In this paper, the effect of hydrogen reduction of silver ions on the performance and structure of new solid polymer electrolyte polyetherimide (PEI)/Pebax2533 (Polynylon12/tetramethylene oxide block copolymer, PA12-PTMO)/AgBF₄ composite membranes is investigated. For PEI/Pebax2533/AgBF₄ composite membranes prepared with different AgBF₄ concentration, the permeances of propylene and ethylene increase with the increase of AgBF₄ concentration due to the carrier-facilitated transport, resulting in a high selectivity. But for propylene/propane mixture, the mixed-gas selectivity is lower than its ideal selectivity. The hydrogen reduction strongly influences the membrane performance, which causes the decrease of propylene permeance and the increase of propane permeance. With the increase of hydrogen reduction time, the membranes show a clearly color change from white to brown, yielding a great selectivity loss. The data of X-ray diffraction and FT-IR prove that silver ions are reduced to Ag⁰ after hydrogen reduction, and aggregated on the surface of PEI/Pebax2533/AgBF₄ composite membranes.

Nano-MnFe₂O₄ particles were synthesized by co-precipitation phase inversion method and low-temperature combustion method respectively, using MnCl₂, FeCl₃, Mn(NO₃)₂, Fe(NO₃)₃, NaOH and C₆H₈O₇. X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC) were used to characterize the structure, morphology, thermal stability of MnFe₂O₄ and its catalytic performance to ammonium perchlorate. Results showed that single-phased and uniform spinel MnFe₂O₄ was obtained. The average particle size was about 30 and 20 nm. The infrared absorption peaks appeared at about 420 and 574 cm^-1, and the particles were stable below 524℃. Using the two prepared catalysts, the higher thermal decomposition temperature of ammonium perchlorate was decreased by 77.3 and 84.9℃ respectively, while the apparent decomposition heat was increased by 482.5 and 574.3 J·g^-1. The catalytic mechanism could be explained by the favorable electron transfer space provided by outer d orbit of transition metal ions and the high specific surface absorption effect of MnFe₂O₄ particles.

In order to enhance phosphorus removal in traditional step-feed anoxic/oxic nitrogen removal process,a modified pilot-scale step-feed anaerobic/anoxic/oxic (SFA²/O) system was developed,which combined a reactor similar to UCT-type configuration and two-stage anoxic/oxic process.The simultaneous nitrogen and phosphorus removal capacities and the potential of denitrifying phosphorus removal,in particular,were investigated with four different feeding patterns using real municipal wastewater.The results showed that the feeding ratios(Q₁)in the first stage determined the nutrient removal performance in the SFA 2/O system.The average phosphorus removal efficiency increased from 19.17% to 96.25% as Q₁ was gradually increased from run 1 to run 4,but the nitrogen removal efficiency exhibited a different tendency,which attained a maximum 73.61% in run 3 and then decreased to 59.62% in run 4.As a compromise between nitrogen and phosphorus removal,run 3 (Q₁=0.45Q_total) was identified as the optimal and stable case with the maximum anoxic phosphorus uptake rate of 1.58mg·(g MLSS)^-1·h^-1.The results of batch tests showed that ratio of the anoxic phosphate uptake capacity to the aerobic phosphate uptake capacity increased from 11.96% to 36.85% with the optimal influent feeding ratio to the system in run 3,which demonstrated that the denitrifying polyP accumulating organisms could be accumulated and contributed more to the total phosphorus removal by optimizing the inflow ratio distribution.However,the nitrate recirculation to anoxic zone and influent feeding ratios should be carefully controlled for carbon source saving.

