Pt/Ga_2O_3/WO_3/ZrO_2催化剂上正庚烷异构化反应动力学研究

在固定床微反应器上,研究了Ga对Pt/Ga2O3/WO3/ZrO2(Pt/GWZ)催化剂上正庚烷异构化反应性能的促进作用.在433～463 K、正庚烷液体空速0.5～4 h-1、氢/正庚烷摩尔比5～20范围内,研究了Pt/1.0GWZ和Pt/WZ催化剂上正庚烷异构化反应动力学.结果表明,引入适量Ga提高了催化剂对正庚烷异构化反应的催化活性,以及异构化产物中多支链异庚烷与单支链异庚烷的比值.Pt/1.0GWZ和Pt/WZ催化剂上正庚烷异构化反应对于正庚烷均为一级,H2反应级数分别为-1.4和-0.9,表观活化能分别为1.0717×105J·mol-1和1.2957×105J·mol-1.研究分别得出了用Pt/1.0GWZ和Pt/WZ两种催化剂时正庚烷异构化反应的动力学方程.     

正庚烷在5A分子筛上的高温吸附/脱附及扩散性能

用智能重量分析仪(IGA-100)在较高温度下测定了5A分子筛(自制)对正庚烷吸附/脱附等温线及其滞后环;计算TIE庚烷在5A分子筛上的吸附热和吸附、脱附扩散系数,分析了正庚烷在5A分子筛微孔内吸附作用.结果表明:吸附温度升高,正庚烷吸附等温线优惠程度明显降低,有吸附滞后环;在523 K下,5A对正庚烷的平衡吸附量为0...     

反相微乳液法制备纳米TiO_2

以CTAB/正丁醇/正庚烷/NH.3H2O和CTAB/正丁醇/正庚烷/TiCl4反相双微乳液方式制备纳米TiO2,且采用SEM和FI-IR等分析手段对纳米TiO2的粒径、物相等方面进行分析。结果表明,在CTAB6.83g,正丁醇8.54mL,正庚烷30mL,2.4mo.lL-1的NH.3H2O6mL,0.6mo.lL-1的TiCl43mL的条件下,可以制备纳米TiO2。     

硅胶柱层析纯化利普司他汀工艺研究

采用硅胶柱层析法对利普司他汀粗品进行分离纯化,确定最佳纯化工艺条件如下:以120目硅胶为固定相,依次用1 BV 5％ 丙酮-正庚烷、1 BV 10％ 丙酮-正庚烷、7 BV 15％ 丙酮-正庚烷、2 BV 30％ 丙酮-正庚烷梯度洗脱,洗脱流速为0.75 BV·h-1,载样量为3％,收集7 BV 15％ 丙酮-正庚烷的...     

模拟油掺炼脂肪酸催化裂化反应探索

为了探索催化裂化掺炼废弃油脂过程中游离脂肪酸对原料转化的影响,在固定流化床催化裂化实验装置上进行了正庚烷掺炼正辛酸的催化裂化研究,考察了正辛酸的添加量、反应温度对正庚烷转化率、产物分布和液体产物组成的影响。结果表明:正庚烷和正辛酸在酸性催化剂上的反应性能差别明显,正庚烷的转化率较低,其反应后液体产物以烷烃为主;正辛酸转化率非常高,且反应后的液体产物主要以芳烃为主。当在正庚烷中添加少于质量分数10%的正辛酸时,可以促进正庚烷的转化;当正辛酸的添加量大于10%时,反而会阻碍正庚烷的转化,而且正辛酸的添加量对液体产物的组成影响显著。反应温度的提高有利于混合原料的转化,同时可以提高液体产物中芳烃和烯烃的质量分数。     

中压下氮氢氨在正庚烷中的溶解度测定

实验用液相流动法分别测定了在不同温度,压力下氨合成体系中氮、氢、氨三组分气体在正庚烷中的溶解度.根据正庚烷超临界流体中氨合成的工艺条件,确定了溶解度测定的温度,压力范围.温度313.15～353.15K,压力分别为:氮气1～6 MPa,氢气3～9MPa,氨气1～1.5MPa.结果表明在相同的温度和压力下,正庚烷中的溶解度大小顺序依次为:氨＞氮＞氢.测定的溶解度数据可以用来确定超临界氨合成反应的出口工艺条件,实验得到的结论对超临界氨合成新工艺的探索具有一定的参考价值.     

