The great potential of gold catalysts for chemical conversions in both industrial and environmental concerns has attracted increasing interest inmany fields of research. Gold nanoparticles supported by metal oxides with high surface area have been recognized as highly efficient and effective green heterogeneous catalyst even at room temperature under normal reaction conditions, in gas and liquid phase reactions. In the present review, we discuss the recent development of heterogeneous, supported monometallic gold catalysts for organic transformations emphasizing mainly liquid phase hydrogenation reactions. Discussions on the catalytic synthesis procedures and the promoting effect of other noblemetals are omitted since they are already worked out. Applications of heterogeneous, supported monometallic catalysts for chemoselective hydrogenations in liquid phase are studied including potential articles during the period 2000-2013.

This article is concerned with the numerical investigation of one-dimensional population balance models for batch crystallization process with fines dissolution. In batch crystallization, dissolution of smaller unwanted nuclei below some critical size is of vital importance as it improves the quality of product. The crystal growth rates for both size-independent and size-dependent cases are considered. A delay in recycle pipe is also included in the model. The space-time conservation element and solution element method, originally derived for non-reacting flows, is used to solve the model. This scheme has already been applied to a range of PDEs, mainly in the area of fluid mechanics. The numerical results are compared with those obtained from the Koren scheme, showing that the proposed scheme is more efficient.

A 3D numerical investigation has been carried out to examine periodic laminar flow and heat transfer characteristics in a circular tubewith 45° V-baffleswith isothermalwall. The computations are based on the finite volume method (FVM), and the SIMPLE algorithmhas been implemented. The fluid flowand heat transfer characteristics are presented for Reynolds numbers ranging from 100 to 2000. To generate main longitudinal vortex flows through the tested section, V-baffleswith an attack angle of 45° aremounted in tandem and in-line arrangement on the opposite positions of the circular tube. Effects of tube blockage ratio, flow direction on heat transfer and pressure drop in the tube are studied. It is apparent that a pair of longitudinal twisted vortices (P-vortex) created by a V-baffle can induce impingement on awall of the inter-baffle cavity and lead a drastic increase in heat transfer rate at tube wall. In addition, the larger blockage ratio results in the higher Nusselt number and friction factor values. The computational results show that the optimum thermal enhancement factor is around 3.20 at baffle height of B=0.20 and B=0.25 times of the tube diameter for the V-upstreamand V-downstream, respectively.

Confined impinging jet reactor (CIJR) offers advantages for chemical rapid processes and has become an important new reactor used in the chemical industry. The micromixing efficiency in a T-shaped CIJR for two tubes of inner diameter of 3 mm was studied by using a parallel competing iodide-iodate reaction as the working system. In this work, the effects of different operating conditions, such as impinging velocity and acid concentration, on segregation index were investigated. In addition, the effects of the inner nozzles diameter and the distance L between the jet axis and the top wall of the mixing chamber on the micromixing efficiency were also considered. It is concluded that the best range of L in this CIJR is 6.5-12.5 mm. Based on the incorporation model, the estimated minimum micromixing time t_m of CIJR approximately equals to 2×10^-4 s. These experimental results indicate clearly that CIJR possesses a much better micromixing performance compared with the conventional stirred tank (micromixing time of 2×10^-3 to 2×10^-2 s). Hence, it can be envisioned that CIJR hasmore promising applications in various industrial processes.

By using a hybrid lattice-Boltzmann-finite-difference method (hybrid LBM-FDM method), three-dimensional simulations of solutal interfacial convection were conducted for the process of CO₂ absorption into ethanol. A self-renewal interface model is adopted as an interfacial perturbation model. The simulation results revealed some three-dimensional features of the induced interfacial convection, such as the development of diverging cellular flowand Rayleigh plume-like convection in liquid phase. The concentration distribution of the simulation result is validated and found to be in well agreement with the Schlieren visualization results qualitatively. Additionally, the mass transfer enhancements by interfacial convection were investigated via both simulation and experiment for the absorption process, and the mass transfer is shown to be enhanced by the interfacial convection by about two-fold comparing with that by diffusion.

