Effects of superfatting agents on cracking phenomena in toilet soap

Palm stearin (POs) is one of the cheapest sources of C16–C18 fatty acids for use in soap making. Toilet-soap formulations containing a high content of POs, however, would result in hard soaps with a tendency to form cracks on the surface. This phenomenon can be overcome by addition of superfatting agents to increase plasticity of the finished product. In this study, two different blends of soap made from distilled POs, palm oil (PO), and palm kernel oil (PKO) fatty acids in the ratio of 40POs/40PO/20PKO and 70POs/30PKO were evaluated. The soaps were superfatted with glycerin, palm kernel olein, coconut oil, olive oil and canola oil. The levels of incorporation of each superfatting material were 1, 2, 4, and 6%, respectively. The samples were subsequently tested for both wet and dry crackings using the Hewitt Soap Company methods (numbers 78 and 79, respectively). The superfatted soaps had a total fatty matter of 73–83% and an average moisture content of 10%. The penetration value which indicates hardness increased with increasing amount of superfatting agents. Foaming or lathering property was good with the exception of the formulation using palm kernel olein and canola oil as superfatting agents. At all the above levels of superfatting agents added, no cracks were observed during both wet and dry cracking tests. A sample of soap superfatted with 2% canola oil, however, developed cracks during the wet cracking test. This resulted in a test score of 7. Superfatting soaps with 1–2% neutral oils or glycerin resulted in better quality soaps that were free of cracks.     

基于创新型人才培养的毕业论文化学实验的绿色化

我们以本科生/研究生毕业论文相关的无机、分析化学实验为改革研究对象,以全面推进本科生/研究生素质教育为根本目的,建立了基于绿色理念的毕业论文无机、分析化学实验微型化教学指导新体系,以适用理工科大学不同专业教学指导与培养的需要,实现毕业论文研究工作中无机、分析化学实验的绿色化、微型化目标,进一步拓展到整个本科/研究生毕业论文与化学相关的实验研究工作,构建了绿色化的理工科大学创新型人才培养新型模式。     

BASF-Dow公司HPPO工艺介绍

详细介绍并比较了当前环氧丙烷(PO)的几种工业化生产工艺的优缺点,重点介绍了BASF-Dow公司联合开发的过氧化氢-环氧丙烷(HPPO)工艺.该工艺唯一的副产物是水,是当前PO清洁生产工艺中发展最快的一种方法,它具有环境友好、工艺及设备投资低等优点.     

化工专业毕业环节研究开发复合型人才培养的探索

搞好化工专业的毕业设计和毕业论文的教学,是培养研究开发复合型人才的关键环节。本文从毕业论文-设计教学模式、课题选择、教学指导和考评监督体系等方面进行探讨,提出充分利用产学研科研项目,按照因材施教的原则指导教学,通过毕业论文与毕业设计的有机结合和严格而有弹性的考评监督体系,培养学生的研究开发和创新能力。     

基于产学研结合的新建本科院校化工类毕业论文改革

基于新建本科院校毕业论文教学存在的问题,提出了产学研结合是提高新建本科院校毕业论文质量的有效途经。新建本科院校应密切联系产学研实际提前做好选题工作,强化论文实施过程的指导与监控,建立健全论文评审和激励机制。     

萃取精馏生产高纯度环氧丙烷的工艺研究

丙烯环氧化反应获得的粗环氧丙烷(PO)中含有乙醛、甲醇、甲酸甲酯和水等杂质，由于这些杂质与PO相对挥发度接近于1，普通精馏难以提纯PO；同时，分离过程中PO易发生水解生成1,2-丙二醇(PG)，而PG又导致萃取剂萃取性能下降。据此，结合萃取精馏和液液萃取技术，同时考虑PO水解反应，开发了水洗回收PO和侧线采出共沸物脱除PG流程，在有效脱除杂质的同时，提高了PO的回收率和萃取剂的萃取效率，获得了高纯度PO产品。采用流程模拟软件Aspen Plus对上述流程进行了全流程模拟计算，借助NRTL热力学方法，分析了萃取精馏塔的溶剂比、理论塔板数、原料进料位置、溶剂进料温度等主要工艺参数对分离过程的影响。结果表明该工艺流程合理、可靠，经济性优于现有工艺，可指导工业过程设计和操作优化。     

