Zero Refrigerant Liquefaction Developments in the ZR-LNG Technology

Increasing LNG plant complexity and the high capital costs associated with recent mega-scale LNG developments are being challenged to improve project economics and reduce commercial risk. The patented ZR-LNG process requires no external gaseous or liquid hydrocarbon refrigerants, no refrigerant extraction, import system or storage facilities and no ongoing refrigerant make-up. It provides a simpler and safer low-cost liquefaction solution whilst achieving an energy efficiency close to dual mixed refrigerant schemes. Heavy components and aromatics can be removed within the expander-based ZR-LNG liquefaction unit, without need for a scrub column or stand-alone upstream turbo-expander NGL recovery unit, thus significantly reducing investment cost and footprint of the liquefaction train.

This elimination of equipment reduces capital cost and together with the absence of liquid hydrocarbon refrigerants makes the process particularly well suited to FLNG where weight, space constraints and safety are key design drivers.

The paper will describe the design development of a gas turbine driven nominal 1.5 Mtpa FLNG unit and other recent developments around the ZR-LNG process. Data on process efficiency, footprint, weights and costs will be included.