活性白土催化合成三甘醇二异辛酸酯

以三甘醇和异辛酸为原料,在活性白土的作用下,催化酯化合成三甘醇二异辛酸酯。考察酸醇物质的量比、反应时间、催化剂用量、带水剂用量等条件对酯化反应的影响,确定最佳合成工艺条件。合成三甘醇二异辛酸酯的最佳条件为酸醇物质的量比为4∶1,反应时间为5h,催化剂用量为8%,带水剂用量为33%,三甘醇转化率可达93.45%。催化剂不经任何处理重复使用3次后,三甘醇转化率有所下降,但催化剂经过再生后,三甘醇转化率可达93.2%,产品经气相色谱分析三甘醇二异辛酸酯含量为77.01%,三甘醇一异辛酸酯含量是14.48%。     

无溶剂法合成季戊四醇四异辛酸酯的研究

在无溶剂的条件下,以季戊四醇与异辛酸为原料合成了季戊四醇四异辛酸酯。研究了催化剂种类、用量、原料配比、反应时间及温度等因素对酯化反应的影响。结果表明,最佳反应条件是对甲苯磺酸为催化剂,催化剂用量为反应物总质量的2%,季戊四醇、异辛酸的摩尔比为1∶5,反应温度为160℃,反应时间为5 h,酯化率可达97%以上。反应产品经红外光谱确定结构。     

一缩二乙二醇复酯的合成

以对甲苯磺酸为催化剂,以甲苯为携水剂,以一缩二乙二醇、己二酸和异辛酸为原料合成了一缩二乙二醇复酯,考察了原料配比、一元酸类型、加料方式对酯化反应的影响。确定了一缩二乙二醇复酯的最佳合成工艺条件为：己二酸与异辛酸的摩尔比0．4：1,催化剂、携水剂用量分别为2．0％、20%,两步法方式加料,在此条件下,酯化率可达96．3％。通过红外光谱对合成产物进行了确证。     

聚对苯二甲酸丙二醇酯酯化反应过程模拟

为研究聚对苯二甲酸丙二醇酯(PTT)酯化反应过程工艺参数的影响,基于Aspen Plus开发了一种PTT间歇直接酯化合成工艺的数学模型,利用模型研究了单体进料比、反应温度对酯化率和副产物二聚丙二醇醚(DPG)的影响。模型预测值与实验数据相吻合,模型计算表明,为了避免酯化物中副产物DPG含量过高,浆料进料比需要控制在1.6以下。     

强酸性阳离子交换树脂催化合成丙二醇二苯甲酸酯的研究

以苯甲酸、1，2-丙二醇为原料。直接酯化合成丙二醇二苯甲酸酯，分别研究了反应温度、反应时间、原料配比、带水剂、催化剂用量等条件对合成反应的影响，确定了最佳工艺条件。该方法合成丙二醇二苯甲酸酯的最佳工艺条件是：反应温度110℃；反应时间240min；n(苯甲酸)：n(1，2-丙二醇)为2．1：1；催化剂用量为总物料质量的3％：带水剂苯为15mL/（1．2-丙二醇为0．2mol的情况下)。丙二醇二苯甲酸酯的收率达到95．94％。催化剂不经处理可循环使用多次。该催化剂具有价廉易得、催化活性好、不腐蚀设备、无环境污染等优点。     

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。     

合成蒙克汀新工艺研究

采用丙酮将甘油的2个羟基进行保护,再与辛酰氯反应合成辛酸异丙叉甘油醚单酯,水解后得到辛酸甘油单酯;将甘油的相邻二羟基与对甲苯磺酰氯反应,制得对甲苯磺酸甘油二酯活性中间体,然后再与辛酸反应合成辛酸甘油二酯;将质量分数分别为70%和30%的单酯和双酯混合,即得蒙克汀。此种工艺与传统的酯化法相比,双或单酯收率都提高30%以上,所得产品色浅,溶石能力高,达到药用要求。     

亚锡类催化剂催化合成对苯二甲酸二异辛酯的研究

以3种亚锡类催化剂氧化亚锡、氯化亚锡、辛酸亚锡以及它们之间复配后作为催化剂,对对苯二甲酸二异辛酯酯化反应的催化活性进行了研究,实验结果表明,以氧化亚锡和辛酸亚锡复配后的催化活性最高,氧化亚锡和辛酸亚锡作为催化剂的酯化反应最佳合成工艺条件为:催化剂的加量为0.25%(重量比),反应温度为220℃,醇酸摩尔比为3.0?1,在最佳工艺条件下,产品的终点酸值为0.62 mgKOH/g,对苯二甲酸的转化率达99.75%。     