Performance of palm‐based fat blends with a low saturated fat content in puff pastry

Four fat blends based on palm fractions in combination with high oleic sunflower oil (HOSF) with a relatively low saturated fatty acid content (29.2 ± 0.85%, i.e. less than 50% of that of butter) were prepared. The saturated fat was located in different TAG structures in each blend. Principal saturated TAG were derived from palm stearin (POs, containing tripalmitoyl glycerol—PPP), palm mid‐fraction (PMF, containing 1,3‐dipalmitoyl‐2‐oleoyl glycerol—POP) and interesterified PMF (inPMF, containing PPP, POP and rac‐1,2‐dipalmitoyl‐3‐oleoyl glycerol—PPO). Thus, in blend 1, composed of POs and HOSF, the saturates resided principally in PPP. In blend 2, composed of POs, PMF and HOSF, the principal saturate‐containing TAG were PPP and POP. Blend 3, composed of inPMF and HOSF, was similar to blend 2 except that the disaturated TAG comprised a 2:1 mixture of PPO:POP. Finally, blend 4, a mixture of PMF and HOSF, had saturates present mainly as POP. The physical properties and the functionality of blends, as shortenings for puff pastry laminated in a warm bakery environment (20–24°C), were compared with each other, and with butter. Puff pastry prepared with blend 1 (POs:HOSF 29:71) and blend 4 (PMF:HOSF 41:59), was very hard; blend 2 (POs:PMF:HOSF 13:19:68) was most similar to butter in the compressibility of the baked product and it performed well in an independent baking trial; blend 3 (inPMF:HOSF 40:60) gave a product that required a higher force for compression than butter.     

必特螺旋霉素萃取过程研究

从热力学角度考察了温度、pH值、NaH2PO4质量分数对不同溶剂体系中必特螺旋霉素溶解度的影响,研究了磷酸盐缓冲液萃取石油醚洗脱液中必特螺旋霉素过程工艺特性,详细考察了温度、pH值、NaH2PO4质量分数等诸因素对萃取过程分配系数α的影响。萃取实验选择H3PO4-质量分数0.7%NaH2PO4缓冲溶液为萃取剂,以A/O相比=1/10进行萃取。研究发现:萃取过程最佳pH值范围为2.0—2.2,萃取分配系数α随着温度的升高而变小,萃取过程为放热过程,低温与较高的NaH2PO4质量分数有利于萃取过程的进行。在实验基础上推导并建立了萃取分配系数α与pH值及温度T函数关系α-pH及α-T理论数学模型,并用Matlab软件拟合得到α-pH-T函数关系式。     

Enzymatic interesterification of palm stearin and palm kernel olein

Palm stearin (POs) and palm kernel olein (PKOo) blends were modified by enzymatic interesterification (IE) to achieve the physical properties of margarine fats. POs and PKOo are both products of the palm oil industry that presently have limited use. Rhizomucor miehei lipase (Lipozyme IM 60) was used to catalyze the interesterification of oil blends at 60°C. The progress of interesterification was monitored by following changes in triacylglyceride composition. At 60°C interesterification can be completed in 5 h. Degrees of hydrolysis obtained through IE for all blends were decreased from 2.9 to 2.0 by use of dry molecular sieves. The solid fat contents of POs/PKOo 30:70 and 70:30 interesterified blends were 9.6 and 18.1 at 20°C, and 0 and 4.1 at 35°C, respectively. The slip melting point (SMP) of POs/PKOo 30:70 was 40.0°C before interesterification and 29.9°C after IE. For POs/PKOs 70:30, SMP was 47.7 before and 37.5°C after IE. These thermal characteristics of interesterified POs/PKOo blend ratios from 30:70 to 70:30 were comparable to those of commercial margarines. Results showed that IE was effective in producing solid fats with less than 0.5% trans.     

