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1.
何文娟  王志  李雯  李诗纯  王纪孝 《化工学报》2014,65(11):4420-4429
含有醚氧基团的膜与CO2分子具有较强的极性作用,可以实现对CO2/N2物系的高效分离.其中,含丙烯氧(PO)基团的聚合物链段自由体积较大且不易结晶,是一类具有发展潜力的溶解选择性膜材料.以均苯三甲酰氯为油相单体,含PO基团的多胺为水相单体,通过界面聚合,成功制备了含PO基团的复合膜.分别采用聚醚胺D400、D230及T403为多胺水相单体,考察了膜内PO基团数量和交联度对复合膜分离性能的影响.结果表明,采用D400所制的复合膜由于具有最高的PO基团含量及较低的交联度,因此具有最高的CO2渗透速率和CO2/N2分离因子.之后,考察了单体浓度、酸吸收剂种类以及水相溶液pH对复合膜分离性能的影响.通过优化这些制膜条件,制备出了CO2/N2分离性能较好的复合膜.  相似文献   

2.
何玉鹏  王志  乔志华  远双杰  王纪孝 《化工学报》2015,66(10):3979-3990
为了提高CO2分离膜的性能,将接枝了氨基的MCM-41分子筛(MCM-NH2)添加到聚乙烯基胺(PVAm)水溶液中配制涂膜液,并将PVAm-MCM-NH2涂膜液涂覆到聚砜(PSf)超滤膜上制备PVAm-MCM-NH2/PSf混合基质复合膜。复合膜分离层较薄,有利于CO2渗透速率的提高。接枝的胺基提高了分子筛与聚合物的相容性和膜内胺基含量,有利于膜渗透选择性能的提高。使用CO2/N2混合气(15% CO2 + 85% N2,体积分数)考察了不同MCM-NH2添加量的PVAm-MCM-NH2/PSf膜的渗透选择性能。当涂膜液中mMCM-NH2/mPVAm为0.2、湿涂层厚度为50 μm,测试温度为22℃ 、进料气压力为0.11 MPa时,膜的CO2渗透速率可达4.66×10-7 mol·m-2·s-1·Pa-1,CO2/N2分离因子可达150。较高的CO2/N2分离性能表明PVAm-MCM-NH2/PSf膜在烟道气碳捕集领域具有良好的应用前景。此外,考察了湿涂层厚度、热处理、添加小分子胺等条件对膜渗透选择性能的影响。  相似文献   

3.
为了获得经济节能的烟道气CO2回收方法,制备了一种新型的N2优先渗透ZIF-8复合膜。以柔性聚砜(PSf)多孔膜为支撑层,采用Zn2+与壳聚糖的交联溶液对聚砜支撑层表面改性,使Zn2+固定在PSf膜表面;然后与2-甲基咪唑(Hmim)配位得到ZIF-8晶种层;最后通过界面聚合法二次生长制得ZIF-8复合膜。采用FTIR、XRD及SEM对ZIF-8复合膜的形貌结构进行表征,结果显示成功制备了致密的ZIF-8复合膜。在进料气为纯气条件下,探究了二次生长时间、Zn2+溶液的浓度、测试时间及测试压力对ZIF-8复合膜N2/CO2分离性能的影响,阐明其N2优先渗透机理;并进一步考察了混合气分离性能。结果表明:在25℃和0.1 MPa下,最优ZIF-8复合膜的N2渗透性为523 GPU,N2/CO2选择性为19;同条件下混合气的N2渗透性和N2/CO2选择性分别为517 GPU和18。所制备的ZIF-8复合膜可以使N2优先渗透,实现烟道气中高浓度N2渗透,低浓度CO2截留在膜的上游侧。原因主要是ZIF-8复合膜含有较多的CO2强吸附位点,使CO2被吸附在膜内不易从膜的下游侧脱附,渗透性小,而N2优先渗透,这为N2优先渗透膜的制备提供了一种新思路。  相似文献   

