative of the composition of the main stream, is fed directly to the analyser through a probe, a heated particulate filter (which protects the burner against clogging) and a heated sampling line — the whole heated to at least 180 °C in order to avoid condensation; the residence time of the sample in the system is below 60 s, and with long lines an external pump with a bypass is recommended.
What is the measuring range and accuracy?
Range: up to 1000 mg/m³ as C (under reference conditions, dry gas); Temperature of the sampling system: ≥ 180 °C throughout (PTFE lines max. 200 °C); residence time < 60 s; Gases: fuel: hydrogen, H₂/He or H₂/N₂; zero gas and combustion air: TVOC < 0.2 mg C/m³ or purity 99.998 %; span gas: propane in synthetic air (uncertainty ≤ 2 %), about ½ of the ELV or 50–90 % of the range; Checks (table 1 of the standard): response time ≤ 200 s (every series); repeatability at zero and at span ≤ 2 % (once a year); linearity ≤ 2 %; influence of oxygen ≤ 2 %; zero and span drift < 5 % (at the beginning and at the end of the period, at least once a day); leak-tightness and check of the sampling system — every series.
How long does the test take?
The procedure comprises 6 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
FID analyser complying with the requirements of EN 15267-3, Heated sampling probe of stainless steel or PTFE, Heated particulate filter, Heated sampling line (≥ 180 °C) with regulation and control of the temperature, Cylinders with gases: fuel (H₂ or a mixture), zero gas, span gas propane, Equipment for checking the response time, the leak-tightness and the drift.
Where is this test used?
Periodic and control measurements of TVOC emissions from waste incineration and co-incineration plants; Installations using organic solvents: paint shops, printing works, manufacture of paints and adhesives, surface treatment, drying plants; The reference method for the calibration and the control of permanently installed measuring systems (AMS) for TVOC in accordance with EN 14181; Measurements of emissions for integrated permits and for reporting under Directive 2010/75/EU; Testing of the effectiveness of thermal and catalytic afterburners and of adsorbers.
What safety precautions apply?
Hydrogen as the fuel gas — a leak-tight installation, the cylinders secured, no open flames; ignition of the FID according to the instructions (annex D of the standard); The heated parts of the sampling system (≥ 180 °C) are liable to cause burns; insert the probe into the port wearing heat-resistant gloves; Work on the measurement platform of the stack: protection against falling, protection of the respiratory tract where the port is not leak-tight.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN 12619.