Hydrogen production in industrial facilities and petroleum refineries predominantly relies on natural gas, specifically methane. Although hydrogen atoms are one of the most abundant chemical elements on Earth, their gaseous form is much more scarce. Harnessing power through gaseous hydrogen is a priority of power generation entities worldwide. The most prominent method of harnessing the power of gaseous hydrogen is Steam-Methane reforming.

Steam-Methane reforming involves the use of high-temperature steam to produce hydrogen from a methane source, typically natural gas. By introducing a catalyst, the steam and methane react to produce hydrogen, carbon monoxide, and a small amount of carbon dioxide. Another catalyst is introduced to enact pressure-swing absorption, removing undesired elements from the gas stream. This allows only mostly pure hydrogen to remain.

The Challenge of Steam-Methane Reforming

pH and conductivity measurements are crucial monitors of general water and steam quality throughout the process. As the gasses travel between the scrubbers, reformers, and converters, pH and conductivity measurements are a key aspect of analyzing the removal of sulfur and other harmful byproducts from the process. These aggressive byproducts can cause severe corrosion to occur within the process infrastructure if left unchecked.

Obtaining these measurements can be challenging, given the volatile conditions under which steam methane reforming takes place. The presence of steam and high concentrations of hydrogen and carbon monoxide can create a highly corrosive environment. Corrosion can damage sensors and equipment, affecting their accuracy and reliability over time. Additionally, the presence of large amounts of hydrogen ions in the process can interfere with pH measurements, particularly in aqueous solutions. Specialized pH sensors with selective ion-sensitive membranes may be required to accurately measure pH in the presence of high concentrations of hydrogen ions.

The Solution

The process environment of steam methane reforming is hazardous. Uniquely qualified equipment is necessary to achieve maximum safety and meet regulatory requirements. Many of Knick’s solutions feature hazardous approval ratings that meet these qualifications.

Sensors

The ion-sensitive membrane of the SE 555x is designed specifically for processes in which high-ionic activity threatens the accuracy of measurements. The sensor can withstand extreme pH ranges and aggressive media. An integrated NTC 30K temperature element also assures that all pH measurements are accurately compensated for the process media temperature.

The SE 605 H conductivity sensor has a wide measuring range of 0.001…1,000 µS/cm. The sensor has robust, coaxially-arranged stainless steel electrodes, ideal for the aggressive process conditions of steam methane reforming. Operators can easily clean the sensor thanks to the detachable outer electrode.

Holders

M4 Knick tailors its sensor holders for virtually any process. Static, retractable, and flow-through fittings are available for even the most aggressive processes. The ARI 106 H is suitable for static installations in hazardous locations. The design of the holder body protects the sensor from damage while enabling accurate measurement.

For operators seeking retractable holders, the Sensogate WA 131 M offers several features focused on the safety of the operator. An internal scraping ring and “cyclone” cleaning chamber ensure minimal process media exposure. In addition, the SensoLock function prevents process leak paths, even if the holder contains an improperly installed sensor. 

Finally, for flow-through fittings, the ARF 210 is suitable for up to three pH or conductivity sensors at once. The fitting is a modular system with various connection geometries and process connections. The fitting, made of 316 SS stainless steel, can withstand high pressures and temperatures. A large flow cross-section and integrated cleaning nozzles also make the fitting ideal for polluted media found

Transmitter

The intuitive user interface of the Stratos Multi transmitter features full-text menu navigation, graphical icons, and charts to communicate the device’s condition and guided automatic sensor calibration. The diagnostic features and sensor health diagram allow operators to remain up-to-date on sensor health and performance. This is a key feature when working with volatile processes like Steam-Methane Reforming.

Customer ROI

• Promote Corrosion Prevention: Improper pH levels can increase the threat of corrosion to equipment on process streams. Monitoring pH accurately lets operators detect conditions that could accelerate corrosion within the reactor or associated piping. Maintaining optimal pH levels with adept sensors can minimize corrosion rates, extending equipment lifespan and reducing maintenance costs.

• Boost Operational Efficiency: Reliable pH measurement systems with safe and durable sensor holders minimize downtime associated with sensor maintenance, calibration, or replacement. This enhances overall process efficiency by reducing unplanned shutdowns and maximizing production uptime.

• Enhance Safety: Implementing intrinsically safe and durable equipment only enhances operator safety. The increased efficiency of process measurement minimizes the potential of process fouling and exposure.