CONTROLLED FREEZE ZONE™ COMMERCIAL DEMONSTRATION PLANT ADVANCES TECHNOLOGY FOR THE COMMERCIALIZATION OF SOUR GAS RESOURCES

摘要

The Controlled Freeze Zone (CFZ™) technology, developed at ExxonMobil UpstreamResearch Company, provides for the single-step removal and liquefaction of CO2 aswell as other acid gas components present in sour natural gases. It uses a novel threephase (vapor, liquid, solid) separation scheme, taking advantage of the behavior of CO2to form a pure solid phase as part of a low temperature distillation process, to effect thedirect separation of CO2 from methane without requiring use of a solvent or additive.The resulting high pressure liquid bottoms product can then be readily reinjected forgeosequestration or enhanced oil recovery purposes.A 14 MMSCFD CFZ™ Commercial Demonstration Plant (CDP) has been constructedand is undergoing testing and demonstration operations at our Shute Creek TreatingFacility in Wyoming, USA. The CDP is designed to process feed streams with CO2contents ranging from 15 to 65% and H2S contents of 0 to 35% at pressures up to 625psig. The CDP also demonstrates the advantages of discharging the sour gascomponents as a high pressure liquid stream by re-injecting the acid gas components viaan existing acid gas injection (AGI) facility.This paper will describe how the CFZ™ technology works and share highlights of theoperational experience to date of the CFZ™ Commercial Demonstration Plant. Theeffect of feed composition and process pressure on CDP operations will be presentedalong with information on process robustness, lessons from longer term testexperiences, and gas dehydration requirements.