化工专业毕业实习与毕业论文模式改革与探索

毕业实习与毕业论文是本科教学忑作中的一个重要环节,针对化工专业学生毕业实习与毕业论文中存在的问题,对毕业实习与毕业论文教学模式进行了研究与探讨,提出了三种模式,取得了较好的效果。     

意大利艾尼化学公司高效一体化HPPO工艺简介

过氧化氢-环氧丙烷(HPPO)清洁生产工艺是当前环氧丙烷(PO)工业中发展最快的一种方法,它具有环境友好、工艺和设备投资低等优点.详细介绍了意大利Eniehem公司的高效一体化HPPO工艺,它包括在双金属催化剂存在下氢氧直接合成H2O2及在钛硅分子筛(TS-1)催化剂存在下丙烯与H2O2在甲醇溶剂中环氧化2个工序.该工...     

Solubilization and Adsolubilization of Polar and Nonpolar Organic Solutes by Linker Molecules and Extended Surfactants

Adsolubilization reaches its maximum when a surfactant adsorbed onto the solid–liquid interface achieves complete bilayer or maximum adsorption. The attempt to enhance the adsolubilization of organic solute is accomplished by increasing interaction between the hydrophobic core of adsorbed admicelles and the organic solute. Solubilization and adsolubilization were studied with linker-based and extended-surfactant-based systems. Extended surfactants have propylene oxide (PO) groups of intermediate polarity inserted between hydrophobic and lipophilic moieties in the surfactant molecule. This study evaluated the adsolubilization of polar (phenylethanol) and nonpolar (ethylcyclohexane) solutes into conventional linker-based and extended-surfactant-based admicelles. The results demonstrated that the extended-surfactant-based systems showed higher solubilization capacity than the conventional sodium dodecyl sulfate alone or with linker. For the polar solute, the presence of PO group has a greater effect than the number of PO groups or the tail length, while for the nonpolar solute as the number of POs groups and the tail length increased, the adsolubilization capacity also increased. Preliminary explanations for these observations are provided.

鲁棒模型预测控制系统的评估基准

在控制系统的性能评估中,基准的设计是个重要问题。将基本设计极限理论推广到模型预测控制系统(MPC),建立性能评估基准。直接考虑多输入多输出系统的频域扰动,建立输出反馈鲁棒模型预测控制器。此控制器仅仅依赖于过程参数,也是令闭环系统达到控制性能极限的基准控制器。建立了用于评估的性能指标,提出基于此基准的性能评估程序,用以评价其他模型预测控制系统的性能。数学算例证实了这一评估程序的有效性。     

Degussa—Uhde公司的HPPO工艺介绍

介绍国外过氧化氢-环氧丙烷（HPPO）清洁生产工艺的开发和产业化情况。重点介绍了Degussa—Uhde公司合作开发的HPPO工艺。HPPO工艺唯一的副产物是水,是当前环氧丙烷清洁生产工艺中发展最快的一种方法,它具有环境友好、工艺和设备投资低等优点。     

化学工程与工艺专业毕业实践教学模式改革研究

本文对传统毕业实习、毕业设计、毕业论文存在的问题进行了分析,结合化学工程与工艺专业特色,提出毕业实习、毕业设计、毕业论文三者有机结合的教学模式,并在教学中进行实践和探索。实践证明,该教学模式教学成果显著,适应我国对化工实用型人才培养的要求。     

基于广义最小变差基准的多变量控制性能评估方法

This paper is concerned with the control performance assessment based on the multivariable generalized minimum variance benchmark. An explicit expression for the feedback controller-invariant (the generalized minimum variance) term of the multi-variable control system is obtained, which is used as a standard benchmark for the assessment of the control performance for multi input multi output (MIMO) process. The proposed approach is based on the multivariable minimum variance benchmark. In com-parison with the minimum variance benchmark, the developed method is more reasonable and practical for the control performance assessment of multivariable systems. The approach is illustrated by a simulation example and an industrial application.     

