Techno-economic feasibility study of membrane based propane/propylene separation process

One of the most important issues for developing propylene/propane gas separation membranes is to identify the minimum required membrane performances. Herein, we reported the technical and economic feasibility of facilitated propylene transport membranes containing silver nanoparticles, which produces 99.6% purity of propylene with 97% recovery for 46,000kg/h capacity. In order to suggest minimum specification, the membrane separation process is compared with advanced distillation process employing direct vapor recompression process. The distillation process is optimized using a stochastic solver interfaced with a commercial process simulator. With the distillation process, the energy and total costs are approximately $4.40 and 18.6$ to produce per ton of propylene, respectively. The single-stage membrane processes with various stage-cut conditions were evaluated to meet the same total propylene production cost. Result indicates that required membrane permeance and selectivity ranges between 11.3 to 251.5 GPU (permeance unit, 1 GPU=1×10−6cm3 (STP)/(cm s cmHg)) and 61.9 to 1950 depending on stage-cut. Sensitivity analysis was also performed according to membrane costs, feed flow rates and composition.