A novel solid support adsorbent for CO₂ capture was developed by loading pentaethylenehexamine (PEHA) on commercially available mesoporous molecular sieve MCM-41 using wet impregnation method. MCM-41 samples before and after PEHA loading were characterized by X-ray powder diffraction, N₂ adsorption/desorption, thermal gravimetric analysis and scanning electron microscope to investigate the textural and thermo-physical properties. CO₂ adsorption performance was evaluated in a fixed bed adsorption system. Results indicated that the structure of MCM-41 was preserved after loading PEHA. Surface area and total pore volume of PEHA loaded MCM-41 decreased with the increase of loading. The working adsorption capacity of CO₂ could be significantly improved at 60% of PEHA loading and 75℃. The effect of the height of adsorbent bed was investigated and the best working adsorption capacity for MCM-41-PEHA-60 reached 165 mg·(g adsorbent)^-1 at 75℃. Adsorption/desorption circle showed that the CO₂ working adsorption capacity of MCM-41-PEHA kept stable.

A high performance composite membrane was prepared under the inspiration of bioadhesion principles for pervaporative dehydration of ethanol. Chitosan (CS) and polyacrylonitrile (PAN) ultrafiltration membranes were used as the active layer and the support layer, respectively. Guar gum (GG), a natural bioadhesive, was introduced as the intermediate bonding layer to improve the separation performance and stability of the fabricated CS/GG/PAN composite membranes. The contact angle of the GG layerwas just between those of the CS layer and the PAN layer, minimizing the difference of hydrophilicity between the active layer and the support layer. The peeling strength of the composite membrane was significantly enhanced after the introduction of the GG layer. The effects of preparation conditions and operation conditions including GG concentration, operating temperature and ethanol concentration in feed on the pervaporation performance were investigated. The as-fabricated CS/GG/PAN composite membrane showed the optimum performance with a permeation flux of up to 804 g·m^-2·h^-1 and a separation factor higher than 1900. Besides, the compositemembranes exhibited a desirable long-term operational stability.

The traditional method to refine crude cottonseed oil is time-consuming and expensive. This study evaluates the effectiveness of coagulation-flocculation-sedimentation process using quaternary polyamine-based polymers in refining crude cottonseed oil. Flocculated by four commercial polyamine-based cationic polymers (SL2700, SL3000, SL4500 and SL5000) with varied molecular weight (MW) and charge density (CD) and followed by coagulation with sodiumhydroxide, crude cottonseed oil can be effectively purified. Free fatty acids, gossypol, pigments and trace elements are all effectively and sufficiently removed by the four polymers in a MW- and CDdependentmanner. Our results suggest that the use of polyamine-based cationic polymers may offer an effective and feasible alternative to the traditional method for crude cottonseed oil refining.

The production of Ph₃Sn-O-SBA-15 (Ph₃SnSBA) was achieved by heating triphenyltin chloride and SBA-15 in N-methylpyrrolidone at 190℃ for 5 h using triethylamine as a catalyst. The composition, structure, and surface physical and chemical properties of Ph₃SnSBA were characterized using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), ¹³C, ¹¹⁹Sn and ²⁹Si solid-state nuclear magnetic resonance (NMR) spectroscopy in situ pyridine infrared spectroscopy (Py-IR), N₂ adsorption-desorption isotherms, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results of ICP-AES and organic elemental analysis showed that the grafting yield of Sn was 17% (by mass) for Ph₃SnSBA. The elemental analysis and solid-state NMR results for Ph₃SnSBA were consistent with grafting of triphenyltin on SBA-15. The N₂ adsorption-desorption, XRD and TEM analyses showed that Ph₃SnSBA retained an ordered hexagonal mesoporous structure, resulting in decreases in the surface area, pore size and mesopore volume, and an increase in acidity as compared with SBA-15. The Hammett acidity function (H₀) value and the number of acid sites for Ph₃SnSBA, obtained by the Hammett methods, were 2.77-3.30 and 2.07 mmol·g^-1, respectively. The Friedel-Crafts acylation of toluene and acetic anhydride over Ph₃SnSBA was investigated. The yield of methylacetophenone (MAP) and the selectivity for 4-methylacetophenone (PMAP) were 79.56% and 97.12%, respectively, when the conditions were n(toluene):n(anhydride)=2.0:1.0 with 6% (by mass) catalyst, and heating under reflux for 5 h. The PMAP selectivity still reached 93.11% when Ph₃SnSBA was used for the fifth time under the same reaction conditions.

