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Author: Terri Melle-Johnson

Process Analytical Spectroscopy Monitoring

Why Use Process Analytical Spectroscopy for Real-Time Monitoring?

Traditionally, absorption spectroscopy has been the gold standard for precise sample analysis in laboratories. However, with the rapid advancements in electronic circuitry and optical components over the years, the broader UV/VIS/NIR spectrum has emerged as a powerful tool in process analytical technology. As a result, fiber optic-based dispersive grating spectrometers have revolutionized the process, offering unparalleled acquisition speed, measurement range, and sensitivity. For example, a comprehensive set of data that would typically require hours of painstaking laboratory analysis can now be captured in just about a minute with a process spectrometer, significantly speeding up the analytical workflow.

Moreover, Process Analytical Technologies (PAT) have been field-proven for nearly three decades, offering consistent and reliable performance in a variety of industrial applications. For instance, a Guided Wave scanning spectrometer, when operated continuously 24/7, can last over 10 years with more than 99% uptime. This durability ensures long-term reliability and minimal disruption to production. Furthermore, the maintenance requirements for process spectrometers are considerably lower compared to other monitoring techniques, such as process gas chromatographs and online titrators. This reduces both downtime and maintenance costs, making Guided Wave analyzers not only a practical but also a cost-effective solution. The low operational costs, combined with the high return on investment, make these spectrometers a sensible and proven choice for industries focused on long-term sustainability and performance.

In addition, near-infrared (NIR) spectroscopy offers a non-destructive and highly efficient technique that delivers fast, accurate, and reproducible results for monitoring process conditions. By shining light on the sample and analyzing how the light interacts with it, NIR spectroscopy enables real-time monitoring of multiple constituents simultaneously. This capability is especially beneficial for industries that require continuous process monitoring. Moreover, NIR spectroscopy eliminates many of the high maintenance costs, frequent calibrations, and extensive upkeep typically associated with gas chromatography (GC). Unlike GC systems, which often require costly sample systems and fast loops to ensure accuracy, optical technology in NIR spectroscopy reduces or completely eliminates these needs.

Notably, gas chromatography can lead to significant ongoing costs for routine maintenance, column degradation, and carrier gas consumption. These expenses can quickly add up, making it a costly and inefficient choice in the long term. By replacing traditional gas chromatography with a Guided Wave inline spectrometer-based analyzer, companies can significantly reduce operational costs, maintenance efforts, and potential downtime, leading to greater overall cost savings and increased process efficiency.

Ultimately, the shift toward process spectrometers based on fiber optic technology and NIR spectroscopy represents a significant advancement in industrial process monitoring, combining speed, accuracy, and low maintenance in one powerful tool. This transition enables businesses to achieve better analytical results, improved efficiency, and substantial cost savings over time.

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Impurity Monitoring In Fuel-Cell Hydrogen

A Single-Supplier Solution For Impurity Monitoring In Fuel-Cell Hydrogen

Global efforts to reduce harmful emissions have focused on lowering carbon output, particularly in transportation. Fuel cells provide a flexible solution, powering everything from laptops to power stations, and are seen as key to transitioning to a zero-emission energy sector. A hydrogen fuel cell efficiently produces electricity with water and heat as the only byproducts, making it ideal for zero-emission vehicles.

While most hydrogen is still made from fossil fuels, a strong hydrogen infrastructure can shift production to carbon-free methods in the future. Fuel cells are more efficient than combustion engines and offer similar range (500-700 km) while refueling quickly at stations, unlike battery-electric vehicles.

However, hydrogen purity is critical to fuel cell performance. Impurities, such as methane, moisture, carbon monoxide, and carbon dioxide, can affect the fuel cell depending on hydrogen production methods. Maintaining low impurity levels is essential for fuel cell efficiency, as specified by standards like ISO 14687 and SAE J2719.

Process Insights provides accurate tools to monitor hydrogen quality. Their analyzers, based on Cavity Ring-Down Spectroscopy (CRDS), detect trace contaminants at ppm and ppb levels, ensuring compliance with purity standards and supporting fuel-cell performance. These instruments are drift-free, highly specific, and require no expensive calibrations, saving time and money.

Fuel Cell Hydrogen Solutions

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Cryogenic Gases: Dew Point Measurement

Cryogenic Gases: Dew Point Measurement

Cryogenic gases are normal atmospheric components which have been liquefied, separated and purified.

Although they may be supplied as a high-pressure gas, most are shipped to the customer in a liquid state and vaporized on site. The primary cryogenics are O2, N2, Ar, H2 and He are supplied in much smaller quantities.

Cryogenic gases are purchased for their particular properties. They may be used as an inert blanket, in a chemical reaction or as a catalyst. Due to this usage, they are sold in various degrees of purity. Moisture (H20) is obviously an impurity, although on a very small scale. Moisture levels will, typically, be in the 0-5 PPM range.

