In this work, a partial element stage cut electrochemical hydrogen pump (EHP) model for multiple H2-contaning gases separation and hydrogen compression which embed real factors (anode impurity diffusion, hydrogen back-diffusion and anode catalyst deactivation) was established to study EHP performance accurately under full hydrogen concentration. The accuracy and reliability of proposed model were verified from four aspects (current density distribution, polarization curve, hydrogen recovery and purity) under different feedstock systems and wide pressure range. The model has good applicability and accuracy (R^2≥0.96, simulation and experiment results comparison). Simulation results show that high hydrogen back-diffusion ratio can cause low energy efficiency under high cathode pressure and low feedstock hydrogen content. The variation law of hydrogen purity under multi-operating conditions was studied, which shows dual-effect (PEM and GDL resistance) can affect hydrogen purity prominently through current density under low feedstock hydrogen content and applied potential.

Accurate cooling crystallization is vitally important in the production of highly specialized fine chemicals and pharmaceutical engineering, etc. Herein, a novel hollow fiber membrane-assisted cooling crystallization (MACC) was developed to achieve precise nucleation and self-seeding process control. Poly-tetrafluoroethylene (PTFE) and polyethersulfone (PES) membrane with diverse interfacial induced nucleation and thermal conduction properties were introduced to accelerate the nucleation and then transfer the automatically detached crystal seed into the crystallizer. Polymeric membrane can dominate the nucleation kinetic and hinder the secondary nucleation, which was validated from the theoretical model and on-line detective experiments. The crystal product manufactured by MACC possessed better morphology, larger mean size (>1.35 mm), higher purity (>99.5 wt%) and narrower size distribution than the conventional cooling crystallization. Space-time process decoupling between nucleation and crystal growth can be realized via auto-screening uniform nuclei in the membrane modules and controllable growth in the crystallizer during MACC.