Abstract
Over the last five decades of the LNG industry, there has been a significant evolution in the drivers used to power the refrigeration compressors, spanning a wide range of solutions including steam turbines (ST), heavy duty or aeroderivative gas turbines (GT), electric motors, and their combinations [1]. The trend is currently driven by the need to reduce greenhouse gas emissions. A viable solution to reduce the CO2e/tonne LNG produced of LNG liquefaction plants with GT drivers is to utilize bottoming power cycle(s) (e.g., Steam Rankine Cycle or Organic Rankine Cycle) to recover the waste heat energy from the GT exhaust gases. Other options include a combination of hybrid drives (e.g., GT and ST, or GT and motor) for the refrigeration compressors. This paper is intended to describe opportunities, challenges, and design options for decarbonization of LNG liquefaction plants by focusing on gas turbine drivers of refrigeration compressors. It describes different design options for reducing carbon emissions in both brownfield and greenfield LNG liquefaction plants. Also covered are different design options for CO2 compression systems in LNG liquefaction plants, and transcritical compression pathways.