Due to the purity of the gas and cleanliness of the application, there are few problems with this application. The sensor should be in a bypass after the vaporizer and not directly in the flow. This will warm the sample and ensure that the flow past the sensor is not excessive.  Learn more on dew point measurement.

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Moisture Detection in Electronic-Grade Bulk Gases

Parts-Per-Trillion Moisture Detection in Electronic-Grade Bulk Gases

The semiconductor market is entering a new era of innovation. New applications are driving demand for advanced devices with stricter requirements for reliability, power handling, and power consumption. These devices must also be smaller and more functional, with smaller technology nodes.

Powerful smartphones, tablets, automotive sensor systems, the Internet of Things (IoT), 5G, and smart power grids are all growing rapidly. Self-driving cars, for example, need huge amounts of computing power to process data from cameras and sensors in real-time, and the processors must be both reliable and power-efficient.

The Need for Better Gas Quality and Analytics

To meet these challenges, the semiconductor industry is focusing on improving manufacturing quality. The International Roadmap for Devices and Systems (IRDS) emphasizes stricter controls across all stages of production, from cleanroom conditions to raw materials, including gases. As a result, controlling gas quality has become a top priority to increase yields and reduce failure rates.

With tighter gas quality control, there is also a growing need for more sensitive and accurate analytical tools. Real-time process control has become essential for fab operators.

In advanced semiconductor fabs, Cavity Ring-Down Spectroscopy (CRDS) analyzers are the gold standard for ensuring the quality of bulk gases like N2, CDA, O2, H2, Ar, and He.

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HCl Continuous Emissions Monitoring

HCl Continuous Emissions Monitoring

Hydrogen Chloride (HCl) is a major atmospheric pollutant associated with the combustion of fossil fuels, such as coal and heavy oils, and also with a number of manufacturing processes, including cement production.

HCl in the atmosphere has an adverse effect on both human health and the wider environment. The inhalation of even low concentrations of HCl can cause irritation of the respiratory tract in healthy individuals and exacerbate symptoms associated with conditions such as asthma and emphysema.

Dissolved HCl is a contributor to acid rain pollution, the results of which include damage to building materials and reduced crop yields.  Atmospheric HCl pollution is also a factor in the production of photochemical smog. The economic impact makes the reduction of HCl pollution a priority for regulators and industry. HCl is generated by multiple industrial processes, with combustion of coal and oil for household and industrial power generation as the primary source. Here, chlorides present in the fuel are converted to HCl in the combustion process and emitted with other by-products. In addition, industrial processes emit HCl as a result of chlorides present in raw materials that are converted to HCl during production. In cement production, for instance, raw materials, including calcium carbonate, silica, clays, and ferrous oxides, all contain chlorides, resulting in generation of HCl.

Regulators worldwide dictate strict emissions limits for many atmospheric pollutants, including HCl. In the United States, the Environmental Protection Agency (EPA) has recently reduced emissions limits to further lessen the impact of the issues.  These emissions limits require HCl emitters to monitor and report the level of the gas present in stack emissions and to ensure that steps are taken to guarantee that emissions fall below the specified limits. This may require the emitter to either refine their process, via the use of cleaner fuels, for example, or to add abatement technology downstream of the process to reduce emissions of HCl.

Current analytical methods for HCl CEM applications include GFC/NDIR, FTIR, and cross-stack TDLAS. These methods have, to date, been adequate to monitor HCl emissions, based on existing emissions limits. The detection limits for some of these techniques will not be sufficiently low, however, to meet the revised limits, and so alternative techniques will be necessary.

CRDS gas analysis technology offers the performance and range to cope with these regulations, delivering accurate measurements at levels far below the new limits in diluted stack gas.

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Next-Generation Monitoring of Airborne Molecular Contaminants in Cleanrooms

Monitoring Airborne Molecular Contaminants in Cleanrooms

Airborne Molecular Contaminants in Cleanrooms

The dust-free and controlled environment of a cleanroom is vital to prevent product failure in semiconductor manufacturing but controlling particulates in cleanrooms is not nearly sufficient to protect semiconductor devices that feature structural sizes on a molecular level. Micro-particles are the main source of physical contamination, but modern filtration systems for air supply, cleanroom attire and specialized surface materials have been successful in keeping particle contamination under control.

There are, however, molecular contaminants, which can range from small inorganic molecules like acids and bases, to more complex organic species like VOCs. These molecules are known to cause chemical contamination (i.e. they react with the materials and surfaces of the semiconductor devices to cause oxidation, unintended doping, dislocations, and more).

