Gas analysis

Solutions · Recycling

Gas analysis for recycling plants

Q: Which gases are measured in recycling plants?

That depends on the material stream. In refrigerator recycling, you measure refrigerants such as R11 and R12, cyclopentane and oxygen. In plastics and pyrolysis, it is methane, carbon dioxide, carbon monoxide and oxygen. In battery and aluminium processing, it is hydrogen. In organic waste and landfill, you measure methane, carbon dioxide, oxygen and hydrogen sulphide.

Q: How are CFCs and pentane measured in refrigerator recycling?

With infrared (NDIR) in the dual-pressure reference method. In the raw gas, at the shredder for example, a short cell measures the high concentrations. Depending on the number of components, you use the GA 220 or the GA 320. In the exhaust air, the GA 320 is usually used. It covers up to six IR components and has humidity compensation. Its long cell also captures traces. The refrigerants correct each other.

Q: How do you identify the blowing agent in refrigerator insulation foam?

With the Smart Control 300. At the robot, it detects by infrared whether the insulation foam was blown with R11, R141b or c-pentane. It passes the result to your control system via switching outputs or fieldbus. Your diverter sends the refrigerator to the right line. A new result is available every 20 seconds.

Q: Why is oxygen measured in refrigerator recycling?

The shredder runs under nitrogen. This prevents released blowing agents such as pentane from forming an ignitable mixture. The oxygen content shows whether inerting holds. The GA 210 O₂ paramagnetic measures it; a gas cooler dries the sample gas beforehand. A zirconia sensor is ruled out here: CFCs, sulphur compounds, silicones and pure nitrogen damage it.

Q: Is there a certified measurement for CFC emissions?

There is no certified measuring system for CFCs in the exhaust air of refrigerator recycling plants. Our exhaust air measurement works according to the state of the art, usually with the GA 320. We clarify with you which measurement your authority accepts.

Q: How is hydrogen measured in battery recycling?

By thermal conductivity, for example: the FTC300 measures hydrogen in nitrogen or air from 0–0.5 % up to 100 %. Which measurement fits depends on the full gas composition, including the solvents. We check that using your information sheet.

Q: Which device measures landfill gas?

Permanently installed, the BioBasic measures CH₄, CO₂, O₂ and H₂S at up to five measuring points. For spot checks at wells and pipes, use the portable GAP 100.

Q: May the device stand in the hazardous area?

We measure extractively: a pump draws the gas through the sampling line to the device. The device stands outside the hazardous area. Only the sampling point remains at the measuring location.

Q: Which solution fits my recycling plant?

That depends on the material stream, the gases and the measuring ranges. The configurator on this page suggests the right devices. Tory, our digital advisor, asks for the details and takes you to a quote request. Or you talk to our team directly.

Fridges, plastics, metal, batteries, organic waste or landfill: you bring materials back into the loop. Gases determine safety, recovery and clean exhaust air. Process measurement technology from Fresenius Instruments keeps these gases in view.

Gas analysis in recycling measures the gases that arise or are used when materials are recovered. In fridge recycling, these are refrigerants and blowing agents. During inerting under nitrogen, it is oxygen. In organic waste and landfill, they are hydrogen, methane and carbon dioxide. The measurement is extractive: the device stands outside the hazardous area.

Explore measuring points Request advice

Tracesrefrigerants down to the milligram range – in clean gas
Raw gashigh concentrations right at the shredder, too
5material streams, one measurement partner

Interactive loop

Five material streams – which gas matters where

Pick a material stream or filter by substance. Below, you see which measurement technology works there.

Measuring point 1

Refrigerators

R11/R12Refrigerants (CFC)
c-C₅H₁₀Cyclopentane
O₂Oxygen

In the raw gas, at the shredder for example, refrigerants and pentane reach concentrations in the range of grams per cubic metre. Depending on the number of components, the GA 220 or the GA 320 measures them. In the exhaust air, the GA 320 is usually used. It covers up to six IR components and has humidity compensation. You monitor oxygen during inerting with the GA 210 O₂ paramagnetic. At the robot, the Smart Control 300 checks which blowing agent was used in the insulation foam.

