KROHNE is expanding its process measurement solutions for sustainable aviation fuel (SAF) production, targeting the demanding feedstocks, hydrogen services and high-temperature and high-pressure conditions encountered as SAF plants move towards larger-scale deployment.
The German process instrumentation specialist says measurement reliability is becoming increasingly important as producers seek to scale SAF technologies while maintaining process stability, asset reliability and commercially viable operating performance. Its portfolio covers applications across the SAF production chain, from feedstock pretreatment and hydrogenation to isomerisation, fractionation and final fuel transfer.
The SAF production chain combines renewable feedstocks with process technologies traditionally associated with oil and gas refining. Depending on the pathway, feedstocks can include used cooking oil, other oils, ethanol and biogas-derived intermediates, creating different measurement requirements throughout the plant.
“SAF production brings together two very different worlds,” said Yannick Farine, industry manager, biofuels and bioenergy at KROHNE. “Success depends on understanding the behaviour of renewable feedstocks upstream while also meeting the demands of downstream refining.”
According to Farine, KROHNE’s objective is to help producers optimise processes, reduce maintenance requirements and build plants capable of reliable long-term operation.
SAF production creates complex measurement requirements
The integration of renewable feedstocks with refining processes introduces challenges that are not necessarily present in conventional hydrocarbon processing.
Feedstock pretreatment can involve abrasive media and impurities, while downstream hydrogenation and isomerisation require measurement equipment capable of operating under elevated pressures and temperatures. Hydrogen management adds another layer of complexity because accurate flow measurement is required for injection, recycling and process control.
KROHNE’s SAF portfolio includes flow, level and pressure measurement technologies designed for these applications. The company also provides integrated systems for custody transfer and other plant requirements.
Ultrasonic flow measurement for demanding services
KROHNE identifies ultrasonic flowmeters as one of the technologies applicable across several challenging SAF services.
The company’s SAF application material highlights ultrasonic measurement for abrasive feedstocks, hydrogen-rich streams, steam and other process services. Its hydrogenation guidance also identifies ultrasonic flowmeters for feedstock and gas applications where avoiding internal restrictions and reducing wear can be important.
For hydrogen applications, KROHNE says advanced signal processing can support measurement despite the high velocity of sound associated with hydrogen. The company also lists ultrasonic technologies capable of operating at high temperatures and pressures across liquid and gas applications.
Coriolis measurement addresses feedstock and two-phase flow
KROHNE is also positioning straight-tube Coriolis mass flowmeters for applications where direct mass measurement and high accuracy are required.
The company says straight-tube designs can be suited to abrasive feedstocks, while entrained-gas management technology can support measurement when two-phase flow occurs. Its OPTIMASS 6400, for example, is identified for high-temperature applications and can operate with entrained gas under challenging process conditions.
This becomes relevant downstream of hydrogenation, where the process stream can contain multiple phases. KROHNE’s technical description states that the outlet of the hydrogenation reactor can involve a high-temperature, two-phase fluid, with its instrumentation designed to maintain measurement performance under such conditions.
Hydrogen management is central to SAF process control
Hydrogen is particularly important in HEFA-type SAF processing, where it is used to remove oxygen from renewable feedstocks during hydrogenation.
KROHNE’s technical documentation describes hydrogen being injected upstream of the reactor and pre-heated before entering the hydrogenation stage. The company states that reactor conditions can reach approximately 350°C and 100 bar, making accurate and redundant process measurement important for stable operation.
The hydrogenation reaction produces paraffins and water, while propane and carbon dioxide are among the by-products. KROHNE also says a significant portion of the hydrogen remains unreacted and is recycled, creating a further measurement requirement around gas handling and recovery.
Following hydrogenation, the process stream moves through separation and isomerisation stages. KROHNE identifies guided radar, differential-pressure measurement, ultrasonic flowmeters and other instrumentation for monitoring these stages.
Measurement extends through final SAF separation and transfer
The final stages of SAF production require measurement not only for process control but also for product handling and commercial transfer.
During fractionation, the isomerate is separated into SAF and other hydrocarbon fractions. KROHNE recommends level measurement for fractionation columns and flow measurement for high-temperature streams.
For finished SAF transfer, the company identifies custody-transfer measurement as an important requirement. Its portfolio includes the OPTIMASS 2400 Coriolis mass flowmeter and ALTOSONIC 5 ultrasonic flowmeter for applications requiring high-accuracy measurement, including large line sizes. KROHNE states that the OPTIMASS 2400 is compliant with MID MI-005 and OIML R117 requirements for custody-transfer measurement of liquid hydrocarbons.
The company also supplies integrated metering skids combining flowmeters, process instrumentation, piping and control equipment. According to KROHNE, pre-assembled systems can reduce installation and commissioning requirements at the project site.
Scaling SAF production raises instrumentation requirements
The measurement challenge comes as the SAF sector moves beyond individual demonstration projects towards commercial-scale facilities.
For developers and engineering, procurement and construction contractors, instrumentation selection has implications for process stability, maintenance and measurement accuracy across multiple sections of a plant. Feedstock characteristics can vary considerably between projects and pathways, while hydrogen service and high-temperature processing impose additional operating requirements.
KROHNE says its approach draws on experience across oil and gas as well as renewable-feedstock industries including edible oils, ethanol and biogas. The company has been developing process measurement technologies since its establishment in Germany in 1921 and currently provides instrumentation and measurement solutions across multiple industrial sectors.
As SAF capacity expands, the role of measurement systems is therefore extending beyond individual instruments. Integrated custody-transfer systems, process monitoring, leak detection and other engineered solutions can form part of the instrumentation architecture required for commercial-scale facilities. KROHNE lists these capabilities among its solutions for SAF plants.