Morphology and mechanical properties of blends of thermoplastic polyurethane and polyolefins

Polyolefins (PO) were melt mixed with thermoplastic polyurethane (TPU) in a 20 : 80 weight ratio with or without compatibilizer containing 0.5 wt % of maleic anhydride. Effects of component viscosities on morphology and on mechanical properties of the blend were studied by scanning electron microscope (SEM), tensile property analysis, and dynamic mechanical analysis (DMA). It was found that the disperse particle size of compatibilizer‐free blends decreased with the decreasing viscosity ratio of the disperse phase to TPU. The efficiency of the compatibilizer in reducing the particle size varied with viscosity ratios of the disperse phase to compatibilizer. However, the particle size did not decrease with the decreasing viscosity ratio monotonically. With lower viscosity ratio, addition of 5 wt % compatibilizer resulted in a greater reduction of particle size and less loss in the tensile properties as compared to the TPU matrix. For the polyethene (PE) that has the lowest viscosity value among all the POs, its size in the blend was stabilized with the addition of compatibilizer and no compatibilization was detected by DMA and by tensile property analysis. The mobility of the disperse phase and compatibilizer and the dispersion competition between them seemed important. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 875–883, 2006     

基于T-S模糊模型与粒子群优化的非线性预测控制

引言模型预测控制属于一种基于模型的多变量的控制算法,发展至今已在化工过程控制方面得到了广泛的应用[1-5]。状态反馈预测控制[6-8]是模型预测控制技术的一种,基于状态空间模型,采用实测状态     

Effect of chemical interesterification on triacylglycerol and solid fat contents of palm stearin,sunflower oil and palm kernel olein blends

Palm stearin (POs) with an iodine value of 41.4, sunflower oil (SFO) and palm kernel olein (PKOo) were blended in various ratios according to a three‐component mixture design and subjected to chemical interesterification (CIE). Triacylglycerol (TAG) and solid fat content (SFC) profiles of the chemically interesterified (CIEed) blends were analyzed and compared with those of the corresponding non‐CIEed blends. Upon CIE, extensive rearrangement of fatty acids (FA) among TAG was evident. The concentrations of several TAG were increased, some decreased and several new TAG might also have been formed. The changes in the TAG profiles were reflected in the SFC profiles of the blends. The SFC of the CIEed blends, except the binary blends of POs/PKOo which experienced an increase in SFC following CIE, revealed that they were softer than their respective starting blends. Randomization of FA distribution within and among TAG molecules of POs and PKOo led to a modification in TAG composition of the POs/PKOo blends and improved miscibility between the two fats, and consequently diminished the eutectic interaction that occurred between POs and PKOo.     

Relay feedback identification for processes under drift and noisy environments

Relay feedback identification methods are widely used to find the process ultimate information and tune proportional‐integral‐derivative controllers. The conventional relay feedback method has several disadvantages, which include poor estimates of the process ultimate information for low‐order processes, chattering of relay for noisy environments, and asymmetric relay responses for constant biases or slow drifts in the process outputs. Methods to mitigate each of the above disadvantages are available. However, a systematic method to treat all of them has not been studied yet. Here, simple relay feedback methods that resolve these problems by introducing band‐pass filters in the feedback loop are proposed. The high‐pass filter part in band‐pass filter removes a constant bias or low frequency drift, and the low‐pass filter part removes high frequency noise and high‐order harmonic terms in the relay feedback oscillation, resulting better estimates of the process ultimate information. Because filters used for the proposed methods are able to reject constant biases, the process steady state gains can be estimated without disturbing the relay feedback oscillations and first order plus time delay (FOPTD) models can be obtained by combining the process steady state gains with the relay oscillation information. © 2010 American Institute of Chemical Engineers AIChE J, 2011