Beijing Qinglian Measurement and Control Technology Co., Ltd

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Beijing Qinglian Measurement and Control Technology Co., Ltd

Tel：18500242456
Email：sales@qingliancekong.com

Address: Inside Beijing Taixing Art Institute, Shuipo Village, Gaoliying Town, Shunyi District, Beijing

TLG-837 Sulfur Recovery Tail Gas Ratio Analyzer

Industry-leading sulfur recovery H ₂S/SO₂ Ratio Analyzer

Utilizing the advanced nova II™ UV-Vis diode array detector, full-spectrum monitoring is achieved, avoiding component interference, eliminating measurement errors, and enhancing accuracy.

The patented anti-fouling probe design effectively prevents sulfur blockage. Steam tracing is recommended—it’s highly efficient, reliable, and cost-effective. The probe connects to the analyzer solely via an optical fiber cable, offering flexibility in the analyzer’s installation location. Moreover, the sample never enters the analyzer’s housing. This unique design maximizes both safety and flexibility of the product. The probe’s automatic back-blowing function addresses the issue of sulfur blockage in pipelines under special conditions. When problems arise with the process gas sample, the analyzer can send an alarm signal, activate nitrogen purging to clean the probe, and then seal it off, thereby preventing sulfur vapor from condensing and blocking the probe.

Perfectly suited for sulfur recovery processes such as Claus, Super Claus, and Ultra-Claus.

Product Features

Performance

Fast, continuous measurement The entire system’s response time is less than 10 seconds. High precision ±1% of full scale It can maintain high performance even when the ratio data undergoes significant changes. H ₂ S:SO ₂ The ratio data maintains high accuracy across a range from 100:1 to 1:20. Also capable of measuring carbonyl sulfide and carbon disulfide. Utilizing advanced multi-component measurement technology

Reliability

Continuous online monitoring The system's uptime is above 99.6%. Fog-detection probe with automatic maintenance function Automatic steam purging and cleaning function and sulfur removal function Fully automated operation under unmanned supervision Automatic system purging and zeroing function; remote automated control

Security

The sample will not enter the inside of the analyzer housing. Toxic and harmful gases circulate only within the probe itself. The analyzer can be manually operated or the probe can be plugged in and unplugged without shutting down the sulfur recovery process. The specially designed ball valve offers high sealing performance and easy operability.

Operating costs

Easy to install The lightest and smallest ratio analyzer All-solid-state structure of the analyzer There are no moving parts or filters that require periodic replacement, and no consumable reagents, liquids, or equipment are needed to keep the ratio meter functioning properly. Low utility consumption Low power consumption, low steam consumption

Compatibility

The Claus process, suitable for various retrofit and upgrade applications. Can be used in Super Claus or Ultra-Claus processes. Explosion-proof certificate for hazardous areas Class I Div 1 & 2; ATEX; GOST, etc. Customizable alarm and signal outputs 4-20 mA analog output; MODBUS; HART, etc. No need to analyze the hut or sunshade. Can be directly installed outdoors.

Application areas

Claus process

A hydrogen sulfide concentration of 10 ppm is toxic, while a concentration of 800 ppm is lethal. Moreover, hydrogen sulfide is highly corrosive to equipment. In air, hydrogen sulfide becomes flammable when its volume concentration exceeds 4.3%, and it emits an extremely unpleasant odor at concentrations greater than 1 ppb.

Hydrogen sulfide is abundantly present in fossil fuels. Sulfur recovery units at refineries convert hydrogen sulfide extracted from hydrocarbons into elemental sulfur and water. Elemental sulfur can be used in the fertilizer, explosives, and other industries.

Claus is currently the industry-standard process for treating hydrogen sulfide in acidic gases. In the reactor, hydrogen sulfide reacts with oxygen:

3H₂ S + 3/2O ₂ SO ₂ + H ₂ O + 2H ₂ S

The catalytic reactor further promotes the oxidation reaction products from the previous step to react, yielding sulfur in different crystalline forms:

2H₂ S + SO ₂ 2H₂ O + 3/ _X S _X

H ₂ S and SO ₂ An accurate 2:1 molar ratio is crucial for conversion efficiency. As can be seen from the combustion reaction, maintaining this ratio requires constant adjustment of the oxygen flow rate. Consequently, the efficiency of the Claus process depends on the accurate and continuous measurement of H₂. ₂ S and SO ₂ the concentration. In addition, the monitoring instrument also needs to be capable of detecting CS. ₂ And carbonyl sulfide (COS)—when these components are present in the exhaust gas, it indicates potential issues with the catalyst bed.

