Analytical Experts Blog

Comprehensive Multi-Component Gas Analysis

Jim Cahill — Wed, 18 Feb 2026 14:00:40 GMT

I saw the recent news of a first for continuous gas analyzers that combines laser and paramagnetic detection methods. The Rosemount™ QX1000 Continuous Gas Analyzer is designed for comprehensive multi-component gas analysis for various industrial applications.

The post Comprehensive Multi-Component Gas Analysis appeared first on the Emerson Automation Experts blog.

Precisely Measuring Watercut in Crude Oil

Jim Cahill — Wed, 29 Oct 2025 13:00:02 GMT

In a Fluid Handling Pro article, “Achieving Precision Measurement with the Roxar Watercut Meter from Emerson” Kelda Dinsdale shares the story of a Chinese refinery that needed to monitor and analyze the crude oil and water going into the desalter unit.

The post Precisely Measuring Watercut in Crude Oil appeared first on the Emerson Automation Experts blog.

Continuous Emission Monitoring in Natural Gas Turbine Applications

Jim Cahill — Mon, 04 Aug 2025 13:00:00 GMT

Emerson’s Keith Linsley presented Extract for Emerson Solution for CEMS and Performance Testing in Natural Gas Turbine Applications at the 2025 Emerson Exchange in San Antonio, Texas.

Here is the presentation abstract:

The Natural Gas turbine market is witnessing stunning growth globally to meet energy and electricity demands. In the United States alone, 133 new turbine plants are at various phases of planning and construction. Capacity additions (35,807 MW) outpaced the total capacity retired (15,722 MW) in 2023. This will contribute more emissions to existing aggressive plans to lower greenhouse gas emissions. Limiting global warming to 1.5 degrees C above preindustrial levels requires cutting emissions across sectors by nearly 50% by 2030. Global government agencies continue to add new required emissions measurements at lower detection limits to meet these climate change goals, requiring advanced analytical gas measurement and reporting capabilities through continuous emissions monitoring.

Keith opened by sharing current U.S. Environmental Protection Agency emissions limits regulated under EPA CFR Part 75. These regulations govern facilities generally producing more than 25 Megawatts. The limits include:

NO_x less than 20 ppm
CO less than 20 ppm
NH3 less than 20 ppm

Traditionally, gas turbine measurements have required significant costs, including those for NOx and O2 analyzer systems. NO2 must be converted rather than directly measured. NH3 is measured with a dual NOx analyzer with an ammonia converter. There are challenges around converter efficiency and interfering gases. The stack gas cannot be validated and zeroed per EPA PS2 and PS3.

Combined-cycle gas turbines have been used for electric power generation for decades. Existing extractive analyzer technology has been measuring NOx, CO, O2, and CO since the inception of gas turbine power generation.

However, as the required measurement levels and detection limits of CO and NOx have decreased substantially, it has become increasingly challenging for some of these analyzer technologies to measure these components at these low ppm levels, especially in a single analyzer. Most often, these four gas components have been measured in at least three separate gas analyzers at significant cost.

New requirements for compliance have added the measurement of NH3 at levels below 10 ppm, further complicating the issue. The most common method for measuring NH3 accurately has been in situ. Still, this approach is not universally accepted as a global standard for CEMS, particularly in the US, due to a lack of calibration and quality confirmation.

The preferred methodology is complete extractive sampling, but it is problematic at these very low levels in traditional analyzer technologies. Additionally, to provide a complete solution, analytical systems integrators need to bundle multiple analyzer technologies, including volumetric gas flow rate analyzers, with a third-party data acquisition system, bundling it as their own complete, integrated product or packaged solution, albeit at some risk.

Keith explained that Emerson has a solution to measure NO2, rather than converting it to another form. Quantum Cascade Laser (QCL) technology enables direct measurement without interference, eliminating the need for oxidation or an NO2 furnace.

He compared hot, wet versus cold, dry gas analysis. Traditional analyzers rely on the cold, dry approach. Traditional continuous emissions monitoring systems (CEMS) and process gas analyzers remove moisture with gas conditioners and chillers. Approximately 95% of all CEMS maintenance is attributed to the chiller and the removal of water from the gas sample. QCL technology can work in this mode.

Hot wet analysis is limited to QCL technology. The sample and flow cell remain heated inside the QCL, eliminating the need for a chiller.

