用改性高炉水淬渣吸附水中硝基苯

取包钢4号高炉水淬渣进行酸热联合改性后用于模拟含硝基苯废水的吸附处理,研究了吸附的影响因素及等温吸附行为。结果表明：在室温、自然pH、模拟废水硝基苯质量浓度为10 mg/L、改性水淬渣粒度和用量分别为-100目和8 g/L、吸附时间为60 min条件下,硝基苯的去除率可达81.8%;改性水淬渣对硝基苯的等温吸附行为较好地符合Langmuir和Freundlich模式,室温下饱和吸附容量为33.56 mg/g,吸附过程较易进行。     

A novel integrated, thermally coupled fluidized bed configuration for catalytic naphtha reforming to enhance aromatic and hydrogen productions in refineries

In the recent years, refineries have focused on developing new ways to gain more from their asset utilization owing to increasing demand for high octane gasoline. In this regard, a thermally coupled fluidized bed naphtha reactor (TCFBNR) is proposed in this study. The first and the second reactors of a conventional catalytic naphtha reactor configuration (CR) are substituted by thermally coupled fluidized bed reactors. In this novel configuration, naphtha reforming reactions which are highly endothermic are coupled with the exothermic hydrogenation of nitrobenzene to aniline. Some drawbacks of CR such as pressure drop, internal mass transfer limitation and radial gradient of concentration and temperature are successfully solved in this novel configuration. In addition to some mentioned advantages of this novel configuration, TCFBNR configuration enhances the aromatic production rate about 20.54% and 7.13% higher than CR and TCNR, respectively. Also, the TCFBNR is capable to enhance hydrogen production rate in the shell side, the aniline flow rate in the tube section and simultaneously improves the thermal behavior of endothermic side and reduces the undesirable temperature drop. The modeling results of TCFBNR is compared with the results of CR and thermally coupled fixed-bed naphtha reactor (TCNR). These studies provide a good initial insight for some modifications and revamping of the old facilities with more efficient ones.     

Experimental studies of nitrobenzene hydrogenation in a microstructured falling film reactor

Nitrobenzene hydrogenation over palladium catalyst was performed in a microstructured falling film reactor at a range of flowrates (0.5-3 ml/min) and pressure (1-6 bar). Confocal microscopy was used to measure liquid film thickness. Comparison with film thickness prediction equations showed an overprediction of 10-30%. The k_La of this system was estimated to be 3-8 s⁻¹ with interfacial surface area per reaction volume 9000-15000 m²/m³. Conversion was found to be affected by both liquid flowrate and hydrogen pressure, and the reactor operated between the kinetic and mass transfer controlled regimes.     

含硝基苯或硝基氯苯的废水处理研究

用四氯化碳作萃取剂，处理含硝基苯或硝基氯苯的废水，使硝基苯含量降低到８０ｍｇ／Ｌ，硝基氯苯的含量降低到６０ｍｇ／Ｌ。     

Quantum Chemical Studies on the Formation of Ozone Adducts to Aromatic Compounds in Aqueous Solution

The rate constants of the reactions of ozone with nitrobenzene, chlorobenzene, benzene, methylbenzene, methoxybenzene, phenol, 1,3,5-trimethoxybenzene and phenolate ion in aqueous solution span ten orders of magnitude. The logarithms of the rate constants correlate with the Gibbs free energies of adduct formation (ranging from +18.5 to ?21.6 kcal mol^?1) calculated with the help of the Jaguar 7.5 program using a dielectric continuum model to account for solvent effects. The electrophilic nature of these reactions is reflected by good correlations with Mulliken charge and similar parameters of these compounds accessible to quantum chemical calculations. Data on the Gibbs free energies of Criegee ozonide formation are also provided.     

Synthesis and characterization of α-Fe2O3 Micro-/Nanorods-modified glassy carbon electrode for electrochemical sensing of nitrobenzene

α-Fe₂O₃ Micro-/Nanorods were synthesized via a co-precipitation method at room temperature. The obtained products were characterized by XRD, SEM, and BET techniques. XRD analysis showed the formation of α-Fe₂O₃ Micro-/Nanorods. The nitrobenzene sensing of α-Fe₂O₃ Micro-/Nanorods-modified glassy carbon (GC) electrode was characterized using a cyclic voltammetric (CV) electrochemical technique. The CV curves exhibited redox peaks with a detection limit of 30.4 ppb. I_p was found to be linearly co-related to nitrobenzene (NB) concentration (R²=0.9916). A substantial enhancement in cathodic peak current (C₁), and sensitivity (~446 nA/µM) was observed for the α-Fe₂O₃ Micro-/Nanorods-modified GC electrode than those of bare electrodes.     

