Oleic acid esterification with ethanol under continuous water removal conditions

The production of ethyl ester was investigated using a new reaction system consisting of a reactor coupled to an adsorption column. The adsorption system was used to shift the equilibrium toward ethyl ester production by removing the water from commercial ethanol and the water produced during the esterification reaction. A condenser placed above the adsorption column was responsible to condensate the vapor, returning water free ethanol to the reactor. Ethyl ester was produced by esterification of oleic acid and ethanol using sulfuric acid as catalyst. The results showed a yield of 99.9%. The best operating condition was found operating the reactor at 110 °C, 1% of catalyst (w/w) and with an oleic acid to ethanol ratio of 1:3.     

油溶性表面活性剂甘油硼酸油酸酯的合成研究

以硼酸和油酸为原料采用直接酯化法合成水溶性的甘油硼酸酯,再在催化剂的作用下与油酸反应制得甘油硼酸油酸酷,设计出较佳的酸化条件：甘油硼酸酯与油酸摩尔比1：0．9,温度220℃,时间4h,催化剂甩量（脂肪酸质量分数）0．5％,酸转佬率98．5％。     

固体超强酸SO4^2-/ZrO2-CeO2催化油酸酯化反应的研究

以固体超强酸SO4^2-/ZrO2-CeO2为催化剂,以油酸和甲醇为原料,在高温高压反应釜中进行酯化反应。对反应条件的研究表明,当甲醇与油酸的体积比为2：1（摩尔比为15：1）,反应温度为160℃,反应时间4h,催化剂用量8％（与油酸的质量百分比）时,反应的酯化率达到97．34％。动力学计算表明,该酯化反应的反应级数为1．42,反应活化能为25．25kJ／mol。     

月桂酸单甘酯的催化合成

文章以磷钨酸为催化剂,4分子筛为脱水剂,在无溶剂条件下月桂酸和甘油为原料合成月桂酸单甘酯,考察了反应温度、摩尔比（月桂酸/甘油）、反应时间、催化剂用量、分子筛用量对反应产率的影响,并确定了反应最佳条件是：反应温度200℃,摩尔比（月桂酸/甘油）1∶2.5,反应时间为2 h,磷钨酸用量为3%,分子筛用量为5%（月桂酸与...     

Enzyme,medium, and reaction engineering to design a low-cost,selective production method for mono- and dioleoylglycerols

The selective enzymic production of mono- and diolein (MO, DO) was optimized at high yields. A comparative study of the following distinct enzymic reactions was conducted: ethyl oleate glycerolysis, triolein (TO) glycerolysis, and direct esterification Solvent-free systems were compared with media that contained different solvents. Native, modified (with polyethylene glycol), and immobilized lipases were used. Mechanical resistance, the support effect on enzyme and glycerol dispersion and on process reproducibility, and hydrophilicity of the support were considered in the process optimization. We report the use of an immobilized lipase on an inorganic support (Celite), which has high activities in both solid-phase glycerolysis (99% reaction conversion) and esterification (100% conversion). The optimum conditions for the distinct reactions were compared by considering their selectivities, conversions, yields, and cost of the substrates. We found less costly and more selective processes in the absence of solvents for glycerolysis of triolein and direct esterification. Although glycerolysis was the most interesting process to produce diolein, esterification was better for monoolein preparation with this biocatalyst. The esterification reaction yielded 93 wt% of MO, in the absence of either TO or oleic acid (OA), at low cost because of the 100% reaction conversion. Similar costs of the substrates (10.6 and 10.1 $/g) were necessary to obtain 67 and 80 wt% of DO in esterification and glycerolysis, respectively. The glycerolysis conversion was 96%. In esterification, the product mixture was impure, with a high amount of residual OA due to the low conversion (59%). The high activity of PSL-Celite in these solid-phase reactions has an advantage over the reactions with nonimmobilized lipases due to the ease of enzyme recovery. The absence of organic solvents reduces the need for solvent removal from the reaction mixtures.     

