Bimodal polyethylene are widely used to produce high performance pipes, such as PE100 and PE100RC, and shows increasing importance in polyethylene market because of their excellent mechanical and processing properties. Nowadays, commercialized bimodal polyethylene is synthesized primarily in tandem-reactor process, which needs high energy consumption and capital investment in equipment, beside, the technology is under monopoly of foreign companies. By contrast, bimodal polyethylene synthesis using bimetallic catalyst in single reactor process is becoming research hotspot in domestic and abroad, because this process is more environment friendly and needs much lower cost in equipment investment and operation. Recent work in this group on Cr-based bimetallic catalysts is reviewed. Development on other bimetallic catalysts is also introduced and future trend is prospected.

An Integrated method of desulfurization and denitrification using dual ammonia solution (DAS) is presented to treat coke oven flue gas, which has advantages of low investment and operating costs. It not only makes full use of ammonia produced from coking main process as desulfurization and denitration agent but also produces ammonia sulfate product with the current devices. Firstly, the impact of the amount of ozone, ammonia concentration and temperature is experimentally studied, next, the amount of ammonia aqueous solution and flow-rate of circulating absorbent in industry test is optimized by simulation, finally, a novel multi down-comer (MD) slant-hole tray (SHT) with liquid self-distribution is designed and used as the internals for integrative desulfurization and denitration tower in industry test. Combing the process and device designing, an industrial test system of integrative desulfurization and denitration for coke-oven flue gas with feedstock as 10×10⁴ m³·h^-1 is completed. After a long and stable operation, concentration of SO₂ and NO in emission flue gas after purification, respectively, can be reduced below 10 mg·m^-3 and 150 mg·m^-3, satisfactorily meets the requirements of GB 16171-2012.

Co-crystals have advantages in physiochemical properties over their constituent components and are expected to use in product formulation such as enhanced active pharmaceutical ingredients, food components with improved absorbability, and specialty chemicals with better performance. The development of pharmaceutical co-crystals might offer advantages over the active pharmaceutical ingredients and overcome some of the limitations encountered with classical strategy (polymorph, solvate and salt formation). In recent years, co-crystals have recently gained much attention for pharmaceutical development especially because it has great advantages in improving the solubility, dissolution, melt point and oral bioavailability. Since the co-crystals lattice comprises two or more kinds of molecules, compared with the conventional structure of the drug crystal, intermolecular force comprising more types such as hydrogen, halogen bond, van der Waals forces, π-π interaction, so the structure is more complex. The research on the co-crystals structure can be helpful to understand the formation mechanism. The definition, application, preparation and structure of co-crystals were reviewed, it will provide theoretical guidance for the studies of the following research.

CO₂ solubility in diethyl carbonate (DEC), ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([Bmim] [NTf₂]), and their mixtures at various mass ratio were measured isovolumetrically at temperature of 308.15-328.15 K and pressure of 0-3 MPa. Effect of[Bmim] [NTf₂] on DEC vapor pressure was studied using COSMO-RS model. The experimental results showed that CO₂ solubility in DEC and[Bmim] [NTf₂] increased with increasing pressure at constant temperature but decreased with increasing temperature at constant pressure. CO₂ solubility in DEC was lower than that in[Bmim] [NTf₂] under same conditions, which could be enhanced by adding[Bmim] [NTf₂] to DEC. CO₂ solubility in mixture of[Bmim] [NTf₂] and DEC increased with increasing mass ratio of[Bmim] [NTf₂] at constant temperature while CO₂ solubility in mixtures of constant mass ratios decreased with increasing temperature. COSMO-RS simulation showed that percentage of DEC vapor pressure drop increased with increasing mass ratio of[Bmim] [NTf₂] whereas DEC vapor pressure changed a little at temperature of 308.15-328.15 K for mixtures of same mass ratio.

