Process analytic technology/tools (PAT) are widely used in industrial production and process monitoring with the advantages that the system can be developed, designed, analyzed and controlled through timely measurement of varieties of parameters, with the goal of ensuring final product quality.In view of the wide application of PAT in the field of crystallization, firstly, the working principle of several PAT tools were briefly introduced.The application of Raman (Raman), attenuated total reflection Fourier transformed infrared spectroscopy(ATR-FTIR), focused beam reflectance measurement (FBRM) and particle vision measurement (PVM) in the determination of solubility, the detection of nucleation and the transformation of polymorphic systems were summarized and discussed in detail. The successful application of PAT will promote the further understanding of the mechanism of crystallization process and will help to guide the development, optimization, design and scaling up of the industrial crystallization process.
The loose and porous cobalt-cerium complex oxides were prepared by sol-gel method with high specific surface area and larger pore volume. The catalytic degradation effect of the prepared cobalt-cerium composite oxides on 2,4,6-trichlorophenol as model compound in the wastewater has been studied. The results showed that the cobalt-cerium composite oxides have good degradation activity on 2,4,6-trichlorophenol, because of redox ability and synergistic catalysis of cobalt-cerium composite oxides. The initial pH value of the solution was proven to have significant effect on the degradation, lower pH of the solution brought high degradation efficiency. 100 mg of cobalt-cerium composite oxide and 10 mL of 100 mg/L 2,4,6-trichlorophenol were vibrated at 25℃ for 30 h, the degradation efficiency of 2,4,6-trichlorophenol can reach 86.3%,and the amounts of the organic compounds apt to be oxidized decreased by 36.7%.
This paper mainly explored the influence of acid treatment on the Br nsted and Lewis acid distribution of Beta zeolites and their catalytic activity for the selective ring opening of decalin. The Beta zeolites treated by different concentration of hydrochloric acid were characterized by XRD, BET, XRF and Py-FTIR. The crystallinity and pore size had no obvious change after acid treatment. The specific surface area of the HCl treated zeolites increased first and then decreased as the concentration of hydrochloric acid increased. Meanwhile, the ratio of SiO2/Al2O3 increased and the total acid content gradually decreased with the increase of the concentration of hydrochloric acid. The Br nsted acid site was mainly modified by the acid treatment as the acid concentration was higher than 0.1 mol/L. The results of activity experiments showed that the Br nsted acid sites played a dominant role in the ring opening of decalin. Higher Br nsted acid sites easily led to deactivation. The catalyst treated by 0.1 mol/L HCl solution exhibited optimum activity owing to its suitable acid sites and high surface area.
Finding low-cost and efficient electrocatalysts towards hydrogen evolution reaction (HER) is a crucial step towards a sustainable "hydrogen economy". In this paper, MoS2-Ni2P/reduced graphene oxide (RGO) has been prepared by a solvothermal reaction. The MoS2-Ni2P/RGO composite exhibits high HER activity in the acidic media, with overpotentials of 160 mV at the current density of 10 mA·cm-2 and a low Tafel slope of 35.9 mV·dec-1. The synergistic effect of the combination of Ni2P and MoS2 is attributed to hydrogen spillover from Ni2P to MoS2.
In this paper, we used a BDDIPY with near-infrared fluorescent properties as imaging group to produce a new type of near infrared fluorescence molecular probe for detecting tumor cells. Firstly, BOD was used as the starting materials, and then introduced N-phenyl iminodibenzyl with strong electron-donating ability into the BDDIPY dye through condensation reaction. Then we gained the glycine-BDDIPY compound which has the near-infrared fluorescence spectrum. Next, with N-hydroxy succinimide as an activator,glycine methyl ester was introduced into the BDDIPY. Finally we get a biocompatible glycine-BDDIPY molecular fluorescent probe which having affinity with tumors. All the intermediates and target products were characterized by 1H NMR and MALDI-TOF. These BODIPYs were tested to characterize their optical and biological properties. Experimental results showed that the fluorescence emission wavelength of glycine-BDDIPY is longer than 700 nm. And it had a good affinity with lung cancer cells at about 23.65. This indicates that glycine-BDDIPY has a good application prospect for detecting tumor cells.