4.
Thin film composite (TFC) membranes with nanofillers additives for CO2 separation show promising applications in energy and environment-related fields. However, the poor compatibility between nanofillers and polymers in TFC membranes is the main problem. In this work, covalent organic frameworks (COFs, TpPa-1) with rich —NH— groups were incorporated into polyamide (PA) segment via in situ interfacial polymerization to prepare defect-free TFC membranes for CO2/N2 separation. The formed covalent bonds between TpPa-1 and PA strengthen the interaction between nanofillers and polymers, thereby enhancing compatibility. Besides, the incorporated COFs disturb the rigid structure of the PA layer, and provide fast CO2 transfer channels. The incorporated COFs also increase the content of effective carriers, which enhances the CO2 facilitated transport. Consequently, in CO2/N2 mixed gas separation test, the optimal TFC (TpPa0.025-PIP-TMC/mPSf) membrane exhibits high CO2 permeance of 854 GPU and high CO2/N2 selectivity of 148 at 0.15 MPa, CO2 permeance of 456 GPU (gas permeation unit) and CO2/N2 selectivity of 92 at 0.5 MPa. In addition, the TpPa0.025-PIP-TMC/mPSf membrane also achieves high permselectivty in CO2/CH4 mixed gas separation test. Finally, the optimal TFC membrane showes good stability in the simulated flue gas test, revealing the application potential for CO2 capture from flue gas.  相似文献   

5.
SAPO-34 zeolite membranes show high efficiency for CO2/CH4 separation but suffer from the reduction of separation performance when exposed to humid atmosphere. In this work, n-dodecyltrimethoxysilane (DTMS) was used to modify the hollow fibers supported SAPO-34 membranes to increase the external surface hydrophobicity and thus sustain their performance under moisture environment. The modified membranes were fully characterized. Their separation performance was extensively investigated in both dry and wet gaseous systems and compared with the un-modified ones. The un-modified SAPO-34 membrane exhibited a high separation selectivity of 160 and CO2 permeance of 1.18×10-6 mol·m-2·s-1·Pa-1 for separation of dry CO2/CH4 at 298 K. However, its separation selectivity declined to 0.9 and the CO2 permeance was only about 1.7×10-8 mol·m-2·s-1·Pa-1 for wet CO2/CH4 at same temperature. High temperature (e.g. 353 K) could reduce the effect of moisture to improve SAPO-34 separation selectivity, but further increasing temperature (e.g. 373 K) led to decrease in CO2/CH4 separation selectivity. A significant decrease of selectivity was observed at higher pressure drop. The modified SAPO-34 membrane showed decreased CO2 permeance but increased separation selectivity for dry CO2/CH4 gas mixture, and super performance for wet CO2/CH4 gas mixture due to the improved hydrophobicity of membrane surface. A separation selectivity of 65 and CO2 permeance of 4.73×10-8 mol·m-2·s-1·Pa-1 for wet CO2/CH4 mixture can be observed at 353 K with a pressure drop of 0.4 MPa. Furthermore, the modified membrane exhibited stable separation performance during the 120-hour test for wet CO2/CH4 mixture at 353 K. The hydrophobic modification paves a way for SAPO-34 membranes in real applications.  相似文献   

6.
SSZ-13 membranes with high separation performances were prepared using ball-milled nanosized seeds by once hydrothermal synthesis. Separation performances of SSZ-13 membranes in CO_2/CH_4 and N_2/CH_4 mixtures were enhanced after synthesis modification. Single-gas permeances of CO_2, N_2 and CH_4 and ideal selectivities were recorded through SSZ-13 membranes. The effects of temperature, pressure, feed flow rate and humidity on separation performance of the membranes were discussed. Three membranes prepared after synthesis modifications had an average CO_2 permeance of 1.16 × 10~(-6) mol·(m~2· s·Pa)~(-1)(equal to 3554 GPU) with an average CO_2/CH_4 selectivity of 213 in a 50 vol%/50 vol% CO_2/CH_4 mixture. It suggests that membrane synthesis has a good reproducible. The membrane also displayed a N_2 permeance of 1.07 × 10~(-7) mol·(m~2·s·Pa)~(-1)(equal to 320 GPU) with a N_2/CH_4 selectivity of 13 for a 50 vol%/50 vol% N_2/CH_4 mixture. SSZ-13 membrane displayed stable and good separation performance in the wet CO_2/CH_4 mixture for a long test period over 100 h at 348 K. The current SSZ-13 membranes show great potentials for the simultaneous removals of CO_2 and N_2 in natural gas purification as a facile process suitable for industrial application.  相似文献   

