Research Article Separation of CO 2 from Small Gas Molecules Using Deca-Dodecasil 3 Rhombohedral (DDR3) Membrane Synthesized via Ultrasonically Assisted Hydrothermal Growth Method Muhammad Mubashir , 1 Yeong Yin Fong, 2 Sidra Saqib, 3 Ahmad Mukhtar, 2 Sikander Rafiq , 4 Muhammad Bilal K. Niazi , 5 Muhammad Babar, 2 Sami Ullah , 6 Abdullah G. Al-Sehemi, 6 and Farrukh Jamil 3 1 Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Netherlands 2 Department of Chemical Engineering, Universiti Teknologi PETRONAS (UTP), Seri Iskandar, Perak 32610, Malaysia 3 Department of Chemical Engineering, COMSATS University Islamabad (CUI), Lahore Campus, Punjab 54000, Pakistan 4 Department of Chemical, Polymer and Composite Materials Engineering, University of Engineering and Technology Lahore, New Campus, Pakistan 5 School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad 44000, Pakistan 6 Department of Chemistry, College of Science, King Khalid University, Abha 61413, P.O. Box 9004, Saudi Arabia Correspondence should be addressed to Muhammad Mubashir; m.mubashir@tue.nl and Sikander Rafiq; sikanderafiq@gmail.com Received 27 March 2020; Revised 11 June 2020; Accepted 19 June 2020; Published 20 July 2020 Academic Editor: Gyorgy Szekely Copyright © 2020 Muhammad Mubashir et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Deca-dodecasil 3 rhombohedral (DDR3) membrane has received much attention in CO 2 separation from small gas molecules because of its molecular sieving property and stable characteristics. Therefore, the present work is focusing on the utilization of previously fabricated membrane (synthesized in 3 days as reported in our previous work) to study the effect of hydrocarbons and its durability at the previously optimized conditions. Subsequently, gas permeation study was conducted on the DDR3 membrane in CO 2 separation from small gas molecules and it was found that the permeance of H 2 , CO 2 ,N 2 , and CH 4 decreased in the order of H 2 > CO 2 > N 2 > CH 4 , according to the increase in kinetic diameter of these gas molecules. Besides, it was observed that the ideal selectivities of the gas pairs decreased in the sequence of CO 2 /CH 4 > CO 2 /N 2 > H 2 /CO 2 . On the other hand, it was found that the presence of hydrocarbon impurities in the gas mixture containing CO 2 and CH 4 has directly affected the performance of DDR3 membrane and contributed to the losses of CO 2 permeability, CH 4 permeability, and CO 2 /CH 4 selectivity of 39.1%, 14.8%, and 4.2%, respectively. Consequently, from the stability test, the performance of DDR3 membrane remained stable for 96 h, even after the separation testing using CO 2 and CH 4 gas mixture containing hydrocarbon impurities. 1. Introduction Over the last few decades, much research has been done on the CO 2 separation especially in syngas production (mainly H 2 ) and natural gas purification. The presence of CO 2 in the syngas reduces the yield of hydrogen and methane recov- ery during the Fischer-Tropsch (FT) process [1, 2]. Similarly, the presence of CO 2 decreases the heating value of natural gas and caused equipment corrosion in the existence of water [3, 4]. Meanwhile, membrane separation technology has received much attention in CO 2 separation mainly due to its advantages compared to the conventional separation tech- nologies [5–11]. Zeolite membrane is favored in the CO 2 sep- aration among the membrane materials over polymeric and mixed matrix membranes due to its characteristics, including well-specified pores, the molecular filtering property, and Hindawi Advances in Polymer Technology Volume 2020, Article ID 1097309, 8 pages https://doi.org/10.1155/2020/1097309