随着人类社会发展,CO2的过量排放造成了温室效应的加剧。我国作为农业大国,秸秆产量巨大但资源化利用水平不高。本文以玉米秸秆为原材料制备了生物炭,掺入Pebax 1657中制成混合基质膜(MMMs)用于CO2分离纯化和玉米秸秆高价值利用。结果表...随着人类社会发展,CO2的过量排放造成了温室效应的加剧。我国作为农业大国,秸秆产量巨大但资源化利用水平不高。本文以玉米秸秆为原材料制备了生物炭,掺入Pebax 1657中制成混合基质膜(MMMs)用于CO2分离纯化和玉米秸秆高价值利用。结果表明,与纯Pebax 1657膜相比,生物炭填料的掺入提升了MMMs的性能,且随着掺杂比的提升气体分离性能呈现上升趋势。在掺杂比为4 wt%时性能最佳。玉米秸秆生物炭最佳CO2渗透系数和选择性分别为125.7 Barrer和81.78,相比纯Pebax 1657膜提升了69%和34%。生物炭掺杂Pebax 1657混合基质膜具有良好的分离CO2性能。With the development of human society, the excessive emission of CO2 has exacerbated the greenhouse effect. As a large agricultural country, straw production of China is huge, but its resource utilization level remains low. In this study, biochar was prepared from corn stalk, and then dopped into Pebax 1657 to produce mixed matrix membranes (MMMs), the obtained MMMs was used for CO2 separation from gas mixture. The results show that, compared to pure Pebax 1657 membranes, the doping of biochar enhanced the CO2 separation performance of MMMs. Additionally, the CO2 separation performance increased with elevating the doping rate, the best performance was achieved at a doping ratio of 4 wt%. The optimal CO2 permeability and selectivity of MMMs were 125.7 Barrer and 81.78, respectively, which separately improved 69% and 34% compared to pure Pebax 1657 membranes. Biochar-doped Pebax 1657 mixed matrix membranes exhibit excellent CO2 separation performance.展开更多
In this study,Pebax■2533 polymer was used as the continuous phase and UiO-67 was employed as the filler to prepare mixed matrix membranes.UiO-67 is usually synthesized using two ligands:biphenyl-4,4'-dicarboxylat...In this study,Pebax■2533 polymer was used as the continuous phase and UiO-67 was employed as the filler to prepare mixed matrix membranes.UiO-67 is usually synthesized using two ligands:biphenyl-4,4'-dicarboxylate(bpdc)and 2,2'-bipyridine-5,5'-dicarboxylic acid(bpy).In this research,UiO-67 was synthesized not only with these two ligands but also using a mixed ligand approach(50% bpdc and 50% bpy).The synthesized UiOs were incorporated into the polymer matrix at mass percentages ranging from 0% to 2% to form the mixed matrix membranes(MMMs).Membranes containing UiO-67 with mixed ligands exhibited a greater affinity for CO_(2) compared to other membranes.Various analytical techniques,including X-ray diffraction,thermogravimetric analyzer,Fourier transform infrared spectroscope(FTIR),field emission scanning electron micro scope(FESEM),and differential scanning calorimetry,were used to analyze the properties of the prepared membranes.The FTIR spectrum confirmed all desired bands of Pebax?2533 and UiO-67 in the MMMs.The FESEM images showed that the pure Pebax membrane has a uniform structure,and the developed membranes are uniformly incorporated with the synthesized UiO-67 nanoparticles.Gas permeation measurements indicated that CO_(2) permeability and CO_(2)/CH_4 selectivity increased from 402.7 Barrer(1 Barrer=1.33×10^(-14)m^(3)(STP)·m·m^(-2)·s^(-1)·kPa^(-1))and 9.32 for the pure Pebax membrane at 1.0 MPa to 770.1 Barrer and 16.96 in the modified membrane.Additionally,the gas permeation test results demonstrated that adding functionalized porous nanofillers increases the CO_(2)separation performance.Permeability tests at different temperatures revealed that as temperature was raised,at constant pressure,CO_(2) permeability for the membrane containing the mixed ligand increased from 682.2 Barrer to 733.5 Barrer,While CO_(2)/CH_(4) selectivity decreased from 15.46 to 13.43.展开更多
