Research Progress on Removal of Oxygenatesin Fischer-Tropsch Oil by Adsorption

The oxygen-containing compounds in Fischer Tropsch synthetic oil greatly affect the downstream deep processing of hydrocarbons,and effective removal is required.Com-pared to traditional removal technologies such as hydrogenation deoxygenation,solvent extraction,and extraction distillation,adsorption deoxygenation technology has the advantages of low cost,mild operating conditions,easy removal and recovery,and mini-mal impact on oil quality.Therefore,adsorption deoxygenation technology has devel-oped rapidly in various removal processes and has become a research hotspot in the cur-rent Fischer Tropsch oil deoxygenation.Adsorbents are the core of adsorption deoxygen-ation technology.Therefore,this article briefly introduces the adsorption mechanism and summarizes the research progress of adsorbents widely used in recent years,such as silica gel,alumina,molecular sieves,and metal organic frameworks,in adsorbing oxygen-containing compounds in Fischer Tropsch synthetic oils.And provide reference sugges-tions for further adsorption and deoxygenation directions in the future.

Behavior of large post-liquefaction deformation in saturated Nanjing fine sand

Laboratory tests on the large post-liquefaction deformation of saturated Nanjing fine sand were performed by using a hollow cylinder apparatus. The stress-strain responses and the characteristics of excess pore water pressure after liquefaction were studied. It was found that the relationship between deviatoric stress and axial strain presented a sigmoid curve, and there was a good linearity relationship between normalized pore water pressure and deviatoric stress. On this basis, a constitutive model of stress-strain responses and a dissipation model of excess pore water pressure were established. It was found that the results predicted by the two models were in good agreement with the experimental data. The influence of relative densities and confining pressure on the characteristics of liquefied soil were studied, The results showed the relative densities and initial effective confining pressure all had an important influence on the stress-strain responses of liquefied saturated Nanjing fine sand. However, the dissipation model of excess pore water pressure after liquefaction was only affected by the confining pressure.

Undrained dynamical behavior of Nanjing flake-shaped fine sand under cyclic loading

A series of dynamic behavior tests on Nanjing flake-shaped fine sand were performed by using the WFI cyclic triaxial apparatus made in England. The dynamic behaviors of Nanjing flake-shaped fine sand under different static deviator stress levels and cyclic stress ratios were studied. Through comparing the effective stress path under cyclic loading with static loading, the processes of liquefaction of saturated Nanjing flake-shaped fine sand with development of dynamic pore-water pressure, including the initial compact state, compression state and dilative state, were investigated. The variation of the shear stiffness with the number of cycles and cyclic strain was investigated by analyzing the secant shear modulus in each unload-reload loop of dynamic stress-strain relationship. And by means of the exponential function, the empirical equations of the relationship between secant shear modulus Gsec, shear modulus ratio Gsec/Gmax and cyclic strain ε were established based on series of test results. The results show that according to different combinations of static deviator stress and cyclic stress, two kinds of failure patterns with deviator stress reversal or no deviator stress reversal are observed in the samples tested in this series, including cyclic mobility and the failure of accumulation residual strain. In addition, the degradation of dynamic shear modulus is due to the development of vibration pore-water pressure and it is observed that the shear modulus reduces with the progressive number of cycles.

Effect of Initial Stress Conditions on the Threshold Shear Strain of Nanjing's Saturated Fine Sand

By using GDS dynamic hollow cylinder torsional apparatus, a series of cyclic torsional triaxial tests under complex initial consolidation condition are performed on Nanjing saturated fine sand. The effects of the initial principal stress direction αo, the initial ratio of deviatoric stress η0, the initial average effective principal stress Po and the initial intermediate principal stress parameter b0 on the threshold shear strain γt of Nanjing saturated fine sand are then systematically investigated. The results show that γt increases as η0,p0 and b0 increase respectively, while the other three parameters remain constant. ao has a great influence on γt, which is reduced when ao increases from 0° to 45°and increased when α0 increases from 45° to 90°. The effect of α0 on γt, plays a leading role and the effect of η0 will weaken when ao is approximately 45°.

Cyclic Variability in Chemical Composition and Swelling-Shrinkage Properties of the Xiashu Loess Stratum near Nanjing,China

Xiashu loess strata are widely distributed along the middle-lower reaches of the Yangtze River in East China with the stratum near Nanjing,Jiangsu Province being typical.The cyclic variability of the stratum was investigated through comparison of geological features,chemical composition,and swelling-shrinkage properties between the loess and the paleosol layers.Based on the investigation of such a cyclic variability,soil behavior associated with the unsaturated state of the Xiashu loess stratum and its usefulness for geotechnical design and construction in the Nanjing area was analyzed. The stratum consisted of two types of cyclically alternating soil layers,namely the loess and the paleosol layers,which was the major cause for its cyclic variability.The loess and the paleosol layers were formed in different sedimentary environments.In order to avoid detrimental results from the differential engineering properties between them,this study suggested for the practitioners the importance of inspecting the variation of water content and controlling the downward net fluxes during geotechnical construction in the Nanjing area.

