氨基树脂化学进展Ⅰ合成化学进展

就原料结构、合成反应动力学、贮存、废物处理、树脂基团分析和甲基化三聚氰胺树脂等方面,评介了氨基树脂合成化学的进展。提出了开辟氨基树脂新原料来源、正确选择合成工艺及发展新品种的途径。

Kinetic and Phase Behaviors of Catalytic Cracking Dry Gas Hydrate in Water-in-Oil Emulsion

The systematic experimental studies were performed on the hydrate formation kinetics and gas-hydrate equilibrium for a simulated catalytic cracking gas in the water-in-oil emulsion. The effect of temperature, pressure and initial gas-liquid ratio on the hydrate formation was studied, respectively. The data were obtained at pressures ranging from 3.5 to 5 MPa and temperatur.es from 274.15 to 277.15 K. The results showed that hydrogen and methane can be separated Irom the （~2＋ ti＇action by tOrming hydrate at around 273.15 K which is much higher temperature than that of the cryogenic separation method, and the hydrate formation rate can be enhanced in the wa- ter-in-oil emulsion compared to pure water. The experiments provided the basic data for designing the industrial process, and setting the suitable operational conditions. The measured data ot gas-hydrate equilibria were compared with the predictions by using the Chen-Guo hydrate thermodynamic model.

Reaction kinetics for synthesis of sec-butyl alcohol catalyzed by acid-functionalized ionic liquid

The acid-functionalized ionic liquid([HSO3Pmim]HSO4) was synthesized by a two-step method. Nuclear magnetic resonance(NMR) and Fourier transform infrared spectroscopy(FT-IR) show that the synthesis method is feasible and high purity of ionic liquid can be obtained. Using [HSO3Pmim]HSO4as the catalyst, we studied the reaction kinetics of synthesizing sec-butyl alcohol from sec-butyl acetate and methanol by transesterification in a high-pressure batch reactor. The effects of temperature, initial molar ratio of methanol to ester, and catalyst concentration on the conversion of sec-butyl acetate were studied. Based on its possible reaction mechanism, a homogeneous kinetic model was established. The results show that the reaction heat ΔH is 10.94 × 103J·mol-1, so the reaction is an endothermic reaction. The activation energies Ea+and Ea-are 60.38 × 103 and 49.44 × 103J·mol-1,respectively.

Simulation of gas-solid fluidized bed reactor for F-T synthesis

Using the lumping method, CH_4, C_3H_8, C_10H_22, and C_22H_44 were chosen as themodel products, and CO as the key component. The mathematical model of a gas-solidfluidized bed reactor was established based on some hypotheses. The consumption kinetic model of CO was investigated, and the parameters were estimated by UniversalGlobal Optimization with the Marquardt method. Residual error distribution and a statisticaltest show that the intrinsic kinetic models are reliable and acceptable. A model of carbonchain growth probability was established in terms of experiments. Coupled with the Ander-son- Schulz-Flory (ASF) distribution, the amount of specific product could be obtained.Large- scale cold model experiments were conducted to investigate the distribution of thegas (solid) phase and determine the function of the voidage with the location of the catalytic bed. The change tendencies of the components in the catalytic bed at different temperatures were computed and figured out. The calculated value computed by the modelestablished for the Fe-based F-T synthesis catalyst fit the experimental value very wellunder the same operating conditions, and all the absolute values of the relative deviationsare less than 5%.

Dynamic Kinetics of Methanol Synthesis over a Commercial Copper-Based Catalyst

Adsorption, surface reaction and process dynamics on the surface of a commercial copper-based catalyst for methanol synthesis from CO/CO2/H2 were systematically studied by means of temperature programmed desorption (TPD), temperature programmed surface reaction (TPSR), in-situ Fourier transform-inferred spec-troscopy(FTIR) and stimulus-response techniques. As a part of results, an elementary step sequence was suggested and a group of ordinary differential equations (ODEs) for describing transient conversations relevant to all species on the catalyst surface and in the gas phase in a micro-fixed-bed reactor was derived. The values of the parameters referred to dynamic kinetics were estimated by fitting the solution of the ODEs with the transient response data obtained by the stimulus-response technique with a FTIR analyzer as an on-line detector.

