从粗甘油蒸馏残渣中回收聚合甘油

粗甘油蒸馏过程中,部分甘油在高温下发生聚合,聚合甘油沸点很高,在通常真空蒸馏条件下无法蒸出而留在残渣中。实验证明,甘油蒸馏残渣经过化学处理除杂后,通过离子交换,可以回收得到色泽（Hazen）100以下的甘油质;采用短程蒸馏（Short-path distillation）技术,可以得到高质量的甘油和聚合甘油。回收率为总甘油质的80％以上。此外,还对皂化甘油蒸馏操作提出了建议,以提高甘油蒸馏得率和聚合甘油的富集。     

Solvent‐free synthesis of glycerol carbonate and glycidol from 3‐chloro‐1,2‐propanediol and potassium (hydrogen) carbonate

BACKGROUND: An indirect solvent‐free synthetic approach for obtaining glycerol carbonate and glycidol from glycerol and CO₂ through their more reactive and easily synthesizable derivatives 3‐chloro‐1,2‐propanediol (HAL) and potassium (hydrogen) carbonate has been studied. RESULTS: The reaction is fast with source of carbonation and temperature having a strong influence on the results. A yield of 80% glycerol carbonate together with a simultaneous substantial production of glycidol (0.56 mol mol^?1 glycerol carbonate) are obtained using K₂CO₃ as the carbonation source at 80 °C, a reaction time of 30 min and a 3:1 HAL/K₂CO₃ molar ratio. A lower yield of glycerol carbonate (60%) is obtained from KHCO₃ after 50 min with the other experimental conditions remaining unchanged. In this case, glycidol formation is zero or insignificant. Glycerol is also obtained in high yields, although in much lower amounts from KHCO₃ (～0.59 mol mol^?1 glycerol carbonate independent of operating conditions) than from K₂CO₃ (0.84–1.1 mol mol^?1 glycerol carbonate, depending on experimental conditions). CONCLUSIONS: The proposed synthetic strategy overcomes the currently difficult direct reaction between glycerol and CO₂, leading to the simultaneous synthesis of two valuable chemicals: glycerol carbonate and glycidol. However, glycerol is also obtained in substantial amounts thus decreasing the overall yield of the process. Thus, methods for preventing its formation must be developed for industrial feasibility. Copyright © 2010 Society of Chemical Industry     

KF/C催化甘油酯交换合成碳酸甘油酯

以三嵌段共聚物(EO-PO-EO)F127为结构导向剂,甲阶酚醛树脂为碳源,KF·2H₂O为无机前驱体,用溶剂诱导挥发自组装的方法合成KF/C复合材料。采用XRD、BET和XPS等手段对合成的材料进行结构表征,并考察KF/C在甘油与碳酸二甲酯酯交换合成碳酸甘油酯反应中的性能,结果表明,在甘油加入量为0.184 6 g、碳酸二甲酯加入量为0.900 7 g、溶剂N,N-二甲基乙酰胺为5.426 g、催化剂KF/C加入量为0.1 g、反应温度100 ℃、反应时间2 h和搅拌速率600 r·min^-1条件下,甘油转化率达98.5%,碳酸甘油酯选择性达99.8%,催化剂具有较好的循环使用性能。     

负载型KI催化甘油与CO2合成甘油碳酸酯

添加不同组分对氧化铝载体进行调变改性,再以改性氧化铝为载体,负载KI制备了一系列负载型催化剂KI/Al₂O₃-MgO、KI/Al₂O₃-ZnO、KI/Al₂O₃-TiO₂和KI/Al₂O₃-ZrO₂,并通过CO₂、环氧丙烷和甘油合成甘油碳酸酯反应评价其催化活性,发现KI/Al₂O₃-MgO具有最高的活性。由不同载体的CO₂-TPD分析可以发现,载体表面少量碱性位的存在有利于反应进行。实验研究了不同负载量KI/Al₂O₃-MgO的活性及稳定性,发现KI负载量为1.5mmol/g较为适宜。同时,实验又通过N₂吸附/脱附(BET)、X射线衍射(XRD)等手段对不同负载量的KI/Al₂O₃-MgO进行了表征,进一步说明了负载量过多会导致KI晶粒团聚,并阻塞载体孔道。优化了反应条件,在最佳条件下(环氧丙烷0.3mol,甘油0.1mol,反应温度130℃,反应时间2h,反应压力6.0MPa),甘油的转化率为65.5%,甘油碳酸酯的产率为60.8%。     

