The technology and processes of liquefied natural gas (LNG) production are various and complex, from liquefying natural gas to ensuring minimal loss due to regasification in storage. Like other sectors of the oil and gas industry, automation is poised to better monitor and improve LNG operations, providing greater efficiency and profitability. But how specifically can LNG plants benefit?
Honeywell has identified eight automation requirements (PDF) for those wishing to improve the processes of an LNG terminal, including reducing risks to assets, investment costs, process variability, and unplanned downtime. Automation can also help limit cost overruns, provide early detection of equipment problems, and improve compliance management. Honeywell also points out that physical and systems security can be improved, particularly among port complexes where national and international acts and codes require increased security considerations.
Automation helps meet those requirements in different ways. Automating process control means maximizing LNG feeds and improving energy use. It also means that the inventory, safety, and security of LNG tank farms and liquefaction/regasification components can be more effectively managed, typically via sensors, host interfaces, fire control systems, gas monitors, and closed-circuit television systems. Truck and vessel loading processes at terminals can also benefit from automated systems, which can more carefully measure quantities and better stabilize the safety of those processes. In most cases all these systems and data connect to a central control room, where compression systems, pipelines, integrity management systems, and safety systems can all be managed to better meet efficiency and safety requirements.
Of course simply turning to a control system to improve LNG operations isn’t enough. Expertise in both the system and business processes is necessary so that integration of automation components with all those processes is sensible and effective. As many point out, automation is still just a tool that must be wielded and integrated properly.
Major vendors of automation tools for LNG plants include Honeywell and Yokogawa, both of which offer integrated process control and safety control systems, often referred to as integrated control and safety systems (ICSS). The ICSS has been effectively integrated into onshore LNG processing stations, and it’s likely to be incorporated into offshore infrastructure, including Exmar’s delayed floating liquefaction, re-gasification, and storage unit (FLRSU).