A series of Cu-ZnO-Al₂O₃ catalysts with various metal compositions of Cu/Zn/Al were prepared by the co-precipitation method,and screened for glycerol hydrogenolysis to propylene glycol.The catalyst with a Cu/Zn/Al molar ratio of 1:1:0.5 exhibited the best performance for glycerol hydrogenolysis,and thus selected for kinetic investigation.Under elimination of external and internal diffusion limitation,kinetic experiments were performed in an isothermal fixed-bed reactor at a hydrogen pressure range of 3.0-5.0 MPa and a temperature range of 493-513 K. Based on a dehydration-hydrogenation two-step hydrogenolysis mechanism,a two-site Langmuir-Hinshelwood kinetic model taking into account competitive adsorption of glycerol,acetol and propylene glycol was proposed and successfully fitted to the experimental data.The average relative errors between observed and predicted outlet concentrations of glycerol and propylene glycol were 6.3% and 7.6%,respectively.The kinetic and adsorption parameters were estimated by using the fourth-order Runge-Kutta method together with the Rosenbrock algorithm.The activation energies for dehydration and hydrogenation reactions were 86.56 and 57.80 kJ·mol^-1,respectively.

The alkylation of toluene with 1,3-pentadiene to produce pentyltoluene was carried out to obtain 2,6-dimethylnaphalene, which is an important intermediate during the production of 2,6-naphthalene dicarboxylic acid. Based on our previous work using anhydrous AlCl3 as catalyst, [bupy]BF4-AlCl3 ionic liquids were employed to catalyze the reaction of 1,3-pentadiene with toluene. The experimental results show that [bupy]BF4-AlCl3 ionic liquids are suitable for the reaction especially when the molar ratio of AlCl3 to [bupy]BF4 is 1.75︰1, and the reaction could proceed at the temperature as low as 0℃. It could be as active as pure AlCl3, but much more environmentally friendly.

Performic acid (PFA) is an oxidant used in chemical processing, synthesis and bleaching. The macro kinetic models of synthesis, hydrolysis and decomposition of PFA were investigated via formic acid-autocatalyzed reaction. It was found that the intrinsic activation energies of PFA synthesis and hydrolysis were 75.2 kJ·mol^-1 and 40.4 kJ·mol^-1 respectively. The observed activation energy of PFA decomposition was 95.4 kJ·mol^-1. The experimental results indicated that the decomposition of PFA was liable to occur even at the ambient temperature. Both the spontaneous decomposition and the radical-introduced decomposition contributed to the decomposition of PFA.

A cylindrical pore model was used to represent approximately the pore of β-zeolite catalyst that had been used in the alkylation of benzene with ethylene and spherical Lennard-Jones molecules represented the components of the reaction system-ethylene, benzene and ethylbenzene. The dual control volume-grand canonical molecular dynamics (DCV-GCMD) method was used to simulate the adsorption and transport properties of three components under reaction in the cylindrical pore at 250℃ and 270℃ in the pressure range from 1 MPa to 8 MPa. The state map of the reactant mixture in the bulk phase could be dividded into several different regions around its critical points. The simulated adsorption and transport properties in the pore were compared between the different near-critical regions. The thorough analysis suggested that the high pressure liquid region is the most suitable region for the alkylation reaction of benzene under the near-critical condition.

An optimal medium (300 g·L^-1 initial glucose) comprising 6.3 mmol·L^-1 Mg²⁺, 5.0 mmol·L^-1 Ca²⁺, 15.0 g·L^-1 peptone and 21.5 g·L^-1 yeast extract was determined by uniform design to improve very high gravity (VHG) ethanol fermentation, showing over 30% increase in final ethanol (from 13.1% to 17.1%, by volume), 29% decrease in fermentation time (from 84 to 60 h), 80% increase in biomass formation and 26% increase in glucose utilization. Experiments also revealed physiological aspects linked to the fermentation enhancements. Compared to the control, trehalose in the cells grown in optimal fermentation medium increased 17.9-, 2.8-, 1.9-, 1.8- and 1.9-fold at the fermentation time of 12, 24, 36, 48 and 60 h, respectively. Its sharp rise at the early stage of fermentation when there was a considerable osmotic stress suggested that trehalose played an important role in promoting fermentation. Meanwhile, at the identical five fermentation time, the plasma membrane ATPase activity of the cells grown in optimal medium was 2.3, 1.8, 1.6, 1.5 and 1.3 times that of the control, respectively. Their disparities in enzymatic activity became wider when the glucose levels were dramatically changed for ethanol production, suggesting this enzyme also contributed to the fermentation improvements. Thus, medium optimization for VHG ethanol fermentation was found to trigger the increased yeast trehalose accumulation and plasma membrane ATPase activity.

