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Frances K. 

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Original Title: "The World's Most Rich University", Membrane Separation Releases "Nature"! Published 3 Science/Nature articles in 20 days! One Research background Natural gas accounts for at least a quarter of the world's energy supply, a share that is expected to overtake coal around 2032. This growth poses a challenge to conventional natural gas purification technologies because natural gas reservoirs are contaminated with nitrogen (N2) and carbon dioxide (CO2). In fact, about 50% of the world's natural gas reserves, known as substandard reservoirs, exceed the maximum of 4% of N2 pipeline specifications. Therefore, it is necessary to explore energy-efficient and low-cost technologies that can separate N2 from methane (CH4). In contrast to the different CO2 capture pathways (e.g. liquid-based absorbents, solid-state sorbents, and membranes), cryogenic distillation is currently the only technology employed for plant-scale N2 removal. In theory, N2 selective membranes or CH4 selective membranes can distinguish between N2 and CH4; however, N2 selective membranes are preferred because CH4 is trapped at high pressures, saving the high cost of recompression compared to using CH4 selective membranes. However, due to the small size difference, the ideal N2/CH4 selectivity, even for the polymer membranes of the prior art, remains below 3. Inorganic membranes based on narrow pore size zeolites (about 3.8 ?) can perform better with an optimal N2/CH4 selectivity higher than 10. However, this is at the expense of low productivity due to the small pore size, and there is also a trade-off behavior between permeability and selectivity among zeolite membranes. Two Research results To use natural gas as an alternative to coal and oil, its main component, methane, needs to be separated in high purity. In particular, nitrogen dilutes the calorific value of natural gas and is therefore critical to cleanup. However,hemp extraction centrifuge, the inertness of nitrogen and its similarity to methane in terms of kinetic size, polarizability, and boiling point pose special challenges for developing energy-efficient nitrogen removal processes. Today, Professor Mohamed Eddaoudi's team at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia reported a mixed-junction metal-organic framework (MOF) membrane based on fumarate (fum) and mesaconate (mes) junctions, Zr-fum67-mes33-fcu-MOF. Which has a specific aperture shape for efficient removal of nitrogen from natural gas. The intentional introduction of asymmetry in the parent trilobal pore results in an irregular shape that prevents the transport of tetrahedral methane while allowing linear nitrogen penetration. The Zr-Fum67-Mes33-Fcu-MOF membrane exhibits record high nitrogen/methane selectivity and nitrogen permeability at realistic pressures up to 50 bar, removing carbon dioxide and nitrogen from natural gas. Techno-economic analysis shows that this membrane has the potential to reduce the cost of methane purification by about 66% relative to cryogenic distillation and amine-based carbon dioxide capture, while reducing the cost of carbon dioxide and nitrogen removal by about 73%. Relevant research work was published in the top international journal Nature under the title of "Asymmetric pore windows in MOF membranes for natural gas valorization" ". According to reports, King Abdullah University of Science and Technology just published two Science blockbuster achievements on membrane separation on June 3. Less than a month later,rotovap distillation, Nature was published again. It's too strong! King Abdullah University of Science and Technology (KAUST), known as "the richest university in the world", is a private, international and research-oriented university specializing in science and engineering. Known as the "House of Wisdom", the "Arab MIT" was established in 2009 and is located in Jeddah, Saudi Arabia.
The school has the world's top scientific research facilities and laboratories, and is committed to promoting global scientific and technological progress through interdisciplinary research, education and innovation. Its establishment concept draws lessons from the "small but fine" model of California Institute of Technology in the United States, and recruits master's and doctoral students globally. In 2007, King Abdullah of Saudi Arabia spent more than $10 billion to build a science and technology university named after himself in Thuwal, a small fishing village near Jeddah, near the holy city of Mecca, to fulfill his long-cherished wish 25 years ago. He wants to build a university in his own land, like the "Palace of Wisdom" built by the Abbasid Caliph Maimon in 832 A.D., to gather the world's academic elites to explore the secrets of the universe and solve the most pressing problems facing not only Saudi Arabia or the Middle East, but also all mankind. He wants the university to be a beacon of knowledge for the new generation. Expand the full text As a young university, molecular distillation systems ,nutsche filter dryer, KAUST has become one of the fastest growing academic institutions in the world in terms of academic research and citation rates. KAUST ranked first in the world for two consecutive years in 2015 and 2016, surpassing Stanford University, Zurich Institute of Technology, Cornell University and other world-class universities, according to the QS World University Ranking- "Citation Number of Papers on Unit Teaching Positions" (Citations per faculty) ranking report. It highlights the influence of KAUST in the field of global scientific research. According to the Academic Ranking of World Universities (ARWU), KAUST ranked 29th in the world in the field of engineering and 101-150 in the field of science in 2016. Three Picture and text express Figure 1. Schematic Diagram of Aperture Editing and Shape Mismatch Induced Separation Based on Shape Difference Figure 2. Aperture editing Synthesis and Characterization of Zr-fum (100-x) -mesx-fcu-MOF Film In contrast to the smaller size difference, the molecular shape difference between N2 and CH4 is significant because N2 is linear and CH4 is tetrahedral (Figure 1A). The side view of these two molecules shows the trilobal profile of CH4 and the circular circumference of N2 (Figure 1A). MOFs constructed from metal clusters and organic linkers provide a highly tunable platform for structural design, allowing precise editing of pore shape/size. Among the MOFs, the Zr-fum-fcu-MOF is assembled from a hexanuclear cluster [Zr6O4 (OH) 4 (O2C ??) 12] and a bis-selective-junction fumarate (fum) with a face-centered cubic (FCU) topology, presenting the desired narrow pore size with a special trilobal shape (Figure 1B). Typically, the CH4 tetrahedra are expected to penetrate by aligning their edges parallel to the triangular inlet boundary to fit exactly with the trilobal pore (fig. 1b). In principle, this penetration of CH4 can be blocked by changing the pore shape, thereby destroying the original match of tetrahedral CH4 (Figure 1 C). The shape irregularity is caused by replacing the fumarate edge of the triangular window with a 2-methylfumarate, i.e., a mesaconate (mes) moiety containing a prominent methyl group. Authors' experimental exploration of the hybrid junction, Zr-fum-MES-fcu-MOF membranes showed an optimal molar ratio of fum to mes of 2:1 for N2/CH4 separation, i.e., a Zr-fum67-mes33-fcu-MOF with two fumarates and one mesaconate surrounds a triangular window.
