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Altech Environmental

HCl - Hydrochloric Acid Monitoring Systems


Altech is unique in that we have supplied HCl monitoring systems with great success for many years. HCl CEMS are primarily used compliance and scrubber efficiency determination.

Why is HCl so difficult to measure? Its high reactivity, water solubility and relatively high acid dew point make sample handling and calibration especially challenging. HCl can measured on a dry basis provided the sample is conditioned using a permeation dryer, which is ideal for low level measurements, or on a hot/wet basis. Hot/wet HCl analyzers may experience difficulties with low level measurements due to moisture interference in certain applications.

Altech offers 3 solutions for HCl analysis:

The MIR 9000 and MIR-IS series analyzers use non-dispersive infrared technology (NDIR) using the Gas Filter Correlation (GFC) technique is used to measure HCl. The infrared bench consists of a light source; chopper, multi-pass sample cell, filter wheels, and solid-state detector (see Figure 1). The filter wheel containing the optical filter and gas cells provides a dual function. One is to modulate the light; the second is to isolate the wavelengths for measurement. This configuration provides for a much simpler optical and mechanical system. The modulated light is sent into a temperature stabilized (50ºC) multipass sample cell. Interfering gases such as residual H20, SO2, THC and others are measured and corrected for to provide the highest precision. The MIR 9000 measures the gas after it has been dried using our exclusive “SEC” permeation based sample conditioning system.

The MIR 9000H series analyzers use non-dispersive infrared technology (NDIR) using the Gas Filter Correlation (GFC) technique is used to measure HCl. The infrared bench consists of a light source; chopper, multipass sample cell, filter wheels, and solid-state detector (see Figure 1). The filter wheel containing the optical filter and gas cells provides a dual function. One is to modulate the light; the second is to isolate the wavelengths for measurement. This configuration provides for a much simpler optical and mechanical system. The modulated light is sent into a temperature stabilized (180ºC) multipass sample cell. Interfering gases such as H20, SO2, THC and others are measured and corrected for to provide the highest precision. The MIR 9000H measures the gas on a hot/wet basis with the sample controlled above 185ºC.

In our MIR FT analyzer, Fourier Transform Infrared spectroscopy is used. Fourier transform infrared spectroscopy is a variant of infrared absorption spectroscopy. Rather than measuring the absorption of each narrow band of wavelengths consecutively to generate an absorption spectrum, the amount of light from a broad band source transmitted through a scanning interferometer is measured as a function of interferometer optical path length. The Fourier transform of this is the absorption spectrum. FTIR analyzers are generally supplied in a hot/wet configuration.

The MIR 9000 and MIR IS are ideally suited to measure HCl under the new PC MACT rules Field proven @ 0-10 ppm full scale range, the MIR series analyzers are extremely accurate at low levels. The HCl CEMS can be either wall or rack mounted allowing for customizable solutions based on customer specifications.

Contact Altech for any questions you may have related to HCl CEMS or HCl analyzers at 630.262.4400 or sales@altechusa.com.

Altech can provide the following complete systems to measure HCl:

Emission Monitoring