The methylotrophic yeast Pichia pastoris is a highly successful system for production of a variety of heterologous proteins due to its unique features/abilities for effective protein expression, and tremendous efforts have been made to increase heterologous protein productivity by P. pastoris in recent years. When new engineered yeast strains are constructed and are ready to use for industrial protein production, process control and optimization techniques should be applied to improve the fermentation performance in the following aspects: (1) increase recombinant cell concentrations in fermentor to high density during growth phase; (2) effectively induce heterologous proteins by enhancing/stabilizing titers or concentrations of the proteins during induction phase; (3) decrease operation costs by relieving the working loads of heat-exchange and oxygen supply. This article reviews and discusses the key and commonly used techniques in heterologous protein production by P. pastoris, with the focus on optimizations of fermentation media and basic operation conditions, development of optimal glycerol feeding strategies for achieving high density cultivation of P. pastoris and effective heterologous protein induction methods by regulating specific growth rate, methanol concentration, temperatures, mixture ratio of multi-carbon substrates, etc. Metabolic analysis for recombinant protein production by P. pastoris is also introduced to interpret the mechanism of sub-optimal heterologous protein production and to explore further optimal expression methods.

The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-solvent precipitation(HGAP) process.Intensified micromixing and uniform nucleation environment are created by the high-gravity equipment(rotating packed bed) in carrying out the anti-solvent precipitation process to produce nanoparticles.The average particle size decreases from 55 μm of the raw danazol to 190 nm of the nanoparticles.The Brunauer-Emmett-Teller(BET) surface area sharply increases from 0.66 m²·g^-1 to 15.08 m²·g^-1.Accordingly,the dissolution rate is greatly improved.The molecular state,chemical composition,and crystal form of the danazol nanoparticles remains unchanged after processing according to Fourier transform infrared(FTIR) and X-ray diffraction(XRD).The high recovery ratio and continuous production capacity are highly appreciated in industry.Therefore,the HGAP method might offer a general and facile platform for mass production of hydrophobic pharmaceutical danazol particles in nanometer range.

Nowadays, extractive distillation is the main technique to produce 1, 3-butadiene.This study simulated the 1, 3-butadiene production process with DMF extractive distillation by Aspen Plus.The solvent ratio is the most important parameter to the extractive distillation process.The article has given out the proper solvent ratios, reflux ratios, distillate ratios, and bottom product ratios of the columns.It also discusses the thermal loads of several columns.The results of simulation are consequently compared with the plant data, which shows good accordance with each other.

Due to their negligible volatility,reasonable thermal stability,strong dissolubility,wide liquid range and tunability of structure and property,ionic liquids have been regarded as emerging candidate reagents for CO₂ capture from industries gases.In this review,the research progresses in CO₂ capture using conventional ionic liquids,functionalized ionic liquids,supported ionic-liquids membranes,polymerized ionic liquids and mixtures of ionic liquids with some molecular solvents were investigated and reviewed.Discussion of relevant research fields was presented and the future developments were suggested.

Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical nature of surface and the preparation of new catalyst. The production of R₃Snl-O-MCM-41 (R₃SnlM) was obtained by heating tributyltin chloride and Al-MCM-41 mixture at 170℃ for 5 h under stirring in nitrogen atmosphere. The composition, structure and surface physical and chemical properties of the samples were characterized by inductively coupled plasma mass spectrometry (ICP-MS), ¹³C, ¹¹⁹Sn, ²⁹SI and ²⁷Al solid state NMR (nuclear magnetic resonance) spectra, in-situ pyridine infrared spectroscopy (Py-IR), N₂ adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), etc. The results of ICP and organic elemental analysis shows that the grafting yield w_Sn was 6.46% for R₃SnlM. H₀ (the negative logarithm of the acid concentration)and the number of acid sites for R₃SnlM respectively were 2.77-0.99 and 4.8 mmol·g^-1 by the Hammett method. N₂ adsorption-desorption, XRD, TEM analysis showed that R₃SnlM with ordered hexagonal mesopore structure, resulted in the decease of surface areas and pore size as well as the increase of mesoporous volume and surface acidity, as compared to Al-MCM-41. R₃SnlM was used in the synthesis of isoamyl acetate. The yield of isoamyl acetate was 96% when n(isoamyl alcohol):n(acetic acid) 1.0:1.0,w_R3SnM 5%, 138℃ for 5 h. The catalyst can be reused and the yield of 86% can be attained when catalyst was reused five times at the same catalytic conditions.

In the absence of catalyst, 70% hydrogen peroxide was used to oxidize succinic anhydride to solid monoperoxysuccinic acid (PSA). Then PSA was applied to synthesis of ε-caprolactone (ε-CL) by oxidation of cyclohexanone in the heterogeneous system. In order to achieve material recycle, solid precipitated in the process of synthesizing ε-CL was dehydrated via reactive distillation followed by recrystallization to prepare succinic anhydride, which was characterized by IR (infrared spectra) and ¹HNMR (¹H nuclear magnetic resonance). Effects of molar ratio of PSA to cyclohexanone, acetic acid dosage, reaction temperature, reaction time on conversion of cyclohexanone, yield and selectivity of ε-CL were investigated respectively. The results indicated that conversion of cyclohexanone, yield and selectivity of ε-CL were upto 98.1%, 97.5% and 99.4% respectively under the optimal conditions. In addition, in the process of synthesizing succinic anhydride, the optimal yield of succinic anhydride reached 67.4%.

A chemical model,based on Pitzer activity coefficient model,is developed with a speciation approach to describe the solubility and chemistry of nesquehonite in concentrated chloride solutions.The chemical equilibrium constants for nesquehonite and aqueous species,i.e. MgCO₃⁰ MgHCO₃⁺,and MgOH⁺,are precisely calculated as a function of temperature according to the Van’t Hoff equation by use of standard Gibbs free energy,standard formation enthalpy and heat capacity.The most recent solubility data are regressed to obtain new Pitzer parameters with good agreement.The predictive ability of the new model is improved significantly in comparison with previous models.The behavior of speciation chemistry for nesquehonite in various chloride media is explained through this modeling work on the basis of the Mg/CO₃^2- bearing species distribution,activity coefficient and pH changes.

Solubility data of carbon dioxide (CO₂) (1) in methanol (2), 1-octyl-3-methylimidazolium bis(trifluoro- methylsulfonyl)imide ([omim]⁺[Tf₂N]^-) (3), and their mixtures (w₃ 0.2, 0.5, and 0.8) at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique. The solubility of CO₂ in methanol (w₃=0), [omim]⁺[Tf₂N]^- (w₃=1.0) and their mixtures follows the order of (w₃=0)<(w₃=0.2)< (w₃=0.5)<(w₃=0.8)<(w₃=1.0) at the same temperature and pressure, while the magnitude of Henry's constants follows the reverse order at a given temperature, which is consistent with the COSMO-RS (conductor-like screening for real solvents) calculation. The solubility data of CO₂ in methanol and [omim]⁺[Tf₂N]^- are correlated with the Peng-Robinson equation of state, and the solubility of CO₂ in the mixtures of methanol and [omim]⁺[Tf₂N]^- can be well predicted based on the mole fraction average of methanol and [omim]⁺[Tf₂N]^- over the solubility of CO₂ in pure methanol and [omim]⁺[Tf₂N]^-. The mixtures of methanol and [omim]⁺[Tf2N]^- may be used as physical solvents for capturing CO₂ with high partial pressures since they combine the advantages of organic solvents and ionic liquids.

