Preparation of Biodiesel via Two-step Catalyzed Process

生物柴油，是植物柴油和动物柴油的总称，它是从可再生的生物质资源中获得的一种理想的柴油替代燃料,具有可生物降解性、排放污染小、生产原料来源广泛等特点。大力发展生物柴油，不仅可以降低环境污染，而且对于缓解我国的能源危机，增强我国能源安全，以及对促进农副产品的综合开发利用都有着深远的意义。 本文选取酸化的菜籽油为原料，采用两步法，先采用阳离子交换树脂催化酯化法进行脱酸，以降低原料中的游离脂肪酸（FFA）含量至酯交换所要求（1mgKOH/g以下）；脱酸后的菜籽油在Mg-Al水滑石固体碱催化剂作用下与甲醇进行酯交换反应得到生物柴油。 筛选不同树脂对脱酸催化效果为：CD-552>HD-8>...Biodiesel, a generic name of both plant diesel and animal diesel, is produced as alternative diesel fuel from renewable resources. Biodiesel is characterized by excellent properties such as biodegradation, less contamination, wide source of raw material, etc. Developing biodiesel, not only let out less of contamination, but also alleviates the energy crisis in our nation, strengthens the energy sa...学位：工学硕士院系专业：化学化工学院化学工程与生物工程系_化学工程学号：1922005130175

Removal of free fatty acids from acid oil by esterification with cation exchange resin

采用阳离子交换树脂为催化剂研究了酸性油脂的酯化脱酸工艺。分别筛选了001x4,001x7,d113,Hd-8,Cd-552等几种型号的树脂,其中以Cd-552催化效果最好。研究了反应时间、醇酸摩尔比和酸性油脂中催化剂质量分数对Cd-552催化酯化脱酸效果的影响。在醇酸摩尔比30∶1,反应温度60℃,树脂质量分数5%和反应时间5 H的工艺条件下,酸性油脂经Cd-552催化酯化脱酸后,酸值从10.97 Mg/g降低到0.689 Mg/g。反应后树脂易分离,能够循环使用,有效地解决了传统的脱酸催化剂不足,对以酸性油脂为原料的生物柴油的生产具有应用前景。Using acidic cation exchange resins as a solid esterification catalyst,the removal of free fatty acids(FFA) from acid oil by esterification with methanol was researched.The resins such as 001×4,001×7,D113,HD-8,CD-552 were selected for the experiments.The results show that the resin CD-552 is the best catalyst for FFA reduction.The effects of reaction time,mole ratio of alcohol to FFA and mass fraction of catalyst in acid oil on acid reduction by esterification with CD-552 were investigated.Under the reaction conditions: molar ratio of alcohol to FFA 30 ∶1,reaction temperature 60 ℃,catalyst mass fraction 5% and reaction time 5 h,the acid number of the oil is reduced from 10.97 mg/g to 0.689 mg/g after removal of free fatty acids from acid oil by esterification with CD-552.It indicates that the resin is easy to be separated and recycled,which overcomes the deficiency of traditional FFA reduction catalyst,and has a good application prospects for producing biodiesel by using acid oil as raw material

一种抗菌含氟聚合物中空纤维微孔膜的制备方法

本发明涉及一种抗菌含氟聚合物中空纤维微孔膜的制备方法。含氟聚合物中空纤维微孔膜表面细菌和微生物易附着、生长，造成膜污染。本发明方法首先将分子筛和AgNO3溶液混合得到载银分子筛，然后将含氟聚合物、溶剂、络合剂和载银分子筛顺序加入到配料罐中，溶解后得到分散均匀的纺丝液，纺丝液脱泡后经过单层喷丝头挤出，形成液膜，液膜进入水槽进行固化，形成中空纤维膜；固化后的中空纤维膜经过卷绕机进行收集，在水中浸泡后得到中空纤维微孔膜。本发明方法具有制备方法简单、抗菌能力强、抗菌效果持久、能同时提高水通量和截留率的特点，能够减少膜污染，延长膜的使用寿命

