Hybrid FSC Membrane for CO2 Removal from Natural Gas: Experimental, Process Simulation, and Economic Feasibility Analysis

The novel fixed-site-carrier (FSC) membranes were prepared by coating carbon nanotubes reinforced polyvinylamine/polyvinyl alcohol selective layer on top of ultrafiltration polysulfone support. Small pilot-scale modules with membrane area of 110-330 cm(2) were tested with high pressure permeation rig. The prepared hybrid FSC membranes show high CO2 permeance of 0.084-0.218 m(3) (STP)/(m(2) h bar) with CO2/CH4 selectivity of 17.9-34.7 at different feed pressures up to 40 bar for a 10% CO2 feed gas. Operating parameters of feed pressure, flow rate, and CO2 concentration were found to significantly influence membrane performance. HYSYS simulation integrated with ChemBrane and cost estimation was conducted to evaluate techno-economic feasibility of a membrane process for natural gas (NG) sweetening. Simulation results indicated that the developed FSC membranes could be a promising candidate for CO2 removal from low CO2 concentration (10%) NGs with a low NG sweetening cost of 5.73E-3 $/Nm(3) sweet NG produced. (c) 2014 American Institute of Chemical Engineers AIChE J 60: 4174-4184, 2014