Covalent organic skeletons(COFs)have been widely used in gas separation due to their excellent pore structure,high crystallinity,and high specific surface area.In this work,Dha Tab-COF was synthesized by solvothermal ...Covalent organic skeletons(COFs)have been widely used in gas separation due to their excellent pore structure,high crystallinity,and high specific surface area.In this work,Dha Tab-COF was synthesized by solvothermal method and filled in polyether block polyamide(PEBAX)to form mixed matrix membranes(MMMs).Various characterization methods such as Fourier transform infrared spectroscopy(FT-IR),Xray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and X-ray diffractometry(XRD)were used to characterize the structure of Dha Tab-COF as well as the MMMs.The effects of operating pressure,operating temperature and the content of Dha Tab-COF particles on the CO_(2)/CH_(4)separation performance of the membranes were investigated.The best separation performance with a CO_(2)permeability of 295.8 barrer(1 barrer=7.52×10^(-18)m^(3)·(STP)·m^(-2)·m·s^(-1)·Pa^(-1))and a CO_(2)/CH_(4)selectivity of 21.6 was achieved when the Dha Tab-COF content is 2%(mass),which were 45.7%and 108.1%higher than that of the pure PEBAX membrane,respectively.展开更多
In this investigation, polymeric nanocomposite membranes（PNMs） were prepared via incorporating zinc oxide（ZnO） into poly（ether-block-amide）(PEBAX-1074) polymer matrix with different loadings. The neat membrane a...In this investigation, polymeric nanocomposite membranes（PNMs） were prepared via incorporating zinc oxide（ZnO） into poly（ether-block-amide）(PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy（FESEM） to survey cross-sectional morphologies and thermal gravimetric analysis（TGA）to study thermal stability. Fourier transform infrared（FT-IR） and X-ray diffraction（XRD） analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO, CHand Nthrough the prepared neat and nanocomposite membranes was studied at pressures of 3–18 bar and temperature of 25 °C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25 °C and pressure of 3 bar, COpermeability, ideal CO/CHand CO/Nselectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer,13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8 wt% ZnO.展开更多
文摘随着人类社会发展,CO2的过量排放造成了温室效应的加剧。我国作为农业大国,秸秆产量巨大但资源化利用水平不高。本文以玉米秸秆为原材料制备了生物炭,掺入Pebax 1657中制成混合基质膜(MMMs)用于CO2分离纯化和玉米秸秆高价值利用。结果表明,与纯Pebax 1657膜相比,生物炭填料的掺入提升了MMMs的性能,且随着掺杂比的提升气体分离性能呈现上升趋势。在掺杂比为4 wt%时性能最佳。玉米秸秆生物炭最佳CO2渗透系数和选择性分别为125.7 Barrer和81.78,相比纯Pebax 1657膜提升了69%和34%。生物炭掺杂Pebax 1657混合基质膜具有良好的分离CO2性能。With the development of human society, the excessive emission of CO2 has exacerbated the greenhouse effect. As a large agricultural country, straw production of China is huge, but its resource utilization level remains low. In this study, biochar was prepared from corn stalk, and then dopped into Pebax 1657 to produce mixed matrix membranes (MMMs), the obtained MMMs was used for CO2 separation from gas mixture. The results show that, compared to pure Pebax 1657 membranes, the doping of biochar enhanced the CO2 separation performance of MMMs. Additionally, the CO2 separation performance increased with elevating the doping rate, the best performance was achieved at a doping ratio of 4 wt%. The optimal CO2 permeability and selectivity of MMMs were 125.7 Barrer and 81.78, respectively, which separately improved 69% and 34% compared to pure Pebax 1657 membranes. Biochar-doped Pebax 1657 mixed matrix membranes exhibit excellent CO2 separation performance.