This class of contaminants is collectively known as Airborne Molecular Contaminants (AMCs). They are harder to control than particles. Firstly, the molecules are much smaller than particles and require more advanced chemical filtration of the cleanroom air. Secondly and more importantly, however, many AMCs are created within the cleanroom itself. For instance, HF is used for wafer cleaning within the process, and NH3 is emitted naturally by any person present in the cleanroom. As feature sizes have decreased over the decades, both devices and equipment became more and more susceptible to significant damage from AMCs. They can have various detrimental effects: Acids, such as HF or HCl, can cause micro-corrosion and accelerate oxidation. Bases, such as NH3, can cause hazing and attack coatings on the optics of UV lithography equipment. Hydrides, such as AsH3, PH3, or B2H6, can cause unintended doping, which can dramatically impact a devices functionality.

Monitoring AMCs is Key to Contamination Prevention
Because many AMCs are generated within the cleanroom, they cannot be completely avoided, even though wafers are shielded as much as possible from exposure nowadays, e.g., by transporting them in closed pods (FOUPs) between process steps. Precise monitoring of the cleanroom environment for these molecules has emerged as a key for semi fabs to further mitigate the threat of AMCs. By immediately detecting the presence of harmful molecules, engineering controls can be implemented to protect devices and processes from exposure.

Due to the low concentration of AMCs and the need for fast detection, measurement instruments have to fulfill stringent requirements. As a result, ultra-sensitive laser-based analyzers have emerged as the primary class of instrument used to detect small AMCs, such as HF, HCl or NH3. Semiconductor fabs require all of these molecules to be measured at levels below 1 part per billion (ppb) with a response of 1-3 minutes to any presence of molecules. More importantly, the instruments readings have to return to baseline as fast as possible after the molecules’ presence is eliminated to minimize delays in the manufacturing process. The International Roadmap for Devices and Systems (IRDS) even calls out detection requirements below 0.1 ppb as part of the future technological challenges.

Introducing our NEW T-I Max Next-Generation AMC Monitors
To address this challenge, Process Insights manufacturers the TIGER OPTICS™ T-I Max™ series of cleanroom analyzers for detecting AMCs like HF, HCl, and NH3 with unprecedented speed and sensitivity. The T-I Max uses powerful Cavity Ring-Down Spectroscopy (CRDS) Technology but uses an all-new electronic and optical platform that enables lower measurement noise and up to ten times faster measurement rate. This platform takes CRDS to the next level and dramatically lowers detection limits compared to previous generation analyzers.

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Cost-Effective Purity Analysis in the Cryogenic Air Separation Process

Cost-Effective Purity Analysis in the Cryogenic Air Separation Process

Did you know you can improve safety and your process efficiency by using CRDS gas analyzers?   

CRDS analyzers offer many opportunities to improve the air separation process by saving time and money and alerting plant operators quickly in case of unsafe impurity levels.  Key advantages of using CRDS gas analyzers include:

  • Freedom from calibration
  • No consumables or service gases required
  • All solid-state design, no moving parts
  • Plug-and-play, easy to operate
  • Accurate detection of H2O, CO2, CH4, C2H2 and H2
  • Fast speed of response, ideal for process control

Cryogenic Air Separation
Cryogenic air separation units (ASUs) are the gas industry’s workhorses for the production of gaseous and liquid high purity nitrogen, oxygen and argon. The cryogenic process can be modified to manufacture a range of desired products and mixes.

Controlling Impurities to Ensure Safe ASU Operation
Following compression, the air pre-treatment step consists of cooling and purification to remove process contaminants, such as H2O, CO2 and others. The most common purification methods are Temperature Swing Adsorption (TSA), which exploits the difference in adsorption capacity of adsorbents at different temperatures, and Pressure Swing Adsorption (PSA), which operates similarly via pressure variations.

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Monitoring Gasification with a Mass Spec Gas Analyzer

Monitoring Gasification with a Mass Spec Gas Analyzer

Research in the field of biomass gasification is increasingly important as industry continues to find new uses for syngas. At the Energy & Environmental Research Center (EERC) an Extrel MAX300-RTG process mass spectrometer was used to monitor the exit stream of a Fluid Bed Gasifier. The quadrupole mass spectrometer provided fast, quantitative analysis of the syngas composition.

Over the last several years, concern about the economic and environmental impact of traditional fossil fuel combustion and petrochemicals has led to a search for viable alternatives with gasification emerging as a powerful technique for generating fuel and hydrocarbons. The gasification process makes use of materials such as coal, biomass, and waste to produce synthesis gas, or syngas. Syngas is a combustible mixture of hydrogen, carbon monoxide and carbon dioxide that generally contains a small amount of methane and some trace contaminants. Syngas is used as a fuel source to generate power and heat, or converted into products like hydrogen, for use in fuel cells or fertilizer generation, or liquid fuels via a Fischer-Tropsch reaction.