Electrode properties and phase composition of Ti_(0.5)Ni_(0.25)Al_(0.25) hydrogen storage alloys and theoretical simulation

Ti0.5Al0.25Ni0.25 alloy prepared by vacuum induction melting was studied.The phase composition was analyzed with X-ray technique and EDS analysis,and its electrochemical properties were investigated at various temperatures.Electrochemical reaction kinetic parameters were also studied with proper electrochemical techniques.The influence of the secondary corrosion reaction on the anodic linear polarization measurement was also analyzed by theoretical simulation.The results show that,proper ball-milling with nickel powders is beneficial to electrochemical performance.The theoretical simulation proves that,the existence of the side reaction can disturb the measurement of electrochemical reaction kinetic parameters.

Reaction kinetics of isopropyl palmitate synthesis

In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalytic method. The liquid-phase diffusion effect on the reaction process was eliminated by adjusting the stirring rate. The results showed that the two-step reaction followed a tetrahedral mechanism and conformed to second-order reaction kinetics. Nucleophilic attack on the carbonyl carbon afforded an intermediate, containing a tetrahedral carbon center. The intermediate ultimately decomposed by elimination of the leaving group, affording isopropyl palmitate. The experimental data were analyzed at different temperatures by the integral method. The kinetic equations of the each step were deduced, and the activation energy and frequency factor were obtained. Experiments were performed to verify the feasibility of kinetic equations, and the result showed that the kinetic equations were reliable. This study could be very signi ficant to both industrial application and determining the continuous production of isopropyl palmitate.

Overview of Fischer-Tropsch Synthesis in Slurry Reactors

A brief review of Fischer-Tropsch synthesis specially in slurry reactors is presented, covering reaction kinetics, activity and selectivity of catalysts, product distribution, effects of process parameters, mass transfer and solubility of gas. Some important aspects of further research are proposed for improving both theories and production.

Zirconium Diboride Powders Synthesized by Boro/Carbothermal Reaction Using Sol-Gel Technology

A single phase of zirconium diboride （ZrB2） powder was successfully synthesized by sol-gel method in Zr-B-C-O system, using zirconium oxychloride （ZrOC12 ~ 8H20）, nano-scale boron and suerose（C12H22011）as the starting materials and propylene oxide （PO） as complexing agent at a low temperature. Simultaneously, the experimen- tal and theoretical studies of ZrB2 synthesized by boro/carbothermal reduction from novel sol-gel technology were discussed. The results indicated that the pure rod-like ZrB2 powder without residual ZrO2 phase could be obtained with a B/Zr molar ratio of 3.5 at 1 400~C in argon atmosphere. Besides, in this study, a kinetic model for the Zr-B-C-O sys- tem producing ZrB2 by boro/carbothermal reaction was established based on thermodynamic analysis. It was also ob- served that, with the increase of reaction temperature, the reaction which produced ZrB2 powders changed from the borothermal reaction to boro/carbothermal reaction in the Zr-B-C-O system.

POCl_3-mediated H-bonding-directed one-pot synthesis of macrocyclic pentamers,strained hexamers and highly strained heptamers

Previously we have shown that POCl3-mediated H-bonding-directed one-pot macrocyclization allows for the highly selective preparation of five-residue macrocycles as the predominant product with low yields of hexamers and an undetectable occurrence of both tetramers and heptamers.Replacing the interiorly arrayed methyl groups with ethyl groups in these 4-7 residue macrocycles alters the relative stability order among them.Specifically,ethoxy-substituted six-residue macrocycle,rather than pentamer,turns out to be computationally the most stable,suggesting that ethoxy-containing hexamer possibly can be formed as the major product under suitable conditions.We have investigated this possibility by varying reaction temperatures and concentrations,invariably affording pentamer as the major macrocycle with strained circular hexamers and highly strained circular heptamers produced in substantial amounts.This discrepancy can be reasonably explained on the basis of bimolecular reactions between two oligomers higher than monomers via kinetic simulations.In this scenario,the acyclic pentamer is kinetically "trapped" to undergo an intramolecular cyclization to yield circular pentamer,rather than to produce acyclic hexamer.As a result,acyclic hexamer precursor is generated largely from sterically demanding bimolecular reactions between a dimer and a tetramer,or between two trimers that are kinetically slower than the pentamer-producing chain-growth reactions.We additionally found that one-pot macrocyclization proceeds to the largest extent at 40 ℃,an intriguing finding that highlights the low reactivities of acid chloride and amine groups in these H-bond-enforced acyclic oligomeric intermediates.