This study aims to use Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) to describe the phase behavior of systems containing DESs and ILs. The DESs are based on Tetrabutylammonium chloride ([N4444]Cl) and Tetrabutylammonium bromide (TBAB) as hydrogen bond acceptors, and levulinic acid (LevA) and Diethylene Glycol (DEG) as hydrogen bond donors in the mole ratio of 1:2 and 1:4, respectively. The predicted phase equilibrium data from PC-SAFT has been compared to those from COSMO-RS and NRTL predictions. ILs studied in this work are low viscosity ether-functionalized pyridinium-based ILs [EnPy][NTf2] and [CmPy][NTf2], while 1-(2-methoxyethyl)-1-methylpyrrolidiniumbis(trifluoromethylsulfonyl)-amide) ([COC2mPYR][NTf2]) and 1-propyl-3-methylimidazolium bis{trifluoromethylsulfonyl}imide ([Pmim][NTf2]) were used for the study of the LLE systems with n-heptane + thiophene and n-hexane + ethylbenzene, respectively. In the last part, mixtures of linear alkanes and perfluoroalkanes have been studied to predict the phase behavior of perfluoroalkylalkanes with their linear alkane counterparts and comparisons have been made against SAFT-Mie pair potential.

A new type of composite tridimensional rotational flow sieve tray is proposed. The flow pattern and operation domain of the tray were defined and divided by the image shooting method, combined with the standard deviation of the pressure difference sequence. There are membrane--drip column and foam--embolic flow in the TRST area of the internal packing--type tray, while bubbly and milk froth-ribbon flow are present in the packing area of the external packing-type tray. This study focused on the influence of the tray structure parameters on the pressure drop. Under the experimental operating conditions, the dry pressure drop was within 160 Pa, while the wet pressure drop was within 900 Pa. Under the same structural parameters, the internal packing--type pressure drop of the tray was higher than that of the external packing-type tray. A mathematical model of the pressure drop between dry and wet trays was established.

An advanced comprehensive and transient multiphase model for a trickle bed reactor with solid foam packings was developed. A new simulation model for isothermal three-phase (gas–liquid–solid) catalytic tubular reactor models was presented where axial, radial and catalyst layer effects were included. The gas, liquid and solid phase mass balances included most of the individual terms for solid foam packing (e.g. kinetics, liquid-solid and intraparticle mass transfer effects). Hydrogenation of arabinose and galactose mixture on a ruthenium catalyst supported by carbon-coated aluminum foams was applied as a fundamentally and industrially relevant case study. Parameter estimations allowed to obtain reliable and significant parameters. To test the model performance, a sensitivity analysis was performed and the effect of the kinetic parameters and the operation conditions on the arabinose and galactose conversions was studied in detail. The model described here is applicable for other three-phase continuous catalytic reactors with solid foam packings.

The dissociation conditions of hydrate in clayey silts are of great significance for its efficient production. In this work, the dissociation conditions of methane hydrate in clayey silt cores were experimentally measured by step-heating method. Various cores including quartz powder, montmorillonite and South China Sea sediments were used for investigation. The results showed that the dissociation temperatures of methane hydrate in clayey silt cores depressed compared to bulk hydrate. In comparison to grain size, salinity and lithology had a more significant influence on the equilibrium temperature depression. A water activity meter was used to measure the water activity in clayey silt cores. The influence of salt and minerals on water activity was investigated. By combining the measured water activity data with the Chen-Guo model, a novel water activity measurement method (WAM) for the hydrate dissociation conditions prediction was proposed. The predicted results are in good agreement with the experimental data.