7.
This communication reports experimental efforts to synthesize defect-free mesoporous MCM-48 membranes with improved gas flux. We demonstrate a facile and inexpensive method of synthesizing defect-free supported MCM-48 membranes with improved N2 and CO2 permeance (>2 × 10−7 mol/m2 s Pa) employing asymmetric supports for the membrane synthesis which contain layers of macropores possessing different pore sizes. The membranes prepared on asymmetric -alumina supports displayed higher gas permeance than those fabricated on symmetric supports (N2 permeance <10−7 mol/m2 s Pa) as confirmed by unsteady-state gas permeation experiments. Further improvement in gas permeance was achieved by covering one face and the sides of the support with a ceramic tape during membrane synthesis.  相似文献   

8.
The special channels and intrinsic defects within GO laminates make it a very potential candidate for gas separation in recent years. Herein, the gas separation performance of GO membranes prepared on the surface of ceramicα-Al_2O_3 hollow fibre was investigated systematically. The microstructures of ceramic hollow fibre supported GO membranes were optimized by adjusting operation conditions. And, the GO membrane fabricated at 30 min exhibited great promising H_2 recovery ability from H_2/CO_2 mixture. At room temperature, the H_2 permeance was over 1.00 × 10~(-7)mol·m~(-2)·s~(-1)·Pa~(-1)for both single gas and binary mixture. The corresponding ideal selectivity and mixture separation factor reached around 15 and 10, respectively. In addition, humility, operation temperature, H_2 concentration in the feed and the reproducibility were also studied in this work.  相似文献   

9.
制备高性能的气体分离膜,是实现CO2高效回收的关键。为了提高CO2分离膜的性能,将中空管状结构的埃洛石纳米管(HNTs)添加到聚乙烯胺(PVAm)中配制涂膜液,并将PVAm-HNTs涂膜液涂覆到聚砜(PSf)超滤膜上制备PVAm-HNTs/PSf混合基质膜。其中PSf超滤膜作为支撑层,PVAm-HNTs致密涂层作为功能层,功能层结构与形态对CO2分离具有关键作用。采用XRD、SEM对HNTs的结构与形态进行表征,并借助FTIR和SEM对膜的形态与结构进行分析。在进料气为纯气条件下,系统地研究了HNTs添加量、进料压力、PVAm-HNTs涂层厚度对PVAm-HNTs/PSf膜的CO2分离性能影响,并考察了混合基质膜的CO2/N2混合气分离性能。结果显示:在水溶液中显示正电性的PVAm与负电性的HNTs具有较好的界面相容性。HNTs添加量为1%(质量)、PVAm-HNTs湿涂层厚度为50 μm的混合基质膜,表现出最优的CO2分离性能。在进料气压力为0.1 MPa、测试温度为25℃、CO2/N2(15/85,体积比)混合气进料的条件下,膜的CO2渗透速率为178 GPU,CO2/N2选择性为83;该膜具有较好的稳定性,经过120 h运行后,渗透性和选择性仍能保持稳定。  相似文献   

10.
To obtain high-performance gas separation membranes and realize high-efficiency separation and recovery of CO2/N2 in flue gas, the amino-rich semi-interpenetrating network blend membranes were prepared by in-situ crosslinking reaction, which provided CO2 transport channels and affinity sites. Sulfonated poly(ether ether ketone) (SPEEK) and polysuccinimide (PSI) were used as raw materials, and hexamethylenediamine was crosslinking agent. The structure of the blend membranes was characterized by Fourier-transform infrared spectroscopy. The effects of water content, PSI dosage and feed gas pressure on the gas separation performance were studied, and its gas separation performance and the long-time stability were investigated under mixed gas conditions. The results showed that SPEEK and PSI have a good compatibility, and there is a strong interaction between them, which exhibited the semi-interpenetrating network microstructure in the membranes. When the PSI loading is 60%(mass), the CO2 permeability of pure gas and mixed gas are 652 and 601 Barrer, respectively, and the corresponding CO2/N2 selectivity is 67.6 and 60.3, which is better than that in pristine SPEEK membrane, surpassing 2008 Robeson upper bound. The CO2 permeability and CO2/N2 selectivity are still stable after 360 h durability test of SPEEK/PSI-60 blend membrane. This is mainly due to the formation of the amino-rich semi-interpenetrating network microstructure between SPEEK and PSI, which not only provides CO2 facilitated transport carriers, but also enhances the water retention performance of the blend membranes and forms a large number of CO2 transport water channels.  相似文献   