A double-input-multi-output linearized system is developed using the state-space method for dynamic analysis of methanation process of coke oven gas. The stability of reactor alone and reactor with feed-effluent heat exchanger is compared through the dominant poles of the systemtransfer functions.With single or double disturbance of temperature and COconcentration at the reactor inlet, typical dynamic behavior in the reactor, including fast concentration response, slow temperature response and inverse response, is revealed for further understanding of the counteraction and synergy effects caused by simultaneous variation of concentration and temperature. Analysis results showthat the stability of the reactor loop ismore sensitive than that of reactor alone due to the positive heat feedback. Remarkably, with the decrease of heat exchange efficiency, the reactor system may display limit cycle behavior for a pair of complex conjugate poles across the imaginary axis.

In response to many multi-attribute decision-making (MADM) problems involved in chemical processes such as controller tuning, which suffer human's subjective preferential nature in human-computer interactions, a novel affective computing and preferential evolutionary solution is proposed to adapt human-computer interaction mechanism. Based on the stimulating response mechanism, an improved affective computing model is introduced to quantify decision maker's preference in selections of interactive evolutionary computing. In addition, the mathematical relationship between affective space and decision maker's preferences is constructed. Subsequently, a human-computer interactive preferential evolutionary algorithm for MADM problems is proposed, which deals with attribute weights and optimal solutions based on preferential evolution metrics. To exemplify applications of the proposedmethods, some test functions and, emphatically, controller tuning issues associated with a chemical process are investigated, giving satisfactory results.

Vapor pressures were measured for acetonitrile +1-butyl-3-methylimidazolium chloride ([C₄mim][Cl]), +1-butyl-3-methylimidazolium tetrafluoroborate ([C₄mim][BF₄]) and +1-hexyl-3-methylimidazolium chloride ([C₆mim][Cl]) at temperatures of 313 to 353 K by a quasi-staticmethod. The experimental data for the binary systemswere correlated by the non-randomtwo liquid (NRTL) equationwith an average absolute relative deviation (AARD) of within 1.84%. The results indicate that the three ionic liquids (ILs) can result in a negative deviation from the Raoult's law for the binary solutions containing acetonitrile, and the affinity between ILs and acetonitrile molecules follows the order [C₄mim][BF₄]+acetonitrile > [C₄mim][Cl]+acetonitrile > [C₆mim][Cl]+acetonitrile.

The study is focused on the extraction of valuable metals from automotive shredder residue (ASR) by different leaching solutions. First, ASR samples were roasted at 600℃ to simulate a thermal treatment processing. Distilled water, citric and sulphuric acid were preliminarily investigated, thus two further full factorial systems entailing H₂SO₄-H₂O₂ and H₂SO₄-H₂O₂-Fe³⁺ were tested. The preliminary experimental results showed that 0.1 mol·L^-1 H₂SO₄ solution extracted 100% of Cu, Fe and Zn, whereas citric acid leached 100% of Zn and Pb, 59% of Fe and 62% of Cu; whereas, H₂SO₄-H₂O₂ and H₂SO₄-H₂O₂-Fe³⁺ (Fenton's) leaching media showed that Cu, Fe and Zn can be extracted simultaneously and completely from the ASR ashes before final disposal.

A research on the heat transfer performance of kerosene flowing in a vertical upward tube at supercritical pressure is presented. In the experiments, insights are offered on the effects of the factors such asmass flux, heat flux, and pressure. It is found that increasing mass flux reduces the wall temperature and separates the experimental section into three different parts, while increasing working pressure deteriorates heat transfer. The extended corresponding-state principle can be used for evaluating density and transport properties of kerosene, including its viscosity and thermal conductivity, at different temperatures and pressures under supercritical conditions. For getting the heat capacity, a Soave-Redlich-Kwong (SRK) equation of state is used. The correlation for predicting heat transfer of kerosene at supercritical pressure is established and shows good agreementwith the experimental data.