Lithium ions are highly concentrated in super capacitors and lithium battery, and to construct an accurate interaction model for lithium ions plays an important guiding role in predicting the performance of super capacitors and lithium battery and designing of electrode material. In this work, the interaction model was established for lithium ion in super capacitors and lithium battery by employing quantum density functional theory. It was focused on the characteristics and the solvation effect on the van der Waals interaction between lithium ions. It was revealed that the Coulombic repulsion was highly screened by the van der Waals interaction, and the solvation effect resulted a prodigious contribution to the van der Waals interaction. The molecular interaction model for lithium ion in different solvents was established by numerical fitting (primitive model). Besides, the three-body interaction for lithium ions was also considered and was revealed that the three-body interaction was an attraction, which was effective only when the ions were highly concentrated.

Isobaric vapor-liquid equilibrium data of the binary systems isoamyl acetate+isoamyl alcohol and isoamyl acetate+n-hexanol at 50.00 and 101.33 kPa were measured using a vapor-liquid equilibrium still. The isoamyl acetate+isoamyl alcohol system formed a minimum temperature azeotrope at 50.00 kPa. The thermodynamic consistency of the VLE experimental data were checked by Herington method, and the results were satisfied with Gibbs-Duhem's thermodynamic consistency. The experimental measurements for the binary systems were correlated by nonrandom two-liquid (NRTL), Wilson and universal quasichemical (UNIQUAC) activity coefficient models. Then, the corresponding parameters for the three models were obtained. Compared with the experimental data, the root-mean-square deviations of the boiling temperature and the vapor mole fraction calculated with the correlated parameters were less than 0.20 K and 0.0050, respectively. The calculated results showed that the experimental data agreed well with NRTL, Wilson and UNIQUAC models. Wilson activity coefficient model was used to predict the azeotropic phenomenon of isoamyl acetate+isoamyl alcohol, which indicated that the azeotrope would disappear at 98.4 kPa. This work provided important engineering data for chemical database and further study in the engineering design containing isoamyl acetate.

An extensional TraPPE-UA force field for N,N-dimethyl-formamide(DMF) was developed by combination of the quantum chemistry calculation and Gibbs ensemble Monte Carlo simulation, which lays the foundation for the simulation of vapor-liquid phase equilibrium with DMF. First of all, the vapor-liquid phase equilibrium for DMF was calculated in the NVT-Gibbs ensemble by using this new force filed. The results show that the new force field can be used to accurately calculate the saturated liquid densities, vapor pressures, normal boiling point, critical point and heats of vaporization of DMF. Secondly, the vapor-liquid equilibrium for binary mixtures of acetonitrile-methanol, DMF-methanol, DMF-acetonitrile were computed in the NPT-Gibbs ensemble by adopting the TraPPE-UA force field. These simulation results were in good agreement with the experimental data, which validated the reliability of this model. Finally, the vapor-liquid equilibrium data of ternary mixture of acetonitrile-methanol-DMF were predicted in the NPT-Gibbs ensemble, which can provide basic data for design and optimization of the separation process of acetonitrile and methanol.

The commercial software Fluent 15.0 is employed to carry out the numerical simulation on the internal and external flow fields of the pressure-swirl nozzle. The axisymmetric 3-D flow field is represented by an equivalent 2-D grid. The VOF multiphase flow model and Reynolds stress model (RSM) are chosen. Numerical simulations on flow fields are performed in two different circumstances:① Gas phase is specified as air and there is no heat and mass transfer between phases; ② Gas phase is saturated steam, heat and mass transfer exists between phases. Lee model, a computational model embedded in Fluent 15.0, is specified as the phase-transition model of heat transfer. Comparisons between CFD simulations and experiment are launched. The internal and external flow fields are analyzed based on simulation datum. Results indicate that an air core forms inside the nozzle due to the helical motion of liquid phase, velocity of which increases sharply at the junction of contraction section and orifice's straight pipe section of the nozzle. Furthermore, comparisons are also performed between circumstance ① and ②. Numerical simulation results indicate that when heat and mass transfer exists between phases (i.e. in case of circumstance ②), (1) pressure of the flow fields is slightly lower and peak velocity is larger; (2) heat transfer coefficient of liquid film decreases gradually along the flow direction; (3)the film is thicker due to the vapor condensation, and liquid film breakup length is larger.