Emerson CEMS Data Acquisition Handling System (DAHS)

QCL Continuous Gas Analyzers can measure up to 12 constituents within a gas with a single analyzer, requiring minimal sample conditioning. Measurements are not affected or damaged by any water vapor in the gas.

QCL analyzers can be used in CEMS, combustion, and other process gas applications. TDL analyzers operate in the near-infrared spectrum, with wavelengths ranging from 800 to 2500 nanometers. QCL expands gas analysis to longer mid-infrared wavelengths (2500-12,000nm). Absorptions are due to fundamental vibrations and atomic bond motion in the molecules. The absorption peaks are more intense and sharper. This high resolution enables the identification of peaks in congested spectral regions, allowing for the measurement of more analytes with excellent cross-interference immunity.

The Emerson CEMS Data Acquisition Handling System (DAHS), which is used to accumulate the data, is based on the PACSystems PLC and an industrial computer. This RX3i PLC is used for data acquisition and control. It communicates with the analyzers via Modbus, TCP/IP, Serial, or Hardwired methods. It manages the sample handling system, calibration gas, and HVAC. An RXi2 industrial PC (IPC) hosts operator screens and a web HMI with multi-browser support.

These screens include a comprehensive summary, featuring graphical health indicators for each component, key emissions metrics for each component, including 20-minute and daily period averages, and are customizable for specific compositions.

It integrates with the DeltaV system via MTP and OPC-UA and can interface with cloud applications via MQTT or OPC-UA.

As a result of advances in spectroscopic analyzers, stack gas flow analyzer advances (Flexim), and DAHS development, Emerson’s measurement and solutions organization now provides all required measurements with minimal hardware in a turnkey, engineered solution featuring maximum Emerson content, thereby eliminating execution risk and responsibility challenges. This pre-engineered solution meets all requirements in the most technically advanced manner, effectively, reliably, and sustainably.

Visit the Quantum Cascade Laser Analyzers section on Emerson.com for more information to help drive more sustainable operations.

The post Continuous Emission Monitoring in Natural Gas Turbine Applications appeared first on the Emerson Automation Experts blog.

Sensing Hydrocarbon Gas Leaks and Avoiding False Alarms

Jim Cahill — Fri, 28 Mar 2025 13:30:47 GMT

Posts that describe advanced measurement technologies are pretty popular with our readers. That’s why I wanted to highlight a recent press release, Emerson’s New Fixed Point Gas Detector Provides Fast and Reliable Detection without False Alarms.

Rosemount 625IR Fixed Gas Detector

This fixed gas detector uses advanced optical absorption detection technology to provide reliable and fast gas detection in all plant environments. It offers fast and reliable detection of hydrocarbon gases without false alarms. It’s essential that these gas detectors be able to operate reliably in hazardous environments, in ducts, and all-weather conditions.

The Rosemount 625IR Fixed Gas Detector transmits infrared light through a sapphire lens. When a gas cloud moves through the detector, the target gas wavelengths absorb some light wavelengths, reducing their energy. The light is reflected back into the detector, where the infrared light sensors measure what wavelengths and how much infrared light has been received to determine the gas concentration.

These fixed gas detectors can be placed in areas with potential leak points. As a gas cloud needs to come into contact with the gas sensor to signal a warning, and since ambient air movement affects where a gas cloud may drift, it’s recommended to locate multiple gas detectors across the facility.

The Rosemount 625IR Fixed Gas Detector is certified to SIL2, SIL3, ATEX, US and IECEx safety standards. It can operate in an ambient temperature range from -40 to 167degF (-40 to 75degC). An upcoming release will have an arctic configuration option in which the ambient temperature range will be -76 to 149degF (-60 to 65degC).

Visit the Fixed Gas Detectors section on Emerson.com to learn more about these devices used to detect gas leaks and inadvertent releases of combustible and toxic gases.

The post Sensing Hydrocarbon Gas Leaks and Avoiding False Alarms appeared first on the Emerson Automation Experts blog.

Simplifying Natural Gas Analysis

Jim Cahill — Mon, 17 Feb 2025 14:30:34 GMT

Gas chromatographs (GCs) separate and analyze the various components in a mixture. Natural gas analysis applications often use these to identify the hydrocarbon components of varying carbon chain lengths. For instance, C6 refers to a carbon molecule consisting of six carbon atoms.

