Ultrasonic hydrogenation of soybean oil

The rate of hydrogenation of soybean oil with either copper chromite or nickel catalysts increased more than a hundredfold with the aid of ultrasonication. In a continuous reaction system, the selectivity with copper catalyst for linolenate reduction was somewhat lower when ultrasonic energy was applied than when not applied. With ultrasonic energy, 87% hydrogenation of linolenate in soybean oil was obtained in 9 sec at 115 psig H₂ with 1% copper chromite at 181 C and 77% linolenate hydrogenation with 0.025% nickel. Without ultrasonic energy, only 59% linolenate hydrogenation was obtained in 240 sec with copper chromite at 198 C and 500 psig H₂ and 68% linolenate hydrogenation in 480 sec with nickel at 200 C and 115 psig H₂. This innovation may offer an important advantage in increasing the activity of commercial catalysts, particularly copper chromite, for fats and oil hydrogenation.     

超声波化学沉积的研究现状

介绍了超声波的工作原理,概述了超声波化学镀镍及镍合金、超声波化学镀复合镀层、超声波化学镀银和镀铜等的国内外研究现状,分析了超声波在化学镀中的4个作用:降低镀液温度,提高镀层沉积速度,提高镀层性能,促进微纳米颗粒分散和沉积。     

Continuous ultrasonic hydrogenation of soybean oil. II. Operating conditions and oil quality

In previous work we found that ultrasonic energy greatly enhanced the rate of hydrogenation of soybean oil. We have now investigated parameters of ultrasonic hydrogenation and the quality of the resulting products. Refined and bleached soybean oil was hydrogenated continuously with and without ultrasonic energy at different temperatures, pressures and catalyst concentrations. Flavor and oxidative stability of the oils were compared with a commercially hydrogenated soybean oil. The extent of hydrogenation (ΔIV) was not affected by temperature between 245 and 290 C, but was greater at 106 psig than at 65 psig hydrogen pressure. The ΔIV of hydrogenated oils increased linearly with catalyst concentration from 40 ppm to 150 ppm nickel. At the same catalyst concentration the IV drop was significantly increased when ultrasonic energy was used. By reducing the amount of power supplied to the ultrasonic reactor to 40% of full power, the specific power (watts/ΔIV) was lowered by 60%. Linolenate selectivities and specific isomerization (%trans/ΔIV) remained the same, but linoleate selectivities were lower than for batch hydrogenation under varied operating parameters. Flavor scores were not significantly different, initially or after storage eight days at 60 C, for oils continuously hydrogenated with and without ultrasonic energy. Hydrogenation of soybean oil with ultrasonic energy offers a method to produce good quality products at potentially lower cost than present methods.     

混合癸烯制备润滑油加氢工艺技术

为了降低加氢后合成油的溴值,以Mo和Ni为加氢催化剂,考察不同反应温度、空速、氢压和氢油体积比对溴值的影响。结果表明,在反应温度320 ℃、空速0.8 h-1、氢压4.0 MPa和氢油体积比550∶1最佳工艺条件下,加氢后合成油的溴值降为0.043 g-Br·（100g油）^-1。Mo和Ni加氢催化剂具有优良的烯烃饱和作用。     

Electrochemical hydrogenation of canola oil using a hydrogen transfer agent

A novel low-temperature process for the electrochemical hydrogenation of canola oil is described. An emulsion of oil and water containing formic acid and a nickel hydrogenation catalyst, placed in the cathode compartment of an electrolysis cell and subjected to an electrical current, underwent hydrogenation at temperatures as low as 45°C. At these low temperatures of hydrogenation, the trans FA content of the hydrogenated canola oil was very low as compared with that of the edible oils hydrogenated by commercial processes using high temperature and high partial pressure of hydrogen gas. Because of its adverse health effects, a high trans FA content in edbile oils is viewed as undesirable. In addition to the commercially available nickel supported on silica, amorphous nickelphosphorus alloys supported on a variety of substrates were also used. Amorphous alloys are generally very corrosion resistant because of the absence of grain boundaries. A mechanism for hydrogenation using the hydrogen transfer agent of formic acid and its continuous regeneration at the cathode was evoked to explain the experimental data.     

Raney镍上松香催化加氢本征动力学

测定在不同类型搅拌器下高压釜的持气量和反应效果 ,认识到松香在Raney镍上催化加氢反应受到外扩散的严重影响 ,利用加入 2 0 0号溶剂油、改造搅拌器类型、提高搅拌速度的方法消除外扩散 ,使反应处于化学动力学控制区 ,然后采集动力学数据 ,经对 17种可能的反应机理模型进行筛选 ,推测的反应机理为 :松香中的主要成分枞酸分子不吸附 ,枞酸分子与催化剂表面上被吸附的氢原子进行反应 ,氢原子的吸附为控制步骤 ,据此导出其本征动力学方程 .     