功能化离子液体催化合成辛酸苄酯

以苯甲醇与正辛酸为原料合成了辛酸苄酯,咪唑类和吡啶类具有PS(丙烷磺酸基)功能基团的离子液体作催化剂,考察了其阴、阳离子对催化活性的影响。并选择[PSPy]HSO4为催化剂,研究了酸醇摩尔比、催化剂用量、反应温度和反应时间等对酯化率的影响,实验结果表明,催化剂用量为正辛醇的20%(摩尔分数),反应温度120℃,反应时间2.5h,酯化率达95.3%;此外,该催化剂重复使用10次后,酯化率达94.2%。     

植物甾醇酯的酶法合成

以油酸和植物甾醇为反应底物,利用脂肪酶催化合成植物甾醇油酸酯。对脂肪酶和反应介质进行了筛选,同时对影响合成植物甾醇油酸酯反应的因素进行了探究,考察了底物摩尔比(油酸甾醇比)、酶添加量(脂肪酶质量/底物总质量)、反应温度及反应时间对酯化反应的影响。在单因素的基础上,经酯化率响应曲面实验优化反应条件,确定最佳反应条件:催化酯化反应的酶为柱状假丝酵母脂肪酶(CRL,Candida rugosa lipase),反应介质为正己烷,底物摩尔比为3∶1,酶添加量为7.2%,反应温度为45.3℃,反应时间为25.3h,验证试验酯化率可达72.95%。     

纤维级1,3-丙二醇的制备

研制了一种细颗粒改性Ｒａｎｅｙ镍催化剂,考察了３－羟基丙醛(３－ＨＰＡ)加氢时,催化剂量、氢压、催化剂使用寿命及搅拌速度等影响因素。结果表明,在一定的条件下,加氢转化率可达１００%,１,３－丙二醇(１,３－ＰＤＯ)选择性大于９９%。但经加氢制得的１,３－ＦＤＯ中仍有较高醛含量,为此又制备了一种脱除１,３－ＰＤＯ中醛基的催化剂。在固定床反应器中,当反应温度为５０~９０℃、液时空速为１－５ｈ－１、待精制的粗１,３－ＰＤＯ中醛基含量小于２０００ｐｐｍ时,成品１,３－ＰＤＯ中的醛基含量可降至３０ｐｐｍ以下,符合生产高质量ＰＴＴ纤维的要求。     

固定化Candida sp. 99-125脂肪酶催化合成蜡酯(英文)

Wax esters were synthesized in a solvent free system catalyzed by immobilized lipase from Candida sp. 99-125, with oleic acid and cetyl alcohol. The effects of substrate molar ratio, lipase dosage and water removal were investigated in a 50 ml flask incubated in a thermostatic cultivation cabinet. The optimized conditions were: temperature 40 ℃, shaking at 170 r·min-1, acid/alcohol molar ratio 1:0.9, lipase dosage in 10% (by mass) of oleic acid, and open reaction for water removal. As a result, the conversion rate reached 98% for reaction of 8 h. The volume of reactor was scaled up to 1 L three-neck flask. The optimized parameters were: 200 r·min-1 agitation speed, 2.5% (by mass) lipase dosage, others were the same as the parameters described above. The conversion rate reached 95% for reaction of 24 h. The lipase retained 46% conversion rate after reuse for 6, 7 batches. The products were purified by removing remained cetyl alcohol and fatty acids with ethanol and saturated sodium carbonate so-lution, respectively. The purity of the wax ester, cetyl oleate, was 96%. The physical and chemical properties of cetyl oleate were tested and compared with those of jojoba oil. The results show that the product cetyl oleate has great potential to use as the substitute of natural jojoba oil.     