The Rosemount 470XA Gas Chromatograph is a compact, economical, and reliable solution that simplifies natural gas analysis in fiscal and custody transfer applications. The wealth of data in these intelligent analytical instruments that can be integrated at the edge or into cloud-based applications for global accessibility is part of Emerson’s Boundless Automation vision to help manufacturers and producers drive more efficient and sustainable operations.

It provides accurate C6+ BTU/CV measurement that is fully traceable to international standards and doesn’t require a shelter for most environments, lowering the total cost of ownership.

With an oven design based on the industry-proven Rosemount 770XA Gas Chromatograph, it offers flexible gas path configurations suitable for applications in renewable natural gas/biomethane and hydrogen markets.

Visit the Rosemount 470XA Gas Chromatograph page for more about its specifications and capabilities.

Transcript

Throughout the natural gas industry, gas chromatographs are utilized during custody transfer events. When the gas changes ownership between sellers and buyers to measure the component content of the gas and calculate its energy value, usually expressed in BTU or calories, as well as the Wobbe index of the gas.

The Emerson Rosemount XA family of gas chromatographs have been mainstays in traditional natural gas custody transfer applications for the past decade. As natural gas sources have evolved to include sustainable and renewable sources, the need for greater flexibility and gas chromatograph capability has accelerated.

Emerson’s Rosemount 470XA GC provides the standardized C6+ BTU/CV measurement for which the Rosemount line of gas chromatographs has been historically known while also providing the platform for expanding our based GC line to new emerging applications and engineered-to-order solutions.

With an oven design based on our top-of-the-line Rosemount 770XA natural gas chromatograph, the 470XA has the flexibility to support new gas measurement capabilities within the carbon capture and storage market. Hydrogen measurements for hydrogen injection in natural gas, low BTU gas applications like biogas generation and transmission, and custody transfer of renewable natural gas products.

The Rosemount 470XA delivers the long-term stability and expected performance with the serviceability support and MON2020 interface of the XA series product line. As an industry leader in the natural gas space, Emerson has more than half a century’s experience designing and manufacturing gas chromatographs and thousands of units installed globally.

With the introduction of the 470XA, we’re providing more options for sustainability activities in the natural gas marketplace while maintaining the same level of accuracy, reliability, durability, and performance expected.

-End of transcript-

The post Simplifying Natural Gas Analysis appeared first on the Emerson Automation Experts blog.

Managing Biofuel Processing Corrosion Risks

Jim Cahill — Mon, 10 Feb 2025 15:22:38 GMT

Several advancements are being made to reduce carbon emissions, including the production of sustainable aviation fuel (SAF) and renewable diesel. However, there are significant challenges in the production and storage of these biofuels, particularly concerning corrosion risks.

In a Decarbonisation Technology article, Managing corrosion risk in SAF and renewable diesel processes, Emerson’s William Fazackerley describes how non-intrusive real-time corrosion monitoring provides early warning of corrosion issues to enable early mitigation actions.

William opens the article by highlighting this challenge.

The production of SAF and renewable diesel involves complex processes and the use of diverse feedstocks, ranging from used cooking oils to agricultural residues. These new feedstocks and processes introduce novel corrosion risks that threaten the integrity of production facilities.

He contrasts SAF with traditional jet fuel.

Unlike traditional jet fuel, SAF is produced from sustainable feedstocks such as used cooking oil, agricultural residues, and even MSW [municipal solid waste].

Renewable diesel, the successor to biodiesel, is targeted for road-based transportation to replace traditional diesel.

Renewable diesel offers several advantages over biodiesel. It burns more cleanly and efficiently, produces lower emissions, and can be used in high concentrations without blending with traditional diesel…

Feedstock to make these biofuels has evolved from earlier biofuel initiatives.

Hydrotreated vegetable oils (HVO) have emerged as a popular option for producing drop-in fuels. These fuels closely resemble fossil-based fuels and offer better engine compatibility than traditional biodiesel.

A basic overview of a biofuel production process, with the main corrosion mechanisms and areas of concern highlighted

William highlights the corrosion challenges in processing these feedstocks.

The high acidity of some renewable feedstocks, combined with high temperatures and pressures in the refining process, can accelerate corrosion rates in equipment…

Causes of corrosion include:

Acidic corrosion
Microbiologically influenced corrosion (MIC)
High-temperature hydrogen attack (HTHA) (hydrogen embrittlement)
High-temperature H₂/H₂S corrosion
Carbonic acid (wet CO₂) corrosion
Ammonium bisulphide corrosion
Hydrochloric acid corrosion

Given the variability of feedstock quality, traditional corrosion monitoring methods from manual to risk-based inspections are not as effective as in traditional processes with more consistent feedstock.