At present, the development of high-performance protein imprinted materials is still a research hotspot in the field of protein imprinting. Herein, anti-protein adsorption segment (CBMA)-assisted self-driven BSA surface imprinted fibers MTCFs@SIP@CBMA with high recognition selectivity are pioneered using the strategies of combining magnetic nanomaterial surface imprinting technique with amino-Michael addition. The special structure of the carrier MTCFs endows MTCFs@SIP@CBMA with magnetic performance and self-driven adsorption performance, which simplifies the separation process while improving the adsorption capacity and accelerating the adsorption rate. The adsorption capacity for BSA reached 395.26 mg/g within 30 min. The introduction of CBMA segments on the surface after imprinting by amino-Michael addition makes its polymer chain length and position controllable. Under the strongest anti-nonspecific adsorption effect, MTCFs@SIP@CBMA exhibit excellent specific identification to BSA from mixed proteins. Additionally, MTCFs@SIP@CBMA show considerable reusability. Therefore, MTCFs@SIP@CBMA are expected to be applied in efficient separation of proteins in biological samples.

Cell penetrating peptides (CPPs) are short peptides that can carry biomolecules of varying sizes across the cell membrane into the cytoplasm. Correctly identifying CPPs is the basis for studying their functions and mechanisms. Here, we propose a novel CPP predictor that is able to predict CPPs and their uptake efficiency. In our method, five feature descriptors are applied to encode the sequence and compose a hybrid feature vector. Afterward, the wrapper + random forest algorithm is employed, which combines feature selection with the prediction process to find features that are crucial for identifying CPPs. The jackknife cross validation result shows that our predictor is comparable to state-of-the-art CPP predictors, and our method reduces the feature dimension, which improves computational efficiency and avoids overfitting, allowing our predictor to be adopted to identify large-scale CPP data.

We review theories of polyelectrolyte (PE) coacervation, which is the spontaneous association of oppositely charged units of PEs and phase separation into a polymer-dense phase in aqueous solution. The simplest theories can be divided into “physics-based” and “chemistry-based” approaches. In the former, polyelectrolytes are treated as charged, long-chain, molecules, defined by charge level, chain length, and chain flexibility, but otherwise lacking chemical identity, with electrostatic interactions driving coacervation. The “chemistry-based” approaches focus on the local interactions between the species for which chemical identity is critical, and describe coacervation as the result of competitive local binding interactions of monomers and salts. In this article, we show how these approaches complement each other by presenting recent approaches that take both physical and chemical effects into account. Finally, we suggest future directions towards producing theories that are made quantitatively predictive by accounting for both long range electrostatic and local chemically specific interactions.

The temporal analysis of products (TAP) reactor provides a route to extract intrinsic kinetics from transient measurements. Current TAP uncertainty quantification only considers the experimental noise present in the outlet flow signal. Additional sources of uncertainty such as initial surface coverages, catalyst zone location, inert void fraction, gas pulse intensity and pulse delay, are not included. For this reason, a framework for quantifying initial state uncertainties present in TAP experiments is presented and applied to a carbon monoxide oxidation case study. Two methods for quantifying these sources of uncertainty are introduced. The first utilizes initial state sensitivities to approximate the parameter variances and provide insights into the structural certainty of the model. The second generates parameter confidence distributions through an ensemble-based sampling algorithm. The initial state covariance matrix can ultimately be merged with the experimental noise covariance matrix, providing a unified description of the parameter uncertainties for a TAP experiment.

Fe-Ni materials with varying Ni loading are developed for separate H2 and CO production by CH4-CO2 chemical looping. The product streams are obtained by first feeding CH4, which decomposes to H2 and carbon. The latter acts as reductant for the subsequent CO2 feed, which together with Fe re-oxidation yields CO. After 25 CH4-CO2 cycles, 10Fe5Ni@Zr has a higher H2 space-time-yield than 10Fe0Ni@Zr (〖20mmol∙s〗^(-1)∙kg_(Fe+Ni)^(-1) vs. 〖15mmol∙s〗^(-1)∙kg_(Fe+Ni)^(-1)), a 2.6 times higher CO (〖57mmol∙s〗^(-1)∙kg_(Fe+Ni)^(-1)) and lower deactivation. This improvement has two reasons: (i) CH4 activation over Ni leading to cracking, (ii) product hydrogen causing deeper FeO reduction. Deactivation follows from accumulated carbon, non-reactive for CO2. On Ni and Fe sites, carbon can be removed by lattice oxygen or CO2, yielding more CO compared to the theoretical value for Fe oxidation. However, carbon that migrates away from the metals requires oxygen for removal, which restores the activity of the Ni-containing samples.

