REACTIONS OF BENZYL PHENYL SULFIDE NEAT AND IN DENSE POLAR SOLVENTS

ABSTRACT

The reactions of benzylphenylsulfide (BPS) neat, in tetralin, in dense water, and in supercritical methanol were studied. A free-radical mechanism described the neat pyrolysis of BPS to the major products toluene, thiophenol, diphenyldisulfide, and diphenylsulfide. An analytical rate expression deduced from this mechanism was consistent with results from both neat pyrolysis and copyrolysis with added thiophenol. Reaction in dense water yielded benzaldehyde, whereas reaction in super critical methanol yielded methylphenylsulfide and benzaldehyde, as additional primary products. Thus reaction in water and methanol was by parallel pyrolysis and solvolysis pathways.     

REACTIONS OF METHOXY-SUBSTITUTED AROMATIC COAL MOOELS IN SUPERCRITICAL SOLVENTS

Abstract

Reactions of α- and β-methoxy naphthalene and anisole in supercritical benzene and toluene were studied at 420 °C and 3.9-4.4 MPa pressure. The decomposition of these lower rank coal related model compounds in both solvents was found to obey the first order rate law. While naphthols were present in the reaction mixture of methoxy naphthalenes, phenol and cresoles were present in that of anisole. In addition to these products, diphenyl or dibenzyl was also present in the reaction mixture of supercritical benzene or toluene, respectively. The reactions between models and solvents might be explained by free radical and intermolecular rearrangement reaction pathways.     

POLYMER SOLUBILITY THEORY PREDICTS EFFICIENCY OF RESIDUAL OIL EXTRACTION BY POLAR SOLVENTS

ABSTRACT

Light paraffinic solvents (C2 to C7) have traditionally been utilized by the petroleum refining industry to extract oils from crude distillation residua. Extracted oils constitute feedstock to lubricants manufacture and, to a lesser extent, additional cracking stock. More recent literature reveals a growing interest in polar, non-hydrocarbon partially oil-soluble solvents such as alcohols, ketones, and esters of lower carboxylic acids. In this work, articles and patents which report the separation of residua into asphalt and extracted oil by means of polar solvents are briefly reviewed, and the separation performance of same of those solvents is correlated to the solute-solvent interaction parameter (?) in the Flory-Huggins theory of polymer solubility. The three dimensional solubility parameter (δ) approach is followed to estimate ? for the solvents of interest at the appropriate operating conditions. The saturate, aromatic, and polar compounds fractions of a bitumen are characterized by solubility parameters equal to the values of δ of the solvents or mixtures thereof used by the standard ASTM D-2007 chromatographic fractionation of the deasphaltenated oil (DAO). A mean value of ? is found for every DAO-solvent pair, treatment ratio and temperature. For each solvent considered, yields of extracted oil at varying operating conditions (temperature, pressure, solvent /feed ratio) are found to be well correlated to ?, in according with theoretical predictions that the lower a value of ? a solvent has for a given solute, the better it dissolves the solute and the higher the yield.

It is suggested that this type of approach could supply criteria to select solvents and operating conditions for applications requiring high yields (to produce additional cracking stock) or lower yields but high rejection of metals and heteroatoms (e.g. for lube oil bases extraction).     

POLYMER SOLUBILITY THEORY PREDICTS EFFICIENCY OF RESIDUAL OIL EXTRACTION BY POLAR SOLVENTS

Light paraffinic solvents (C2 to C7) have traditionally been utilized by the petroleum refining industry to extract oils from crude distillation residua. Extracted oils constitute feedstock to lubricants manufacture and, to a lesser extent, additional cracking stock. More recent literature reveals a growing interest in polar, non-hydrocarbon partially oil-soluble solvents such as alcohols, ketones, and esters of lower carboxylic acids. In this work, articles and patents which report the separation of residua into asphalt and extracted oil by means of polar solvents are briefly reviewed, and the separation performance of same of those solvents is correlated to the solute-solvent interaction parameter (ϰ) in the Flory-Huggins theory of polymer solubility. The three dimensional solubility parameter (δ) approach is followed to estimate ϰ for the solvents of interest at the appropriate operating conditions. The saturate, aromatic, and polar compounds fractions of a bitumen are characterized by solubility parameters equal to the values of δ of the solvents or mixtures thereof used by the standard ASTM D-2007 chromatographic fractionation of the deasphaltenated oil (DAO). A mean value of ϰ is found for every DAO-solvent pair, treatment ratio and temperature. For each solvent considered, yields of extracted oil at varying operating conditions (temperature, pressure, solvent /feed ratio) are found to be well correlated to ϰ, in according with theoretical predictions that the lower a value of ϰ a solvent has for a given solute, the better it dissolves the solute and the higher the yield.

