聚甘油的合成工艺研究

生物柴油和油脂加工业的发展造成其副产物粗甘油严重过剩,甘油的深加工成为必然,以甘油为原料制备高附加值的聚甘油是一个重要的方向。本文对聚甘油的来源、合成方法、表征方法及其应用进行了论述。以甘油为原料,氢氧化钠作为催化剂,考察了反应时间、反应温度和反应时间对甘油聚合的影响。实验结果表明,当甘油的用量为150 g,氢氧化钠的投加量为3.0 g,反应温度约260℃时,反应时间约4 h,可以获得黄色的五聚甘油。     

酯交换法合成聚甘油丙烯酸酯

以聚甘油、丙烯酸甲酯为原料，利用酯交换法，以硫酸为催化剂，对苯二酚为阻聚剂，无溶剂，在共沸温度下，合成了一种水溶性聚甘油丙烯酸酯破乳剂。考察了催化剂用量、阻聚剂用量、反应时间、聚甘油中羟基与丙烯酸甲酯之摩尔比、不同聚合度聚甘油合成的聚甘油丙烯酸酯对原油乳状液脱水率的影响。实验表明，考察的影响条件均存在最佳值，即在催化剂用量占反应物总量的2％（w），阻聚剂用量占丙烯酸用量的2％（w），反应时间16h，聚甘油中羟基与丙烯酸甲酯之摩尔比为2．6：1，聚甘油聚合度为6．3，在破乳剂用量为300mg／L时，破乳脱水率达69％。     

植物油基环氧化聚甘油多酯增塑剂的合成及应用

以生物柴油的副产物粗甘油为原料,通过聚合反应得到聚合甘油;再与油酸通过酯化反应得到中间产物聚甘油不饱和脂肪酸多酯。然后在无溶剂条件下,以硫酸为催化剂进行环氧化反应得到增塑剂环氧化聚甘油多酯。考察了反应温度、反应时间、甲酸用量以及 H2O2用量对产物的环氧值的影响。同时采用了傅立叶变换红外光谱和热重分析对产物的结构和热稳定性进行表征。结果表明,最佳环氧化条件为：反应温度65℃,反应时间6 h,聚甘油不饱和脂肪酸多酯、甲酸、30％ H2O2质量比为1∶0.5∶1.2。产品的酸值为1.24 mg KOH／g,环氧值为6.4％,残留碘值为6.8 mg／100 g,具有较好的热稳定性,应用到 PVC 树脂中可有效地提高 PVC 的增塑性。     

碘化铯催化二氧化碳与甘油合成甘油碳酸酯

以不同碱金属(铵)卤化物为催化剂,考察了其在二氧化碳与甘油合成甘油碳酸酯反应中的活性。采用环氧丙烷为溶剂及耦合剂,极大提高了反应的转化率。实验结果发现碘化物具有较好的催化活性。以碘化铯为催化剂,考察了反应温度、反应时间、反应压力、反应物摩尔比和催化剂用量对反应结果的影响。在最佳反应条件下(环氧丙烷0.3 mol,甘油0.1 mol,反应温度120℃,反应时间1.5 h,反应压力3.0 MPa,催化剂用量0.15 g),甘油的转化率为86.5%,甘油碳酸酯的产率为81.6%。     

氢化松香甘油酯的合成反应研究

以氢化松香和甘油为原料、ZnO为催化剂进行酯化反应的研究。探索了原料配比、催化剂用量、反应温度、反应时间以及甘油加入方式对酯化反应的影响,找出了最佳反应参数为:原料松香与甘油的摩尔比2.0∶1、催化剂用量(质量分数)0.2%、反应温度270℃、反应时间3h、甘油的加入方式为一次性全部加入。     

微晶纤维素复合溶剂醇解制备乙酰丙酸甲酯的研究

以微晶纤维素为原料,甘油-甲醇复合溶剂为液化剂,研究了不同催化剂、反应温度、催化剂用量、反应时间、甘油/甲醇质量比对微晶纤维素液化及乙酰丙酸甲酯得率的影响。实验的较佳工艺条件为:硫酸为催化剂,液化温度为200℃,硫酸用量为0.25 g,反应时间为30 min,甘油/甲醇质量比为10/50,该条件下液化转化率为93.7%,乙酰丙酸甲酯得率为25.05%。对液化产物进行GC-MS分析结果表明,反应温度为180℃时,液化产物中含有大量未反应的甘油和部分甲基糖苷;200℃时绝大部分甘油已反应,且此温度条件下乙酰丙酸甲酯的含量最高,达到26.838%;在220℃和240℃时,甘油完全反应,液化产物更加复杂。     

甘油法制备二氯丙醇工艺研究

研究了以甘油和氯化氢为原料制备二氯丙醇的反应,考察了催化剂的种类、催化剂用量、反应温度、反应时间等因素对二氯丙醇收率的影响,结果表明,在以丙酸作为催化剂,催化剂用量为甘油质量的5％,反应温度为110℃,反应时间为11h的条件下,二氯丙醇收率可达到94％以上.     

