The evaluation of the flexibility of four small-scale LNG liquefaction processes using multiple natural gas feedstocks

Liquefied natural gas (LNG) is increasingly recognized as a cost-effective and adaptable solution for meeting global energy demands, particularly in remote and underserved regions. Small-scale LNG facilities offer key benefits, including lower capital costs, reduced infrastructure needs, and faster deployment. However, their high energy demands and sensitivity to feedstock variability pose significant challenges. This study addresses these issues through an optimization and flexibility framework for four LNG technologies: Single Mixed Refrigerant, Nitrogen Expander, Dual Mixed Refrigerant, and Mixed Fluid Cascade. The processes were optimized for a base feedstock and evaluated for their ability to adapt to light and heavy feedstocks under fixed design constraints. Results reveal Dual Mixed Refrigerant and Mixed Fluid Cascade configurations as the most energy-efficient and economically viable. Flexibility analysis indicates that Single Mixed Refrigerant, Nitrogen Expander, and Dual Mixed Refrigerant processes adapt effectively, liquefying both heavy and light feedstocks using the base design. However, the Mixed Fluid Cascade process struggled with light feedstocks due to inadequate heat transfer capacity. These findings underscore the importance of selecting suitable configurations for balancing energy efficiency, adaptability, and economic performance, providing valuable insights for sustainable LNG development.