FTIR Stack Gas Analyzer

What is the FTIR Stack Gas Analyzer?

A fixed or portable spectrometer that resolves many flue gas components at once from a single infrared spectrum. It is the right choice for waste incineration and complex emissions where many gases, including HCl and NH3, must be monitored together.

Overview

The FTIR analyzer passes infrared light through a heated sample cell and records the full spectrum with an interferometer, then applies a chemometric or classical least-squares model to quantify each gas of interest. Because water and carbon dioxide absorb strongly across the mid-infrared, their spectra are included in the model rather than removed, which allows hot-wet measurement without a dryer. This lets the instrument measure water-soluble and reactive species such as hydrogen chloride, ammonia, hydrogen fluoride and nitrous oxide that would be lost in a cooler. Detection limits from low parts per million to sub-parts per million and up to dozens of components are achievable in one unit. Heated cells and lines avoid condensation, and calibration uses reference spectra and gas standards. The technique is well suited to waste incinerators, cement kilns and chemical plants with varied and overlapping emission profiles.

How does it work?

Stack gas analyzers combine gas extraction or in-situ probes with one or more detection techniques. Electrochemical cells and zirconia sensors measure oxygen and select gases in portable instruments, while non-dispersive infrared detectors quantify carbon monoxide, carbon dioxide and sulfur dioxide by absorption at characteristic wavelengths. Chemiluminescence or ultraviolet absorption is used for nitrogen oxides. Fourier transform infrared analyzers resolve many gases at once from a single spectrum, including hydrogen chloride, ammonia and moisture. Tunable diode laser analyzers scan a narrow absorption line in situ and give fast, interference-resistant readings of species such as ammonia or hydrogen chloride. A heated sample line and conditioning system remove water and dust so the composition reaching the detector represents the stack. Flow monitors, temperature probes and data acquisition complete a continuous emission monitoring system.

What are the key features?

• Single spectrometer quantifies dozens of gases from one spectrum.
• Hot-wet measurement avoids loss of HCl, NH3 and other soluble gases.
• No drying step means water is treated as a measured component.
• Heated cell and sample line prevent condensation and corrosion.
• Chemometric models handle overlapping spectral absorptions.
• Suitable for reactive and acidic species that other detectors miss.

What are the technical specifications?

A typical ftir stack gas analyzer configuration offers measurement principle of Fourier transform infrared spectroscopy, spectral range of 600–4500 cm⁻¹ (mid-infrared), measurable components of Up to 50 gases including HCl, NH3, N2O, HF, lower detection limit of < 1 ppm for many components, cell temperature of 180–200 °C, heated and response time of 10–60 s, configurable. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The FTIR Stack Gas Analyzer is used in waste incineration emission monitoring, cement kiln and glass furnace analysis, chemical plant process and abatement control and ammonia slip and DeNOx optimization. Across the wider Stack Gas Analyzers class, laboratories also deploy it for power plant continuous emission monitoring, cement and steel plant flue gas analysis and waste incineration emission control.

Which standards and certifications apply?

Relevant standards and methods include EN 14181, ISO 16911-1, ISO 12039, US EPA 40 CFR Part 60 Appendix B, HJ 75 and GB 13223. Certification candidates for this model are CE, China environmental monitoring instrument certification and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Locate the sampling point where the gas is well mixed and within the acceptable temperature range, and keep the heated line above the acid dew point to prevent sulfur trioxide and water condensation. Calibrate with certified standards and check linearity, and run zero and span checks on the schedule required by the quality assurance standard. For continuous systems, annual surveillance audits and periodic reference method comparisons are commonly required. Replace filters, dryer components and pump parts regularly, and verify flow and temperature sensors. Protect optics and sensors from dust and corrosion, and record all calibration and maintenance events. Document the measurement uncertainty and apply the applicable quality assurance levels for reporting.

How do I select the right FTIR Stack Gas Analyzer?

Select FTIR when many gases, especially water-soluble or reactive species, must be measured together in one instrument. For simple CO, NOx and SO2 limits, an NDIR CEMS is less costly. In an RFQ, specify the component list and detection limits, cell temperature, response time and whether wet or dried sample is used.

How does it compare with other Stack Gas Analyzers variants?

Choose by purpose: portable analyzers for combustion tuning and periodic checks, fixed systems for continuous emission compliance. Define the gas list and the ranges: oxygen typically 0 to 25 percent, carbon monoxide 0 to 1000 ppm, sulfur dioxide 0 to 500 ppm and nitrogen oxides 0 to 500 ppm for many combustion sources, with wider ranges for waste incineration and cement kilns. Select the extraction or in-situ format according to the need for fast response, the corrosiveness of the gas and the number of components. For multi-component compliance, NDIR plus chemiluminescence or FTIR systems are standard; for specific acidic or reactive species, TDLAS offers low interference. Confirm heated sampling, dust and moisture removal, calibration gas arrangements and conformity with the applicable method.