Laser induced fluorescence (LIF) technique was employed to investigate the influence of additive component in gas phase on interfacial convection in the process of water-CO₂ dissolution. CO₂ concentration distributions in the liquid and their evolutions were obtained. Liquid side mass transfer coefficients were estimated using the measurement results. Rayleigh convection in the liquid occurred during water-CO₂ dissolution due to density gradient near the interface. The results showed that with the addition of ethanol of a low concentration (<8.47 mg·L^-1) in the gas, the Rayleigh convection enhanced and liquid side mass transfer was enforced. With further increase of ethanol concentration in the gas, Rayleigh convection and thus the liquid side mass transfer were inhibited. The experimental results also showed that the addition of dichloromethane in the gas is enhanced by both Rayleigh convection and the liquid side mass transfer for the process of CO₂ dissolution in water. With the increase of the concentration of dichloromethane in the gas, the liquid mass transfer coefficient tended to become constant.

The evaporator is one of the common heat exchangers, which is widely used in chemical industry and food industry etc. The traditional evaporator with metal tubes is extremely limited in utilization for some reasons that the metal tubes are apt to be corroded by acid or alkali and the serious surface scaling. These problems could be well settled by using excellent performance polymer hollow fibers and good application foreground could be in foresight. In this study, the self-made polymer hollow fibers were used to manipulate the non-metal evaporator and the related evaporation experiments were carried out. The results showed that the performance of the hollow fiber evaporator relied on the thermal conditions of the feed solution. The heat transfer coefficient, the water production and the heat efficiency were better when feed with boiling solution than with low temperature solutions. The heat transfer resistances of fiber walls and the shell side were the main heat transfer resistance. The percentage of the heat transfer resistance with fiber walls can be more than 66% when feed with boiling solution. However, the percentage of heat transfer resistance in the lumen side was as low as 15.3%, and can be lower than 5% when the solution velocity increased. The heat transfer coefficient, the heat efficiency and the water production decreased dramatically when the feed temperature became lower. The results in this study can serve data support for the design and operating parameters optimization of the polymer hollow fiber evaporators, and can promote the further researches and applications of polymer hollow fiber evaporators.

The mass transfer behavior of CO₂ absorption into ionic liquid/ethanol mixture in microchannel was investigated experimentally using a high speed camera. The influences of the ratio of gas to liquid phase flow rates, the concentration of ionic liquid on the liquid side volumetric mass transfer coefficient (k_La) and liquid side mass transfer coefficient (k_L) for slug flow were studied. For a given concentration of ionic liquid, both k_La and k_L increase gradually with increasing the ratio of gas to liquid phase flow rates and then level off. For different concentrations of ionic liquid at a given liquid phase flow rate, there is a transition point in the curve of k_La(k_L) as a function of the flow rate ratio of gas to liquid phase. Before this point, k_La(k_L) decreases with increasing the concentration of ionic liquid, while reverse tendency is found after the point. A new dimensionless empirical correlation for predicting k_La was proposed, and the predicted values coincide well with the experimental data.

The acoustic emission (AE) signal characteristics were measured under different inlet gas velocity of gas solid fluidized bed. The hydrodynamics of the bed and the transition velocity from bubbling to turbulent fluidization were investigated by acoustic energy and recurrence quantification analysis (RQA). Because the acoustic energy analysis could not distinguish the regime transition velocity at different bed height, RQA was further applied to analysis the acoustic signals due to its ability to predict periodicity of a system. The results of RQA indicated that the motion of solids was more periodic when the bed was at the bubble regime compared to the turbulent regime. And the transition velocity of the solids at the lower bed height calculated by RQA was higher than that at the higher bed height. Therefore, the acoustic emission technique based on RQA should be an effective way to monitor the transition of flow regimes in the gas-solid fluidized bed and indicate the process of regime transition at different bed heights.