Figure 3. Separation Performance of Zr-fum (100-x) -mesx-fcu-MOF Membrane and Diffusion Barrier Figure 4. Under actual conditions Comprehensive evaluation of the performance of Zr-fum67-mes33-fcu-MOF membrane for N2/CH4 separation, techno-economic comparison of distillation system with membrane distillation system and hybrid membrane distillation system Molecular modeling showed that the diffusion energy barrier of CH4 increased by more than 150% after replacing one fumarate with mesalazine in the triangular window, while the diffusion energy barrier of N2 increased by only 33%, thereby improving the N2/CH4 selectivity (Fig. 3D ?? J). In addition to its excellent separation performance, the Zr-fum67-mes33-fcu-MOF membrane also exhibits excellent thermal stability. Both the N2 permeability and the N2/CH4 selectivity increase at elevated temperatures, and the apparent activation energies for N2 and CH4 permeation are 6.8 and 4.4 kJ · mol-1, respectively. Compared with other membranes, the Zr-Fum67-Mes33-Fcu-MOF membrane showed excellent performance, including N2 permeability and N2/CH4 selectivity, exceeding the upper limits of polymer and zeolite membranes (Figure 4A). From the viewpoint of practical application, N2/CH4 separation at high pressure (30-60 bar) is preferred. For a zeolite membrane, such as the SSZ-13 membrane of the prior art, the high feed pressure results in a severe selectivity loss, with the selectivity being reduced by half to only about 6 for a 25 bar feed (fig. 4 B). In contrast, the Zr-fum67-mes33-fcu-MOF membrane still maintains excellent N2/CH4 separation performance when the feed pressure is increased to 50 bar and the permeate side is kept at 1 bar without purge gas (fig. 4 B). The N2 permeability decreased at higher pressures due to the nonlinear adsorption behavior of Zr-fum67-mes33-fcu-MOF, but did not significantly affect the selectivity. Four Conclusion and prospect The authors finally evaluated the simultaneous removal of CO2 and N2 from natural gas. In particular, the absorption of a 35% CO2/15% N2/50% CH4 mixture by methyldiethanolamine (MDEA) mimics amine-based CO2 capture, which requires 11.5 MW heating load and 10.9 MW cooling load for CO2 removal, This corresponds to a purification cost of 0.34 MMBtu ?? 1 (metric million British thermal units). Combined with the cost of the N2 suppression tower for continuous N2 removal, the total energy load and utility costs for CO2 and N2 removal are 26 MW and $1.58 ? 106, respectively (Figure 4 I). Thus, the CH4 purification cost increases to 0.62 MMBtu ?? 1 USD (Fig. 4L). In contrast, for this particular stream composition (35% CO2/15% N2/50% CH4), this membrane can actually replace mixed amine scrubbing/cryogenics, removing both CO2 and N2, saving 100% of the heating and cooling duty (Figure 4 I), and providing the required purity to achieve pipeline specifications. Ultimately, for a 35% CO2/15% N2/50% CH4 feed, about 72 kilotons of CH4 were purified, and the application of this membrane reduced the purification cost by about 73% compared to a conventional amine/distillation combination. Shi Chunfeng, president of King Abdullah University of Science and Technology, said that King Abdullah University of Science and Technology will focus on new energy development, climate and environmental governance, bioengineering applications and other worldwide scientific and technological topics closely related to human life. He is confident that he will work with academic elites from all over the world to build a world-class scientific research institution. Congratulations to King Abdullah University of Science and Technology! Five Literature Literature link: Original document: Reply to "Natural Gas" in the background to get the original text of the document.
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