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...     

氢化松香甘油酯的合成反应研究

以氢经松香和甘油为原料、ZnO为催化剂进行酯化反应的研究。探索了原料配比、催化剂用量、反应温度、反应时间以及甘油加入方式对酯化反应的影响，找出了最佳反应参数为：原料松香与甘油的摩尔比2．0：1、催化剂用量（质量分数）0．2％、反应温度270℃、反应时间3h、甘油的加入方式为一次性全部加入。     

丙酮缩甘油的制备

将生物柴油生产副产物甘油加工成高附加值的丙酮缩甘油可以提高生物柴油的经济效益。采用干燥剂原位除水法,在无溶剂体系中,丙酮与甘油通过原位除水、酸催化缩合反应制备丙酮缩甘油,通过单因素实验以及正交实验考察了原料配比、催化剂用量、反应温度、反应时间等因素对甘油丙酮缩合反应的影响。实验表明GT-450阳离子树脂为合适的催化剂;优选实验条件(催化剂用量2 g?mol-1丙酮、反应温度80℃、反应时间1 h、丙酮与甘油的摩尔比为1:1.4)下,丙酮的转化率达到87.8%。     

Effects of Reaction Parameters in Catalysis of Glycerol Oxidation by Citrate-Stabilized Gold Nanoparticles

Abstract  

This work describes a catalytic oxidation of glycerol using citrate-stabilized gold nanoparticles (citrate-AuNPs) having a mean diameter of 22 ± 3 nm. A careful product analysis was performed by mean of high-performance liquid chromatography, liquid chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy. Effects of reaction temperature, oxygen pressure, catalyst and reactant concentration, and NaOH/glycerol molar ratio on glycerol conversion, and product yields were investigated. The glycerol conversion and glyceric acid yield were optimum when the oxidation was performed using 0.6 M glycerol and NaOH at 80 °C under 3 bar of O₂ pressure in the presence of 50 ppm citrate-AuNPs catalyst for 3 h.     

以生物甘油为原料制备环氧氯丙烷的研究

以生物甘油为原料,经氯化反应和环化反应制备了环氧氯丙烷。首先以生物甘油为原料、以氯化氢气体为氯化剂、以己二酸为催化剂,采用无水Na2SO4除水4次,制得二氯丙醇（DCP）,氯化收率达90.09%;再以二氯丙醇和氢氧化钠反应制得环氧氯丙烷,通过单因素实验,得到环化反应的最佳工艺条件为：反应时间30min、氢氧化钠与二氯丙醇摩尔比1.15∶1、反应温度95℃,在此条件下的环化收率为88.2%。     

以丙三醇和氯化氢为原料制备环氧氯丙烷的工艺研究

介绍了以丙三醇和氯化氢为原料制备环氧氯丙烷的工艺,以己二酸为催化剂进行丙三醇的氯化反应,生成的二氯丙醇再和碱反应生成环氧氯丙烷。对影响反应的因素进行了研究,得出了最佳工艺条件：氯化反应温度120℃,氯化氢的通气量326．4mL／min,反应时间20h,催化剂物质的量为丙三醇的16％,环化反应采用1．9mol／L的氢氧化钠在30℃下进行较为合适。在此条件下得到的环氧氯丙烷收率为91．79％。     

Glycerolysis of Soybean Oil with Crude Glycerol Containing Residual Alkaline Catalysts from Biodiesel Production

The glycerolysis reaction of soybean oil was evaluated using crude glycerol obtained from the transesterification of soybean oil with methanol, catalyzed by sodium methoxide and sodium hydroxide, without any purification step other than the methanol removal. Crude glycerol with the lower content of remaining inorganic catalyst produced the highest concentration of monoglycerides (about 42%). The effect of the addition of water on the glycerolysis reaction was analyzed, evidencing a low formation rate of products in the first stages of the reaction due to the transformation of the inorganic catalyst to soaps, which are weaker bases. The sample of crude glycerol that led to the best results was evaluated at several temperatures. It was observed that the reaction with crude glycerol exhibits a lower formation rate of monoglycerides at low temperatures (160 and 180 °C) compared with the reaction with pure glycerol and catalyzed with NaOH. This behavior was explained by the lower activity of the soaps present in the crude glycerol respect to the inorganic base. Above 200 °C the reaction is very fast and the monoglycerides formed are consumed to produce diglycerides.     