Liquid-solid flow and stable operation of a loop reactor were affected by the reactor's structural parameters. CFD simulation of the industrial polypropylene loop reactor showed clear non-uniform flow phenomenon with segregation at bend and particulate rope in straight tube. Hence, the non-uniform flow under different straight tube height/diameter ratios and straight tube number was quantitatively analyzed by introducing a non-uniformity parameter. Simulated results indicated that non-uniformity of particulate distribution at 2-leg loop reactor's outlet did not change after the height/diameter ratio exceeded 43. The flow uniformity of particulate distribution at 4-leg loop reactor's outlet kept increasing with larger height/diameter ratio. When the height/diameter ratio was fixed at 65 and height of the straight tube was kept at 39 m, flow uniformity of particulate distribution at the outlet was improved with more straight tubes. But, the influence of the height/diameter ratio on the outlet's non-uniformity was more significant than that of straight tube number. The research results could provide guidance for design and optimization of industrial loop reactors.

The liquid backmixing characteristics were investigated experimentally using pulse tracing technique in an ebullated bed reactor of 7.2 m in height and 0.3 m in diameter. Air and water were used as the gas and liquid phases, respectively. The superficial gas velocity ranged from 0.26 to 12.97 cm·s^-1, while the liquid velocity was fixed at 0.86 cm·s^-1. The particles of aluminum oxide with an average diameter of 0.4 mm were used as the solid phase. All experiments were carried out under the solids holdup from 0 to 42.9%(vol). The results showed that each response curve demonstrated obvious long tail phenomenon, which implied that there existed evident liquid backmixing in the ebullated bed reactor at different operating conditions. A tanks-in-series with backflow model was adopted to interpret the response data, which showed an excellent agreement between the prediction and experimental data. It also indicated that the number of stages N was 8, while the backmixing coefficient k varied between 1.320 and 4.218. Most of the variances of the predicted model were within +18% of their corresponding experimental values.

Signal of punched rigid-flexible combination impeller disturbance of oil-water biphase pressure fluctuation in the mixer-settler were collected and processed by LabView, plus Matlab software. The largest Lyapunov exponent (LLE) and multiscale entropy (MSE) reflected the degree of the chaos in the fluid field. At the same time, the fluid field's visualization technology was adopted to observe fluid mixing performance. It indicated that compared with the rigid combination impeller, with utilizing punched rigid-flexible combination impeller, the fluid field's structure, coupled with the way of energy dissipation was controlled by the synergetic effect of punch hole and flexible impeller. Furthermore, the chaos of fluid and mixing performance were superior to the rigid combination impeller. At rotation speed 88 r·min^-1, the chaotic mixing of fluids was at the optimal state, and the LLE was over zero, testifying the fluid mixing system in chaotic state. Punched rigid-flexible combination impeller system of MSE was significantly higher than that of the rigid combination impeller, indicating mixing performance of punched rigid-flexible combination impeller superior to the rigid combination impeller system. The number of punched holes on the flexible and the thickness of flexible blade had obvious influence on the chaotic mixing performance.

A high speed camera was used to investigate the gas-liquid two-phase flow and mass transfer performance of CO₂/N₂ gas mixture absorption into monoethanolamine (MEA) aqueous solution in a 400 μm×400 μm T-shape microchannel. The pressure drop along the microchannel was determined by a pressure sensor. The effects of the gas and liquid phase flow rates, MEA concentration on the pressure drop, specific surface area and mass transfer performance were investigated experimentally. The results showed that for a given concentration of MEA aqueous solution, the pressure drop, the mass transfer coefficient, the specific interfacial area, the volumetric mass transfer coefficient and the enhancement factor increased gradually up to a constant value with increasing gas phase or liquid phase flow rates. With increasing MEA concentration or the pressure drop, the mass transfer coefficient, the volumetric mass transfer coefficient and the enhancement factor increased, but the specific interfacial area decreased. Under experimental conditions, the range of pressure drop was 2.00 to 5.23 kPa and the mass transfer coefficient of gas-liquid two-phase flow accompanied with chemical absorption was ranged from 7.74×10^-4 to 2.97×10^-3 m·s^-1. A correlation for predicting the volumetric mass transfer coefficient was proposed by taking Sherwood number, Reynolds number, Schmidt number and the enhancement factor into account. The average deviation of the model was 5.09%, indicating a good prediction performance.