铝–油酸/正庚烷基纳米浆体燃料液滴着火燃烧特性

采用液滴悬挂法研究了正庚烷液滴、油酸/正庚烷混合燃料液滴、含20wt%纳米铝粉的铝–油酸/正庚烷基纳米浆体燃料液滴在不同温度下(600~800℃)的着火燃烧特性。用高速摄像机观测液滴进入管式电阻炉后的着火燃烧过程,使用热电偶记录液滴周围的气相温度变化,同时通过对应的温度曲线计算液滴的着火延迟时间。结果表明,纳米铝粉和油酸的添加均能降低正庚烷液滴的着火延迟时间。随温度升高,正庚烷、油酸/正庚烷混合燃料、铝–油酸/正庚烷基纳米浆体燃料液滴的着火延迟时间显著降低,但变化趋势逐渐趋于平缓。铝–油酸/正庚烷基纳米浆体燃料液滴的着火延迟时间与环境温度满足阿累尼乌斯方程。与纯正庚烷、油酸/正庚烷混合液滴的燃烧过程相比,铝–油酸/正庚烷基浆体燃料液滴的燃烧过程有显著差异,其燃烧经历3个阶段：正庚烷稳定燃烧阶段、正庚烷微爆炸阶段和表面活性剂微爆炸阶段。铝–油酸/正庚烷基浆体燃料液滴燃烧时间延长,火焰熄灭后又复燃,且燃烧过程中发生剧烈的火焰形变和铝颗粒溅射现象,大部分铝以团聚体形式在第三阶段完成氧化还原反应。     

用正己烷代替正庚烷试剂测定聚丙烯等规度

目前国内大多数聚丙烯生产厂家均用正庚烷作为测定聚丙烯等规度的试剂。测定聚丙烯等规度耗费试剂量大,且正庚烷价高、货源短缺,洛阳吉利化工厂用正己烷代替正庚烷进行了试验研究,获得满意结果。用杭州炼油厂生产的正己烷和苏州第二     

有机溶剂萃取加拿大油砂应用研究

介绍了溶剂作为萃取剂分离油砂的技术,溶剂萃取油砂过程包含两个阶段:沥青相向溶剂的溶解过程和沥青、溶剂与砂粒的分离过程。考察了单一溶剂甲苯、丙酮、乙酸乙酯和甲苯/正庚烷、丙酮/正庚烷、乙酸乙酯/正庚烷组成的复合溶剂体系在相同条件下对油砂沥青的萃取率,在此基础上进一步对比了不同溶剂体系对沥青四组分饱和分、芳香分、胶质和沥青质的萃取效果,同时考察了不同浓度的沥青-溶剂溶液的表面张力,结果表明在油砂萃取过程中沥青-溶剂体系的表面张力主要取决于所选溶剂的种类,而沥青的浓度对溶液表面张力的影响不大。混合溶剂体系甲苯/正庚烷、丙酮/正庚烷、乙酸乙酯/正庚烷相比纯溶剂萃取率较高,其沥青溶液表面张力较低,是良好的分离油砂溶剂体系。     

转化器新型冷却剂的应用

分析了正庚烷代替热水作为氯乙烯转化器反应冷却剂的优势，介绍了用正庚烷作为冷却剂的工艺流程和运行情况。     

Double-bond patterns of fatty acids and alcohols in steer and human meibomian gland lipids