Influence of Reaction Conditions on Diacid Formation During Au-Catalyzed Oxidation of Glycerol and Hydroxymethylfurfural

The selective oxidation of glycerol and 5-hydroxymethylfurfural (HMF) to diacids over supported gold catalysts (Au/C and Au/TiO₂) in liquid water at mild temperatures was a strong function of the added base such as NaOH. Use of hydrotalcite as a solid base in place of NaOH in the HMF reaction medium facilitated the production of diacid over Au/TiO₂, but extensive leaching of magnesium suggested that hydrotalcite was consumed stoichiometrically in the reaction. Production of diacids from glycerol oxidation over supported Au catalysts was promoted by operating in a continuous flow reactor and by increasing the catalyst loading in a semi-batch reactor. Trace inhibitors formed by conversion of the product monoacid are proposed to account for the generally low selectivity to diacids over gold catalysts.     

Synthesis and characterization of mono‐acylglycerols through the glycerolysis of methyl esters obtained from linseed oil

Here we investigate the production and characterization of mono‐acylglycerols through the glycerolysis of biodiesel, a methyl ester mixture, obtained from linseed oil. The biodiesel employed was derived from linseed oil through transesterification according to transesterification double step process 1 . The efficiency of H₂SO₄, CaO, and NaOH as catalysts was evaluated for the production of mono‐acylglycerols. The glycerolysis reactions were performed by varying the molar ratio of the reagents (biodiesel:glycerol), the type and amount of catalyst, reaction time and temperature. Systematic evaluation of reaction yield is shown as a function of these parameters. Reaction products were characterized through IR spectroscopy, hydrogen NMR, and the GC techniques. The study of three different catalysts indicated that the most efficient was 5% NaOH in a 1:5 biodiesel–glycerol molar ratio with 10 h reaction time. The reaction reached a maximum of 85% biodiesel conversion with a mono‐acylglycerol yield of 72% at 130°C.     

High yield of monoacylglycerols production through low‐temperature chemical and enzymatic glycerolysis

The present study aimed to produce MAG through low‐temperature chemical glycerolysis. Over 80% MAG yield with 97% TAG conversion was obtained within short reaction times at temperature of 35–55°C, when tert‐butanol (TB) or tert‐pentanol (TP) was used as reaction medium and sodium hydroxide (NaOH) as catalyst. TB gave a faster reaction rate than TP. Catalysts were important for the low‐temperature chemical glycerolysis reaction. Of the eight common base catalysts evaluated, only NaOH and potassium hydroxide (KOH) were effective, and NaOH was better than KOH. Reaction parameters were studied and optimized. The optimum conditions were TB dosage 3:1 (TB to oil in weight ratio), NaOH concentration 0.45 wt% based on oil, molar ratio of glycerol to oil 5:1. Under these conditions, similar MAG yield and TAG conversion was also observed by Novozym 435 catalyzed glycerolysis, however, a 4 h reaction was required. Practical applications: The process of NaOH catalyzed chemical glycerolysis for MAG production in TB solvent system described in this study provides several advantages including short reaction time and high product yield, which is potential for industrial considerations.     

Efficient Conversion of Glycerol into High Value-Added Chemicals by Partial Oxidation

Glycerol can be effectively converted to glyceric acid, a high value-added pharmaceutical raw material, through its partial oxidation over an Au/Al₂O₃ catalyst under strongly basic conditions. The factors important for the highly selective production of glyceric acid were investigated experimentally. It was clarified that NaOH was involved in the glycerol activation step to a glycerol alkoxide intermediate (2, 3-dihydroxypropoxide) in the liquid phase, then glyceric acid was formed by OOH species derived from O₂ on an Au catalyst in the partial oxidation step. We have newly discovered the concerted effect of NaOH and O₂ in different reaction steps.     

长链烷基二甲基聚甘油基氯化铵的合成与性能

以甘油、N,N-十二烷基二甲基叔胺(DTA)与环氧氯丙烷(ECH)为主要原料合成了一种表面活性剂长链烷基二甲基聚甘油基氯化铵。考察了反应时间、温度和反应物质的量比对合成产率的影响,并测得该表面活性剂的表面张力为γ=28.14 mN/m、临界胶束浓度cmc为0.112 g/L,初步的性能研究结果表明,该表面活性剂即使在高浓度的电解质溶液中亦具有很好的溶解性,且与阴离子表面活性剂具有优异的配伍性,能以任何比例与阴离子表面活性剂复配。     

3，3＇-二氯联苯胺的合成

以邻硝基氯苯(Ⅰ)为起始原料,经过三步化学反应合成3,3＇-二氯联苯胺(Ⅳ)I在0.2g1,4萘醌催化下与CH