Zhuoheng Tu,Ping Zhang,Mingzhen Shi,Xiaomin Zhang,Youting Wu,Xingbang Hu
Efficient recovery of CO and H 2 from offgas streams is environmentally and economically meaningful from the view point of the wide use of syngas (CO/H 2 ) in the chemical industry. This work reports selective and simultaneous separation of CO and H 2 from N 2 using protic chlorocuprate ionic liquids (PCILs)-based membranes. The chemical structures of the prepared PCILs were characterized using FTIR , NMR and ESI-MS, and the thermal stability, melting points, viscosity and density of PCILs were determined. The morphology and elemental distribution of PCIL-based membranes were characterized by SEM and EDS. Facilitated transport of CO is observed in these membranes, and the CO permeability is up to 178.3 barrers (0.1 bar, 40 °C) in [TEAH][CuCl 2 ], with a CO/N 2 selectivity of 26.2. H 2 permeability and H 2 /N 2 selectivity are also found to reach 198.2 barrers (0.5 bar, 40 °C) and 29.1, respectively. The permeability of CO and the selectivity of CO/N 2 can be further optimized to 405.9 barrers and 69.9 by altering the Cu(I) content, respectively. In addition, the selectivity of CO/H 2 can be tuned drastically via varying the Cu(I) content (from 0.77 to 12.0) and the operating temperature (from 2.14 to 0.42), which may be applied to the composition adjustment of syngas. In a word, this work offers a new strategy for designing IL-based membranes that used for CO and H 2 capture.
Spent hydrodesulfurization catalysts contain more than 10 ∼ 25 wt% V, Mo and Co, which are not only hazardous materials, but also can be considered as valuable secondary resources. The complete separation of these complex critical metals by solvent extraction still needs to be improved. Here, a selective extraction route for the separation of V/Mo/Co is proposed based on the weak interaction differences between extractants and metal, which is realized by theoretical calculation and experimental verification. This process does not require pretreatment of N1923 and Cyanex272 (C272), thus reduced the consume of acid and base as well as generation of waste water. With the preliminary results of V/Mo, Co/Mo, and V/Co separation, the weak interaction between extractants and metal molecules was revealed by quantum chemical calculations quantitatively. The molecular charge distribution, surface electrostatic potential distribution (ESP) and the average local ionization energy (ALIE) shows the priority reactivity of the metal molecules as: H 6 V 10 O 28 > H 2 Mo 4 O 13 > H 4 V 4 O 12 > H 3 VO 4 > H 2 MoO 4 . The independent gradient model based on Hirshfeld partition (IGMH) show differences in the weak interaction forces as: N1923-V>C272-Mo > C272-V>N1923-Mo > C272-Co. The selective separation process of V/Mo/Co was designed with the guide of above results. The combined recovery of the three metals V, Mo and Co amounted to 83.88 %, 87.08 %, and 99.01 %, respectively. The whole route reduces 3.92 t sulfuric acid and 7.83 t sodium hydroxide per solid, and reduces 1.99 t carbon emissions compared to the conventional route.
危险品化学品经营许可证（带存储）