超声波在油砂分离中的应用

以自制的碱液油砂清洗剂,在超声波下对内蒙古扎赉特旗油砂进行分离。考察了超声频率、超声声强、清洗时间和清洗温度对油砂分离的影响。在超声空化作用下,超声频率为28 kHz,超声声强为7.06 W/cm^2,剂和砂质量比为0.8,体系温度为60℃,清洗时间13.0 min的条件下,其出油率可达到94%,结果表明,超声波作用大大提高了油砂的出油率。     

油砂沥青超声波减粘工艺研究

油砂沥青粘度较大,自然状态下不易流动,严重影响了管道输送及加工,针对目前油砂沥青研究中存在的问题,采用超声波进行了减粘的实验研究。实验综合考察了超声波作用时间、温度、超声波频率、超声波功率等因素对减粘效果的影响。实验结果表明,在适当的超声作用时间(20 min)、适宜的温度(30℃)、适宜的超声波频率(20 kHz)和超声波功率(250 W)的条件下,油砂沥青的减粘率可达80%以上。经超声波处理后的油砂沥青粘度略有恢复,但仍远低于处理前的粘度,超声波减粘效果良好。     

Current efficiency for soybean oil hydrogenation in a solid polymer electrolyte reactor

Soybean oil has been hydrogenated electrocatalytically in a solid polymer electrolyte (SPE) reactor, similar to that in H2/O2 fuel cells, with water as the anode feed and source of hydrogen. The key component of the reactor was a membrane electrode assembly (MEA), composed of a precious metal-black cathode, a RuO2 powder anode, and a Nafion® 117 cation-exchange membrane. The SPE reactor was operated in a batch recycle mode at 60°C and one atmosphere pressure using a commercial-grade soybean oil as the cathode feed. Various factors that might affect the oil hydrogenation current efficiency were investigated, including the type of cathode catalyst, catalyst loading, the cathode catalyst binder loading, current density, and reactant flow rate. The current efficiency ordering of different cathode catalysts was found to be Pd>Pt>Rh>Ru>Ir. Oil hydrogenation current efficiencies with a Pd-black cathode decreased with increasing current density and ranged from about 70% at 0.050Acm–2 to 25% at 0.490Acm–2. Current pulsing for frequencies in the range of 0.25–60Hz had no effect on current efficiencies. The optimum cathode catalyst loading for both Pd and Pt was 2.0mgcm–2. Soybean oil hydrogenation current efficiencies were unaffected by Nafion® and PTFE cathode catalyst binders, as long as the total binder content was 30wt% (based on the dry catalyst weight). When the oil feed flow rate was increased from 80to 300mlmin–1, the oil hydrogenation current efficiency at 0.100Acm–2 increased from 60% to 70%. A high (70%) current efficiency was achieved at 80mlmin–1 by inserting a nickel screen turbulence promoter into the oil stream.     

重油中金属杂质脱除技术研究进展

重油的开采与加工日益成为石油化工行业关注的焦点,然而其深加工利用受到内部高含量金属的影响。为此,本文介绍了重油中金属的来源、存在形态及其对石油加工利用的危害。综合对比分析了国内外重油脱金属常用的几种方法。膜分离法虽然工艺简单、经济环保,但该技术不成熟,难以满足工业应用;催化加氢法金属脱除率高,但易受氢源及催化剂性能限制,且工业成本较高;化学法易于操作但副反应多且易污染环境;超声波脱金属法节能降耗明显,脱金属率高,但大型的超声装置如何应用于工业生产,尚需进行深入研究;微生物法投资少,适应性强,但难以筛选合适的菌种。总之,由于重油自身的特性,单一的脱金属技术难以获得佳绩,联合脱金属将成为一种发展趋势。     

超声波对镍镀层硬度的影响

分别在超声波和无超声波条件下,制备了镍镀层。通过镍镀层硬度测试、金相组织观察和镀层内应力的测定,分析了超声波条件下镍镀层硬度提高的影响因素。实验结果表明:增加超声波功率,导致镀层硬度增大。在超声波作用下,镍镀层的晶粒细小,镀层呈现压应力状态。镍镀层晶粒细化、加工硬化和存在压应力是超声波电镀镍层硬度提高的主要因素。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