GA 220 More on this point

From raw gas down to traces in clean gas
Exhaust air usually with the GA 320: up to six IR components
Refrigerants correct each other, with humidity compensation in clean gas
Paramagnetic O₂ for inerting (GA 210 O₂)

Measuring point 2

Plastics & pyrolysis

CH₄Methane
CO₂Carbon dioxide
COCarbon monoxide
O₂Oxygen

The GA 220 measures several IR-active components such as CH₄, CO₂ and CO in one device, even at high concentrations. You monitor oxygen paramagnetically with the GA 210 O₂. A sample gas cooler dries humid gas before measurement.

GA 220 More on this point

NDIR dual-pressure reference method for CH₄, CO₂ and CO
Several components in one device, including the vol.% range
Paramagnetic O₂ (GA 210 O₂)
Full analysis including H₂ and higher hydrocarbons via our partner network

Measuring point 3

Metal & batteries

H₂Hydrogen
O₂Oxygen
NONitric oxide
SO₂Sulphur dioxide

The FTC300, for example, measures hydrogen by thermal conductivity, from 0–0.5 % up to 100 %. Which solution fits depends on the full gas composition. For NO and SO₂ as a process measurement, we can fit the GA 220 with a UV cell.

FTC300 More on this point

H₂ in nitrogen or air 0–100 %, smallest range 0–0.5 % (FTC300)
NO and SO₂ as a process measurement, smallest range 0–50 ppm (GA 220 with UV cell)
Values via RS232 and Modbus TCP to your control system (FTC300)
Certified emission measurement via our partner network

Measuring point 4

Organic waste & digestion

CH₄Methane
CO₂Carbon dioxide
O₂Oxygen
H₂SHydrogen sulphide
H₂Hydrogen

The BioBasic measures CH₄, CO₂, O₂, H₂S and H₂ at up to five measuring points with one device – from digestion to the CHP unit.

BioBasic More on this point

CH₄ and CO₂ 0–100 vol.%, O₂ 0–30 vol.%
H₂S 0–2,000 ppm, optionally up to 10,000 ppm; H₂ 0–10,000 ppm
Up to five measuring points per device
Calibration once a year

Measuring point 5

Landfill

CH₄Methane
CO₂Carbon dioxide
O₂Oxygen
H₂SHydrogen sulphide

Permanently installed, the BioBasic measures landfill gas at up to five measuring points. For spot checks at wells and pipes, use the portable GAP 100.

GAP 100 More on this point

GAP 100: CH₄ 0–100 vol.%, CO₂ 0–65 vol.%
GAP 100: H₂S 0–2,000 ppm, O₂ 0–25 vol.%
BioBasic: up to five fixed measuring points
Measured extractively, the device stands outside the Ex zone

Measuring points and solutions

Five material streams – and the right measurement technology for each

Discarded refrigerators lined up at a recycling yard

Measuring point 01

Refrigerator recycling: refrigerants, pentane and oxygen

R11/R12Refrigerants (CFC)
c-C₅H₁₀Cyclopentane
O₂Oxygen

Refrigerators contain refrigerants, and their insulation contains blowing agents. Older units contain CFCs such as R11 and R12, newer ones cyclopentane. The shredder breaks the units down under nitrogen. This releases the gases, and the plant recovers them. The exhaust air must stay clean.

Solution: In the raw gas, at the shredder for example, refrigerants and pentane reach concentrations in the range of grams per cubic metre. Depending on the number of components, the GA 220 or the GA 320 measures them. In the exhaust air, the GA 320 is usually used. It covers up to six IR components and has humidity compensation. You monitor oxygen during inerting with the GA 210 O₂ paramagnetic. At the robot, the Smart Control 300 checks which blowing agent was used in the insulation foam.