An Eye Movement Study on Visual Search of Web Page Layout

以12名大学生为被试,研究基于网页布局的视觉搜索的眼动特性,探讨了网页布局对被试视觉搜索的影响。实验以眼动仪为主要实验设备。研究结果表明:(1)网页布局对注视点数目、总扫视距离和注视时间影响显著。(2)不同网页布局首视点分布的象限差异不显著,但在同一布局下不同象限的首视点分布差异显著。(3)被试在视觉搜索时,"T"型网页布局的绩效优于其它网页布局

An Eye Movement Study on Visual Search of Web Page Layout

以12名大学生为被试，研究基于网页布局的视觉搜索的眼动特性，探讨了网页布局对被试视觉搜索的影响。实验以眼动仪为主要实验设备。研究结果表明：（1）网页布局对注视点数目、总扫视距离和注视时间影响显著。（2）不同网页布局首视点分布的象限差异不显著，但在同一布局下不同象限的首视点分布差异显著。（3）被试在视觉搜索时，“T”型网页布局的绩效优于其它网页布局

An Eye Movement Study on Visual Search of Web Page Layout

以12名大学生为被试,研究基于网页布局的视觉搜索的眼动特性,探讨了网页布局对被试视觉搜索的影响。实验以眼动仪为主要实验设备。研究结果表明:(1)网页布局对注视点数目、总扫视距离和注视时间影响显著。(2)不同网页布局首视点分布的象限差异不显著,但在同一布局下不同象限的首视点分布差异显著。(3)被试在视觉搜索时,"T"型网页布局的绩效优于其它网页布局

Preparation of Alkyl Polyglucoside by One Step Reaction

分别采用对甲苯磺酸和十二烷基苯磺酸为催化剂进行了一步法由葡萄糖和月桂醇制备烷基糖苷的工艺研究.探讨了反应温度、原料配比和催化剂用量对产品得率、反应时间和多糖含量的影响,确定了较为适宜的操作工艺条件.在对甲苯磺酸催化下,烷基糖苷的得率可达149.63%,而在十二烷基苯磺酸催化下,烷基糖苷的得率可达152.23%.对所得产品的表面活性也进行了测定.Alkyl polyglucosides were prepared from glucose and lauryl alcohol by one step reaction using p-toluenesulfonic acid and dodecyl benzene sulfonic acid as catalysts respectively.The effects of reaction temperature,mole ratio of alcohol to glucose and the amount of catalyst used on product yield,reaction time and content of polyglucose were researched.Appropriate operation conditions for preparation of alkyl polyglucoside are as follows:reaction temperature 115℃,degree of vacuum 96.69 kPa,mole ratio of alcohol to glucose 51 and the amount of catalyst used 1%.Yield of alkyl polyglucoside was reached up to 149.63% after reaction for 6.5 h by using p-toluenesulfonic acid as catalyst,while yield of alkyl polyglucoside was reached up to 152.23% after reaction for 4.5 h by using dodecyl benzene sulfonic acid as catalyst.The sample prepared was studied using infrared spectrum.The surface tensions were measured in different concentrations of aqueous alkyl polyglucoside.厦门市科技计划项目(3502Z20021051)资

Advance in the synthesis of novel high-potency sweetener neotame

介绍了新型强力甜味剂纽甜的结构、性能、合成方法及发展前景,对纽甜的合成方法进行了综述。对具体的合成路线作了比较:化学合成法工艺简单,但收率较低;化学-酶联合法专一性强,但发酵成本较高。阿斯巴甜经济易得,以阿斯巴甜为原料合成纽甜是目前最具有发展前景的工艺。The structure,performance,synthesis methods and development trends of neotame are introduced in this paper.Especially,the methods to synthesize neotame are described in detail and compared with each other.The process of chemical synthesis is simple,whereas this method gives a lower yield of product.The advantage of chemical-enzyme synthesis is high enzyme specificity but the disadvantage is higher cost of zymolysis.It is found that using aspartame as raw material to synthesize neotame is the most promising process because aspartame is cheap and readily available