KF/MgO催化甘油和碳酸二甲酯酯交换合成甘油碳酸酯

采用浸渍法制备KF/MgCO₃前体,经高温焙烧后获得了一系列KF/MgO固体碱催化剂,用于催化碳酸二甲酯（DMC）和甘油（GL）酯交换反应合成甘油碳酸酯（GC）。系统考察了KF负载量和焙烧温度对催化剂活性的影响,并通过X射线衍射、N₂吸脱附等温线、扫描电子显微镜和哈米特酸碱滴定等一系列技术对催化剂的结构性能进行了表征。结果表明,当KF负载量为20%（质量分数）时,经550℃焙烧所获得的20%KF/MgO-550催化剂活性最高。经过反应工艺条件的优化,当催化剂与甘油的相对质量分数为2%,DMC与GL的摩尔比为3∶1,75℃条件下反应1.5h后,GC收率可以达到96.8%。当20%KF/MgO-550催化剂重复使用3次之后,GC的收率由96.8%降低到67.3%,经再生处理后20%KF/MgO-550的催化活性可以恢复并且表现出更优异的稳定性。     

碳酸甘油酯的合成研究及产业化进展

碳酸甘油酯是一种颇具吸引力的高附加值甘油衍生物,研究以甘油为反应底物制备高附加值的碳酸甘油酯,已成为实现生物柴油副产物甘油综合利用的有效途径之一。本文简述了包括光气法、CO氧化羰化法、酯交换法、尿素醇解法、CO ₂转化法等在内的碳酸甘油酯合成方法,总结了现有碳酸甘油酯合成的主要催化剂及催化合成反应机理,并简要介绍了我国原料甘油市场现状及国内外碳酸甘油酯合成的产业化进展。最后,从技术研发和产业化发展两个方面对碳酸甘油酯合成的未来发展进行了展望,指出一方面应在开发具有高性能催化剂的同时注重催化基础理论的研究,另一方面应在优化工艺流程、降低产品成本的同时注重下游产业应用与替代,并提出我国应推进生物柴油副产物甘油合成碳酸甘油酯的规模化生产与应用示范,加快培育具有国际竞争力的生物质能源与废弃物资源化利用产业。     

Coupling reaction and azeotropic distillation for the synthesis of glycerol carbonate from glycerol and dimethyl carbonate

A new process, coupling reaction and azeotropic distillation was proposed for the synthesis of glycerol carbonate (GC) from glycerol (G) and dimethyl carbonate (DMC). The bench scale experimental investigation was systematically conducted for this new process. With calcium oxide (CaO) as the solid catalyst, the high yield of glycerol carbonate can be obtained at a low molar ratio of dimethyl carbonate to glycerol with the method of coupling reaction and azetropic distillation. The effect of azeotropic agents on glycerol carbonate yield was explored, and indicated that benzene was the most effective azeotropic agent. The effects of the process parameters, tower height, amount of added benzene, final temperature of tower bottom and reflux ratio were investigated. Glycerol carbonate yield can be as high as 98% under the conditions at molar ratio of dimethyl carbonate to glycerol 1:1, final temperature of tower bottom 85 °C, 1.5 mass ratio of added benzene to that in the azeotrope with methanol theoretically produced and reflux ratio 4. By continuously removing methanol from reaction system with the method of coupling reaction and azeotropic distillation, the yield of glycerol carbonate can be retained at high level using the recycled catalyst.     