基金Babol Noshirvani University of Technology for financially support of this project(BNUT/393054/2023)。
文摘In this study,Pebax■2533 polymer was used as the continuous phase and UiO-67 was employed as the filler to prepare mixed matrix membranes.UiO-67 is usually synthesized using two ligands:biphenyl-4,4'-dicarboxylate(bpdc)and 2,2'-bipyridine-5,5'-dicarboxylic acid(bpy).In this research,UiO-67 was synthesized not only with these two ligands but also using a mixed ligand approach(50% bpdc and 50% bpy).The synthesized UiOs were incorporated into the polymer matrix at mass percentages ranging from 0% to 2% to form the mixed matrix membranes(MMMs).Membranes containing UiO-67 with mixed ligands exhibited a greater affinity for CO_(2) compared to other membranes.Various analytical techniques,including X-ray diffraction,thermogravimetric analyzer,Fourier transform infrared spectroscope(FTIR),field emission scanning electron micro scope(FESEM),and differential scanning calorimetry,were used to analyze the properties of the prepared membranes.The FTIR spectrum confirmed all desired bands of Pebax?2533 and UiO-67 in the MMMs.The FESEM images showed that the pure Pebax membrane has a uniform structure,and the developed membranes are uniformly incorporated with the synthesized UiO-67 nanoparticles.Gas permeation measurements indicated that CO_(2) permeability and CO_(2)/CH_4 selectivity increased from 402.7 Barrer(1 Barrer=1.33×10^(-14)m^(3)(STP)·m·m^(-2)·s^(-1)·kPa^(-1))and 9.32 for the pure Pebax membrane at 1.0 MPa to 770.1 Barrer and 16.96 in the modified membrane.Additionally,the gas permeation test results demonstrated that adding functionalized porous nanofillers increases the CO_(2)separation performance.Permeability tests at different temperatures revealed that as temperature was raised,at constant pressure,CO_(2) permeability for the membrane containing the mixed ligand increased from 682.2 Barrer to 733.5 Barrer,While CO_(2)/CH_(4) selectivity decreased from 15.46 to 13.43.
基金supported by the National Natural Science Foundation of China(No.22271022,No 22378327).
文摘Covalent organic skeletons(COFs)have been widely used in gas separation due to their excellent pore structure,high crystallinity,and high specific surface area.In this work,Dha Tab-COF was synthesized by solvothermal method and filled in polyether block polyamide(PEBAX)to form mixed matrix membranes(MMMs).Various characterization methods such as Fourier transform infrared spectroscopy(FT-IR),Xray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and X-ray diffractometry(XRD)were used to characterize the structure of Dha Tab-COF as well as the MMMs.The effects of operating pressure,operating temperature and the content of Dha Tab-COF particles on the CO_(2)/CH_(4)separation performance of the membranes were investigated.The best separation performance with a CO_(2)permeability of 295.8 barrer(1 barrer=7.52×10^(-18)m^(3)·(STP)·m^(-2)·m·s^(-1)·Pa^(-1))and a CO_(2)/CH_(4)selectivity of 21.6 was achieved when the Dha Tab-COF content is 2%(mass),which were 45.7%and 108.1%higher than that of the pure PEBAX membrane,respectively.
文摘In this investigation, polymeric nanocomposite membranes（PNMs） were prepared via incorporating zinc oxide（ZnO） into poly（ether-block-amide）(PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy（FESEM） to survey cross-sectional morphologies and thermal gravimetric analysis（TGA）to study thermal stability. Fourier transform infrared（FT-IR） and X-ray diffraction（XRD） analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO, CHand Nthrough the prepared neat and nanocomposite membranes was studied at pressures of 3–18 bar and temperature of 25 °C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25 °C and pressure of 3 bar, COpermeability, ideal CO/CHand CO/Nselectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer,13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8 wt% ZnO.
