Pressure swing distillation (PSD) process was used to separate methyl acetate‐methanol azeotrope. Through the phase diagram analysis, distillation sequence and technological process were determined. On the basis of the principle of the minimum total annual cost (TAC), design variables such as feeding position, reflux ratio, and column plate number were optimized and the optimal parameters were determined. The high‐pressure column (HPC) under various pressures were analysed. The economic results of the PSD without heat integration, with partial heat integration, and with full heat integration were compared. The comparison results indicate that the TAC of the PSD without heat integration is the highest. The PSD with partial integration and full heat integration can effectively reduce the total capital cost and total operating cost. Compared with the PSD without heat integration, the TACs of partial heat integration and full heat integration exhibit 27% and 30% savings, respectively. Therefore, the PSD with full heat integration is more economically reasonable for separating methyl acetate‐methanol azeotrope.
A new coordination polymer of {[Ag(Qina)(Bpp)]·(H 2 O) 2 } n (Qina =2-quinolinecarboxylic-carboxylate, Bpp = 4,4'-trimethylenedipyridine) is successfully synthesized and the structure is determined using single crystal X-ray diffraction. The complex is crystallized in the monoclinic system with P2 1 /c space group: Each atom of Ag(I) is chelated by one Qina group, with each Bpp ligand bridging two Ag(I) atoms to form the 1D polymer chains. Furthermore, the 3D supramolecular architecture is a costructure directed via weak stacking interactions of C-H···π and hydrogen bond. The complex shows competitive binding affinities in calf thymus DNA (ct-DNA) interaction by fluorescence spectroscopy. In addition, the complexes' cytotoxic activity is explored for two kinds of cancer cell lines (Hela, MCF-7), indicating an anticancer activity and cytotoxicity. CCDC: 1553426 Experimental Section Materials and InstrumentsAll reagents and solvents used in experimental and tests are commercially available and directly used without any treatment. As for characterizations, a model Finnigan EA 1112 was employed for Elemental analyses (including C, H, and N); and a Thermo Nicolet 380 FT-IR spectrophotometer for IR analysis by KBr disks method; a Bruker SMART APEX2 CCD diffractometer (Mo Kα, λ = 0.71073Å) for polymorphism analysis by single-crystal X-ray diffraction; as well as a Perkin-Elmer LS55 fluorescence spectrofluorimeter for emission spectrum.
The separation of aqueous acetonitrile solution by pressure swing distillation (PSD) was simulated and optimized through Aspen Plus software. The distillation sequence of the low pressure column (LPC) and high pressure column (HPC) was determined with a phase diagram. The pressures of the two columns were set to 1 and 4 atm, respectively. Total annual cost (TAC) was considered as the objective function, and design variables, such as the tray number, the reflux ratio, and the feeding position, were optimized. The optimum process parameters were obtained. For the reduction of energy consumption, the PSD with full-heat integration was designed. The TAC of this method is lower by 32.39% of that of the PSD without heat integration. Therefore, it is more economical to separate acetonitrile and water mixture by PSD with full-heat integration, which provides technical support for the separation design of such azeotropes.
Poly aluminum-ferric Chloride (PAFC) is a new type of high efficiency coagulant. In this study, high iron type gangue is used as a main raw material. It is calcined at 675 °C for 1 h and 3% CaF2 is added to the calcined powder and reacted with 20% hydrochloric acid at 93 °C for 4 h. The leaching ratio of aluminum ions is 90% and that of iron ions is 91%. After Fe2+ ions are oxidized in the filtrate, CaCO3 is used to adjust the pH of the filtrate to 0.7. The microwave power is adjusted to 80 W and the filtrate is radiated for 5 min. After being aged for 24 h, PAFC product is obtained. The prepared PAFC is used to treat mine water and compared with the results of PAC and PAF, the turbidity removal ratio of PAFC is 99.6%, which is greater than 96.4% of PAC and 93.7% of PAF. PAFC is a mixture with different degrees of polymerization. It demonstrates that extracting aluminum and iron ions from high iron content gangue to prepare PAFC by microwave is efficient and feasible.
The structures and electronic properties of monolayer arsenene doped with Al, B, S and Si have been investigated based on first-principles calculation. The dopants have great influences on the properties of the monolayer arsenene. The electronic properties of the substrate are effectively tuned by substitutional doping. After doping, NO adsorbed on four kinds of substrates were investigated. The results demonstrate that NO exhibits a chemisorption character on Al-, B- and Si-doped arsenene while a physisorption character on S-doped arsenene with moderate adsorption energy. Due to the adsorption of NO, the band structures of the four systems have great changes. It reduces the energy gap of Al- and B-doped arsenene and opens the energy gap of S- and Si-doped arsenene. The large charge depletion between the NO molecule and the dopant demonstrates that there is a strong hybridization of orbitals at the surface of the doped substrate because of the formation of a covalent bond, except for S-doped arsenene. It indicates that Al-, B- and Si-doped arsenene might be good candidates as gas sensors to detect NO gas molecules owning to their high sensitivity.
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