Year-end Sale % OFF 
Abstract
A hydroxypolyamide (HPA) manufactured from 2,2-bis(3-amino-4-hydroxy phenyl)-hexafluoropropane (APAF) diamine and 5′-terbutyl-m-terphenyl-4,4′′-dicarboxylic acid chloride (tBTpCl), and a copolyimide produced by stochiometric copolymerization of APAF and 4,4′-(hexafluoroisopropylidene) diamine (6FpDA), using the same diacid chloride, were obtained and used as polymeric matrixes in mixed matrix membranes (MMMs) loaded with 20% (w/w) of two porous polymer networks (triptycene-isatin, PPN-1, and triptycene-trifluoroacetophenone, PPN-2). These MMMs, and also the thermally rearranged membranes (TR-MMMs) that underwent a thermal treatment process to convert the o-hydroxypolyamide moieties to polybenzoxazole ones, were characterized, and their gas separation properties evaluated for H2, N2, O2, CH4, and CO2. Both TR process and the addition of PPN increased permeability with minor decreases in selectivity for all gases tested. Excellent results were obtained, in terms of the permeability versus selectivity compromise, for H2/CH4 and H2/N2 separations with membranes approaching the 2008 Robeson’s trade-off line. The best gas separation properties were obtained when PPN-2 was used. Finally, gas permeation was characterized in terms of chain intersegmental distance and fraction of free volume of the membrane along with the kinetic diameters of the permeated gases. The intersegmental distance increased after TR and/or the addition of PPN-2. Permeability followed an exponential dependence with free volume and a quadratic function of the kinetic diameter of the gas.
Highlights
Today, renewable energy systems are attracting an increasing interest due to the evergrowing energy demand at a global scale, decreasing prices, and the urgent need to mitigate climate change [1]
According to the most recent report of the International Energy Agency, fossil fuels are the main source of H2 production, which is responsible for at least 830 million tons of CO2 emissions per year
H2 production accounted for 6% of global natural gas and 2% of global coal demand [3]
Summary
Renewable energy systems are attracting an increasing interest due to the evergrowing energy demand at a global scale, decreasing prices, and the urgent need to mitigate climate change [1]. In this context, hydrogen (H2) could play a key role in the energy sector since it represents a clean and cost-effective gaseous energy vector with a high specific energy content [2] that can substitute fossil fuels and reduce CO2 emissions [3,4,5]. According to Luo et al [6], membrane separation is considered an energy-efficient and sustainable alternative since it does not require the regeneration of the adsorption materials or a high energy demand to decrease the temperature of the gas mixture below −78 ◦C
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