The surface modification of natural Halloysite nanotubes by grafting with γ-aminopropyltriethoxysilane (APTES) was firstly got. So we modified the functional groups of Halloysite nanotubes (HNT) from hydroxyl groups (HNT-OH) to amino groups (HNT-NH2) and to carboxylic acids (HNT-COOH), which was found to have perfect performance on adsorption desulfurization, and the materials were characterized by SEM, FTIR, XRD and BET. The desulfurization rate of HNT-NH2 was 72.06%, which was 19.47% bigger than natural Halloysite nanotubes. But the rate of HNT-COOH was only 8.42% bigger than that of natural Halloysite nanotubes. The bigger the pore volume of the modified materials was, the bigger the desulfurization rate of functional materials was.
A series of Ru-doped perovskite-type La0.7Sr0.3Co1-xRuxO3 catalysts was synthesized using sol-gel method. The samples were characterized with XRD and H2-TPR. The results showed that the structures of perovskite became more integrated than that of the undoped perovskite, and the segregation of the unitary oxides of the component metal ions was suppressed with Ru doping. The catalysts performed a storage trap of NOx with a considerable trap width, as well kept a good storage capacity of NOx during storage-reduction test all under 325℃. The strontium carbonate was the major adsorption site of NOx, and its proportion decreased as Ru doping, with the contribution to NOx adsorption declining indicated by the parameter of carbon-nitrogen ratio.
The thermodynamics of hydrogenation of acetic acid or acetic ester to ethanol had been analyzed. The enthalpy changes and the standard equilibrium constants of the three reactions were calculated. The effects of temperature, pressure and the molar ratio of reagents on the equilibrium conversion of acetic acid or acetic ester were researched. The result shows that all the enthalpy changes of the three reactions are less than 0, so the reactions are exothermic. The reaction conditions can not make a great influence on the conversion of acetic acid, because the standard equilibrium constant is comparatively large. However, the reaction conditions make a great effect on the conversion of acetic esters due to their small standard equilibrium constants. For the hydrogenation of acetic ester to ethanol, the suitable reaction temperature is 423-550 K and the suitable reaction pressure is 2-3 MPa and the suitable molar ratio of hydrogen and acetic ester is 10-20.
Trimethoxysilyl-propyl-trithiocarbonyl-benzyl ester(BTPT), which is one of the silicone-based RAFT agents, was grafted onto the surface of silica nanospheres. Using the reversible addition-fragmentation chain transfer polymerization, silica nanospheres modified with the pH-and temperature-sensitive polyelectrolyte poly(N, N-dimethylaminoethyl methacrylate) (PDMAEMA) were prepared. Then silica nanospheres grafted with PDMAEMA were transformed to the hollow mesoporous structure by surface-protected etching strategy using ammonia at ambient temperature, thereby obtained the hollow mesoporous silica nanospheres modified with the PDMAEMA (HMS@PDMAEMA). The resultant composite nanoparticles with pH-and temperature-sensitive polymer shell and HMS core were characterized by a variety of techniques such as 1HNMR, FTIR, GPC and TEM, etc. The pH-sensitive behavior was tested by nano-size and zeta potential analyzer. We envision that the HMS@PDMAEMA should have potential applications in controlled release of anticancer drug and gene delivery.
CuO-K2CO3/TiO2 catalysts were calcined at different temperatures (350, 450, 550, 650 and 750℃). The catalytic performance of the CuO-K2CO3/TiO2 catalysts for NOx storage and reduction was evaluated. Multiple techniques including BET, XRD, HR-TEM, H2-TPR and in-situ DRIFTS were employed for catalyst characterization. The results indicate that in the catalysts calcined at different temperatures, the main copper species are CuO. The catalyst calcined at 450℃, displays not only the largest NOx storage capacity of 1.808 mmol/g at lean condition but also the highest NOx reduction percentage of 99.8% in cyclic lean/rich atmospheres; moreover, after used for 22 cycles of NOx storage and reduction at alternative lean/rich atmospheres, the catalytic activity changes very little, showing high catalytic stability.