From raw gas down to traces in clean gas
Exhaust air usually with the GA 320: up to six IR components
Refrigerants correct each other, with humidity compensation in clean gas
Paramagnetic O₂ for inerting (GA 210 O₂)
Testing insulation foam with the Smart Control 300

Testing and sorting insulation foam → Measuring refrigerants → Measuring cyclopentane →

Pyrolysis plant with reactor and condensing column, bales of plastic waste in front

Measuring point 02

Plastics and pyrolysis: gas components in view

CH₄Methane
CO₂Carbon dioxide
COCarbon monoxide
O₂Oxygen

Pyrolysis breaks down plastics in the absence of air. The pyrolysis gas contains methane, carbon dioxide and carbon monoxide, among other components. Oxygen has no place in the reactor.

Solution: The GA 220 measures several IR-active components such as CH₄, CO₂ and CO in one device, even at high concentrations. You monitor oxygen paramagnetically with the GA 210 O₂. A sample gas cooler dries humid gas before measurement.

NDIR dual-pressure reference method for CH₄, CO₂ and CO
Several components in one device, including the vol.% range
Paramagnetic O₂ (GA 210 O₂)
Full analysis including H₂ and higher hydrocarbons via our partner network

Measuring carbon monoxide →

Dismantled battery modules and cells in crates, a conveyor with shredded material behind

Measuring point 03

Metal and batteries: hydrogen and process gases

H₂Hydrogen
O₂Oxygen
NONitric oxide
SO₂Sulphur dioxide

Hydrogen can form when batteries and aluminium are processed. Nitrogen oxides and sulphur dioxide form when scrap is melted. If you detect these gases early, you can control extraction and process.

Solution: The FTC300, for example, measures hydrogen by thermal conductivity, from 0–0.5 % up to 100 %. Which solution fits depends on the full gas composition. For NO and SO₂ as a process measurement, we can fit the GA 220 with a UV cell.

H₂ in nitrogen or air 0–100 %, smallest range 0–0.5 % (FTC300)
NO and SO₂ as a process measurement, smallest range 0–50 ppm (GA 220 with UV cell)
Values via RS232 and Modbus TCP to your control system (FTC300)
Certified emission measurement via our partner network

Measuring hydrogen →

Compost windrow in front of a digestion plant

Measuring point 04

Organic waste and digestion: measuring biogas

CH₄Methane
CO₂Carbon dioxide
O₂Oxygen
H₂SHydrogen sulphide
H₂Hydrogen

Digestion turns organic waste into biogas. It contains methane and carbon dioxide. Hydrogen sulphide, oxygen and hydrogen are also present. They show how the biology is doing.

Solution: The BioBasic measures CH₄, CO₂, O₂, H₂S and H₂ at up to five measuring points with one device – from digestion to the CHP unit.

CH₄ and CO₂ 0–100 vol.%, O₂ 0–30 vol.%
H₂S 0–2,000 ppm, optionally up to 10,000 ppm; H₂ 0–10,000 ppm
Up to five measuring points per device
Calibration once a year

BioBasic

Gas analysis for biogas plants →

Measuring point 05

Landfill: measuring landfill gas fixed and portable

CH₄Methane
CO₂Carbon dioxide
O₂Oxygen
H₂SHydrogen sulphide

Over the years, landfill gas made of methane and carbon dioxide forms in the landfill body. Oxygen shows whether air gets in. Hydrogen sulphide puts a strain on pipes and gas utilisation.

Solution: Permanently installed, the BioBasic measures landfill gas at up to five measuring points. For spot checks at wells and pipes, use the portable GAP 100.

GAP 100: CH₄ 0–100 vol.%, CO₂ 0–65 vol.%
GAP 100: H₂S 0–2,000 ppm, O₂ 0–25 vol.%
BioBasic: up to five fixed measuring points
Measured extractively, the device stands outside the Ex zone

Measuring methane →

Application example · Refrigerator recycling

Testing insulation foam: which blowing agent was used?

This is how you use our process measurement technology in a refrigerator recycling plant.

