Automation is the key to LNG present and the future scenario for hydrogen

With a growing demand for both LNG and hydrogen, more infrastructure must be built on a short schedule to capture this opportunity and get first mover advantage.

The vision is LNG and hydrogen plants, including floating LNG (FLNG) vessels, with greater safety, sustainability, reliability, and productivity - tackling these challenges almost automatically. This can be achieved by using specialised automation solutions designed specifically for LNG and hydrogen challenges. Industrial software is also used in the design phase of these infrastructure projects to accelerate the engineering and deployment of these plants and reduce risk from uncertainties. Similarly, using a single vendor, which not only sells but also manufacturers the automation further reduces the risk of delays.

LNG in the present

But LNG has challenges: it must be brought to and kept at cryogenic temperature for transport and storage, and the gas phase is highly flammable. At each stage from gathering stations, processing plants, pipeline compressor stations, liquefaction plants, carrier vessels, storage and regassification terminals, power stations and other offtake there is a myriad processes and equipment that must be managed to perform.

Hydrogen for the future

Hydrogen has similar challenges, but when transported as compressed gas the pressure is even higher, and as liquid the temperature is even lower, and it is even more flammable. At each stage from electrolyser or reformer plant, compression, gas pipeline injection, or liquefaction plant, carrier vessel, storage and regassification terminals, all the way to fuel cell power stations, and refueling stations.

Safety considerations

Specialised automation solutions to make LNG and hydrogen plants safer include:

• Ultrasonic sensors to detect high-pressure gas leaks
• Point and open path IR methane detectors
• H2S gas detectors
• Hydrogen capable flame detectors
• 2-in-1 radar-based independent high level and overfill alarm with automatic self-testing for carriers and terminal storage
• Level, temperature, and density (LTD) profile sensor to predict LNG roll-over
• Multiple spot temperature sensor to identify LNG tank leaks
• Isolation valves without cavity avoids trapped LNG flashing causing catastrophic failure

Sustainability

The specialised automation solutions that make LNG and hydrogen plants more sustainable include:

• Pressure relief valves (PRV) with bubble tight seating reduce methane loss, venting, and flaring
• Specialised valve stem packing reduces fugitive methane emissions
• Zero methane leak metal-to-metal seal triple offset cryogenic isolation valves

Reliability

Automation solutions designed specifically to make LNG and hydrogen plants more reliable include:

• Isolation and control valves designed specifically for cryogenic applications
• Control valves with specialised body design and dirty service trims to avoid the damage from outgassing in natural gas amine treatment
• High-capacity anti-surge valves and actuators with fast-response optimised digital valve controllers to avoid compressor surge damage
• Non-rubbing triple offset cryogenic isolation valves

Productivity

LNG and hydrogen plants are made more productive using specialised automation solutions including:

• Full-bore large volume custody transfer ultrasonic flow meter with low pressure drop, minimising the risk of LNG flashing, no moving parts, and cryogenic grade redundant transducers
• Frequency Modulated Continuous Wave (FMCW) radar level-based custody transfer system for cryogenic bullet and full containment storage tanks up to 50m tall with high accuracy, no moving parts, with only two-wires for all tank top devices such as integrated pressure sensor for vapour influence correction, radar antenna designed to measure LNG even under surface boiling conditions
• Gas chromatograph (GC) to measure very low levels of CO2 in LNG to prevent solids formation
• Dual cryogenic-grade Coriolis mass flow measurement sensors with no moving parts for LNG dispensers in vehicle refueling stations, one for LNG filling, the other for boil-off gas return

Solutions in action

For example, an energy giant producing natural gas offshore off Western Australia, mostly operated from onshore, built the world’s largest FLNG vessel using Emerson as the main automation contractor on the project with Emerson automation solutions for the LNG production, liquefaction, and storage.

Automation and energy transition

Automation is a key driver of every industrial revolution and energy transition. Process licensors and contactors may not be aware of all these.