The micromixing characteristics of a tubular reactor packed with different packings were investigated by adopting the competitive parallel reaction, namely, the Villermaux-Dushman reaction. Experimental results showed that the tube packed with rhombus mesh frame packing (RMFP) presented better micromixing efficiency, compared to the tube with mini ring or empty tube. It could be found that the segregation index (X_S) decreased as Reynolds number increased while it increased with increasing volumetric flow ratio. Moreover, the micromixing time (t_m) was calculated using an incorporation model based on the experimental data. The minimum t_m value of the tube packed with RMFP (t_m=2.27 ms) was less than that of the tube with mini ring (t_m=2.73 ms) or empty tube (t_m=3.79 ms).

Computational fluid dynamics (CFD) method was employed to study the effect of a novel internal-hollow cross disk (HCD) on flow and cracking in coil by coupling flow and energy equations with cracking reaction kinetics. Simulation results implied that geometrical structure change of inner wall surface by HCD embedment in cracking coil re-distributed patterns of flow field and strengthened radial velocity at reasonable pressure loss. The resulting longitude vortex disrupted flow boundary layer and improved near-wall turbulence, which in turn reduced thermal resistance and enhanced homogeneity of temperature distribution. Compared to regular cracking coils, the coil with HCD modification increased C₃H₈ conversion by 7.24%, olefin selectivity by 3.67%, and overall olefin yield by 6.94% which C₂H₄ yield had a slight decrease of 0.87% while C₃H₆ yield had a notable rise of 16.50%. Moreover, radial velocity from longitudinal vortex was found to promote exchange of near-wall high-temperature fluid to central low-temperature fluid with maximum temperature difference between fluids of 0.7℃. At the outlet, concentration of coking component of C₆ and higher, was found decreased by 28.33% in coil with HCD than that in counterpart, indicating that HCD introduction could prevent near-wall high temperature and over-cracking and inhibit occurrence of coking. HCD strengthening mechanisms on heat and mass transfer were quantitatively analyzed and an overall evaluation was performed with consideration of pressure loss and performance improvement.

CO₂ hydrogenation directly producing value added chemicals over Fe based catalysts is an important approach to achieve its resource-oriented utilization. In this work, ZSM-5 supported iron catalysts with different ratios of Si/Al (25, 70, 150) were prepared by conventional impregnation method and the effects of supports with different Si/Al ratios on the catalytic performance were investigated. The catalyst activity increased first, then decreased with the increase of Si/Al ratio, and the optimal ratio of Si/Al was 70. With the combination of CO₂-DRIFTS and CO₂-TPD, it was found that ZSM-5 (Si/Al=70) zeolite supported Fe catalyst possessed more and stronger basic sites, which promoted the dissociative activation of CO₂. The evolution of catalysts structure was explored using multiple techniques such as H₂-TPR, XRD and Raman spectroscopy. After reduction, Fe2O3 on the catalyst surface was converted into metallic iron, which was then transferred to Fe₃O₄ and FeC_x during the reaction. It was also found that the discrepancy in the interaction between Fe and C under different coordination environments (Si/Al) affects the formation of FeC_x, thereby affecting the activity and products selectivity of CO₂ hydrogenation.

Activated carbon (AC) and carbon nanotubes (CNTs) supported Pt catalysts with similar particle sizes prepared by incipient wetness impregnation method were used for study of base-free oxidation of glycerol. The results showed that carbon support of Pt-C composite catalysts had significant impact on reactivity, selectivity, and steady state of glycerol oxidation. Compared to Pt/CNTs catalyst, Pt/AC catalyst had a lower binding energy of Pt 4f leading to a higher oxygen coverage on catalyst surface which reduced glycerol adsorption and initial activity of glycerol oxidation. Pt/AC catalyst further favored oxidation of glyceraldehyde to glyceric acid and C-C bond cleavage of C₃ products. With regards to catalyst deactivation, oxygen poison and adsorption of intermediates were main factors to Pt/AC catalyst while blockage of Pt active sites by adsorption of glyceric acid was a significant contributor to Pt/CNTs catalyst.

