Considerations in the Sizing of Power Generation Facilities for LNG Liquefaction Plants

High power demands of large scale LNG liquefaction plants have created the need for a careful and structured approach in selecting power generation facilities. Simultaneously, high thermal efficiency of LNG liquefaction plants is imperative to minimize feed usage and to reduce CO₂ emission.   Further, in gas constrained situations,  any savings in fuel auto consumption of the plant for liquefaction chilling and power generation can be converted into LNG production. Apart from optimal sizing of power generation, utilization of electrical infrastructure to support Spinning Reserve (SR) is one of the most important resources used by LNG plant operators to respond to unforeseen events such as generation outages and sudden load changes.

With focus on high overall plant efficiency, it is becoming increasingly popular to integrate process heat recovery and electrical power generation facility sizing. This paper delineates an integrated approach to process & power management, including optimal sizing of Gas Turbine (GTG), use of plant configurations including cogeneration by expanders and heat recovery steam generators, essential service diesel generators and load management. A number of indices for the GTG and project NPV calculation are finally discussed.