ZnMgAl复合氧化物五催化合成丙二醇苯醚

以不同类水滑石化合物为前驱体制得的复合氧化物作为合成丙二醇苯醚反应的固体碱催化剂，考察了催化剂组成、结构及反应条件对催化合成丙二醇苯醚反应的影响。结果发现，在所制备的固体碱催化剂中ZnMgAl复合氧化物显示出高效的催化活性和选择性，在催化剂用量为1. 1%，C₆H₅OH/PO摩尔比为1∶1，反应温度为413 K和反应时间为5 h的条件下，环氧丙烷的转化率达到97. 2%，丙二醇苯醚的选择性达93. 4%。     

Over‐expression of glycerol dehydrogenase and 1,3‐propanediol oxidoreductase in Klebsiella pneumoniae and their effects on conversion of glycerol into 1,3‐propanediol in resting cell system

BACKGROUND: Glycerol dehydrogenase [EC.1.1.1.6] and 1,3‐propanediol oxidoreductase [EC.1.1.1.202] were proved to be two of the key enzymes for glycerol conversion to 1,3‐propanediol in Klebsiella pneumoniae under anaerobic conditions. For insight into their significance on 1,3‐propanediol production under micro‐aerobic conditions, these two enzymes were over‐expressed in K. pneumoniae individually, and their effects on conversion of glycerol into 1,3‐propanediol in a resting cell system under micro‐aerobic conditions were investigated. RESULTS: In the resting cell system, over‐expression of 1,3‐propanediol oxidoreductase led to faster glycerol conversion and 1,3‐propanediol production. After a 12 h conversion process, it improved the yield of 1,3‐propanediol by 20.4% (222.1 mmol L⁻¹ versus 184.4 mmol L⁻¹) and enhanced the conversion ratio of glycerol into 1,3‐propanediol from 50.8% to 59.8% (mol mol⁻¹). Over‐expression of glycerol dehydrogenase in K. pneumoniae had no significant influence both on 1,3‐propanediol yield and on the conversion ratio of glycerol into 1,3‐propanediol in the resting cell system. CONCLUSION: The results were important for an understanding of the significance of glycerol dehydrogenase and 1,3‐propanediol oxidoreductase in 1,3‐proanediol production under micro‐aerobic conditions, and for developing better strategies to improve 1,3‐propanediol yield. Copyright © 2008 Society of Chemical Industry     

一种选择性拆分布洛芬对映体的固定化脂肪酶

为了提高扩展青霉TS414脂肪酶(PEL)对布洛芬的拆分效率,建立了适于非水相中选择性拆分(R,S)-布洛芬的固定化方法. 结果表明,固定化介质的类型、冻干pH和外加水量等因素对固定化PEL酶促拆分(R,S)-布洛芬有较大影响. 在冻干pH为9.0、外加水量为0、以大孔吸附树脂AB-8为固定化载体的体系中,40℃反应30 h后,拆分反应的转化率可达47%,对映体过量值eeP可达98.75%. AB-8固定化后,PEL在有机相反应体系中的分散性得到了明显改善,大幅度提高了酶促拆分反应的效率;大孔吸附树脂AB-8固定化PEL具有较高的操作稳定性,连续10批拆分反应的平均转化率在47%以上,eeP值均稳定在98%以上.     

甘油催化氢解制1,3-丙二醇的纳米铜基催化剂

采用共沉淀法制备用于甘油催化氢解制1,3-丙二醇的纳米CuO-TiO₂/SiO₂催化剂,用X射线粉末衍射及扫描电子显微镜对催化剂的结构及形貌进行表征。在微型固定床反应器上考察了纳米催化剂对甘油氢解制备1,3-丙二醇的催化性能,结果表明,在反应温度190 ℃、H₂压力4.5 MPa、n(H₂)∶n(甘油)=50∶1和液空速0.30 h^-1的较佳条件下,甘油转化率为35.66%,1,3-丙二醇选择性达78.18%。     

玉米油酶法合成甘油二酯工艺优化研究

以玉米油、甘油为原料,在无溶剂体系中用固定化脂肪酶Lipozyme TL IM催化合成甘油二酯,通过单因素试验和响应面试验研究底物摩尔比(亚油酸/甘油)、反应温度、反应时间、酶质量分数和初始水质量分数等因素对亚油酸转化率的影响。得出:反应温度、底物摩尔比、反应时间、酶质量分数对亚油酸转化率影响较大;影响酯化反应中亚油酸转化率的主次因素依次为反应温度、底物摩尔比、反应时间、酶质量分数;最佳工艺条件为亚油酸和甘油的摩尔比为2.10∶1,反应温度为61.16℃,反应时间为12.17 h,酶质量分数为20.09%,亚油酸转化率达到75.69%。Lipozyme TL IM连续反应3批次,其相对酶活仍有65.7%。     