Advanced oxidation processes (AOPs) are considered a new type of environmental-friendly technology used for wastewater treatment. AOPs are based on the generation of a large amount of hydroxyl radicals rapidly through a variety of reinforcement technologies, then organics in the sewage can be quickly and efficiently degraded into harmless inorganic salts by chain reaction induced between hydroxyl radicals and the organic matters. As two typical technologies of the AOPs, Electro-Fenton and ozone were introduced for ship sewage treatment by integrated method. The efficiency of this new E-Fenton/O3 system on the ship sewage treatment was evaluated in terms of its removal efficiency of chemical oxygen demand (COD). The results showed that under optimal reaction conditions that included a current density of 20 mA/cm2, Fenton reagent (H2O2 and Fe2+) ratio of 3:1 with Fe2+ dosage of 0.01 mol/L, the O2 flow rate of 2 L/min and the ozone dosage of 6 g/L, the integrated process by E-Fenton/O3 system could effectively degrade sewage and achieve the removal of COD as high as 86.4% in 120 min.
Compaction density of graphite anode is one of the main factors on the cycle performance and rate performance of lithium ion batteries. The electrochemical performances of three kinds of graphite anode with different compaction density are conducted in this article. Both the resistance of cell and the absorption time of electrolyte have increased with increasing the compaction density of graphite anode. Among these batteries with different compaction density of graphite anode, the cycle performance and rate performance with a compaction density of 1.7 g/cm3 is the best. After 500 cycles at 0.5 C discharge, the capacity retention ratio of battery with a compaction density of 1.7 g/cm3 is 86.8%. The 3.0 C discharge capacity retains 95.1% of 0.2 C discharge capacity.
Toluene, n-heptane, petroleum ether and naphtha were used as the solvent to extract bitumen from water-wet oil sands amended with CPAM (cationic polyacrylamide) aqueous solution and pure[Emim]BF4. The bitumen recovery, infrared spectrum of bitumen and SEM microphotographs of the residual sands/clay constitute the three aspects of evaluation of the solvents and additives. Finally, naphtha amended with CPAM aqueous solution were regarded to be reliable and practical. After the optimization, the bitumen recovery increased from 72.29% to 78.29% while the ratio of naphtha to 0.05% CPAM aqueous solution to oil sands was 3:2:1 at room temperature. In addition, CPAM aqueous solution demonstrated the ability to reduce clay/fines entrainment both in bitumen and naphtha systems.
SST k-ω turbulence model was adopted to simulate the hydrodynamics in the wave-plate mist eliminator with or without auxiliary capture by considering the gas-liquid two-phase flow as single flow. With this model, the gas flow field and pressure drop in the wave-plate mist eliminator were obtained. Under different entrance gas speed of 2 m/s and 4 m/s, maximum gas speed increased respectively from 7.32 m/s and 14.80 m/s to 8.97 m/s and 18.57 m/s when there were auxiliary captures in the channel, and its sites also increased. At the meantime, the region of high fluid speed became larger, whereas the region of low speed became smaller. The gas speed near the wall increased from 1.5 m/s to 3.5 m/s at the entrance speed of 2 m/s. Then we discovered the change tendency of the pressure drop following the capture height at different gas speeds, and that it had similar tendency between the first stage and the third stage, meanwhile the situation was significantly different in the second stage. The conclusion above could be applied to the practical design.
A novel thickener feedwell was developed based on the traditional feedwell. It was easy to reform and had a simple structure. The flow field of the novel thickener feedwell was researched by computational fluid dynamics. The distribution of path line, the solid volume fraction and the velocity distribution in the exit plane were studied. The novel thickener feedwell could cope with variations of the flow rate, dissipate the kinetic energy of the feed stream and provide a uniform discharge pattern. The direction in which suspensions flowing out of the feedwell had an angle with the radial direction. The time increased for the feed to reach the overflow weir, making high solid-liquid separation efficiency. The novel thickener feedwell could work without any power and had a number of applications.
Wire-Mesh mist eliminators are widely used in petroleum, chemical and gas industries. Wire-Mesh mist eliminators are divided into two kinds:spiral wound and layered structure. Literature on wire mesh mist eliminators is still fewer, and majority of research have reported on layered structure and little on spiral wound structure. In this work, a set of experimental data was obtained by investigating the separation capacity of different spiral wound wire mesh eliminators, the effects of gas velocity and design characteristics on the droplet separation efficiency were analyzed. Finally, a mathematic model is proposed. A good agreement was obtained between the experimentally measured values and the model predictions.
