Modular LNG plant design: Safety, efficiency and scalability
LNG plants have undergone significant changes in their design, construction timelines and overall project management approaches in recent years. These shifts are driven by multiple factors, including rising global demand for natural gas, technological advancements and the need for cost-efficiency. One of the most notable changes is the shift towards modular construction. This involves assembling large sections (modules) of the LNG plant at offsite fabrication yards and then transporting them to the project site for final assembly. This method offers several benefits, including faster assembly and reduced risks, since a significant portion of the work is performed offsite. Modular construction can reduce overall capital expenditure (CAPEX), as fabrication facilities often operate in lower-cost environments compared to the location of the LNG plant.
Delivering flexibility and scalability. There is a growing demand for small- and mid-scale LNG plants, which are quicker to build and can be deployed in more remote or niche markets that do not require the massive capacity of traditional LNG plants. The advantages include faster development and lower costs to build, making them viable in emerging markets or areas where gas demand is smaller. For example, floating LNG (FLNG) units are inherently modular and benefit from quicker deployment because they do not require extensive site preparation. They can be moved to different gas fields, offering flexibility in production, and since they avoid much of the onshore environmental footprint, FLNG units can also be considered a more environmentally friendly option.
Small- and mid-scale LNG plants offer the advantage of scalability, allowing for expansion as demand increases and providing flexibility in response to shifting market conditions. To address financial pressures, many LNG plants are now constructed in phases. This phased approach enables operators to begin production at a smaller capacity and gradually expand, rather than waiting for the entire plant to be completed before producing LNG.
Besides modular plant construction, many smaller components are now being prefabricated, which enables construction to proceed rapidly and smoothly once onsite work begins. Additionally, LNG plants are increasingly designed using standardized components and layouts. This reduces engineering time and makes construction faster, as the same blueprints can be used across multiple projects. Enhanced project management techniques and software help reduce inefficiencies, allowing for faster decision-making and better coordination between different contractors and stakeholders.
Modular vs. site-built: Pros and cons. Modular components are often readily available from suppliers, enabling quicker repairs and easier sourcing of replacement parts. This availability reduces downtime and ensures more efficient maintenance operations. The use of modular systems may also streamline service contracts, as standardized components can be supported more effectively by the manufacturer or supplier, reducing operational complexity. In contrast, site-built structures can offer more customization and may be advantageous in certain conditions, such as when local regulations, climate or logistical challenges make it difficult to transport and assemble large modular components.
Modular buildings are constructed in a factory setting where quality control is more easily managed than traditional onsite construction. This controlled environment ensures that each component of the modular structure meets high standards for safety and performance. This consistency is invaluable for LNG plants because precision and reliability are paramount. While each design is third-party tested for safety, each unit is also subject to a factory acceptance test for quality. This happens before transporting it to the site to ensure that the final assembled structure meets all quality, safety and performance criteria.
Modular construction often produces less waste and a smaller environmental footprint than traditional building methods. Prefabrication allows for more precise material use and reduces the amount of construction debris. Additionally, modular buildings can be disassembled and relocated, which extends the lifecycle of the materials used, a common sustainability goal. In the context of LNG plants, where environmental impact is a significant concern, these benefits contribute to more sustainable operations.
Overall, for many LNG projects, modularization provides a more efficient and flexible approach, especially in the initial stages of construction and for ongoing operational needs.
Technical buildings in a modular plant design. Technical buildings are often prefabricated buildings constructed to enclose and protect equipment located in hazardous or harsh environments and are used for various jobs. Electrical houses, motor control centers, power control centers, local control rooms, remote instrument enclosures and local equipment rooms all serve the purpose of housing and protecting critical electrical, control and monitoring equipment. Electrical houses and power control centers safeguard power assemblies and electrical distribution systems, while motor control centers centralize control for multiple motors, especially in industrial settings. Local control rooms and remote instrument enclosures provide a controlled environment for monitoring equipment and protecting sensitive instruments, especially in extreme or hazardous locations. These structures are designed to meet specific certifications and standards for safety, including fire suppression, heating, ventilation and air conditioning (HVAC) systems and blast ratings where needed. Because they are often deployed in hazardous environments, technical buildings are constructed to withstand extreme conditions. They are also highly customizable and can be designed to meet a client’s exact technical specifications, allowing them to be utilized in various situations.