Interpretation of Low-carbon City Planning and Design——A Case Study of Gaochun Zijin Science and Technology Special Community

It is an important and unique approach of achieving sustainable urban development to save and use energy intensively, reduce carbon emission, and take the low-carbon development road. Taking Gaochun Zijin Science and Technology Special Community for example, this paper introduced planning measures for building a low-carbon city, including building a green network, compound utilization of urban spaces, establishing green transportation, using renewable resources, development of green architecture, so as to provide references for the future researches on the low-carbon urban development.

Research on the Reform of Teaching Management Emergency Mechanism in University Based on Big Data

Sudden major public health events once again test the ability of the whole society to deal with emergencies.Universities are no exception.There are many kinds of management work in Colleges and universities,among which teaching management is the most important one,which is also one of the most affected in this epidemic situation.Therefore,in view of the problems of teaching management in Colleges and universities exposed in the epidemic,combined with the characteristics of independent colleges,starting from the aspects of teaching guarantee mechanism,teaching supervision mechanism,teaching process construction,teaching resources construction and so on,the advantages of big data technology,such as large amount of information,easy to communicate and easy to integrate,are fully used to put forward a set of open-minded,perfect mechanism and advanced technology teaching management emergency response mechanism.

Peanut Shell Activated Carbon： Characterization, Surface Modification and Adsorption of Pb^2＋ from Aqueous Solution

Metal ion contamination of drinking water and waste water, especially with heavy metal ion such as lead, is a serious and ongoing problem. In this work, activated carbon prepared from peanut shell （PAC） was used for the removal of Pb^2＋ from aqueous solution. The impacts of the Pb25 adsorption capacities of the acid-modified carbons oxidized with HNO3 were also investigated. The surface functional groups of PAC were confirmed by Fourier transform infrared （FTIR） spectroscopy, X-ray photoelectron spectroscopy （XPS）, Boehm titration. The textural properties （surface area, total pore volume） were evaluated from the nitrogen adsorption isotherm at 77 K. The experimental results presented indicated that the adsorption data fitted better with the Langmuir adsorption model. A comparative study with a commercial granular activated carbon （GAC） showed that PAC was 10.3 times more efficient compared to GAC based on Langmuir maximum adsorption capacity. Further analysis results by the Langmuir equation showed that HNO3 [20% （by mass）] modified PAC has larger adsorption capacity of Pb^2＋ from aqueous solution （as much as 35.5 mg·g^-1）. The adsorption capacity enhancement ascribed to pore widening, increased cation-exchange capacity by oxygen groups, and the promoted hydrophilicity of the carbon surface.

Investigation of Mg^2＋/Li^＋ Separation by Nanofiltration

The Mg2+/Li+/Cl solutions were filtrated with a commercially available DK nanofiltration membrane to investigate the possibility to enrich the lithium component.The investigation was significant as such an approach might be a competing substitute for the present lithium purification industry and the environmental protection purpose.The Donnan steric pore model(DSPM) was implemented for the prediction.The separation of Mg2+/Li+was mainly affected by the working pressure(or the permeation flux) and a limiting separation factor was found around 0.31.The effective membrane charge density was evaluated and its dependence on the permeation flux as well as the ion pattern was discussed.For predicting an actual separation of electrolytes,the experimental investigation seems necessary for the reliability and efficiency.

Prediction of Leakage Rates Through Sealing Connections with Nonmetallic Gaskets

In this work, a model of gas leakage through nonmetallic gaskets was developed in order to predict leakage rate of gasket sealing connections. The model was verified by the leakage experiments on two types of gaskets： compressed non-asbestos fiber gasket and flexible graphite gasket reinforced with tanged metal sheet. The coefficients in the leakage rate formula were obtained by regression of experimental data for each type of gasket, The model was also validated against the experimental leakage data by other researchers and shown to produce accurate predications. Furthermore, the model was applied to a bolted flanged connection in service in order to assess the tightness of the connection.