Silver (Ag) is an excellent electrocatalyst for carbon dioxide (CO₂) to carbon monoxide (CO) conversion in aqueous or nonaqueous electrolytes. However, polycrystalline silver needs significant overpotentials to achieve ideal selectivity and reaction rate, thus new methods are required to increase catalytic performance of polycrystalline silver. Effects of halides on silver foil for CO₂ electrochemical reduction were studied by Faradaic efficiency and current density of carbon monoxide (CO) as a function of working potential with presence of Cl^-, Br^-, and I^- in KHCO3 solution. The results showed that all of these halides increased CO selectivity and reaction rate with CO enhancement in the order of Cl^- < Br^- < I^-. CO selectivity of I^- added electrolyte was 28 times that of halide-free electrolyte at 590 mV overpotential. Besides enhancement of CO reaction rate, Cl^- and Br^- also improved hydrogen evolution reaction at the same time, which was not observed in I^-. The remarkable catalytic performance of I^- could be attributed to its strong adsorption, which might form nanoparticles on Ag surface and increase number of activity sites for CO, and its easy charge donation to Ag surface, which might enhance interaction with partially positive-charged carbon atom of CO₂. In conclusion, I^- was more suitable for CO₂ reduction than Cl^- and Br^-, which could benefit industrialized CO production and maximize economic output.

Molecular and dissociative adsorption of hydrogen at Pd_N clusters (N=1, 4, 8, 13) supported on AlOOH and ZrO₂ were investigated using density functional theory. Effects of cluster size and carrier were assessed through study of hydrogen adsorption energies and electron transfers among carrier, Pd_N cluster and adsorbed hydrogen. Molecular adsorption occurred preferentially at atop sites of the supported Pd_N clusters while dissociative adsorption favored face sites. With the increase of cluster size, both molecular and dissociative adsorption energies decreased as well as both amount and direction of electron transfer among carrier, Pd_N clusters and adsorbed hydrogen altered. The molecular and dissociative adsorption energies on ZrO₂ supported Pd_N clusters were higher than those on AlOOH supported Pd_N clusters, indicating that carrier was also important to hydrogen adsorption.

The preparation of nesquehonite (MgCO₃·3H₂O) and hydrogen chloride by MgCl₂ and CO₂ based on a coupled reaction-extraction-alcohol precipitation process is an effective way for the comprehensive utilization of brine. The effects of impurity ions Na⁺, K⁺ and Ca²⁺ in brine on the morphology of the solid product obtained in the coupled reaction-extraction-alcohol precipitation process are investigated systematically. The results indicate that Na⁺ and K⁺ have a similar influence on the coupled process. The products are rod-like high purity MgCO₃·3H₂O when Na⁺ and K⁺ are added. Moreover, Na⁺ and K⁺ can be selectively absorbed onto the axial face (101) of MgCO₃·3H₂O, that will hinder the growth along the (1 0 1) direction and resulting a decrease in the diameter of MgCO₃·3H₂O. Ca²⁺ shows a negative effect on the coupled process. The added impurity CaCl2 can react with CO₂ and form spherical amorphous nano Mg/Ca-carbonate, which will decrease the purity of the solid products.

In the present work, rigorous simulation and optimization are used for analysis and comparison, in terms of total annual cost (TAC), five kinds of promising distillation configurations, including simple columns sequences with or without heat-integration, complex column with side-rectifier or side-stripper, and fully thermally coupled (dividing-wall column (DWC)). The analysis results show that the feed composition, the ease of separation index, or the ratio of the relative volatilities of the two pairs of adjacent components, and the separation extent have strong influence on the selection of the optimal distillation configuration. Based on the results of the analysis, influential factors for selecting the best distillation scheme for separating ternary mixtures are discussed.

SAPO-34 membranes for separation of CO₂/CH₄ gas mixture were fabricated on porous α-Al₂O₃ substrates by seeded growth under microwave irradiation. Effects of synthesis conditions, including heating mode, seed size, aging and synthesis time, on membrane morphology and structure were investigated in order to manufacture dense and thin SAPO-34 membranes. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize SAPO-34 membranes. 1.5 μm-thick defect-free SAPO-34 membrane could be obtained with high reproducibility at condition of 0.4 μm-sized seed, 24 h aging, and 4 h microwave heating. The new membrane demonstrated an average CO₂/CH₄ separation selectivity at 81 and high CO₂ permeability at 6.6×10^-7 mol·m^-2·s^-1·Pa^-1.