A divisiona of the authors’ company specializes in modular construction of fully compliant offshore structures and onshore electrical/technical buildings. The company has expanded its business significantly, utilizing multiple waterfront facilities to transport modular units by barge to offshore facilities and LNG plants. For example, the companya recently transported a three-level electrical building to a major offshore facility from its Belle Chase, Louisiana (U.S.) facility and will ship an 80-ft x 30-ft x 16-ft electrical building to a major LNG plant under construction in the future.
Considering blast resistance. Numerous LNG plants are under construction globally, with dozens more under consideration or awaiting a final investment decision (FID). LNG operations demand robust safety measures, and one of the most promising innovations in this field is the use of modular blast-resistant buildings (BRBs). These structures are reshaping how safety is managed in LNG plants, combining modular design principles with blast-resistant technologies. Properly engineered BRBs are widely accepted as the quickest and most cost-efficient way to create a control room space that will withstand an explosion. Blast tests, recent history and the continuous improvement of materials, production and features provides industrial facilities a quality option for control rooms that allow operators to detect releases, sound alarms, shut down systems at risk, order evacuations, communicate with authorities and most importantly, remain at stations through an explosive event to communicate and work with authorities after a blast event.
Material selection: Steel vs. concrete? The choice between steel and concrete in the construction of BRBs is not merely a matter of preference but a critical decision that significantly affects safety, durability and operational efficiency. Both materials play essential roles in the construction industry and form the backbone of modern infrastructure. Understanding the properties of each is vital to selecting the right material for specific applications.
Industrial steel is an alloy primarily composed of iron with approximately 2% carbon. Its strength, flexibility and adaptability make it a versatile choice across various designs and applications. Conversely, concrete is a composite material consisting of fine or coarse aggregates bound together by cement. As the cement cures, it forms a solid, durable structure. Concrete is known for its fire resistance and relatively quick project timelines, making it a popular choice in many standard construction applications.
However, when comparing the two materials for industrial applications, steel often outperforms concrete in both short- and long-term scenarios. Steel’s inherent strength and flexibility make it ideal for structures that need to withstand high loads, blasts or other extreme conditions. In contrast, concrete’s brittleness and limited tensile and shear strength make it less suitable for high-performance requirements, such as those in gas processing or LNG plants, where safety is paramount.
Additionally, concrete structures require more time to prepare, cure and install, and their heavier weight imposes greater loads on foundations. These factors can slow down project timelines and increase costs. Steel, by comparison, offers greater efficiency and sustainability. Steel modular BRBs provide superior structural integrity, lower maintenance needs and enhanced adaptability—qualities essential in environments where safety, resilience and operational reliability are non-negotiable.
In summary, while both materials have their place in construction, steel consistently proves to be the superior option for demanding industrial applications. Its combination of strength, flexibility and reliability makes it the material of choice for critical infrastructure in sectors where performance and safety are crucial.
Safeguarding the control room. Having a well-designed, properly-sited control building is a critical piece of maintaining or regaining control during a safety event. A robustly engineered modular BRB is an ideal upgrade to an aging stick-built or masonry control building that may not withstand an explosion, fire or toxic release.
Properly engineered modular BRBs are widely accepted as the quickest and most cost-efficient way to create a control room space that will withstand an explosion. A modular BRB is uniquely fire resistant, built with steel, and is recognized as a non-combustible building material by the International Building Code (IBC). Fire suppression systems can be installed on the interior, and passive fire protection can be applied on the exterior of a BRB to increase fire-resistance. The improvement and widespread availability of intumescent coatings (spray-applied fire resistive coatings) are very compatible with steel buildings. BRBs can be designed to specific fire protection and thermal transmission duration specs to ensure safe occupation during a fire if an evacuation is not immediately necessary or possible.
Takeaway. LNG plant construction is evolving rapidly to meet the growing global demand for natural gas, faster timelines and cost efficiency. Modularization, smaller and flexible plants, and the integration of sustainability measures are transforming how these facilities are designed, built and operated. As a result, LNG projects are becoming faster to deploy, more adaptable and better aligned with shifting market conditions.
Modular steel BRBs are constructed with reinforced heavy-gauge steel, blast-resistant glass and other robust materials, offering superior protection against explosions. The modular design allows for seamless integration of these safety features, which can be more challenging with traditional construction methods. These buildings are specifically engineered to withstand explosions and reduce damage from blast waves by using materials and techniques that absorb and dissipate explosive energy, safeguarding the structure and its occupants. Prefabricated offsite and assembled on location, modular BRBs provide a unique combination of safety and flexibility, making them ideal for the dynamic needs of LNG plants.
NOTES
a Armoda, a division of RedGuard
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