Rosemount Wireless Permasense ET410 Corrosion and Erosion Monitoring System

William describes the Rosemount Wireless Corrosion and Erosion transmitters that are:

…designed to measure wall thickness in real-time, allowing operators to detect corrosion quickly and take preventive action. They can be installed without the need to penetrate the pipe or vessel wall, minimising installation costs and allowing monitoring in previously inaccessible locations.

Here is how they operate.

The transmitters typically transmit wall thickness measurements twice daily using wireless data retrieval, giving operators a high level of insight into the health of their assets directly from the desk… This frequent data collection allows for the early detection of corrosion trends, enabling proactive maintenance strategies and potentially preventing costly shutdowns or equipment failures.

By locating transmitters in corrosion-prone areas, the operations staff can track the pipe and vessel degradation over time and plan required maintenance activities.

For more details on this innovative solution for tackling these challenges, read the full article or visit the Rosemount Wireless Permasense Corrosion and Erosion Monitoring System page for additional specifications and capabilities.

The post Managing Biofuel Processing Corrosion Risks appeared first on the Emerson Automation Experts blog.

Mitigating Risks with Ultrasonic Gas Leak Detection

Jim Cahill — Wed, 29 Jan 2025 19:53:52 GMT

Leak detection technology is critical for safe and reliable operations for producers and process manufacturers who handle combustible and other hazardous gases. It’s vital to stay ahead of potential safety risks with early detection of gas leaks.

Rosemount Incus Ultrasonic Gas Leak Detector

One leak detection technology, ultrasonic noise detection, can provide constant monitoring across a wide area as it “listens” for the release of pressurized gas. The Rosemount Incus Ultrasonic Gas Leak Detector enables rapid detection of leaks.

This leak detector incorporates four ultra-sensitive acoustic sensors to identify leak conditions. It is designed for hazardous environments and extreme conditions due to inclement weather or other conditions.

These ultrasonic leak detectors are an excellent choice for oil & gas production wellhead monitoring, compressor stations, transfer stations, and hydrogen leak detection to name a few applications.

This ultrasonic acoustic technology offers several advantages over other leak detection technologies, including:

Detects gas leaks before a hazardous concentration is present
The gas cloud does not have to make contact with the sensor for detection to take place
Detection is instantaneous for all types of gas leaks (toxic or combustible)
Wide area coverage with a single unit: up to 131ft (40m) diameter
Unaffected by rain, snow, wind direction, or other environmental factors

Download the Ultrasonic Gas Leak Detection document to learn more about the importance of effective leak detection and the principles of ultrasonic gas leak detection technology.

You can also visit the Ultrasonic Gas Leak Detectors section on Emerson.com to see how this technology can help you drive safer operations.

The post Mitigating Risks with Ultrasonic Gas Leak Detection appeared first on the Emerson Automation Experts blog.

Detect, Distinguish and Defend with Flame and Gas Detection

Jim Cahill — Wed, 06 Nov 2024 20:36:38 GMT

Manufacturing and production facilities with hazardous locations due to the possibility of combustible and/or toxic gases require effective flame and gas detection systems. It’s important to develop and implement a sound strategy to keep personnel and plant assets safe.

Click to view

Developing a risk mitigation strategy that enables the different response levels needed to support your site is critical for the health and safety of your people. This strategy includes comprehensive flame and gas detection technologies for:

Instant detection of pressurized gas leaks
Combustible and toxic gas detection solutions
Detection of the fire type that is a risk in your facility

As part of your strategy to detect, distinguish, and defend against these risks, flame & gas detection technologies play a key role in managing potentially dangerous situations. Emerson’s Rosemount Ultrasonic Leak Detection solutions provide instant detection of pressurized gas leaks.

From a distinguish standpoint, should a gas leak be detected, it is important to receive notification and respond as quickly as possible to avoid potentially hazardous conditions. Combustible gas detection and toxic gas detection solutions help you to distinguish a variety of situations.

An explosive event, such as a high-pressure jet fire and wide area explosive fire can be potentially catastrophic. Each specific fuel releases a unique combination of residual hot gases. Emerson has a broad line of optical flame detectors to detect the type of fire that is a risk in your facility.