SBA-15负载活性组分催化合成油酸乙酯

通过嫁接的方法合成Al-SBA-15介孔分子筛,以油酸和乙醇为原料,在间歇釜中进行酯化反应实验研究。考察反应温度、原料配比、催化剂用量、反应时间和催化剂硅铝原子比等因素对酯化反应的影响,结果表明,反应温度180 ℃、催化剂用量为原料质量的1.25%、n(油酸)∶n(乙醇)＝1.0∶2.5、反应时间5 h和催化剂硅铝原子比为10时,油酸转化率为83.53%。     

Fast synthesis of 1,3‐DAG by Lecitase® Ultra‐catalyzed esterification in solvent‐free system

Lecitase® Ultra, a phospholipase, was explored as an effective biocatalyst for direct esterification of glycerol with oleic acid to produce 1,3‐DAG. Experiments were carried out in batch mode, and optimal reaction conditions were evaluated. In comparison with several organic solvent mediums, the solvent‐free system was found to be more beneficial for this esterification reaction, which was further studied to investigate the reaction conditions including oleic acid/glycerol mole ratio, temperature, initial water content, enzyme load, and operating time. The results showed that Lecitase® Ultra catalyzed a fast synthesis of 1,3‐DAG by direct esterification in a solvent‐free medium. Under the optimal reaction conditions, a short reaction time 1.5 h was found to achieve the fatty acid esterification efficiency of 80.3 ± 1.2% and 1,3‐DAG content of 54.8 ± 1.6 wt% (lipid layer of reaction mixture mass). The reusability of Lecitase® Ultra was evaluated via recycling the excess glycerol layer in the reaction system. DAG in the upper lipid layer of reaction mixture was purified by molecular distillation and the 1,3‐DAG‐enriched oil with a purity of about 75 wt% was obtained. Practical applications: The new Lecitase® Ultra catalyzed process for production of 1,3‐DAG from glycerol and oleic acid described in this study provides several advantages over conventional methods including short reaction time, the absence of a solvents and a high product yield.     

十二烷基苯磺酸催化合成乙酸苄酯的研究

以苄醇和冰醋酸为原料,十二烷基苯磺酸(DBSA)为催化剂,合成了乙酸苄酯。研究了物料比、酯化时间、酯化温度和催化剂用量对酯化率的影响,确定了最佳工艺条件:n(冰醋酸)∶n(苄醇)=1∶6,酯化时间4.5 h,酯化温度40℃,DBSA用量为冰醋酸物质的量的3%时酯化率最高可达78.39%。     

Selective synthesis of triacetin from glycerol catalyzed by HZSM-5/MCM-41 micro/mesoporous molecular sieve

HZSM-5/MCM-41 molecular sieve(H-ZM) catalysts with well-defined micro/mesoporous structures were synthesized and showed high performance for selective synthesis of triacetin via the esterification reaction of glycerol with acetic acid. The conversion of glycerol was demonstrated to be 100% and the triacetin selectivity was over 91%, which can be attributed to the synergistic effect regarding suitable acidic property, excellent diffusion efficiency and good stability derived from the combined advantages of microporous molecular sieve HZSM-5 and mesoporous molecular sieve MCM-41.     

油酸异丁酯的离子液体催化酯化制备与动力学及其低温流动性能

在自行设计的反应装置中,以吡啶硫酸氢盐离子液体为催化剂、油酸与异丁醇为反应原料催化酯化制备油酸异丁酯. 得到最佳反应条件为,温度100℃,时间3 h,催化剂用量2%(w),醇/酸最佳体积比2:1. 对此酯化催化反应进行了动力学分析,表观反应级数为二级,反应活化能Ea=32.0 kJ/mol,频率因子A=66.6,反应动力学模型为-dCA/dt=66.6e-32000/(RT)CACB;所制油酸异丁酯的凝点为-25.5℃,冷滤点为-20.5℃,运动粘度为6.32 mm2/s,其低温性能好,流动性能较差,可很好地改进生物柴油的低温性能和油酸异丁酯的流动性能.     