In view of the poor deoxygenation and low safety for CH₄/N₂/O₂ mixture a two-bed vacuum pressure swing adsorption (VPSA) process for separating 25% CH₄/59% N₂/16% O₂ mixture was developed by numerical simulation and experiment based on the laboratory-made activated carbon adsorbent. The VPSA mathematical models were validated by comparing the influences of feed and replacement flowrates variations on experimental and simulative results, respectively. On the basis, safety analysis of entire VPSA process was performed systematically to seek for the steps in presence of potential safety hazard. On the basis of analysis, a more safe VPSA process was proposed to achieve safe separation operations. The research results showed that the two-bed VPSA process can obtain a rich-methane product with 51.36% methane purity and 85.65% recovery. The adsorption, pressure-equalization and pressurization were the dominating steps in the presence of potential safety hazard, which can be sought for a solution to realize the safe operations of VPSA process by feed gas inserting.

A series of polyvinylidene fluoride (PVDF) porous membranes with different pore structures were prepared from PVDF and sodium allyl sulfonate (SAS) via various phase inversion methods, such as non-solvent induced phase separation (NIPS), vapor induced phase separation (VIPS), and solvent evaporation induced phase separation (EIPS). A concept for membrane structure regulation was proposed on the basis of growth mechanism of polymer crystalline which controlled crystal growth by solvent evaporation time. The membrane was characterized by scanning electron microscopy (SEM), Brunner-Emmet-Teller (BET), X-ray diffraction (XRD), differential scanning calorimetry (DSC), as well as permeability of protons (H⁺), tetravalent vanadium ions (VO²⁺), and other ions. With the increase of solvent evaporation time, spherulites in cross-sectioned membrane was increased gradually till all spherulites grew into each other, such that membrane porous structure changed significantly as well as membrane crystalline percentage and morphology were altered. The decreased membrane pore size improved selectivity for H⁺ relative to VO²⁺ from 12 to 73, which demonstrated high separation properties of the naonporous membrane.

Along with the increasing types of ethylene cracking materials and expensive feed analyzer, clustering of ethylene cracking materials which is to improve ethylene yield modeling, ethylene yield and energy consumption has very important practical significance. In order to improve the accuracy of online identification of raw materials, an intuitionistic fuzzy kernel clustering algorithm based on the theory of intuitionistic fuzzy sets is presented. In the definition of membership, membership considers uncertain information which is the hesitation degree. At the same time, intuitionistic fuzzy entropy is incorporated in the loss function of multiple kernel clustering algorithm. That is to optimize the data points in the class. Further, the cracking material attribute feature selection using random forest, based on the main attributes of contribution of ethylene yield. Finally, the actual ethylene cracking naphtha data of industry is used to verify the effectiveness and superiority of the algorithm.

A finite-scenario-based two-stage stochastic mixed integer linear programming (MILP) model was proposed to optimize tactical decision-making level of multi-period and multi-echelon petroleum supply chains under uncertain circumstances. In the model, environmental objective of CO₂ emission reduction was added to economic objective by collecting carbon tax, and each entity in the supply chain was considered as a “black box” to simplify the complicated system. A relatively reliable optimal result was obtained from the model over a considerably long duration to facilitate plan and management of petroleum supply chain. Further, risks to achieve the optimal outcome were analyzed and the model was revised with risk management constraints. Compared to the original model, the proposed model with risk management constraints could lower risks for the expected profit.