Homogeneous hydrogen transfer reactions of methacrolein (MAL) and isopropanol (IPA) to methallyl alcohol (MAA) were investigated in batch reactor (Conv.89%, Select 93.1%) and tubular reactor (Conv.88.1%, Select 95%) using aluminum isopropoxide (Al(OPri)3) as catalyst. Kinetic experiments on hydrogen transfer reactions and reaction order were investigated in batch reactor and tubular reactor. Response surface methodology (RAM) was applied to optimize the optimum reaction conditions of hydrogen transfer reaction. Purification process of MAA from product mixture after hydrogen transfer reaction was simulated with Aspen Plus software, theoretical stages, reflux ratio and feed stage of distillation tower were optimized. Density Functional Theory (DFT) was used to investigate viable reaction pathway and to probe the catalytic mechanism between reactants and catalyst, including dehydrogenation, coupling and hydrogenation reaction. Microscopic mechanisms of hydrogen transfer reaction from MAA to MAL were acquired in detail and could be easily extended to other series of hydrogen transfer reaction.

In order to address the challenge of pressure swing adsorption system optimization, an optimization framework based on pseudo transient continuation method was used and vacuum rapid pressure swing adsorption process for oxygen production as a typical example. A pseudo transient model library was established and a robust two-stage dynamic tearing model was proposed to deal with the cyclic steady state conditions. Furthermore, the time constants were discussed and a practical time constant strategy and expressions were proposed for the stability and efficiency of calculation. Finally, reduced successive quadratic programming and time relaxation algorithm were used for the optimization of the two systems respectively, and the optimization results showed that although the simulation time of pseudo transient system is slightly higher than that of single discretization system, the optimization expense of single discretization system in two cases were 5.7 times and 11.6 times of that of pseudo transient system respectively.

A bubble coalescence model for a solution with a nonionic surfactant and with a small bubble approach velocity was developed, in which the mechanism of how coalescence is hindered by Marangoni stress was quantitatively analyzed. The bubble coalescence time calculated for ethanol-water and MIBC-water systems were in good agreement with experimental data. At low surfactant concentrations, the Marangoni stress and bubble coalescence time increased with bulk concentration increase. Conversely, in the high concentration range, the Marangoni stress and coalescence time decreased with bulk concentration. Numerical results showed that the nonlinear relationship between coalescence time and surfactant concentration is determined by the mass transport flux between the film and its interface, which tends to diminish the spatial concentration variation of the interface, i.e., it acts as a “damper”. This damping effect increases with increased surfactant concentration, therefore decreasing the coalescence time at high concentrations.

The famous two-balloon experiment involves two identical balloons filled up with air and connected via a hollow tube, and upon onsetting the experiment one of the balloons shrinks and the other expands. Here, we present the liquid version of that experiment. We use superhydrophobic (SHP) substrates to form spherical droplets and connect them with a capillary channel. Different droplet sizes, substrates of different hydrophobicities, and various channel pathways are investigated, and morphometric parameters of the droplets are measured through image processing. In the case of SHP substrates the pumping is from the smaller droplet to the larger one, similar to the two-balloon experiment. However, if one or both of the droplets are positioned on a normal substrate the curvature radius will indicate the direction of pumping. We interpret the results by considering the Laplace pressures and the surface tension applied by the channel at the connecting points.

