LNG Solutions

Boil-Off Gas (BOG) Management 

Boil-off gas management is central to efficient LNG cargo operations. LNG is a cryogenic liquid that naturally generates vapour due to heat ingress, a process known as boil-off. GTT LNG cargo management solutions provide real-time monitoring of energy performance for LNG carriers, tracking fuel consumption of engines, gas combustion units, and marine diesel oil or heavy fuel oil used to manage BOG. 

Our system monitors both natural and forced boil-off gas, ensuring that LNG carriers maintain optimal energy efficiency throughout navigation. Real-time data enables operators to optimise BOG utilisation, reducing fuel costs and minimising unnecessary venting. By continuously analysing energy consumption patterns, our digital solution supports informed operational decisions that improve overall vessel performance while ensuring compliance with environmental and safety regulations. 

Sloshing Management 

Sloshing inside LNG tanks can create significant operational risks. The movement of liquid cargo within partially filled tanks may generate high dynamic pressures, potentially damaging the tank structure and affecting operational safety. GTT provides real-time monitoring of sloshing activity for each tank, helping operators make critical decisions to optimise LNG cargo operations. 

Advanced analytics compare sloshing periods against the vessel’s operational profile, allowing operators to predict potential risks during navigation. By leveraging these insights, LNG carriers can adjust speed, heading, or operational procedures to minimise structural stress and maximise operational windows. Sloshing management is therefore essential to ensuring both tank integrity and vessel safety during loading, transit, and unloading operations. 

LNG Ageing 

LNG is a living cargo, and its thermodynamic and chemical properties evolve over time. Our LNG ageing module predicts changes in methane number, calorific value, temperature, pressure profiles, and holding time. These insights allow operators to monitor the evolution of natural gas properties, optimise cargo quality, and reduce transportation losses. 

Accurate LNG ageing prediction is also crucial for regulatory compliance. For example, nitrogen content may affect the Carbon Intensity Indicator (CII) calculation for LNG carriers. By anticipating changes in LNG composition, operators can plan optimal delivery schedules, adjust cargo conditioning strategies, and ensure that LNG meets charterer specifications throughout the voyage. 

Tank Maintenance Optimisation 

Maintaining LNG tanks is a critical component of operational efficiency. Our sloshing virtual sensor technology incorporates a unique fatigue prediction algorithm applied to the GTT tank digital twin. This enables operators to derive relevant indicators for Alternative Survey Plans (ASP), reducing the frequency of tank inspections without compromising safety. 

Optimising tank maintenance schedules translates into significant cost savings for LNG carriers. Operators can better plan inspections, anticipate potential structural issues, and ensure operational readiness while minimising downtime. The integration of digital twins, advanced analytics, and real-time monitoring enables a proactive maintenance approach that improves both safety and economic performance. 

Operational Window Optimisation for LNG Offshore Units 

Floating LNG units, including FLNGs and FSRUs, face operational constraints imposed by weather conditions, sea states, and vessel characteristics. Our digital solutions provide live sloshing risk prediction based on weather forecasts, ship particulars, and operational conditions. 

By anticipating potentially unsafe periods, operators can maximise the operational window of offshore LNG units. This predictive capability ensures that LNG carriers and floating units operate efficiently, maintaining cargo safety while optimising energy use and operational performance. As a result, units can deliver LNG reliably even under challenging environmental conditions, ensuring uninterrupted supply to meet growing global gas demand. 

Emergency Departure Support 

Loading or unloading LNG cargo may be jeopardised by sudden weather changes, particularly when tanks are partially filled. Our emergency departure tool provides decision support by suggesting optimal tank-to-tank transfer sequences to achieve safe filling levels. 

This functionality ensures that LNG carriers can respond promptly to unexpected conditions, mitigating risks associated with cargo instability, tank pressure variations, and boil-off gas generation. Emergency departure planning supports both operational continuity and crew safety, enabling operators to maintain efficient cargo operations while protecting valuable LNG assets. 

Roll-Over Prevention 

Roll-over is a critical phenomenon in LNG cargo management, occurring when two cargoes with different densities create stratification within the tank, potentially causing a sudden inversion of liquid phases and extreme BOG generation. 

GTT’s solutions assist operators in managing cargo stratification risks and preventing roll-over events. By analysing liquid density profiles and tank conditions in real time, operators can plan and execute cargo operations safely, ensuring that LNG carriers maintain structural integrity and operational safety while minimising boil-off losses. 

Cargo Conditioning 

During loading and unloading operations, constraints such as changes in ETA or discharge port requirements may arise. Our cargo conditioning tool allows operators to adjust LNG properties to meet the requirements of new discharge terminals. 

By calculating the BOG flow required to recondition the cargo, the system ensures that LNG remains within acceptable operational and chemical parameters. This minimises cargo losses and maximises delivered quantities, improving overall efficiency and economic performance. Crews and operators gain the ability to adapt LNG cargoes to changing operational demands without compromising safety or environmental standards. 

Integration of Data and Real-Time Monitoring 

Effective LNG cargo management relies on accurate, real-time data from multiple sources. GTT’s solutions integrate sensor data from tanks, pressure and temperature readings, BOG flow, and vessel operational parameters. This provides a holistic view of LNG cargo conditions across all tanks, supporting decisions related to fuel use, energy management, and operational planning. 

Operators can monitor liquid levels, gas pressures, and the thermodynamic state of methane and other components in real time. This comprehensive monitoring ensures that LNG carriers operate safely, efficiently, and in compliance with international regulations. Furthermore, data-driven insights support predictive maintenance, optimised voyage planning, and informed decision-making in response to changing environmental and market conditions.