Optimizing isotactic polypropylene membrane preparation condition via tips for carbon dioxide and nitrogen separation

• Main Author: Wan Zulaisa Amira, Wan Jusoh
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: Q Science (General); TP Chemical technology
• Online Access: http://umpir.ump.edu.my/id/eprint/15798/13/Optimizing%20isotactic%20polypropylene%20membrane%20preparation%20condition%20via%20tips%20for%20carbon%20dioxide%20and%20nitrogen%20separation.pdf; http://umpir.ump.edu.my/id/eprint/15798/

Over the past few decades, the emission of the flue gases into the atmosphere has increased and warms the earth’s surface. One of the options to minimize this problem is by recovering carbon dioxide (CO2) from flue gas before releasing it to surrounding. Gas separation technology using membrane is a simple system that can effectively remove the CO2 from flue gas as well as offering low installation cost. However, in the flue gas, there is water vapour content that causes the membrane to swell. Thus, for this study, in order to increase the durability and performance of membrane for CO2 and nitrogen (N2) separation, the hydrophobic membrane is proposed. This study focuses on the effect of the addition of adipic acid on the hydrophobicity of the isotactic polypropylene (iPP) membranes. Response Surface Method (RSM) consists of 2-Level Factorial (FFD) and Centre Composite Design (CCD) for screening and optimization processes in the production of iPP microporous membrane were performed respectively. From this study, it was found that there are no such work has been reported in the open literature on the optimization of iPP membrane for gas separation. For morphology by using Scanning Electron Microscopy (SEM), observation on the iPP- DPE membranes exhibited smaller pore size compared to iPP-Methyl Salicylate (MS) membrane. Meanwhile, increasing adipic acid showed decreasing membrane pore size distribution. The result obtained by Fourier Transform Infrared Spectroscopy (FTIR) showed that there is no bonding changes between raw iPP and membrane fabricated by Thermally Induced Phase Separation Method (TIPS). Membrane prepared by Dipenyl Ether (DPE) and without addition of adipic acid produced the highest contact angle, CO2 permeability and selectivity which are 112°, 22.01 GPU and 1.59 respectively. Analysis of variance of FFD showed that the impact of drying temperature and drying time were important than polymer concentration and immersion time in methanol toward contact angle and selectivity. The optimum membranes prepared in this experiment were membranes with the contact angle value and selectivity of 106.49 ° and 1.96 respectively at drying temperature of 54.96 °C and drying time of 18.66 min. These drying temperature and time are adequate for total methanol evaporation from pores which contributed to high selectivity and high contact angle value. The low error (below 30%) between predicted and actual value indicating that regression equations obtained from the FFD and CCD were expected to apply in the preparation of iPP membranes, can reasonably predict and optimize the performance of the iPP membranes.