Experimental results on pressure drop and gas hold-up for gas-liquid flow through packed beds obtained from a second flight on the International Space Station are presented and analyzed. It is found that the gas hold-up is a function of the bed history at low liquid and gas flow rates whereas higher gas hold-up and pressure gradients are observed for the test conditions following a liquid only pre-flow compared to the test conditions following a gas only pre-flow period. Over the range of flow rates tested, the capillary force is the dominant contributor to the pressure gradient and is found to be linear with the superficial liquid velocity but is a much weaker function of the superficial gas velocity. The capillary contribution is also a function of the particle size and varies approximately inversely with the particle diameter within the range of the test conditions.

A three-dimensional, non-isothermal and multiphase model of high temperature proton exchange membrane fuel cells is built to investigate water and phosphoric acid transportation, in which a spherical agglomerate model considering catalyst layer structure and liquid phase fraction is applied to determine the electrochemical kinetics in the cathode catalyst layer. Experimental polarization curve, water proportion in the anode outlet gas and phosphoric acid distribution are selected for validation. It is found that the simulated results can represent the experimental data with reasonable accuracy. Based on the model, the effects of current density and stoichiometry on the variable distributions are analyzed. The results show that water in anode is mainly from cathode by concentration diffusion of liquid water. A higher current density leads to a greater electro-migration of phosphoric acid from cathode to anode and a higher liquid phase fraction in anode,while a lower phosphoric acid concentration in the fuel cells.

Toluene diisocyanate (TDI) is an important chemical intermediate prepared by phosgenation reaction between toluene diamine and phosgene with two steps name cold and thermal phosgenation respectively. In this paper, the reactive distillation model for the thermal phosgenation reaction based the kinetics equations was established for an industrial installation, and the effects of the different parameters on the process performance were studied firstly; then based on the analysis results, a thermal coupling process between the towers of reactive distillation and phosgene purification was presented and investigated; finally, the optimal operation scheme was simulated and the results showed that the proposed process can save the heat and cold energy with 7.29% and 32.78%, respectively, and reduce the total annual cost about 17.11%. The result of the paper can be used to guide the operation configuration or the revampment of the TDI production equipment.

Decoupling and understanding the various mass, charge and heat transport phenomena involved in the electrocatalytic transformation of small molecules (i.e. CO2, CO, H2, N2, NH3, O2, CH4) is challenging but it can be readily achieved using dimensionless quantities (i.e. Reynolds, Sherwood, Schmidt, Damköhler, Nusselt, Prandtl, and Peclet Numbers) to simplify the characterization of systems with multiple interacting physical phenomena. Herein we report the development of a gastight rotating cylinder electrode cell with well-defined mass transport characteristics that can be applied to experimentally decouple mass transfer effects from intrinsic kinetics in electrocatalytic systems. The gastight rotating cylinder electrode cell enables the dimensionless analysis of electrocatalytic systems and should enable the rigorous research and development of electrocatalytic technologies.

The ZIF-8@Agmim core-shell hybrid material was synthesized via a favorable post-modification method of ion exchange (PMIE). This infrequent ZIF-8@Agmim core-shell structure maintains a well- integrated pore size that is almost the same as ZIF-8. The similar equilibrium isotherms with ZIF-8 and better kinetic separation towards propylene/propane than ZIF-8 render ZIF-8@Agmim to be an interesting candidate for propylene/propane separation. The core-shell hybrid nanomaterial was further used as nanofillers in the polymer of intrinsic microporosity matrix (PIM-1) for propylene/propane separation. The resultant MMMs exhibited a simultaneous increase in C3H6 permeability and C3H6/C3H8 ideal selectivity compared to pure polymer membrane owing to a synergistic effect of molecular sieving from ZIF-8 and π-complexation of Ag+ with propylene. The separation performance of the prepared MMM surpasses the upper bound line of polymer membranes. Furthermore, the hybrid materials possess superb photochemical stability and the corresponding MMMs exhibit excellent anti-aging property and long-term stability.