11.
高殷  王永洪  张新儒  李晋平  凌军 《化工学报》2020,71(12):5813-5820
为了获得高性能的气体分离膜,实现烟道气中CO2/N2高效分离回收,以磺化聚醚醚酮(SPEEK)和聚琥珀酰亚胺(PSI)为原料,己二胺为交联剂,原位交联反应制备富含氨基的半互穿网络共混膜,在膜内构建CO2传递通道和亲和位点,并采用红外光谱对共混膜的结构进行表征。研究水含量、PSI用量和进料气压力对膜气体分离性能的影响,在混合气条件下考察其气体分离性能和长时间运行稳定性。研究结果表明:SPEEK与PSI两相界面相容性较好,它们之间存在较强的相互作用,且呈半互穿网络微结构;PSI含量为60%(质量)时,纯气和混合气条件下CO2渗透性分别为652和601 Barrer,对应的CO2/N2选择性为67.6和60.3,优于纯SPEEK膜,且超过2008年的Robeson上限;共混膜运行360 h后,CO2渗透性和CO2/N2选择性仍然稳定。这主要是因为SPEEK与PSI形成富含氨基的半互穿网络微结构后,一方面提供了CO2促进传递载体;另一方面,增强了共混膜的保水性能,形成大量CO2传递水通道。  相似文献   

12.
使用氨基硫脲(TSC)对氧化石墨烯(GO)进行改性,制备GO-TSC层状复合材料。随后,将该复合材料加入到Matrimid®5218(PI)基质中,制备用于二氧化碳分离的混合基质膜(MMMs)。通过TGA、SEM及气体分离性能测试考察了GO-TSC对膜热稳定性、结构和气体分离性能等的影响。SEM结果显示GO-TSC可均匀分散在聚合物基质上并与基质紧密结合;TGA结果显示混合基质膜在250 ℃以上仍保持稳定。与纯PI膜相比,MMMs显著增强了二氧化碳的渗透性。GO-TSC中所含的氨基与二氧化碳具有良好的亲和力,增加的碱性位点可以有效地转运二氧化碳。GO-TSC的层状结构增加了气体的传输路径,不利于大动态直径气体(甲烷、氮气)的通过,从而提高了分离性能。GO-TSC负载量为0.75%(质量分数)时混合基质膜的分离性能最佳。相比较纯PI膜,混合基质膜的二氧化碳渗透系数和二氧化碳/甲烷、二氧化碳/氮气分离系数分别提高了42.16%、95.79%和83.72%。  相似文献   

13.
Membrane technology features inspiring excellence from numerous separation technologies for CO2 capture from post-combustion gas. Polyvinylamine (PVAm)-based facilitated transport membranes show significantly high separation performance, which has been proven promising for industrial scale-up. However, commercialized PVAm with low molecular weight and excessive crystallinity is not available to prepare high-performance membranes. Herein, the synthesis process of PVAm was optimized by regulating polymerization and acidic hydrolytic conditions. The membranes based on PVAm with a molecular weight of 154 kDa and crystallinity of 11.37% display high CO2 permeance of 726 GPU and CO2/N2 selectivity of 55 at a feed gas pressure of 0.50 MPa. Furthermore, we established a PVAm synthesis reactor with an annual PVAm solution (1%(mass)) capacity of over 7000 kg and realized the scaled-up manufacture of both PVAm and composite membranes.  相似文献   