二羟乙基己二酰胺油酸酯的制备与表征

用乙醇胺和己二酸二甲酯反应生成了中间体二羟乙基己二酰胺,当n(乙醇胺)∶n(己二酸二甲酯)=2时,收率95.2%。再将中间体与油酸进行酯化反应合成了具有润滑性能的二羟乙基己二酰胺油酸酯。合成的酯具有优良的热稳定性能、低挥发性、较低的毒性和良好的生物降解性,可成为环境友好型润滑剂。比较了酯化率和产品最终颜色,探讨了反应时间、反应温度对油酸酯化率的影响,优化了二羟乙基己二酰胺油酸酯合成条件:在吸水剂分子筛存在下,醇酸摩尔比为1∶2.2,反应时间为4 h,反应温度为125℃条件下,重复试验油酸的酯化率均在95%以上,产品的收率均在90%以上。     

聚乙二醇400单油酸酯的研发及生产

以油酸、聚乙二醇400(PEG400)为原料,对甲苯磺酸为催化剂,酯化合成聚乙二醇400单油酸酯(PEG400MO)。考察了反应溶剂、温度、催化剂用量、溶剂用量、萃取用量等因素对酯化反应的影响,最终确定最佳的反应条件为油酸与PEG400的摩尔比为1:1.2,对甲苯磺酸投料量为油酸质量的10%,环己烷投料量为油酸的10倍体积,在68℃加热回流反应约7 h,反应完全后加入与对甲苯磺酸等摩尔的碳酸氢钠中和,再以油酸1.0倍质量的PEG400分成等量3次萃取,萃取后减压蒸馏除去环己烷,再经过滤得到产品PEG400MO。以研发的工艺进行工业化生产,平均摩尔收率在90%左右,产品各项指标符合标准要求。     

基于间苯三酚的磺化碳基固体酸催化剂的制备及其催化油酸甲酯的合成

采用间苯三酚与对苯二甲醛缩聚得到的树脂为碳前驱体,分别以1,4-二氧六环与去离子水为溶剂,以溶剂热和水热法、氯磺酸为磺化试剂制备两种磺化碳基固体酸催化剂。SEM、XPS和TGA等分析表明,以1,4-二氧六环为溶剂合成的TP-A-S催化剂为形貌规整、高酸密度、良好稳定性的球形,并表现出良好的催化性能。将其用于油酸与甲醇的酯化反应,最适宜的条件为:醇油物质的量比10∶1,催化剂用量占原料总质量的2.0%,反应温度70℃,反应时间4h,油酸最高转化率达98.3%。且催化剂循环使用5次后,油酸转化率仍达84.4%。将制备的TP-A-S催化剂用于长链游离脂肪酸与甲醇的酯化反应,转化率高于90%,表现出良好的催化效果。     

硫酸改性Hβ沸石催化合成油酸丁酯

以油酸和正丁醇为原料,硫酸改性Hβ沸石为催化剂,催化合成油酸丁酯。结果表明,适宜的酯化反应条件为：酸醇摩尔比为1：2,催化剂用量为原料总质量的5％,带水剂用量为5mL／0．05mol油酸,反应温度120oC,反应时间为5h,此时酯化率可达76．7％。     

苄基磺酸MCM -41催化合成柠檬酸三丁酯

以苄基磺酸化MCM - 41介孔分子筛(SBM)为催化剂,催化合成柠檬酸三丁酯.研究结果表明,SBM在合成柠檬酸三丁酯的反应中具有良好的催化性能,当n(酸):n(醇)=1.0:8.0,w(cat)％=3％,反应时间7h,酯化率为93％,且催化剂重复4次后转化率为76.3％.     