Multiblock strategy is widely used in plant-wide process monitoring to solve problems with complicated relationships between process variables. Traditional multiblock strategies and sub-block modeling methods are not effective in plant-wide process monitoring, because dynamic characteristics of the process have not been considered and knowledge or data information of the process is exclusively exploited. A mixed multiblock DMICA-PCA method was proposed to improve process monitoring performance. First, variables were sliced into initial sub-blocks by obtained process knowledge after analysis of process dynamics and further sliced into final sub-blocks by modified general Dice's coefficient (MGDC) between variables of initial sub-blocks. Then, the DMICA-PCA method was used to establish model and acquire statistical values of variables in final sub-blocks and a combined overall index from weighted sum was developed for fault detection, which improved performances by simultaneous diagnosis on each sub-block. Effectiveness of the proposed method was validated on monitoring the Tennessee-Eastman (TE) process.

With the increase of ethylene content in gas phase fluidized bed, stickiness and agglomeration among high impact polypropylene granules seriously impacted on particle flowability and continuous production. Adding a small amount of inert inorganic superfine powders could effectively reduce the sticky agglomeration. The cold-flow model study was to analyze impact of superfine powders such as spherical silica and layered hydrotalcite (HT), as well as to explore electrostatic formation and effect on flowability. Compared to untreated powders, powders modified by antistatic agents could decrease accumulation of static charges, shorten dropping time, and enhance flowability of particles. Overall, hydrotalcite showed better effect than silica.

A well-defined silane-functionalized comonomer, 7-octenylethoxydimethylsilane (OEMS), was synthesized through hydrosilylation reaction of dimethylethoxysilane with 1,7-octadiene. Catalyzed by a vanadium complex bearing iminopyrrolide ligands (VCIP), the functional ethoxysilane-containing polyethylenes (PE-co-OEMS) were synthesized by copolymerization of ethylene with OEMS. The structure and properties of PE-co-OEMSs were characterized with ¹H NMR, ¹³C NMR, HT-GPC and DSC. It was found that catalytic activity still remained 1.2 kg·mmol^-1·h^-1 when OEMS feeding reached to 60 mmol·L^-1, and the OEMS incorporating in the copolymer was 1.3%(mol). Besides, the OEMS feeding had a great influence on the average molecular weight (M_w) and distribution (PDI) of copolymers. The Mw and PDI of PE-co-OEMS were 16900 and 2.1 when OEMS feeding was 30 mmol·L^-1. With further increasing the OEMS feeding, M_w increased and PDI became wider. The melting temperature (T_m) and crystallization enthalpy (ΔH_c) decreased with the increase of OEMS incorporation. The ethoxysilane-containing copolymers were easily crosslinked under the catalysis of trifluoromethanesulfonic acid, and the copolymer gel contents after crosslinking were nearly 100%.

Aqueous stabilizer-free two-phase copolymerization of acrylamide (AM), 2-methylacryloylxyethyl trimethylammonium chloride (DMC) and acryloyloxyethyl dimethylbenzyl ammonium chloride (AODBAC) with initiator 2,2'-azobis[2-(2-imidazolin-2-yl) propane]-dihydrochloride was studied. UV spectrophotometer was used to monitor in-line transmittance change of reaction mixture and to detect critical point of phase separation. The conversion rate (X_c) and molecular weight (M_c) at the critical point were measured by improved brominating and viscometric methods, respectively, and were investigated on effect of various factors. The cationic surfmer, AODBAC, was found to have a good performance on promoting phase separation of the system. Change of initiator amount and molar fraction of AODBAC had minimal effect on X_c, which however increased linearly at increase of temperature. The increase of initiator amount, temperature, and molar fraction of AODBAC caused linear decrease of M_c. X_c decreased but M_c increased significantly when molar fraction of AM and overall monomer amount were increased.

High impact polystyrene (HIPS) was prepared by bulk graft copolymerization with four tetrafunctional peroxide JWEB50 as initiator. Phase inversion at constant and staged stirring conditions was analyzed through study of particle structure and viscosity of the polymerization system by transmission electron microscope and change in relative torque. Similar results were obtained from both analyses. For constant stirring, conversion at phase inversion decreased with the increase of stirring speed. For staged stirring, conversion at phase inversion increased when stirring speed was reduced before phase inversion and no effect on conversion at phase inversion was observed if stirring speed was reduced after phase inversion. Therefore, only “effective stirring speed” corresponding to the stirring speed at phase inversion process actually influenced phase inversion. These results could be very important for performance control of HIPS.