Download a copy of the Flame and Gas Detection Portfolio Overview to learn more about incorporating detect, distinguish, and defend technologies into your flame & gas risk mitigation strategy.

The post Detect, Distinguish and Defend with Flame and Gas Detection appeared first on the Emerson Automation Experts blog.

Greg McMillan’s pH Measurement Best Practices

Jim Cahill — Wed, 30 Oct 2024 18:00:04 GMT

Greg McMillan presented pH Measurement Best Practices at the recent Mary Kay O’Connor Safety & Risk Conference as part of the 79th Annual Instrumentation and Automation Symposium For the Process Industries. Here is the abstract from the pH Measurement Best Practices paper that Greg also submitted.

pH measurement has the greatest sensitivity and rangeability by far of any ion composition measurement. However, there are many challenges in terms of the installed accuracy and life expectancy. Many electrode designs have severe limitations when used in an industrial plant that could dramatically increase errors and failure rate. Here we provide guidance on the effect of process conditions and electrode designs, and offer best practices to take advantages of the advances in electrode technology, calibration, installation designs, and online diagnostics to get the best performance and reliability.

Many of the best practices Greg shared come from his book Advanced pH Measurement and Control, Fourth Edition. It provides the insights and guidance needed for electrode selection, installation, calibration, troubleshooting, and the advantages of middle signal selection.

He described the operation of Double Junction Combination pH Electrodes. High acid or base concentrations can affect the glass gel layer and reference junction potential. An increase in noise or decrease in span or efficiency indicates a glass electrode problem, which can cause a shift or drift in pH measurement.

The life of an electrode depends on the operating conditions. High acid or base concentrations at the extremes of the titration curve decrease the electrode’s life for a given operating temperature. A reduced life can lead to measurement accuracy and response time deterioration. Control strategies such as pH feedforward control become unreliable due to inaccurate feedforward effects and timing. As glass electrodes age, their response slows. Higher temperatures cause premature aging in these electrodes.

Greg showed some horizontal and vertical piping arrangements. Here is the horizontal piping arrangement.

Here is the vertical piping arrangement.

Wireless pH transmitters eliminate problems caused by electrical ground noise spikes in wired transmitters. He also recommended using a middle signal selection control strategy, which:

Inherently ignores single measurement failure of any type, including the most insidious PV failure at set point
Inherently ignores the slowest electrode
Reduces noise and spikes, particularly for steep curves
Offers online diagnostics on electrode problems
- Slow response indicates coated measurement electrode
- Decreased span (efficiency) indicates aged or dehydrated glass electrode
- Drift or bias indicates coated, plugged, or contaminated reference electrode or high liquid junction potential
- Noise indicates dehydrated measurement electrode, streaming potentials, velocity effects, ground potentials, or electromagnetic interference (EMI)
Facilitates online calibration of a measurement

Greg offers a bulleted list of best practices in the final ten slides of the presentation. Make sure to follow the presentation link to read these. The paper provides additional details about these best practices. Visit the Liquid Analysis Sensors section on Emerson.com to learn more about Rosemount pH/ORP sensors and other analytical probes.

The post Greg McMillan’s pH Measurement Best Practices appeared first on the Emerson Automation Experts blog.

How To Video—Calibrating pH Sensors with Two Buffer Solutions

Jim Cahill — Wed, 23 Oct 2024 19:04:36 GMT

Last week we featured a “How to” video on smart antenna installations and here you can find other “How to” videos we done throughout the years.

An Emerson colleague, Charu Pandey, alerted me to one published this week. In the video, How to Calibrate pH Sensors with Two Buffer Solutions | Emerson (run-time 4:01), Charu demonstrates this calibration process. It’s recommended that before you begin, you have the Rosemount pH/ORP Sensors Quick Start Guide on hand. This is where you will find all the necessary instructions and best practices for installation and calibration.

Visit the Liquid Analysis section on Emerson.com for more information on the complete range of analytical sensors and instruments to help you more efficiently manage your process liquids and equipment.

Transcript

Hi, my name is Charu Pandey and I am a Product Specialist for Liquid Analysis at Emerson. In this video, I will be walking you through how to calibrate a pH sensor with two buffer solutions.

Before you begin, be sure to have on hand the Rosemount pH/ORP Sensors Quick Start Guide, which can be found on the Emerson website. This is where you will find all the necessary instructions and best practices for installation and calibration.