固定化脂肪酶合成肉豆蔻酸异丙酯的研究

采用固定化脂肪酶(Novozym 435)在有机溶剂体系中催化肉豆蔻酸和异丙醇酯化合成了肉豆蔻酸异丙酯.研究了各种因素如有机溶剂种类、反应物摩尔比、反应温度及酶用量等因素对酯化率的影响.结果表明,肉豆蔻酸异丙酯合成的较佳条件为:1.14 g肉豆蔻酸,0.45 g异丙醇,0.02 g Novozym 435,10 mL石油醚(其中加入0.5 g 3A分子筛吸水),在55℃下振荡反应4 h,酯化率为99.2%(肉豆蔻酸可基本完全转化为肉豆蔻酸异丙酯).实验过程中固定化酶稳定性较好,可连续使用7批左右.     

Production of medium-chain glycerides by immobilized lipase in a solvent-free system

Enzymatic synthesis of medium- chain glycerides (MCGs) was studied by using capric acid (decanoic acid) and glycerol as substrates for immobilized lipase (Lipozyme^TM) without any solvents or surfactants. Quantitative analysis of the reaction mixture was conducted by using highperformance liquid chromatography (HPLC), which enabled the exact tracing of the capric glyceride synthesis. Oleic acid was also used for comparison. The esterification activity of Lipozyme was determined at 40°C in an open batch reactor; the activities were 400 and 200 units/g for the capric glyceride and oleic glyceride synthesis, respectively. Maximum initial reaction rate was obtained at 50°C for capric and 60°C for oleic glyceride synthesis. The time course of the capric glyceride synthesis was compared in terms of different molar ratios, from which we infer that this enzyme is 1,3- specific, but not absolute, in this esterification reaction. The final conversion was greatly influenced by the methods used to remove water, among which the cold trap method resulted in a noticeable improvement. *To whom correspondence should be addressed at Department of Biological Science and Engineering, Korea Advanced Institute of Science and Technology, P.O. Box 150, Chongyang, Seoul 130-650, Korea.     

SO_4~(2-)/TiO_2-SiO_2催化聚合松香酯化反应及其动力学研究

研究了固体超强酸SO42-/TiO2-SiO2催化聚合松香与甘油酯化反应的动力学。结果表明:SO42-/TiO2-SiO2催化聚合松香与甘油酯化反应的适宜条件为:n聚合松香∶n甘油=3∶2.5、270°C、反应60 min、搅拌速度800 r/min、催化剂粒径150μm和0.6%的催化剂配比。过量的甘油有利于提高酯化率和产品质景,改变催化剂粒径和搅拌速度,能够消除内外扩散对反应的影响。酯化反应为双分子酰-氧断裂历程的二级反应,动力学方程为k=1.39×1011e-127786/RT,过程限制环节是界面化学反应扩散控制。     

HY分子筛催化合成油酸乙酯

采用NaY分子筛催化剂,经离子交换和高温焙烧制得HY分子筛,以油酸和乙醇为原料,在间歇反应釜进行酯化反应研究。考察反应温度、原料配比、催化剂用量和反应时间等条件对酯化反应的影响。结果表明,在反应温度180 ℃、n(油酸)∶n(乙醇)＝1∶2.5、催化剂用量为原料总质量的1.0%和反应时间4 h条件下,油酸转化率可达81.18%。实验中的HY分子筛表现出较高的活性和良好的稳定性。     

反应器长径比对连续酯化制备1，6-己二酸二甲酯的影响

以DNW—I型强酸型正离子交换树脂为催化剂,己二酸和甲醇为原料,经间歇酯化和连续酯化反应后通过精馏可制备选择性为100％的1,6-己二酸二甲酯。采用长径比分别为32、16、6、3的反应器,控制原料进料速度及甲醇进料速度进行连续酯化实验。结果表明选择合适长径比且催化剂段进行外部加热的反应器是进行酯化法制备1,6-己二酸二甲酯的关键。