Carbon dioxide (CO2) removal from hydrocarbon gas streams such as produced natural gas, associated gas and associated natural gas liquids recovery. The systems are used for high CO2 gas bulk removal as in offshore applications and onshore EOR, and to remove CO2 to meet pipeline gas specifications in low CO2 gas streams onshore.
CYNARA membranes can also be applied to create a high quality CO2 product (+95% CO2) for reinjection. The unique hollow fiber design allows condensation of liquid hydrocarbons from rich gas streams (i.e., EOR) during separation.
Systems use CYNARA asymmetric, hollow membrane fibers to selectively separate CO2 from hydrocarbon streams. The membrane is a polymeric material that, unlike filters, molecularly interacts with the gas components to transport them through the membrane wall.
CYNARA membrane modules contain thousands of hollow fibers bundled to maximize surface area. Membrane modules are housed in vertical cases and skid packaged to reduce installation and site work costs. System configurations (i.e., staged units, primary/secondary units, and parallel units) are quite flexible to meet various process objectives.
Economics: CYNARA membrane systems range from 5 to 750 million scfd and process various feed compositions. Generally, economics favor feed streams containing 15% to 85% CO2, but CYNARA membranes have been successfully applied in lower CO2 streams to polish gas to pipeline specifications. Liquids recovery and environmental factors also favor CYNARA membrane systems over solvents and other membranes. Secondary membrane systems can be designed to further recover hydrocarbons from the primary permeate stream.
Operating conditions: CYNARA membranes can process a variety of gas compositions from 5% to 90% CO2 in the inlet to outlets of 1.5% to 23% CO2. Systems are designed with an application specific pretreatment process that removes harmful contaminants while optimizing feed temperature and pressure for membrane selectivity and efficiency. CYNARA membranes typically operate with CO2 partial pressure less than 500psi.
Licensor: NATCO Group Inc.