Oxygen demand

As shown in the previous section, the efficiency of sulfur recovery depends on maintaining H in the Claus reaction. ₂S/SO₂ The ability to keep the ratio within a specific value or range. This adjustment capability requires real-time knowledge of the precise H. ₂S/SO₂ Ratio data.

TLG-837 Sulfur Tail Gas Ratio Analyzer It can continuously monitor the ratio data of hydrogen sulfide to sulfur dioxide and continuously transmit an oxygen demand signal to the control system. In addition, operators can also request readings of the concentration data for reaction byproducts such as COS and CS2.

Technical concept

Operating principle

TLG-837 uses the UV-visible principle to detect chemical components in sulfur tail gas. The system acquires high-resolution spectra in the 200-nanometer to 800-nanometer wavelength range, where H2S, SO2, COS, and CS2 all exhibit distinct and readily identifiable absorption curves.

Optical structure

The TLG-837 uses a long-life xenon lamp as a light source to emit an optical signal, which comes into contact with the sample via a flow cell plate. This signal is emitted by the light source and transmitted through an optical fiber cable to the top of the probe’s flow cell plate, where it interacts with the sample gas. The sample, composed of various chemical substances, exhibits unique absorption characteristics for light. The resulting optical signal then exits the flow cell, travels back to the detector via the optical fiber cable.

Absorption spectrum of sulfur tail gas

TLG-837 analyzes component concentrations by detecting the absorbance spectra of unique chemical constituents. Through mathematical calculations, it separates the total absorbance curve of the sample into individual absorbance curves corresponding to the concentrations of different components. The combined height of each curve at various wavelength bands accurately reflects the true concentrations of the sulfur tailgas chemical substances.

User interface

AAI’s proprietary ECLIPSE software processes the acquired spectral data into actual concentration readings. On the touchscreen controller, the analyzer operator can easily switch between different interfaces—such as trend graphs, spectra plots, concentration readings, and more—and can independently and at any time set and adjust alarms, outputs, purge functions, zeroing, and other parameters.

Multi-component measurement

The TLG-837 can continuously monitor the concentrations of H2S and SO2 (with optional measurement of COS and CS2). It employs a unique algorithm to separate the total absorbance curve, using hundreds of data acquisition points and regression algorithms to generate a distinct calibration curve for each target substance. This approach is far more advanced than the traditional filter-wheel method, as it eliminates moving parts in the analyzer and prevents interference between filters and components.

In-situ sampling

TLG-837 uses AAI’s patented in-situ fog-control probe to sample sulfur tail gas.

Fog-control probe

The fog-control sampling probe is designed with a lightweight, compact structure, allowing it to be installed by just one worker. The probe is directly mounted onto the sample pipeline via a flange.

The portion of the sample gas that actually comes into contact with the optical signal is located inside the sample-flow cell disc at the tip of the probe. The optical signal enters the interior through one end of the flow cell disc, where it contacts the sample gas, and then exits through the other end.

Automatic desulfurization

Sulfur-containing tail gas contains elemental sulfur, which readily condenses, clogs pipelines, and blocks the passage of optical signals. As the sample gas rises through the probe and enters the flow cell plate, the mist-control probe removes the elemental sulfur, preventing it from obstructing the flow cell plate. The probe utilizes the steam generated by the Claus reaction to regulate its internal temperature, ensuring that at this temperature, the elemental sulfur condenses into droplets and is then returned to the sample pipeline.

Inside the probe, a mist-control pipe is concentrically arranged with the probe itself. Low-pressure steam continuously flows through this mist-control pipe. Since the temperature of the low-pressure steam is significantly lower than that of the sulfur tail gas, the low-pressure steam effectively cools the rising tail gas. Among the various gases in the sulfur tail gas, sulfur itself has the lowest boiling point. Thanks to the cooling effect of the low-pressure steam, elemental sulfur in all the rising gases is efficiently condensed, allowing all other gaseous components to continue rising toward the top of the probe.

The point of contact between the sample gas and the optical signal is located inside the flow cell disc at the top of the probe. The flow cell disc contains a channel through which high-pressure steam flows. The purpose of the high-pressure steam is to heat the flow cell disc, ensuring that any elemental sulfur that has not been condensed in previous steps remains in the gaseous state. This eliminates the risk of elemental sulfur condensing within the flow cell disc.

The ejector creates a Venturi effect, drawing the sample gas into the probe, where it rises to the interior of the flow cell for analysis and then returns to the sample line.