Pervaporation Separation of Butanol-Water Mixtures Using Polydimethylsiloxane/Ceramic Composite Membrane

Pervaporation has attracted considerable interest owing to its potential application in recovering biobutanol from biomass acetone-butanol-ethanol (ABE) fermentation broth. In this study, butanol was recovered from its aqueous solution using a polydimethylsiloxane (PDMS)/ceramic composite pervaporation membrane. The effects of operating temperature, feed concentration, feed flow rate and operating time on the membrane pervaporation performance were investigated. It was found that with the increase of temperature or butanol concentration in the feed, the total flux through the membrane increased while the separation factor decreased slightly. As the feed flow rate increased, the total flux increased gradually while the separation factor changed little. At 40°C and 1% (by mass) butanol in the feed, the total flux and separation factor of the membrane reached 457.4 g·m?2·h?1 and 26.1, respectively. The membrane with high flux is suitable for recovering butanol from ABE fermentation broth.

Disproportionation of Toluene by Modified ZSM-5 Zeolite Catalysts with High Shape-selectivity Prepared Using Chemical Liquid Deposition with Tetraethyl Orthosilicate

Shape-selective catalysts for the disproportionation of toluene were prepared by the modification of the cylinder-shaped ZSM-5 zeolite extrudates with chemical liquid deposition with TEOS （tetraethyl orthosilicate）.Various parameters for preparing catalysts were changed to investigate the suitable conditions.The resulting cata-lysts were tested in a pressured fixed bed reactor and characterized by SEM （scanning electron microscopy）.The conversion of toluene and para-xylene selectivity were influenced remarkably by the n（SiO2）/n（Al2O3） ratio of ZSM-5 zeolite,the type and amount of deposition agent,acid and solvent used,and the time and cycle of deposition treatment.TEOS was proved to be a more efficient agent than the conventional polysiloxanes when the deposition amount was low.The catalyst prepared at the suitable conditions exhibited a high para-xylene selectivity of 91.1% with considerable high conversion of 25.6%.SEM analyses confirmed the formation of a layer of amorphous silica on the external surface of ZSM-5 zeolie crystals,which was responsible for the highly enhanced shape-selectivity.

Preparation and mechanical properties of polypropylene fiber reinforced calcined kaolin-fly ash based geopolymer

To improve the environmental benefits and solve the problems of large shrinkage and high brittleness, the partial replacement of calcined kaolin by fly ash as a raw material for geopolymer synthesis and the influences of polypropylene (PP) fiber on the mechanical properties and volume stability were investigated. The results show that compressive strength of the geopolymer containing 33.3%(mass fraction) fly ash by steam curing at 80 ℃ for 6 d is improved by 35.5%. The 3-day compressive strength, flexural strength and impacting energy of geopolymers containing 0.05%PP fiber increase by 67.8%, 36.1% and 6.25%, while the shrinkage and modulus of compressibility decrease by 38.6% and 31.3%, respectively. The results of scanning electron microscopy (SEM) and the appearances of crack growths confirm that PP fiber can offer a bridging effect over the harmful pores and defects and change the expanding ways of cracks, resulting in a great improvement of strength and toughness.

Pretreatment of Crude Oil by Ultrasonic-electric United Desalting and Dewatering

A technology of ultrasonic-electric united desalting and dewatering of crude oil is studied. The ultrasonic setup is designed to form a standing-wave field, which is more efficient for agglomeration of water particles. The desalting and dewatering results of the ultrasonic-electric united process are compared with those of the electric process. For high salt-contenting crude oil （40-70 mg·L ^-1）, the salt content is still above 10.0 mg·L^-1 after crude oil has been treated by two-stage electric desalting process in refinery, which cannot meet the need of refinery. Ultrasonic-electric united process is a novel technology for treating the high salt-contenting oil. On the optimal operating conditions of the ultrasonic-electric united process, the salt content of crude oil can be reduced from 67 5 mg·L^-1 to 3.97 mg·L ^-1 by one-stage ultrasonic-electric united process, and the water content falls below 0.3% （by volume）. The results show that the ultrasonic-electric united process is more effective than the electric process in high salt-contenting oil desalting. This technology should be useful in the refinery process.

Simulation of 1,3-Butadiene Production Process by Dimethylfomamide Extractive Distillation

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.

Pretreatment of Isopropanol Solution from Pharmaceutical Industry and Pervaporation Dehydration by NaA Zeolite Membranes

NaA zeolite membranes with 80 cm in length and 12.8 mm in outer diameter were prepared by our research group cooperating with Nanjing Jiusi Hi-Tech Co., China. The influence of dissolved inorganic salts and pH value in the feed of isopropanol （IPA） solution on NaA zeolite membranes was investigated. It was found that both factors exhibited strong influence on the stability of NaA zeolite membranes. A set of pretreatment steps such as pH adjustment and distillation of the IPA solution were proposed to improve stability for pervaporation dehydration. An industrial-scale pervaporation facility with 52 m2 membrane area was built to dehydrate IPA solution from industrial cephalosporin production. The facility was continuously operated at 368-378 K to dehydrate IPA solution from water mass content of 15%-20% to less than 2% with a feed flow rate of 400-500 L·h^-1 and an average water flux of 1-1.5 kg·m^-2·h-1. The successful application of this facility suggested a promising application of NaA zeolite mem-brane for IPA recovery from pharmaceutical production.