Continuous production of biodiesel fuel from vegetable oil using immobilized Candida antarctica lipase

Candida antarctica lipase is inactivated in a mixture of vegetable oil and more than 1∶2 molar equivalent of methanol against the total fatty acids. We have revealed that the inactivation was eliminated by three successive additions of 1∶3 molar equivalent of methanol and have developed a three-step methanolysis by which over 95% of the oil triacylglycerols (TAG) were converted to their corresponding methyl esters (ME). In this study, the lipase was not inactivated even though 2∶3 molar equivalent of methanol was present in a mixture of acylglycerols (AG) and 33% ME (AG/ME33). This finding led to a two-step methanolysis of the oil TAG: The first-step was conducted at 30°C for 12 h with shaking in a mixture of the oil, 1∶3 molar equivalent of methanol, and 4% immobilized lipase; the second-step reaction was done for 24 h after adding 2∶3 molar equivalent of methanol (36 h in total). The two-step methanolysis achieved more than 95% of conversion. When two-step reaction was repeated by transferring the immobilized lipase to a fresh substrate mixture, the enzyme could be used 70 cycles (105 d) without any decrease in the conversion. From the viewpoint of the industrial production of biodiesel fuel production, the two-step reaction was conducted using a reactor with impeller. However, the enzyme carrier was easily destroyed, and the lipase could be used only several times. Thus, we attempted flow reaction using a column packed with immobilized Candida lipase. Because the lipase packed in the column was drastically inactivated by feeding a mixture of AG/ME33 and 2∶3 molar equivalent of methanol, three-step flow reaction was performed using three columns packed with 3.0 g immobilized lipase. A mixture of vegetable oil and 1∶3 molar equivalent of methanol was fed into the first column at a constant flow rate of 6.0 mL/h. The eluate and 1∶3 molar equivalent of methanol were mixed and then fed into the second column at the same flow rate. The final step reaction was done by feeding a mixture of eluate from the second column and 1∶3 molar equivalent of methanol at the same flow rate. The ME content in the final-step eluate reached 93%, and the lipase could be used for 100 d without any decrease in the conversion.     

用气相色谱法测定丙烯醛水合加氢制备中的1,3-丙二醇

建立丙烯醛水合加氢制1,3-丙二醇的气相色谱定性定量分析方法。该分析方法能够准确地定量分析水合产物3-羟基丙醛和加氢产物1,3-丙二醇,相对误差为0.86%-1.89%,相对标准偏差为0.81%-3.21%,是一种快速、准确的分析方法。同时,通过分析数据能够计算反应的相关指标,为催化剂的研究评价和工艺条件的研究提供了依据。     

Selective,Green Synthesis of Six‐Membered Cyclic Carbonates by Lipase‐Catalyzed Chemospecific Transesterification of Diols with Dimethyl Carbonate

A facile and green synthesis of six‐membered cyclic carbonates, the potential monomers for isocyanate‐free polyurethanes and polycarbonates, was achieved by transesterification of diols with dimethyl carbonate catalyzed by immobilized Candida antarctica lipase B, Novozym®435, followed by thermal cyclization in a solvent‐free medium. The difference in the chemospecificity of the lipase for the primary, secondary and tertiary alcohols as acyl acceptors was utilized to obtain a highly chemoselective synthesis of the cyclic carbonate in high yield. In the lipase‐catalyzed reaction with diols, the product contained almost equal proportions of mono‐ and di‐carbonates with 1,3‐propanediol having two primary alcohols, a higher proportion of mono‐carbonate with 1,3‐butanediol having a primary and a secondary alcohol, and mainly mono‐carbonate with 3‐methyl‐1,3‐butanediol having a primary and a tertiary alcohol. The chemospecificity of cyclic carbonates formed by thermal treatment at 90 °C was closely related to the proportion of mono‐carbonate. The yield of cyclic carbonate was 99.3% with 3‐methyl‐1,3‐butanediol, 85.5% with 1,3‐butanediol, and 43.2% with 1,3‐propanediol.