Gasification and chemical processes utilizing syngas rely upon the ability to obtain information about the composition of the gas stream exiting the reactor. The MAX300-RTG is a 7th generation process mass spectrometer capable of performing quantitative analysis on a wide variety of compounds at concentrations ranging from 100% down to 10 ppb. The 19 mm quadrupole mass filter used by the system allows for high analytical repeatability and long-term stability.

The MAX300-RTG demonstrated that it has the flexibility to quickly characterize and quantify syngas mixtures. It has the sensitivity to detect trace components at ppm levels and below, and the speed to perform each measurement in under 0.4 seconds. The ability to analyze the complete array of syngas components exiting the gasifier, from 100% down to ppm levels, makes the MAX300-RTG an instrument capable of replacing complicated analysis systems involving multiple devices and technologies. The speed of the mass spectrometer means that the MAX300-RTG can be automated to monitor gas composition at several sample points, delivering a complete set of concentrations at 20 seconds per point.

At the EERC, additional sampling at the ports downstream of the reactor could yield important insight into the operation and efficiency of the fixed beds, or be used to analyze hydrogen membrane separation, or a Fischer-Tropsch product. The speed and flexibility of the MAX300-IG, combined with the capability to run 24/7 in rugged and hazardous industrial environments, make it ideal for monitoring production scale gasification and any associated chemical processes downstream. At large facilities that utilize syngas, like ammonia plants, the MAX300-RTG and its predecessors have set the standard for analyzer automation and process control over the last several decades.

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Total Sulfur and Total Nitrogen in Fuels and Chemical

Total Sulfur and Total Nitrogen in Fuels and Chemicals

Regulatory agencies around the world have been implementing increasingly stricter fuel emissions guidelines over the past decades to limit air pollution. Regulations such as the American Tier III, European Euro 6 or the Indian Bharat VI set quantitative limits on the permissible number of specific pollutants that can be released during combustion.

Sulfur and Nitrogen are both controlled under these regulations due to the health and environmental impact of their oxides: Sulfur Dioxide (SO2), Nitrogen Oxide (NO) and Nitrogen Dioxide (NO2), commonly referred to as NOx. In order to measure sulfur and nitrogen content in fuels, chemicals and petrochemicals, Process Insights delivers the XT-2000 laboratory analyzer for both Total Sulfur (TS) and Total Nitrogen (TN) measurements.

The XT-2000 utilizes patented Excimer UV Fluorescence (EUVF) Technology for TS measurement and proprietary Chemiluminescence (CL) technology for TN measurement offering exceptional sensitivity that does not require a vacuum pump minimizing maintenance requirements and improving analytical stability. The XT-2000 provides accurate, precise and fast analysis for a broad range of samples with a typical analysis time of 3 minutes or less.

The XT-2000 demonstrates outstanding linearity for 0-100 ng/μL TS/TN in isooctane standards with excellent 0.9998 and 0.9995 correlation for both TS and TN measurements. Results for various fuels and chemicals presented on the following page show TS and TN content from ppb level to 31.45 ppm/wt (TS) / 12.48 ppm/wt (TN). All samples were analyzed 5 times with an RSD of 2% or better for samples above 1 ppm. 

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Trace Sulfur in Butane and Other Gas or LNG Applications

Trace Sulfur in Butane and Other Gas or LNG Applications

Increasing need for Total Sulfur trace analysis in gas and LNG products

This remarkable online process analyzer incorporates our patented Excimer UV Fluorescence (EUVF) Technology and is specifically designed for measurement of Trace Total Sulfur content in applications that require the ultimate in low-level sensitivity, such as polymer-related applications.

One application where our TraceS-1000 has demonstrated exceptional analytical performance is the measurement of total sulfur in butane at the ultra-low range of 0-1000 ppb/vol.  Acquired test results reflect excellent linearity, precision and long-term stability for this extremely low range. Analytical results represented were obtained utilizing an oxygen/argon blend for combustion.

The TraceS-1000 provides unparalleled sensitivity and rapid response to concentration changes with a typical analysis time of only 180 seconds. Instrument operation is simplified with intuitive and user-friendly software, with an added feature that allows data averaging for enhanced analytical precision. Eight-hour repeatability using a sulfur dioxide (SO2) permeation tube for sulfur addition to instrument-grade butane demonstrated a SD of 14.7 ppb at 205 ppb/vol. concentration or 7.17% RSD. Using the moving average feature, a 3-run analysis (9-min. response time) further improved repeatability, yielding a SD of 8.5 ppb or 4.16%. Various concentrations run for linearity characterization reflect rapid response, outstanding repeatability and excellent linearity with a 0.9965 correlation.

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