NNI-1型C_5/C_6烷烃异构化催化剂长周期运行分析及建议

中国石化海南炼油化工有限公司0.2 Mt/a C5/C6烷烃异构化装置以连续重整装置的拔头油为原料,使用NNI-1催化剂,采用一次通过流程,不设脱异戊烷塔和稳定塔,经设在连续重整装置内的脱丁烷塔稳定处理后作为汽油调合组分。该装置于2006年9月开工投产,截至2015年3月已连续运行3个周期。长周期运行分析结果表明:前两个周期中NNI-1催化剂具有较高的异构化活性及选择性,C5异构化率为60%左右,C6异构化率为80%左右,C6选择性为15%左右,产品辛烷值基本达到技术指标要求(RON≥78);而在第三周期运行中,催化剂积炭增加等原因导致其异构化活性及选择性降低,异构化产品辛烷值提升能力呈现逐步衰减的趋势,提高反应苛刻度已不能弥补催化剂活性下降造成的产品辛烷值降低。为保证装置长周期运行,建议择机停工对催化剂进行再生,或是直接换用与装置原料性质匹配的异构化催化剂。     

烃分子结构对其催化裂解反应性能的影响

采用脉冲微型反应器和小型固定流化床催化裂解装置，研究了直馏石脑油中不同结构烃分子的裂解反应性能，考察了链烷烃与环烷烃的相互作用，以及催化材料对烃分子裂解性能的影响。结果表明：随着烷烃分子支链度的增加，C8烷烃的反应性能降低，丙烯选择性提高；链烷烃和具有烷基侧链的环烷烃是丙烯的主要来源，双环环烷烃对丙烯也有部分贡献，而芳香烃不易生成低碳烯烃；环烷烃的竞争吸附抑制了链烷烃的转化，而链烷烃在催化裂解过程中生成的碳正离子或烯烃提高了环烷烃的反应性能；与Beta分子筛相比，ZRP分子筛具有较狭窄孔道和较多的Brønsted酸中心，有利于正辛烷的质子化裂解，裂解产物中乙烯和丙烯产率高。     

Toward prediction of surface tension of branched n-alkanes using ANN technique

This study features the application of artificial neural network for prediction of surface tension of branched alkanes. Surface and interfacial tensions of alkanes show a specific interaction between adjacent molecules of the higher n-alkanes which results in an anisotropic dispersion force component of the surface energy. The surface tension of branched alkanes was studied for temperatures between 283.15 and 448.15 K. Two intelligent models named multilayer perceptron model (MLP) and radial basis function (RBF) model were developed and the accuracy of two models was examined by different graphical and statistical methods. Results showed that the both models are accurate and effective in prediction of surface tension of branched alkanes. However, the results were compared with experimental data and it was found that the estimated surface tension by multi-layer perceptron neural network is more accurate than radial basis function network.     

LIQUID PHASE CO-OXIDATION OF THIOPHENOL AND STYRENE BY OXYGEN AND t-BUTYL HYDROPEROXIDE

ABSTRACT

Instability problems in both shale and petroleum derived middle distillate jet fuels have been correlated with the presence of peroxidic species. Although a good body of knowledge exists concerning the formation of peroxides in the liquid phase, relatively little is known about the reaction/ decomposition pathways available when other functional groups are present, since sulfur is the most abundant heteroatam present in jet fuels, the reaction of t-butyl hydroperoxide (tBKP) and/or oxygen with thiophenol in the presence of the active olefin, styrene, was examined in deaerated benzene at 120°C. The complex product mixture was analyzed by combined capillary column GC/MS. Major products included acetone, t-butanol and isdbutylene from the tBHP. Thiophenol and styrene combined to form addition products. Phenyl disulfide was observed from the thiophenol. The results indicated that although the product slate was complex, it was possible to explain the product mix in terms of a few competing reactions.     

Synthesis of ω‐amino‐α‐phenylcarbonate alkanes and their polymerization to [n]‐polyurethanes

Aliphatic [n]‐polyurethanes have recently been synthesized from ω‐isocyanato‐α‐alkanols or, more traditionally, by cationic ring‐opening polymerization of cyclourethanes or by the Bu₂Sn(OMe)₂‐promoted polycondensation of ω‐hydroxy‐α‐O‐phenylurethane alkanes. For the latter procedures, the conditions employed do not seem to be suitable for highly functionalized monomers. In contrast, the polymerization of ω‐amino‐α‐phenylcarbonate alkanes is expected to occur under milder conditions. ω‐Amino‐α‐phenylcarbonate alkanes have been synthesized from 6‐aminohexanol (1) and 3‐aminopropanol (6). The procedure involves the N‐Boc protection of the amino group, followed by activation of the alcohol. Removal of the N‐Boc affords the corresponding ω‐amino‐1‐O‐phenyloxycarbonyloxyalkane hydrochlorides. Other oligomeric comonomers between 1 and 6 have been prepared. The polymerization of these precursors takes place in the absence of metal catalysts to afford the corresponding linear and regioregular [n]‐polyurethanes. The procedure described is useful for the preparation of stable ω‐amino‐α‐phenylcarbonate alkane derivatives, which possess varied chain lengths between the terminal functions. These monomers yield [n]‐polyurethanes having various structures starting from just two aminoalkanols. The polyurethanes were obtained in high yields, with reasonable molecular weight and polydispersity values, and they were characterized spectroscopically and thermally. These studies reveal constitutionally uniform structures that are free of carbonate or urea linkages. Copyright © 2010 Society of Chemical Industry     

Microporous and mesoporous materials with isolated vanadium species as selective catalysts in the gas phase oxidation reactions

The preparation of V-containing micro- and mesoporous (silicates, aluminosilicates and aluminophosphates) materials as well as the nature of V species incorporated in framework positions is reviewed. In addition, the catalytic performance of V-silicalite, VAPO-5 and V-MCM-41 in the gas phase selective oxidation of hydrocarbons has also been compared.     

低温低碳烷烃和氮双元液态混合物密度的推算

将一个饱和液体状态方程(TONG方程)应用于已知的双元液体混合物密度的推算,温度为105K～140K,该混合物的组分是低碳烷烃和氮,它们都是液化天然气(LNG)的主要成分。此模型方程利用纯组分数据来预测液化天然气低温下密度而被检验。本方法的优点是使用简便。     

Selective and effective functionalization of alkanes and cycloalkanes with CO by polyhalomethanes combined with aluminum halides in organic media

Effective and selective transformations of propane, butane, cyclopentane, cyclohexane, methylcyclopentane and adamantane under the action of CO mediated by polyhalomethanes combined with aluminum halides (in the presence of hydride or alkyl (aryl) group donors or without them) resulting in esters, ketones and aldehydes are summarized. This revised version was published online in June 2006 with corrections to the Cover Date.     

Hydrocarbon conversion on ZSM-5 in the presence of N2O: relative reactivity

Conversions of methane, ethane, propane, benzene and hydrogen were studied on HZSM-5 at 418°C using binary mixtures R1:R2:N₂O:He (where R1, R2 are substances under study). Relative reactivities were determined, and it was shown that the rates of conversion of hydrocarbons are determined by the strengths of C–H bonds (H–H for hydrogen). This revised version was published online in July 2006 with corrections to the Cover Date.