Ozonolysis studies of the monoenes of the fatty chain types in lipids of steer meibomian gland excreta (meibum) have confirmed earlier structural assignments based on gas liquid chromatography (GLC) retention data and have assisted in assigning complete structures to a group of recently identified ω-hydroxy fatty acids. The ω-hydroxy acids include straight-chain monoenoic acids (85%), saturated anteiso and iso acids (13%), monoenoic acids of the latter group (1%) and, finally, saturates of the normal monoenoic acids (1%). All the fatty chains of meibum can be biosynthesized by a unified process of chain buildup to primary chain lengths of 12∶0–20∶0 for the straight evens, with 16∶0 predominating, 13∶0–21∶0 for the straight odds with 17∶0 predominating, i16∶0 to i28∶0 for the iso and ai17∶0 to ai29∶0 for the anteiso chain types; then Δ9 desaturation of each of these chain types; and finally chain elongation of 1–10 C₂ units. Some chain degradation may also occur. The meibum lipid components involved are unsubstituted fatty acids, α-OH fatty acids, ω-OH fatty acids, fatty alcohols and some other lipid components incompletely characterized. The carbon skeletons are straight even, straight odd, iso and anteiso except that the α-OH fatty acids are only straight even and straight odd and these chains are not elongated. All fatty chains are almost entirely saturated and monoenoic, the polyenes occurring in only trace amounts. Biosynthesis of the fatty chains of human meibum evidently occurs similarly, except that considerably more 18∶0 than 16∶0 fatty acids are built up by the fatty acid synthetase, before desaturation and extension.     

Theoretical Study of Equilibrium Bipolar Charge Distribution on Nonuniform Primary Straight Chain Aggregate Aerosols

A general theory describing the equilibrium bipolar charge distribution for straight chain aggregate aerosols consisting of primary spheres of different diameters was derived from a theory previously developed for linear chain aggregate of uniform spheres. The present theory is based on the assumptions that (1) the individual primary particles of a straight chain aggregate are charged independently, (2) the probability that a particular primary particle has acquired q elementary charges is governed by the Gaussian distribution predicted by Boltzmann's law, based on particle size; and (3) the resultant charge of a straight chain aggregate is the algebraic sum of the charges carried by the constituent primary spheres. The present theory can be stated as follows: The equilibrium bipolar charge distribution of straight chain aggregate aerosols with nonuniform primary spheres can be expressed by Boltzmann's law with an equivalent diameter such that d_eL = Σ ⁿ _i=1 d_i . The limitations imposed by the assumptions are also discussed.     

Fatty acids of unusual double-bond positions and chain lengths found in rat skin surface lipids

The fatty acids of rat skin surface lipids comprise four main skeletal types of chains which occur both as saturates and monoenes and range from C₁₂ to C₃₈: straight even, straight odd, iso and anteiso (the latter two identified by GC retention data only). Two unidentified series of branched monoenes also occur in trace amounts. Reductive ozonolysis of monoenes reveals two characteristic double-bond position patterns, one for the straight even chain series and the other for the straight odd chain series. The straight even chain pattern comprises four series, of which ω7 ≫ω9>ω5>ω11; the straight odd chain series in contrast shows a large number of ω series with irregular distribution. The biosynthesis of the even chain fatty acid monoenes can be thought of as occurring in two stages: synthesis of 14∶Δ9, 16∶Δ9, 18∶Δ9 and 20∶Δ9, with 16∶Δ9 predominating; elongation of these chains mostly by 1, 2, or 3 C₂ units but up to the unusually long lengths by 11 C₂ units. For the formation of the former, two schemes by known pathways are proposed. Iso and anteiso chains which are nearly all saturated comprised 1/3 the total fatty acids. Special terms and abbreviations: Normal even=a straight chain with an even number of carbon atoms, normal odd=a straight chain with an odd number of carbon atoms, ω=terminal carbon atom, iso=a straight chain with a methyl group at the ω−1 position, anteiso=a straight chain with a methyl group at the w−2 position, Δn=a double bond between the n^th and the (n+1)^th carbon atom from the carbonyl group of the fatty acid or ester, ωn=a double bond between the ω∩n^th and the ω-(n−1)^th carbon atom where n is an integer, aldester=aldehyde methyl ester, Me=methyl, GLC=gas-liquid chromatography, TLC=thin-layer chromatography.     

Sodium dialkyl phosphates: Surfactant properties and use in heavy duty detergents

A study of the physical and surface active properties of the sodium salts of dialkyl phosphates has been made. These compounds have been evaluated for use as surfactants in built detergents and their performance has been compared with commercial surfactants. The dialkyl hydrogen phosphates contained from 16–26 carbon atoms per molecule and were prepared from both straight chain alcohols and commercially available branched chain alcohols. In general, the surface active properties of the branched chain compounds are better than their corresponding straight chain compounds. Good detergency performance is obtained when the number of carbon atoms per molecule is between 17 and 23. Optimum performance is obtained with the symmetrical didecyl hydrogen phosphate salts made from commercial decyl alcohol produced by the oxo-process.     