14.
宁梦佳  代岩  郗元  章星  刘红晶  贺高红 《化工进展》2021,40(10):5652-5659
为了提高Pebax-1657的CO2分离性能,本文制备了对CO2有吸附作用的金属有机骨架Cu(Qc)2,将其加入到Pebax-1657基质中,制备混合基质膜,用于CO2的气体分离。通过扫描电子显微镜、热重分析、红外光谱和X射线衍射对溶液浇铸法制备的膜进行表征,通过膜的气体渗透性能测试考察填料含量、操作压力和混合气对膜气体渗透性能的影响。结果表明,Cu(Qc)2在Pebax基质中随机有效地堆叠形成了高选择性的气体传输通道,极大地提高了CO2/N2的选择性。随着Cu(Qc)2填充量的增加,CO2渗透系数和CO2/N2选择性均呈现先上升后下降的趋势。当Cu(Qc)2的质量分数为3%时,呈现最佳的CO2/N2分离性能,CO2 渗透系数和CO2/N2选择性分别为102Barrer和84,与Pebax-1657膜相比,分别提高了45.7%和40.0%,突破了Robeson分离上限,表明该混合基质膜在CO2的分离应用上具有潜力。  相似文献   

15.
曹晓畅  王志  乔志华  王纪孝  许振良 《化工学报》2018,69(11):4778-4787
采用一步相分离法,制备以聚醚砜(PES)为主体材料,二乙醇胺(DEA)为添加剂和氨基载体的膜,用于CO2分离。考察了PES浓度、DEA浓度、膜厚度对CO2/N2分离性能的影响,同时考察了膜性能的长时间稳定性。当涂膜液中DEA/PES的质量比为12/26、刮刀与无纺布的距离为300 μm、进料气压力为0.11 MPa(表压)时,膜的CO2渗透速率可达274 GPU,CO2/N2分离因子可达50。测试温度低于40℃时,DEA/PES膜的CO2渗透速率和CO2/N2分离因子保持稳定。另外,对CO2/N2分离性能较好的DEA/PES膜(质量比为12/27)进行CO2/CH4分离性能测试,在1 MPa(表压)下性能优于商品膜。上述结果表明,本文研制的DEA/PES膜制备步骤简单,易于规模化制备,性能较优,在CO2分离领域具有良好的应用前景。  相似文献   

16.
-Alumina-supported MFI zeolite membranes were modified by on-stream catalytic thermal cracking of methyldiethoxysilane (MDES) molecules inside the zeolitic channels during the separation of H2/CO2 gas mixture at 450 °C and atmospheric pressure. The MDES vapor was carried by the H2/CO2 feed gas and the effect of modification was monitored continuously through online analysis of the permeate stream. The modified membrane exhibited a significant increase in H2 selectivity over CO2 with a moderate decrease in H2 permeance. At 450 °C, the modified MFI membrane obtained a H2/CO2 permselectivity of 17.5 with H2 single gas permeance of 1.86 × 10−7 mol m−2 s−1 Pa−1 as compared to a permselectivity of 2.78 and permeance of 2.75 × 10−7 mol m−2 s−1 Pa−1 for the membrane before modification. The modified membrane also showed good performance and stability in separation of H2/CO2 gas mixture containing up to 28.4% water vapor at 450 °C and atmospheric pressure.  相似文献   

17.
Tensile strain of porous membrane materials can broaden their capacity in gas separation. In this work, using van der Waals corrected density functional theory(DFT) and molecular dynamics(MD) simulations, the performance and mechanism of CO_2/CH_4 separation through strain-oriented graphdiyne(GDY) monolayer were studied by applying lateral strain. It is demonstrated that the CO_2 permeance peaks at 1.29 × 10~6 gas permeation units(GPU) accompanied with CO_2/CH_4 selectivity of 5.27 × 10~3 under ultimate strain, both of which are far beyond the Robeson's limit. Furthermore, the GDY membrane exhibited a decreasing gas diffusion energy barrier and increasing permeance with the increase of applied tensile strain. CO_2 molecule tends to reoriented itself vertically to permeate the membrane. Finally, the CO_2 permeability decreases with the increase of the temperature from300 K to 500 K due to conserving of rotational freedom, suggesting an abnormal permeance of CO_2 in relation to temperature. Our theoretical results suggest that the stretchable GDY monolayer holds great promise to be an excellent candidate for CO_2/CH_4 separation, owing to its extremely high selectivity and permeability of CO_2.  相似文献   