A new process is developed by using compound Mn as intermediate to produce Cl₂ from HCl, with the following steps. (1) HCl steam is decomposed by intermediate Mn₂O₃ to produce Cl₂ and MnCl₂ at 500℃. (2) Produced MnCl₂ is oxidized by water steam to produce MnO at 450℃. (3) The MnO compound is oxidized by air to yield Mn₂O₃. The X-ray diffraction (XRD) crystallite characterization results indicate the high conversion in each step under the optimum experimental conditions. Long term experiments for continuous conversion of HCl to Cl₂ by using Mn₂O₃ as intermediate in a fixed bed reactor indicate that over 90% of HCl could be converted to Cl₂ on stream of 30 h. The production of Cl₂ fromHClwithMn compound as an intermediate and atmospheric steam is a feasible and recyclable process.

Polypropylene (PP)with different contents of the second generation hyperbranched polyester (HBP) is prepared by melt blending method. The non-isothermal crystallization kinetics of PP and PP/HBP blends is investigated under differential scanning calorimetry (DSC). The Mo equation is used to analyze the DSC data. The results showthat theMo theory is suitable for crystallization kinetics of the blends. Fast cooling rate is not good for crystallizing and nucleating. The values of half crystallization time (t_1/2), crystallization enthalpy (ΔH_c) and temperature range (ΔT) of PP/HBP blends decrease when HBP is added. The required cooling rate of PP is higher than that of PP/HBP blends in order to reach the same relative crystallinity. Crystallization rate increases with the addition of HBP. The crystallization rate reaches a maximumwhen the content of HBP is 5%. In addition, the activation energies of PP and PP/HBP blends are calculated by Kissinger equation, revealing that the content of HBP has a little effect on the crystallization activation energy.

The efficient synthesis of dimethylhexane-1,6-dicarbamate (HDC) from 1,6-hexanediamine (HDA) and methyl carbonate over a series of heterogeneous catalysts (e.g., MgO, Fe₂O₃, Mo₂O₃, and CeO₂) was investigated. The reaction pathway was confirmed as an alcoholysis reaction through a series of designed experiments. Under optimized conditions, 100% HDA conversion with 83.1% HDC_total and 16.9% polyurea was obtained using a onestep with high temperature procedurewith CeO₂ as the catalyst. A newtwo-stepwith variable temperature technology was developed based on the reaction pathway to reduce the polyurea yield. Using the proposed method, the HDC_total yield reached 95.2%, whereas the polyurea yield decreased to 4.8%. The CeO₂ catalyst showed high stability and did not exhibit any observable decrease in the HDC yield or any structural changes after four recycling periods.

In order to facilitate the preparation of paeoniflorin (PF) and albiflorin (AF), two chief bioactive constituents in Paeonia lactiflora Pall (PL), induction and culture of callus from PL were studied. With a modified woody plant medium supplemented with 0.5 mg·L^-1 6-benzylaminopurine, 1.0 mg·L^-1 naphthylacetic acid, 0.1 mg·L^-1 thidiazuron and 30 g·L^-1 sucrose, callus was induced from four kinds of explants: leaf, stems, petiole, and root. The potency to formcallus varies between different explants and leaf explants exhibits the highest capacity (100%). On the other hand, root-derived callus (R-callus) produces the highest level of total amount of PF and AF, 31.8 mg·g^-1 dry mass, which is higher than the corresponding level in the root of field cultivated PL. Furthermore, the timeneeded is only 40 days, remarkably shorter than the cultivation timeof PL, about 4-5years. Higher accumulation levels of PF and AF with shorter production time indicate that callus culture of PL is a promising powerful tool for production of PF and AF in the future.

Mg ion-exchanged samples were prepared with acid-washed Shengli lignite. The chemical composition of the ash of the rawsamplewas determined by X-ray fluorescence. The equilibriumadsorptionwater contents of samples were determined in a range of relative humidity. The ion-exchange process was characterized by FT-IR, ash content, and pH value. A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities. The extent of ion-exchange reaction between Mg²⁺ and lignite is controlled by the concentration of Mg²⁺ in MgSO₄ solution. The effect of Mg²⁺ on equilibrium adsorption water content varies with relative humidity and content ofMg²⁺. The factor that controls equilibriumadsorptionwater content at low relative humidity is water interactions with sorption sites, which are Mg²⁺-carboxyl group complex. At middle relative humidity capillary force between Mg²⁺-water clustersMg+(H₂O)_n and capillary is more important. At high relative humidity, free water-free water interactions are more significant.