This paper focuses on the development of three types of activated carbon (AC) adsorbents, i.e. granular AC, consolidated AC with chemical binder, and consolidated AC with expanded natural graphite (ENG). Their thermal conductivity was investigated with the steady-state heat source method and the permeability was tested with nitrogen as the gas source. Results show that the thermal conductivity of granular AC with different sizes almost maintains a constant at 0.36 W·(m·K)^-1, while the value modestly increases to 0.40 W·(m·K)^-1 for the consolidated AC with chemical binder. The consolidated AC with ENG at the density of 600 kg·m^-3 shows the best heat transfer performance and their thermal conductivity vary from 2.08 W·(m·K)^-1 to 2.61 W·(m·K)^-1 according to its fraction of AC. However, the granular AC and consolidated AC with chemical binder show the better permeability performance than consolidated AC with ENG binder whose permeability changes from 6.98×10^-13 m² to 5.16×10^-11 m² and the maximum occurs when the content of AC reaches 71.4% (by mass). According to the different thermal properties, the refrigeration application of three types of adsorbents is analyzed.

The 0.4 nm molecular sieve supported Cu-Ni bimetal catalysts for direct synthesis of dimethyl carbonate (DMC) from CO₂ and CH₃OH were prepared and investigated. The synthesized catalysts were fully characterized by BET, XRD (X-ray diffraction), TPR (temperature programmed reduction), IR (infra-red adsorption), NH₃-TPD (temperature programmed desorption) and CO₂-TPD (temperature programmed desorption) techniques. The results showed that the surface area of catalysts decreased with increasing metal content, and the metals as well as Cu-Ni alloy co-existed on the reduced catalyst surface. There existed interaction between metal and carrier, and moreover, metal particles affected obviously the acidity and basicity of carrier. The large amount of basic sites facilitated the activation of methanol to methoxyl species and their subsequent reaction with activated carbon dioxide. The catalysts were evaluated in a continuous tubular fixed-bed micro-gaseous reactor and the catalyst with bimetal loading of 20% (by mass) had best catalytic activities. Under the conditions of 393 K, 1.1 MPa, 5 h and gas space velocity of 510 h^-1, the selectivity and yield of DMC were higher than 86.0% and 5.0%, respectively.

In this paper we address the topic of energy and water optimization in the production of bioethanol from corn and switchgrass. We show that in order for these manufacturing processes to be attractive,there is a need to go beyond traditional heat integration and water recycling techniques. Thus,we propose a strategy based on mathematical programming techniques to model and optimize the structure of the processes,and perform heat integration including the use of multi-effect distillation columns and integrated water networks to show that the energy efficiency and water consumption in bioethanol plants can be significantly improved. Specifically,under some circumstances energy can even be produced and the water consumption can be reduced below the values required for the production of gasoline.

Heterogeneous catalysts with ultrafine or nano particle size have currently attracted considerable attentions in the chemical and petrochemical production processes, but their large-scale applications remain challenging because of difficulties associated with their efficient separation from the reaction slurry. A porous ceramic membrane reactor has emerged as a promising method to solve the problem concerning catalysts separation in situ from the reaction mixture and make the production process continuous in heterogeneous catalysis. This article presents a review of the present progress on porous ceramic membrane reactors for heterogeneous catalysis, which covers classification of configurations of porous ceramic membrane reactor, major considerations and some important industrial applications. A special emphasis is paid to major considerations in term of application-oriented ceramic membrane design, optimization of ceramic membrane reactor performance and membrane fouling mechanism. Finally, brief concluding remarks on porous ceramic membrane reactors are given and possible future research interests are also outlined.