18.
靳卓  王永洪  张新儒  白雪  李晋平 《化工学报》2022,73(10):4527-4538
为了获得高性能的CO2/N2分离膜,把空气中氧刻蚀的二硫化钼(a-MoS2)和金属有机框架材料MIP-202通过机械力化学反应制备的双功能填料作为分散相,聚醚嵌段酰胺(Pebax-1657)作为连续相,采用溶液浇铸法制备了Pebax/a-MoS2/MIP-202混合基质膜。采用FT-IR表征了填料的化学结构,借助ATR-FTIR、SEM、TG和力学性能测试表征了混合基质膜的化学结构、微观形貌结构、热稳定性和物理力学性能。研究了水含量、双功能填料配比、含量、膜两侧压差和操作温度对膜气体分离性能的影响,并考察了模拟烟道气(CO2/N2体积比15/85)条件下混合基质膜的长时间运行稳定性。结果表明:在温度为25℃、膜两侧压差为0.1 MPa的操作条件下,a-MoS2与MIP-202质量比为5∶5和双功能填料含量为6%(质量)时,膜的气体分离性能达到最优,CO2渗透性和CO2/N2选择性分别为380 Barrer和124.7,超过了2019年McKeown等提出的上限值。连续测试360 h后,混合基质膜的性能没有明显降低,其平均CO2渗透性和CO2/N2选择性分别为358 Barrer和120.1。这主要是由于a-MoS2和MIP-202协同提高了膜的气体分离性能。  相似文献   

19.
靳卓  王永洪  张新儒  白雪  李晋平 《化工学报》1951,73(10):4527-4538
为了获得高性能的CO2/N2分离膜,把空气中氧刻蚀的二硫化钼(a-MoS2)和金属有机框架材料MIP-202通过机械力化学反应制备的双功能填料作为分散相,聚醚嵌段酰胺(Pebax-1657)作为连续相,采用溶液浇铸法制备了Pebax/a-MoS2/MIP-202混合基质膜。采用FT-IR表征了填料的化学结构,借助ATR-FTIR、SEM、TG和力学性能测试表征了混合基质膜的化学结构、微观形貌结构、热稳定性和物理力学性能。研究了水含量、双功能填料配比、含量、膜两侧压差和操作温度对膜气体分离性能的影响,并考察了模拟烟道气(CO2/N2体积比15/85)条件下混合基质膜的长时间运行稳定性。结果表明:在温度为25℃、膜两侧压差为0.1 MPa的操作条件下,a-MoS2与MIP-202质量比为5∶5和双功能填料含量为6%(质量)时,膜的气体分离性能达到最优,CO2渗透性和CO2/N2选择性分别为380 Barrer和124.7,超过了2019年McKeown等提出的上限值。连续测试360 h后,混合基质膜的性能没有明显降低,其平均CO2渗透性和CO2/N2选择性分别为358 Barrer和120.1。这主要是由于a-MoS2和MIP-202协同提高了膜的气体分离性能。  相似文献   

20.
白璐  张香平  邓靓  李梦蝶 《化工学报》2016,67(1):248-257
离子液体由于具有不易挥发、结构可调、对CO2有良好的吸收性能等特点而成为当前CO2分离领域的研究热点,但因高黏度和高成本问题而限制了其工业化应用。将离子液体与气体分离膜材料结合,得到的新型分离膜材料兼具离子液体和膜的优势,成为当前离子液体研究领域的趋势之一。针对这一热点问题,综述了离子液体支撑液膜、聚离子液体膜和离子液体共混/杂化膜在CO2分离方面的研究现状和进展,讨论了离子液体结构和含量对膜分离性能、稳定性等的影响。相关研究表明,离子液体共混/杂化膜具有较高的分离性能和稳定性,是一种很有应用前景的CO2分离材料。提出该领域的重点发展方向,即开发新的功能化离子液体共混/杂化膜材料是解决高渗透通量与高稳定性之间矛盾、强化CO2分离性能的有效途径,深入研究离子液体共混/杂化膜的形成机制、气体在膜中的渗透行为以及CO2分离机理。  相似文献   

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