Practical Control Panel

The UCP practical control panel can stabilize the pressure and regulate the flow of high-pressure and low-pressure steam, instrument air, calibration gas, and nitrogen entering the probe. The UCP is an optional accessory; we recommend that customers use the配套 practical control panel provided by AAI. Users are also free to manufacture this control panel themselves.

Ultra-safe design

The primary drawback of all other tailgas ratio analyzers is that they introduce the sample into the analyzer’s interior for measurement. This design not only makes the electrical components inside the enclosure more susceptible to corrosion but also poses a potentially lethal threat to personnel: Should a leak occur inside the analyzer—especially in a sealed cabinet or small enclosure—operators could face a life-threatening danger.

The biggest difference between the TLG-837 and other exhaust gas ratio analyzers is that we use optical fibers: We introduce light into the sample, rather than introducing the sample into the light. The toxic and hazardous sample gas flows only within the probe itself and never enters the analyzer’s housing, which contains electrical components.

Technical Parameters

The following technical specifications are based on the premise that all components and the sample system are supplied by AAI, and that the system installation has been approved by AAI. For technical specifications under other conditions, please consult AAI’s sales team directly.

General

Runtime environment
Measurement principle	Ultraviolet-Visible Spectrophotometry Principle
Detector	nova II™ UV-Vis Diode Array Meter
Spectral detection range	200–800 nm
Light source	Pulsed xenon light source (with a service life of over five years)
Signal transmission	600 μm core, 1.8-meter optical cable; other lengths available upon request.
Sampling method	In-situ Fog-Control Probe
Analyzer calibration	Before leaving the factory, the instrument is calibrated using a standard gas certified by the manufacturer; users do not need to recalibrate it again. The system’s accuracy is ensured by an automatic zeroing function.
Reading verification	Simple verification using standard samples
Controller	Industrial controller equipped with an LCD touch screen and ECLIPSE™ operating software.
Data storage	Pure solid-state drive
Analyzer environmental conditions	Suitable for both indoor and outdoor use; no analysis cabin required.
Ambient temperature	Standard: 0–35 °C (32–95 °F) Optional: -20–55 °C (-4–131 °F) To avoid thermal radiation, it is recommended to install the analyzer under a sunshade in environments with direct sunlight.
Utility Equipment Requirements
Electricity	85–264 VAC 47–63 Hz
Power consumption	Less than 65 watts
Instrument air	60-100 psig
Steam pressure	Cold steam: less than 25 psig Heating and back-blow steam for the measurement tank: greater than 55 psig
Output
Standard output	1x galvanically isolated 4-20mA analog output per measured analyte 5x digital relay outputs for indication and control 1x K-type ungrounded thermocouple input
Optional output	Modbus TCP/IP; RS-232; RS-485; Fieldbus; HART
Size specifications
Material in contact with the sample gas	316/316L stainless steel, perfluoroelastomer, other materials available upon request
Analyzer chassis material	Wall-mounted NEMA 4X304 stainless steel enclosure; other enclosures available.
Protection level	IP66
Probe material	316/316L stainless steel; other materials available upon request.
System size	Analyzer: 24 inches high x 20 inches wide x 8 inches deep (610mm H x 508mm W x 203mm D) Probe: 36 inches long × 12 inches maximum diameter (914 mm × 305 mm)
System weight	Analyzer: 32 pounds (15 kilograms) Probe (average): 29 pounds (13 kilograms)

Performance

Measurement parameters
Accuracy/Repeatability	matter	Scope	Accuracy	Repetitiveness
	Hydrogen sulfide H ₂ S	0-2%	± 1% of full scale	± 0.4%
	Sulfur dioxide SO ₂	0-2%	± 1% of full scale	± 0.4%
	Oxygen demand	Customize	± 1% of full scale	± 0.4%
	Carbonyl sulfide COS	0-2,000 ppm	±1% of full scale (±5% below 500 ppm)	± 0.4%
	Carbon disulfide CS ₂	0-2,000 ppm	±1% of full scale (±5% below 500 ppm)	± 0.4%
Dynamic range of ratio	100:1 < H ₂ S:SO ₂ < 1:20
Response time	1-5 seconds
Zero-drift	After a 1-hour warm-up, the accuracy is ±0.1% of full scale and remains stable for 24 hours under constant ambient temperature.
Sensitivity	±0.1% of full scale
Noise	±0.004 AU at 220 nm

Certificate

Standard design	General Purpose
Offer optional	ATEX, IECEx, EAC, PESO, JPN
For other certificates, such as CSA, FM, etc., please contact your sales representative.