超声法提取甘草蔓籽油的研究

采用超声法提取甘草蔓籽油,通过单因素试验和正交试验,以甘草蔓籽油提取率为考察指标,对超声法提取甘草蔓籽油的工艺进行了优化。结果表明:选用石油醚作为萃取溶剂,料液比为1∶8(质量/体积)、超声功率为400W、温度为50℃、超声时间为30min,此条件下甘草蔓籽油的得率达35.37%,为进一步开发甘草蔓籽油提供了科学依据。     

Three-phase catalytic hydrogenation of xylose to xylitol — prolonging the catalyst activity by means of on-line ultrasonic treatment

A novel concept for improvement of the activity of recirculated Raney nickel catalyst by means of on-line ultrasonic irradiation was studied. Qualitatively, acoustic irradiation was clearly found to retard the catalyst deactivation in the three-phase hydrogenation of xylose to xylitol. Two different intensities of the ultrasonic field were utilized in the experiments. The hydrogenation kinetics was modeled with a semi-competitive reaction–adsorption model accounting for interstitital adsorption sites for hydrogen located between larger organic molecules.

The deactivation of the Raney nickel catalyst was found to diminish notably upon the use of on-line acoustic irradiation. Also, the selectivity of the system was found to be improved by the use of ultrasound in comparison to the case when no acoustic energy was dispatched to the system. The kinetic model used in the fitting of the data was able to explain the experimental concentrations fairly well.     

Reaction mechanism of coal hydrogenation: 1. Two-ring solvent system

Taiheiyo coal was hydrogenated in naphthalene, tetralin and decalin under 10 MPa (initial pressure) of hydrogen or nitrogen with stabilized nickel as catalyst at 400 °C for 15 min. Preasphaltene, asphaltene and oil conversions and the conversion of the solvents were measured. The hydrogen absorbed by coal from molecular hydrogen and from the donor solvent was calculated. The main reaction route appears to be the direct hydrogenation of coal by molecular hydrogen, with the side reaction via solvent by molecular hydrogen occurring only slightly, when an active catalyst such as stabilized nickel is present.     

低温超声波化学镀镍工艺研究

为降低常规化学镀的施镀温度,采用低温超声波化学镀镍工艺,研究了镀液成分,工艺条件的影响。与传统化学镀镍工艺相比,该工艺所得镀层含磷量高,硬度高,组织结构致密均匀。     

核桃壳过滤器超声波辅助反冲洗实验研究

基于国内油田常用的核桃壳过滤器,对反冲洗进行了深入系统的实验研究。确定单独水反冲洗的反冲洗时间为10min、反冲洗强度为12m3·.h-1,但对于滤料的再生效果不够理想,且反冲洗强度较高、耗水量大;采用正交实验,确定超声波辅助反冲洗的超声波频率为30kHz、超声波功率为0.7kW、反冲洗时间为12min、反冲洗强度为8m3·h-1;并对两种方式的反冲洗效果进行了对比,发现超声波辅助反冲洗初始过滤压降下降极为明显,反冲洗效果优于单独水反冲洗,并能延长过滤周期、减少反冲洗次数、节约能耗及用水量,应用前景广阔。     

超声波处理对辽河油田稠油黏度的影响

采用变幅杆式声化学反应器进行了辽河稠油超声波降黏的实验研究,考察了超声反应时间、反应温度对辽河稠油降黏率的影响,分析了超声波对稠油降黏的可能机理。并考察了在超声作用下含水稠油与脱水稠油降黏率的关系,超声波作用对稠油C_7沥青质和甲苯不溶物的影响。确定了最优的反应条件,稠油经超声反应4.5 h,温度300℃,处理后50℃时降黏效果最佳,且C_7沥青质和甲苯不溶物含量均较低。     

天然橡胶超声硫化

成功地利用超声波对天然橡胶进行了硫化,所得试件展示了与传统硫化方法制得的试件相同的性能,但该工艺表现出许多传统硫化方法所不具备的优点.用滞后能量损失理论及声化学作用,解释了超声硫化的机理.用温频转换法,得到了天然橡胶混炼胶在高频条件下的动态力学性能,由此得到硫化开始阶段的温升曲线,该曲线与实验结果吻合.     

负载型骨架镍催化剂催化轻质石脑油加氢脱苯

针对当前对溶剂油中苯含量的严格要求,研究负载型骨架镍催化剂在轻质石脑油加氢脱苯反应过程中的加氢性能,并考察反应温度、反应压力、空速以及氢油体积比等对轻质石脑油加氢脱苯反应的影响。结果表明,骨架镍催化剂具有较高的低温加氢活性,适宜条件为:反应温度140℃,反应压力0.2 MPa,空速2 h~(-1),氢油体积比120,此条件下,苯转化率达到99%。