CO2 Removal from Natural Gas Using Membrane Contactor

CO2 is one of the major contaminants in natural gas streams. Its removal from the natural gas stream is necessary prior to entering downstream units of the gas processing plants due to Health, Safety and Environment (HSE) concern, heating value specification, as well as plant and pipeline corrosion issues. CO2 is conventionally removed using acid gas absorption tower and membrane technologies. Application of these technologies in offshore facilities requires high capital and operating expenses, and large foot print. The potential reduction in both capital investment and equipment footprint has made membrane contactor technology a compelling solution for the removal of CO2 in natural gas. A membrane contactor is a device that allows gas-liquid mass transfer without direct contact of the two phases which flow at the different sides of the membrane. Recent findings have shown that membrane contactors have several advantages over those existing separation systems, which include smaller footprint, modular, not sensitive to flooding, channelling or back-mixing, and provide larger contact areas for increased mass transfer rate. Realizing its potential, PETRONAS and Dalian Institute of Chemical Physics (DICP) have successfully completed a development study on membrane contactor which can remove CO2 from feed gas containing a range of 70-10% of CO2 down to as low as 1% at the outlet gas stream. The technology could potentially further remove CO2 down to ppm level meeting LNG specifications. A pilot plant to demonstrate its performance on actual plant conditions will be commissioned at PETRONAS Gas Processing Plant in 2013.