A two-point buffer calibration is the best way to ensure that a pH sensor is providing accurate measurements. Sensors should be calibrated after start-up and if there is a drift in the measurement. During a two-point calibration, the transmitter calculates new values for slope, millivolts, over pH, and offset in millivolts. These values are based on the millivolt response of the sensor when it is submerged in the pH buffer solutions.

There are two ways to perform a pH calibration, Auto and Manual. Today, we will be going through the Auto calibration. First, ensure that the pH sensor is clean by rinsing the sensor with tap water to remove any process liquid and debris To access the auto calibration, first press the ‘Enter/MENU’ button on the transmitter, then select ‘Calibrate’. Next, select the Sensor you are calibrating. And in this case, “S1 Measurement”. Then press the down arrow and select ‘Auto buffer’, hit ‘Enter’. And finally, “Start Calibration.”

Now you can follow the directions on the transmitter screen. Place the sensor in the first buffer solution, and press ‘Enter’ on the transmitter. Wait for the readings to stabilize. The transmitter will display a list of possible buffer solutions. Select the option that matches the label on the bottle.

Now remove the sensor from the first buffer solution and rinse with tap water. Next, repeat these steps with the second solution. Place the sensor in the second buffer, and press ‘Enter’. Wait for the readings to stabilize. Then select the solution that matches the value shown on the bottle and press ‘Enter’.

After this calibration sequence is complete, the transmitter will display a slope and offset. Look at the slope to determine if the sensor needs to be replaced. An acceptable slope for a pH sensor is between 50 and 59.16. Ideally, a healthy pH sensor will have a slope between 57 and 59.16.

The acceptable offset for a healthy pH sensor is between negative 60 and 60 millivolts. Ideally, a pH sensor will have an offset as close to 0 millivolts as possible. The transmitter will return to normal functioning after you select X or Exit. Now, rinse the sensor a final time and place it back into the process.

This completes the overview of how to auto-calibrate a pH sensor with two buffer solutions.

-End of transcript-

The post How To Video—Calibrating pH Sensors with Two Buffer Solutions appeared first on the Emerson Automation Experts blog.

Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer

Jim Cahill — Tue, 03 Oct 2023 14:13:44 GMT

More than 100 years ago, Ivory Soap started claiming, and still says, its bar of soap is “ninety-nine and forty-four-one-hundredths percent pure.” At the time, that was an astonishing figure, but in much of the chemical manufacturing industry today, 99.44% purity doesn’t cut it. With ethylene manufacturing, producers want 99.99% purity. This sounds like a challenging goal, but with a stable and effective process, it’s certainly possible, provided the production unit has the right instruments in the right places to verify everything is operating correctly.

Evaluating and controlling an ethylene unit depends on effective gas analysis, and there are two primary technologies for this purpose: gas chromatographs (GCs) and laser-based analyzers. In my article in the June 2023 issue of Chemical Processing magazine, Choose the Best Measurement Option to Optimize Ethylene Production, I look at how to apply these the most effectively to achieve that 99.99% goal.

The most critical point of the process is the ethylene fractionation tower where the final purification step happens, requiring very precise measurement and control. GCs are the traditional choice in some parts of the process, particularly where heavy hydrocarbon gases are involved. Emerson makes a range of GCs which are well suited to many ethylene applications, but they may not be the best choice for this final measurement application.

GC performance is more than adequate in many ethylene purity applications, where speciation of heavy gases is more important than fast response. But when instantaneous, continuous measurements of smaller molecules are required in critical areas of the purification train and for product certification, other technologies, such as laser-based measurement methods, may be more appropriate.

So, laser is better, but there are various possibilities available. For many, the first thought is a variation of tunable diode laser (TDL) technology. This is a viable approach, as far as it goes, but it has significant limitations. The tuning creates a very specific wavelength in the near-IR range that must be matched with the specific component being measured. It can see what it’s designed to look for, but that’s it. Fortunately, there is a better approach.

The introduction of quantum cascade laser (QCL) technology, the spectral coverage has been extended to cover the valuable mid-infrared part of the electromagnetic spectrum, giving access to a wider spectrum of gas molecules. Detecting mid-IR wavelengths using QCL is advantageous because it enables gas analyzers to detect multiple gas components.