It is suggested that this type of approach could supply criteria to select solvents and operating conditions for applications requiring high yields (to produce additional cracking stock) or lower yields but high rejection of metals and heteroatoms (e.g. for lube oil bases extraction).     

尾气中H_2S的净化及应用

介绍了含硫化氢尾气的各种净化方法以及下游产品的开发与应用。讨论了利用硫化氢开发含硫化工产品应注意的问题和发展趋势。     

硫磺回收工艺中自产氢的控制和利用

介绍克劳斯工艺燃烧炉中影响裂解氢气含量的影响因素。利用模拟计算和现场实际测量,对克劳斯工艺燃烧炉后部的裂解氢气含量进行了对比,确认影响克劳斯工艺燃烧炉裂解氢气的关键因素为炉膛温度和配风量,并提出了综合利用裂解氢气降低装置能耗的措施。     

苯乙酸的电化学合成

简述了苯乙酸的用途及合成方法,用阳极电解法合成了苯乙酸。讨论了影响收率的因素。找出了电解法合成苯乙酸的电解最佳条件。实验总收率７８．３％。     

STRUCTURE,INTERACTION AND PHASE TRANSITION OF VACUUM RESIDUE IN APOLAR SOLVENTS

ABSTRACT

Structure, Interaction, and phase transition of a vacuum residue fractions In various apolar solvents were Investigated, using viscosity measurements and small angle neutron scattering. Both light and heavy ended fractions form colloidal particles of spherical shape with average sizes of -40 and -60 A respectively. The size distributions follow a Schultz distribution function approximately. Rheological studies of these fractions indicated significant particle solvation. The solvation mechanism is through association of the solvent molecules with individual VR colloids, instead of through solvent entrapment between agglomerated colloids. The viscosity, as a function of temperature, suggested a glass-like transition at approximately 254?K for the heavy ended fraction at 0.5 volume fraction. The small angle neutron scattering measurements confirmed the colloidal structure determined from rheological study. It also provided the information about the total colloids/solvent Interfacial area, from which we found that VR colloids have a rough surface     

ELECTRICAL CONDUCTIVITY OF ASPHALTENES IN ORGANIC SOLVENTS

Conductivities of asphaltenes were measured as a function of concentration in solvents of varying permittivity. The molar conductivity was calculated assuming the molecular weight of asphaltenes to be 1000 g/mol

The Fuoss conductivity model was fitted to the experimental data with two free parameters i.e. the association constant and the molar conductivity at infinite dilution. The experimental data show indication of ion-pairs and strong dipole-ion interaction. Accordingly, the measurements were consistent with the model for ion pairs as given by Fuoss and multibody interaction theory given by Petrucci

At low concentration the asphaltenes consist mainly of free ions, as the concentration increases ion pairing leads to a decrease of the molar conductivity. At higher concentration ion-dipole interaction may lead to an increase of the molar conductivity, as is seen in some of the solvents. At even higher concentrations some indications of aggregation are observed

The results indicate that part of the asphaltenic fraction is ionized and behave as ions in solvents of low dielectric constant.     

Ti-MWW分子筛的合成改性及其催化反应研究进展

综述了钛硅分子筛Ti-MWW的合成方法,主要有后处理合成法、水热合成法、干胶合成法等;总结了F-改性、扩孔改性、金属离子改性等Ti-MWW改性方法,改性后的Ti-MWW催化性能得到提高;Ti-MWW在酮类氨氧化、烯烃环氧化、芳香族羟基化及脱硫等工艺上具有优异的催化性能。总结了Ti-MWW在催化方面的研究进展,并展望了其应用前景。