The Rayleigh convection can be induced by solute evaporation in dual solvents,such as acetone-ethyl acetate system and isopropanol-water *** onset of Rayleigh convection and its evolution characteristics were simulate...
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The Rayleigh convection can be induced by solute evaporation in dual solvents,such as acetone-ethyl acetate system and isopropanol-water *** onset of Rayleigh convection and its evolution characteristics were simulated using hybrid LBM-FDM method with liquid-phase random disturbance *** the simulation results were in reasonable agreement with experimental measurements in three aspects:concentration field acquired by schlieren,velocity field acquired by PIV and mass transfer coefficient measurement,so the statistics provided by simulation were *** three mass transfer model including small eddy model,surface divergence model and the model based on dissipation rate of concentration variance were applied to predict the mass transfer coefficient,and the model based on dissipation rate of concentration variance had advantages over other two models as a results of lower field synchronism between velocity field and concentration field caused by quicker velocity changes and concentration changes.
A novel triptycene based polyamide(TPA) thin film composite(TFC) nanofiltration(NF) membrane is synthesized via the interfacial polymerization with piperazine(PIP) and different weight ratios of mixed acyl chloride on...
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A novel triptycene based polyamide(TPA) thin film composite(TFC) nanofiltration(NF) membrane is synthesized via the interfacial polymerization with piperazine(PIP) and different weight ratios of mixed acyl chloride on the polyether sulfone(PES) support *** mixed acyl chloride is made up of triptycene-2,3,6,7,14,15-hexaacyl chloride(THC) and trimesoyl chloride(TMC).The THC is used as the rigid 3D-symmetric monomer to form a TPA selective layer which provides more passageway for water ***,with multiple latent reactive sites,the THC can improve the degree of network cross-linking(DNC)of selective layer which is beneficial to withstand chlorine *** results indicate that the water flux of TPA membrane is increased distinctly from 20 L m-2 h-1 to 38.5 L m-2 h-1 under 0.2 MPa compared to conventional polyamide(PA) membrane while the rejection of multivalent salts basically ***,the TPA membrane also shows more durable chlorine resistance.
Water is one of reaction products for production of allyl alcohol from deoxydehydration of glycerol,it is very difficult to obtain allyl alcohol with a high purity by normal distillation methods owing to the formation...
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Water is one of reaction products for production of allyl alcohol from deoxydehydration of glycerol,it is very difficult to obtain allyl alcohol with a high purity by normal distillation methods owing to the formation of allyl alcohol-water *** on the promising approach for production of allyl alcohol from formic acid-mediated deoxydehydration of glycerol,herein,a separation and purification route was developed to totally separate allyl alcohol from the reaction *** salting-out method was applied for the separation of allyl alcohol-water azeotropic mixture system,and the allyl alcohol with content above 99%could be obtained at *** potassium phosphate salts of K5P3O10,K3PO4 and K4P2O7 were systematically studied as salting-out *** thermodynamic study demonstrated that the salting-out was endothermic and a process of entropy *** solubility of allyl alcohol was correlated well with the molarity of salt in units of mol per 1 kg water,and the solubility of allyl alcohol in the organic phase or the aqueous phase could be predicted by the mass fraction of salts.
The optimal design of a refrigeration system working at multiple pressure/temperature levels is very challenging in process industries because of the process *** optimal synthesis of the refrigeration system,which is ...
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The optimal design of a refrigeration system working at multiple pressure/temperature levels is very challenging in process industries because of the process *** optimal synthesis of the refrigeration system,which is a big energy consumer,can effectively decrease the energy consumption and further reduce the cost of *** problems of simultaneous optimization of heat exchanger network(HEN) and refrigeration system have been usually solved by mathematical *** this paper,a superstructure is proposed,considering the heat exchanges between the refrigerant and the process ***,the modeling process was performed difficult due to the uncertainty of the flow temperature after sub-coolers in the cooling *** this study,the modeling problem was solved by a new method,in which the Generalized Disjunctive Programming(GDP) model was introduced and then reformulated as a Mixed Integer Nonlinear Programming(MINLP) problem by using Big-M ***,the optimization of a propylene refrigeration system in an ethylene industry is applied to test the effectiveness and feasibility of the proposed mathematical *** result shows that,the total shaft work of the compressor in the optimized refrigeration system was reduced by 21.6 percent.
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