The task
The insulation of refrigerators contains a blowing agent: R11 or R141b in older units, c-pentane in newer ones. The blowing agent decides the further route of the unit. But you cannot tell it from the outside.
The solution
At the robot, the Smart Control 300 checks the insulation foam by infrared (NDIR) and identifies the blowing agent: R11, R141b or c-pentane. It sends the result to your control system via switching outputs or fieldbus. Your diverter then sets the line.
The result
Every unit goes to the right line automatically. The Smart Control 300 identifies the blowing agent; it does not measure a concentration. It delivers a new result every 20 seconds. You need no lab sample and, in operation, no test gas.

20 sto the next result
4–8switching outputs for your diverter, plus fieldbus
3blowing agents in view: R11, R141b, c‑pentane

Discuss your application To the Smart Control 300

Smart Control 300 c-pentane → Pentane line

1 Detect Which blowing agent is in the foam?
2 Classify The result sets the recycling route.
3 Route Your diverter sets the right line.

Schematic illustration. We define together with you how your lines are split.

Application example · Inerting

While shredding: only as much nitrogen as needed

This is how you use our process measurement technology when shredding refrigerators and aerosol cans.

The task
Shredding releases flammable propellants and refrigerants. That is why the shredder runs under nitrogen. The UK Environment Agency sets out exactly this for treating aerosol cans: inerted operation, automatic shutdown when oxygen is too high, and continuous O₂ monitoring.
The solution
The GA 210 O₂ paramagnetic measures oxygen extractively and selectively. It also works where zirconia sensors are ruled out: CFCs, sulphur compounds, silicones and pure nitrogen with less than 0.2 vol.% O₂ damage these sensors. Your control system doses nitrogen until the reading is in the target range. Then it keeps the reading there.
The result
You use nitrogen only when it is needed. You always know the real oxygen value. If it rises, your control system can react at once. Your process runs safely and without unnecessary purging time.

1 sto the next reading
< ±0.1vol.% O₂ zero deviation per week
O₂paramagnetic, no consumable sensor

Discuss your application To the GA 210 O₂ paramagnetic

GA 210 O₂ paramagnetic 3.8 vol.% → in the target range, nitrogen off

1 Measure The real O₂ value, every second.
2 Dose Nitrogen only when needed.
3 Hold Stay in the target range.

Schematic illustration. You set the target range and shutdown threshold for your plant.

Refrigerator recycling in detail

Five orders of magnitude – from raw gas to exhaust air

In the raw gas, at the shredder for example, refrigerants and pentane are present in grams per cubic metre. In the exhaust air, only a few milligrams should remain. Our NDIR measurement covers both with two cells: the short one measures concentrated raw gas, the long one measures clean gas. Move the slider and see which cell measures your concentration.

Shredded refrigerator material with housing parts and insulation foam on the conveyor behind the shredder

And while shredding: oxygen

The shredder runs under nitrogen. The GA 210 O₂ paramagnetic shows you whether oxygen stays low. A gas cooler dries the sample gas before measurement.

Concentration 50 mg/m³

Trace range

Raw gas range

Long clean gas cell for traces in clean gas and exhaust air, with humidity compensation
Short raw gas cell for high concentrations in raw gas

Schematic illustration. The refrigerants affect each other in the measurement (cross-sensitivity) – our cross-sensitivity compensation calculates this out. Measuring ranges depend on gas and configuration – we design them for your plant together with you.

Configurator

Which measurement technology does your material stream need?

Choose your measuring tasks. On the right, you see the matching measurement technology. One click takes your selection straight into your enquiry.

Digesters of a digestion plant against a blue sky

Organic waste & landfill

From waste to energy – measured every step of the way

Do you digest organic waste or capture landfill gas? Then methane, carbon dioxide, oxygen and hydrogen sulphide matter. The BioBasic measures these gases permanently at up to five points. The GAP 100 measures them on the move, wherever you are.

BioBasic: CH₄, CO₂, O₂, H₂S, H₂ – up to five measuring points
GAP 100: CH₄, CO₂, H₂S, O₂ – portable
All about biogas: measuring points, devices and the biogas calculator

To the biogas page

Your benefits

What our measurement technology gives you

Safety for plant and team

Oxygen, hydrogen and flammable gases in view – you act before it gets critical.
Precise across five orders of magnitude

From concentrated raw gas down to traces in the exhaust air – NDIR with the right cell.
Protection for your plant

Measured extractively: the device stands outside the hazardous area. The sampling line brings the gas to it.
Less effort in operation

Robust NDIR technology with automatic zero correction. The BioBasic needs calibration just once a year.
Worldwide service

Our service team maintains and calibrates your devices. You can also send devices in for maintenance.