Bestimmung von cyclischen Fettsäuren über eine Harnstoffsäule

Determination of Cyclic Fatty Acids on Urea Column Cyclic monomeric fatty acids (CFA) in the mixture of straight chain saturated and unsaturated fatty acids were determined after methylation (CFA-Me) as non-adducts on an urea column. The method gives quantitative results with mixtures containing 5% or more of cyclic fatty acids. The determination is easy and rapid.     

A comparison by warburg respirometry and die-away studies of the degradability of select nonionic surface-active agents

The relative biodegradability of several classes of nonionic surfactants have been determined by Shake Flask, Die-Away and Warburg Respirometer tests. Analytical techniques used to follow the degradation processes involved the measurement of loss of surfactant properties (surface tension or foamability), colorimetric determinations and oxygen uptake studies. Nonionic products prepared from naturally occurring or synthesized straight chain hydrophobes were shown to exhibit based upon branched chain materials. A good correlation of data by the various analytical techniques was obtained on the straight chain based products.     

异构脂肪醇聚氧乙烯醚硫酸钠的合成和性能

以异构脂肪醇聚氧乙烯醚为原料,合成了不同碳链长度的异构脂肪醇聚氧乙烯醚硫酸钠;测定了产品的表面化学性能,并与直链脂肪醇聚氧乙烯醚硫酸钠产品进行比较。结果显示,异构脂肪醇聚氧乙烯醚硫酸钠降低溶液表面张力的能力略强于直链产品,同时异构产品的去污力、润湿性能都有显著提高,但是它降低了产品的泡沫性和乳化性。异构产品胶束内核的微极性在无机盐环境中大于直链产品,说明其形成的胶束结构比较松散。     

木质素磺酸钠在活性炭/水界面的吸附机理

为了探究木质素磺酸钠在活性炭/水界面的吸附机理,研究了温度、pH 值、无机盐、脲以及直链醇对其吸附动力学及吸附等温线的影响.吸附动力学结果表明,木质素磺酸钠在活性炭/水界面的吸附约在10 min 内快速达到平衡;随着离子强度的增加及脲的加入吸附速率常数增大,pH值增加,吸附速率常数先增大后减小.不同pH值条件下的木质素磺酸钠在活性炭/水界面的吸附等温线符合 Langmuir 方程;随着离子强度增大、脲或直链醇的加入,吸附过程更符合 Freundlich 模型.增加离子强度、降低 pH 值及加入直链醇都可显著提高木质素磺酸钠的平衡吸附量,而脲的加入降低平衡吸附量.在中性条件下木质素磺酸钠主要通过疏水作用和氢键作用吸附在活性炭/水界面,疏水作用有利于加快吸附速率及增加吸附量,该吸附过程不受温度的影响.     

脂肪醇类溶剂对青霉素的萃取

研究了不同醇类及醇酯混合体系对青霉素的萃取. 在pH=4的条件下脂肪醇及醇酯混合体系的萃取能力均高于乙酸丁酯. 具有相同碳原子数、带支链的脂肪醇对青霉素的萃取能力比直链醇强,平衡后的有机相水含量下降. 红外光谱分析表明：乙酸丁酯的加入使脂肪醇羟基谱带变宽且明显向高波数方向位移,能阻止醇的多聚,使羟基活性增强. 激光拉曼光谱结果证明：青霉素是以反相微乳液的形式进入脂肪醇相的;支链的存在使体系的有序性和极性都明显增加.     

Drag on chains and agglomerates of spheres in viscous newtonian and power law fluids

New experimental data on the free settling velocity of straight chains (up to twenty spheres) and planar clusters of touching spheres in Newionian and power law media are reported. The results embrace the following ranges of conditions: 0.65 ≤ n ≤ 1; Re < - 2.5 and 1.22 < m < 48.87 Pa·sⁿ. The straight chain drag measurements are in line with theoretical predictions for Newtonian fluids. The present results in power law fluids seem to suggest that it is possible to express the drag on a straight chain of spheres in terms of that on a single sphere of equal volume. Limited results with planar clusters are satisfactorily correlated using a volume equivalent sphere diameter.