PROMOTION EFFECT OF Mo IN AMORPHOUS Ni-P CATALYSTS FOR THE LIQUID-PHASE CATALYTIC HYDROGENATION OF NITROBENZENE TO ANILINE

Amorphous Ni-P catalysts were prepared by a chemical reduction method, and the promotional effects of Mo on the hydrogenation of nitrobenzene to aniline on Ni-P catalyst were investigated. However, the two crystallization temperatures of the 1% Ni-Mo-P catalyst were 644 K and 723 K, which were 15 K and 43 K higher, respectively, than those of the Ni-P catalyst itself; these results indicate that the presence of Mo increased the thermal stability of the Ni-P catalysts. SEM results showed that the particle size of the active component of Ni-P in the 1.0% Ni-Mo-P catalyst was smaller than that in the amorphous Ni-P catalyst. The N₂ adsorption isotherms for the amorphous Ni-Mo-P catalysts were the III-type, and the N₂ isothermal adsorption-desorption curves exhibited H₃-type hysteresis loops. H₂-TPR results showed that the addition of Mo had no effect on the reduction of NiO in the catalyst but negatively affected the reduction of Ni-P-O. H₂-TPD results showed that the hydrogen adsorption capacity of the amorphous Ni-P catalysts can be enhanced through the addition of Mo, and the optimal amount of Mo was determined to be 1.0%. The XPS results indicated the presence of a small amount of free metallic Mo in the amorphous Ni-Mo-P catalysts in addition to the Mo in MoO₃. The use of 1% amorphous Ni-Mo-P catalyst at 383 K and under 1.0 MPa of hydrogen for 3.0 h resulted in a nitrobenzene conversion rate and aniline selectivity of 64.5% and 98.8%, respectively.     

Three‐Phase Nitrobenzene Hydrogenation over Supported Glass Fiber Catalysts: Reaction Kinetics Study

The catalytic properties of Pd and Pt supported on woven glass fibers (GF) were investigated in the three‐phase hydrogenation of nitrobenzene (NB). Over all catalysts, a 100 % yield of aniline was attained. The catalytic activity for the best catalysts was two times higher than the activity of commercial Pt/C catalyst traditionally used for liquid–phase hydrogenation. The intrinsic reaction kinetics were studied and a reaction scheme is suggested. The direct formation of aniline from NB was observed over Pd/GF with traces of intermediates. Four intermediate products were detected during aniline formation over Pt/GF: nitrosobenzene, phenylhydroxylamine, azoxybenzene, and azobenzene. The Eley‐Rideal kinetic model fits the experimental data well. The parameters of the model were determined as a function of initial NB concentration and hydrogen pressure. Pt and Pd supported on GF in woven fabrics are suggested as suitable materials for reactors with a structured catalytic bed in multi‐phase reactor performance.     

极谱测定苯胺中微量硝基苯的方法研究

通过正交实验和验证实验确定极谱测定苯胺中微量硝基苯的最佳条件,同时对悬汞电极、静态滴汞电极、滴汞电极等3种电极模式以及微分脉冲极谱和经典直流极谱2种极谱类型进行了实验比较,得出相应的结论。     

冰冻条件下水中硝基苯的变化

为了解松花江水中硝基苯在自然冰冻情况下的归趋,进行了硝基苯水样的冰冻实验.同时对松花江达连河断面主河道上冰层中硝基苯含量进行了分层检测.冰冻实验结果表明,在水样全部结冰情况下,冰中硝基苯浓度(以融化后水中硝基苯浓度计,下同)与原水样中硝基苯浓度比值与冰冻速度没有明显关系,该比值一般在0.47～0.80间;在水样不完全结冰情况下,结冰速度对硝基苯在冰相与水相中的分配比具有显著影响,快速结冰时分配比为0.21,而慢速结冰时仅为0.050.冰冻过程中水中硝基苯逐渐被浓缩,部分硝基苯挥发到大气中.污染带流经达连河断面时所结冰的各个层位中硝基苯浓度均远远低于国家《地表水环境质量标准》(GB 3838-2002)限值.