Overview

Measuring point, gases and solution at a glance (extract)

Measuring point	Gases	Solution
Refrigerators	R11/R12 · c-C₅H₁₀ · O₂	GA 320, GA 220, GA 210 O₂ paramagnetic, Smart Control 300
Plastics & pyrolysis	CH₄ · CO₂ · CO · O₂	GA 220, GA 210 O₂ paramagnetic, Gas cooler RCI 100
Metal & batteries	H₂ · O₂ · NO · SO₂	FTC300, GA 220
Organic waste & digestion	CH₄ · CO₂ · O₂ · H₂S · H₂	BioBasic
Landfill	CH₄ · CO₂ · O₂ · H₂S	BioBasic, GAP 100

As of 20.10.2026. The datasheets and brochures of each product are authoritative.

Products

Process measurement technology for recycling plants

Complete system

From sampling to your control system

Open system cabinet with gas analysis, sample conditioning and controls

Measured extractively

A pump draws the gas through the sampling line to the device. The device stands outside the hazardous area. Only the sampling point remains at the measuring location.
Sample gas conditioned

A sample gas cooler such as the RCI 100 dries humid gas before measurement. This keeps values stable with NDIR and paramagnetic O₂ measurement.
Values straight to your control system

Via 4–20 mA, relays or fieldbus. Your data stays with you.
Delivered as a system cabinet

Gas analysis, conditioning and controls come ready-wired in one cabinet. On request, we tailor it to your plant.

To our service

Read on

Recycling topics in detail

Advice

Tory – your advisor for the recycling plant

Refrigerators, pyrolysis, batteries or landfill? Tory asks for material stream, gases and measuring ranges in a few steps. Tory then takes you to the right solution or straight to a meeting with our team.

The right solution for each material stream
GA 220, GA 320, GA 210 O₂, FTC300 or BioBasic
Direct path to a quote request

FAQ

Frequently asked questions on gas analysis in recycling

Which gases are measured in recycling plants?

That depends on the material stream. In refrigerator recycling, you measure refrigerants such as R11 and R12, cyclopentane and oxygen. In plastics and pyrolysis, it is methane, carbon dioxide, carbon monoxide and oxygen. In battery and aluminium processing, it is hydrogen. In organic waste and landfill, you measure methane, carbon dioxide, oxygen and hydrogen sulphide.

How are CFCs and pentane measured in refrigerator recycling?

With infrared (NDIR) in the dual-pressure reference method. In the raw gas, at the shredder for example, a short cell measures the high concentrations. Depending on the number of components, you use the GA 220 or the GA 320. In the exhaust air, the GA 320 is usually used. It covers up to six IR components and has humidity compensation. Its long cell also captures traces. The refrigerants correct each other.

How do you identify the blowing agent in refrigerator insulation foam?

With the Smart Control 300. At the robot, it detects by infrared whether the insulation foam was blown with R11, R141b or c-pentane. It passes the result to your control system via switching outputs or fieldbus. Your diverter sends the refrigerator to the right line. A new result is available every 20 seconds.

Why is oxygen measured in refrigerator recycling?

The shredder runs under nitrogen. This prevents released blowing agents such as pentane from forming an ignitable mixture. The oxygen content shows whether inerting holds. The GA 210 O₂ paramagnetic measures it; a gas cooler dries the sample gas beforehand. A zirconia sensor is ruled out here: CFCs, sulphur compounds, silicones and pure nitrogen damage it.

Is there a certified measurement for CFC emissions?

There is no certified measuring system for CFCs in the exhaust air of refrigerator recycling plants. Our exhaust air measurement works according to the state of the art, usually with the GA 320. We clarify with you which measurement your authority accepts.

How is hydrogen measured in battery recycling?