Also, some next-generation hybrid gas analyzers combine both TDL and QCL lasers, extending detection coverage over both the near- and mid-infrared range to sense many gas species simultaneously using a patented laser chirp technique, which provides instantaneous frequency sweep through many gas analytes of interest.

These hybrid analyzers are changing the industry, led by Emerson’s Rosemount CT5800 Continuous Gas Analyzer. It’s the first hybrid, laser-based analyzer designed for industrial process applications, including ethylene production, and it carries a Class I, Division 2 hazardous area certification. The CT5800 combines QCL and TDL technologies to provide highly sensitive and selective detection of multiple gases in real time. Its ability to measure sub-parts-per-million content of up to 10 gases makes it ideal for ethylene purity and quality applications.

For more information, visit Emerson’s Gas Analysis pages at Emerson.com. You can also connect and interact with other engineers in the Petrochemical Processing Groups at the Emerson Exchange 365 community.

The post Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer appeared first on the Emerson Automation Experts blog.

Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer

Jim Cahill — Tue, 03 Oct 2023 14:13:44 GMT

The post Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer appeared first on the Emerson Automation Experts blog.

Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer

Jim Cahill — Tue, 03 Oct 2023 14:13:44 GMT

The post Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer appeared first on the Emerson Automation Experts blog.

Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer

Jim Cahill — Tue, 03 Oct 2023 14:13:44 GMT

The post Achieving Ethylene Purity Calls for Selecting Right Gas Analyzer appeared first on the Emerson Automation Experts blog.

How Pure Does Hydrogen Need to Be? And How Do We Measure It?

Jim Cahill — Tue, 03 Oct 2023 13:49:24 GMT

One of the interesting aspects of our growing hydrogen economy is the way that it is turning up in all sorts of new places and applications. Ammonia plants and refineries have been handling hydrogen for decades, but the proliferation of electrolyzers, fuel cells, and various residential uses has all sorts of people needing to learn a lot about hydrogen very quickly. For example, one common question: “How pure does hydrogen need to be to run this fuel cell properly?”

Such questions are understandable given the growing number of sources for hydrogen and all those intriguing colors. Is green hydrogen necessarily free of contaminants? Is blue hydrogen purer than gray? How do we determine purity, and are there relevant standards to apply? Looking at these and other questions about purity is the focus of my article in the September 2023 issue of H₂ Tech, Ensure H₂ Purity with Modern Gas Analyzers.

Regardless of the source, H₂ purity is a necessary consideration for every application. The International Standard Organization’s ISO 14687 standard was created to correlate applications and uses with required H₂ purity. It specifies the quality tolerances for H₂ fuel, primarily focused on stationary, vehicular, and proton exchange membrane (PEM) fuel cell uses. Depending on the application, each gas grade defined an acceptable impurity allowance.

The article goes into greater depth on the grades and the allowable levels of contaminants. The contaminants noted are interesting in themselves as they differ from what we expect in natural gas. For example, argon, oxygen, and other odd gases are on the list, along with typical contaminants such as sulfur and ammonia. In any case, the question quickly emerges, how do we measure H₂ purity?

The two main modern ways of measuring H₂ purity are gas chromatography (GC) and continuous gas analysis. GC relies on a thermal conductivity, flame ionization, or micro flame photometric detector. Thermal conductivity detectors are mainly used to measure inert gases and most hydrocarbons, while flame ionization detectors are adept at measuring trace hydrocarbons, and micro flame photometric detectors specialize in measuring low-level sulfur species.

Problems emerge when looking at ISO 14687’s list of contaminants because some analyzers have a hard time measuring those gases. For example, a GC has trouble differentiating argon and oxygen when they’re mixed, but depending on the application, this limitation may not be a consideration. Emerson offers three analyzers that should be in the hydrogen purity analysis toolbox because either separately or in combination they can solve all the hydrogen purity measurement problems:

The article provides examples of actual applications calling for different requirements and matching the best analyzer technology to each.

As the world further reduces its dependency on fossil fuels, the need for uncontaminated H2 gas for power generation and storage will continue to increase. While no single-analyzer solutions are on the market to universally measure all possible H2 contaminants, the technologies are progressing quickly, helping processors ensure pure products for maximum reliability, uptime, and profitability.

For more information, visit Emerson’s Gas Analysis pages at Emerson.com. You can also connect and interact with other engineers in the Hydrogen Processing Groups at the Emerson Exchange 365 community.

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