The Effect of Titania Structure on Ni/TiO_2 Catalysts for p-Nitrophenol Hydrogenation

The catalytic hydrogenation of p-nitrophenol to p-aminophenol was investigated over Ni/TiO2 catalysts prepared by a liquid-phase chemical reduction method. The catalysts were characterized by inductively coupled plasma (ICP), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and temperature-programmed reduction (TPR). Results show that the titania structure has favorable influence on physio-chemical and catalytic properties of Ni/TiO2 catalysts. Compared to commercial Raney nickel, the catalytic activity of Ni/TiO2 catalyst is much superior, irrespective of the titania structure. The catalytic activity of anatase titania supported nickel catalyst Ni/TiO2(A) is higher than that of rutile titania supported nickel catalyst Ni/TiO2(R), possibly because the reduction of nickel oxide to metallic nickel for Ni/TiO2(A) is easier than that for Ni/TiO2(R) at similar reaction conditions.

Analysis of Heat Transfer Performance of Oscillating Heat Pipes Based on a Central Composite Design

Oscillating heat pipes (OHPs) are very promising cooling devices. Their heat transfer performance is af- fected by many factors, and the form of the relationship between the performance and the factors is complex and non-linear. In this paper, the effects of charging ratio, inclination angle, and heat input and their interaction effects on heat transfer performance of a looped copper-water OHP are analyzed. First, suppose that the relationship between the response and the variables approximates a second-order model. And use the central composite design to arrange the ex- periment. Then, the method of least squares is used to estimate the parameters in the second-order model. Finally, multi- variate variance analysis is used to analyze the model. The results show that the assumption is right, that is to say, the re- lationship is well modeled by a second-order function. Among the three main effect variables, the effect of inclination angle is the most significant, but their interaction effects are not significant. In the range of the considered factors, both the optimum charging ratio and the optimum inclination angle increase as the heating water flow rate increases.

Adsorption separation of carbon dioxide, methane and nitrogen on monoethanol amine modified β-zeolite

A new type of composite adsorbents was synthesized by incorporating monoethanol amine （MEA） into β-zeolite. The parent and MEA- functionalized β-zeolites were characterized by X-ray diffraction （XRD）, N2 adsorption, and thermogravimetric analysis （TGA）. The adsorption behavior of carbon dioxide （CO2）, methane （CH4）, and nitrogen （N2） on these adsorbents was investigated at 303 K. The results show that the structure of zeolite was well preserved after MEA modification. In comparison with CH4 and N2, CO2 was preferentially adsorbed on the adsorbents investigated. The introduction of MEA significantly improved the selectivity of both CO2/CH4 and CO2/N2, the optimal selectivity of CO2/CH4 can reach 7.70 on 40 wt% of MEA-functionalized β-zeolite （MEA（40）-β） at 1 atm. It is worth noticing that a very high selectivity of CO2/N2 of 25.67 was obtained on MEA（40）-β. Steric effect and chemical adsorbate-adsorbent interaction were responsible for such high adsorption selectivity of CO2. The present MEA-functionalized β-zeolite adsorbents may be a good candidate for applications in flue gas separation, as well as natural gas and landfill gas purifications.

Adsorption separation of carbon dioxide,methane,and nitrogen on Hβand Na-exchangedβ-zeolite

Adsorption isotherms of carbon dioxide （CO2）, methane （CH4）, and nitrogen （N2） on Hβand sodium exchanged β-zeolite （Naβ） were volumetrically measured at 273 and 303 K. The results show that all isotherms were of Brunauer type I and well correlated with Langmuir-Freundlich model. After sodium ions exchange, the adsorption amounts of three adsorbates increased, while the increase magnitude of CO2 adsorption capacity was much higher than that of CH4 and N2. The selectivities of CO2 over CH4 and CO2 over N2 enhanced after sodium exchange. Also, the initial heat of adsorption data implied a stronger interaction of CO2 molecules with Na＋ ions in Naβ . These results can be attributed to the larger electrostatic interaction of CO2 with extraframework cations in zeolites. However, Naβ showed a decrease in the selectivity of CH4 over N2, which can be ascribed to the moderate affinity of N2 with Naβ. The variation of isosteric heats of adsorption as a function of loading indicates that the adsorption of CO2 in Naβ presents an energetically heterogeneous profile. On the contrary, the adsorption of CH4 was found to be essentially homogeneous, which suggests the dispersion interaction between CH4 and lattice oxygen atoms, and such interaction does not depend on the exchangeable cations of zeolite.