Study of the acyl transfer reaction: Structure and properties of glycerol carbonate esters

A series of glycerol carbonate esters derived from glycerol carbonate was synthesised by acylation of glycerol carbonate in the presence of aliphatic acyl chlorides. These compounds are characterised polyoxygenated by an endocyclic diester function and an exocyclic ester function. Physical and physicochemical properties of glycerol carbonate esters are determined. These compounds present a good thermal and oxidation stability. They exhibit surfactant properties towards water/soybean oil interface. The polyfunctional properties enable developments in existing industrial applications as well as in new niche markets.     

Microwave‐assisted synthesis of polyaspartic acid and its effect on calcium carbonate precipitate

Without organic solvent or catalyst, polyaspartic acid (PASP) was synthesized from maleic anhydride (MA) and ammonia (AN) under microwave irradiation. The influences of the molar ratio of maleic anhydride to ammonia and the microwave output power and irradiation time on product yield were investigated. Also, the function of microwave in the process was simply addressed. The results showed that when the molar ratio of MA/AN was 1.2, the output power was 900 W, the irradiation time was 3.5 min, and the product yield was highest and its inhibition performance on calcium carbonate was as good as the polymer synthesized by conventional pyrocondensation polymerization. The main function of microwave was its heat effect. Characterization of the product was carried out by IR, ¹HNMR, and ¹³CNMR spectra and the results showed that the product was PASP. The microwave‐assisted synthesis process of PASP has many advantages, including quicker reaction rate, high purity, lower cost, and little pollution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:358–364, 2007     

Glycerol carbonate synthesis from glycerol and dimethyl carbonate using guanidine ionic liquids

A large number of surplus glycerol from the biodiesel production can be used as renewable feedstock to produce glycerol carbonate.In this paper,a series of guanidine-based ionic liquids were synthesized to catalyze the transesterification of glycerol and dimethyl carbonate.The tunable basicity and the anion-cation cooperative effect were responsible for the obtained results.The [TMG][TFE] showed the best activity turnover frequency (TOF) of 1754.0 h-1,glycerol (GL) conversion of 91.8％,glycerol carbonate (GC) selectivity of 95.5％) at 80 ℃ with 0.1 mol％ catalyst for 30 min.The reaction mechanism of the transesterification was also proposed.     

锌盐催化尿素和1,2-丙二醇合成碳酸丙烯酯

考察了各种锌盐催化尿素和1,2-丙二醇(PG)合成碳酸丙烯酯(PC)的催化性能。几种催化剂中,氯化锌具有最佳的催化性能。以氯化锌为模板催化剂,考察了反应条件如:反应温度、反应时间和催化剂用量对催化效果的影响。结果表明,在尿素3.0 g、PG 7.62 g、反应温度170℃、反应时间3 h、催化剂用量0.4 g时,PC收率可达到82.9%。傅里叶红外表征进一步说明,催化剂的催化活性与它们活化尿素分解为异氰酸的能力有关;然后,异氰酸与催化剂作用生成中间物种,在PG的作用下最终生成PC。最后,基于以上催化测试和表征结果,提出了尿素和PG反应合成PC可能的催化反应机理。     

Microwave‐assisted one‐pot copolymerization of cyclic monomers and ethyl diazoacetate

The present contribution describes an innovation in the copolymerization of cyclic monomers, ε‐caprolactam (ε‐CL) and 2,2‐dimethyltrimethylene carbonate (DTC), with ethyl diazoacetate (EDA). The characterizations of the obtained copolymers, poly(EA‐ran‐EDA‐ran‐ε‐CL) and poly(EA‐ran‐EDA‐ran‐DTC) (where EA refers to the ethyl acetate group from EDA after nitrogen release), were performed using ¹H NMR and ¹³C NMR spectroscopies and size exclusion chromatography. Under optimized conditions, the copolymer of ε‐CL with EDA possessing a number‐average molar mass (M_n) of 1300 g mol^?1 and dispersity of 2.12 as well as that of DTC with EDA with M_n of 8000 g mol^?1 and dispersity of 1.47 were obtained. The incorporation of the azo group in the obtained copolymers was determined from the results of elemental analysis (3.30–10.22% nitrogen) and Fourier transform infrared spectroscopy. Furthermore, the thermal properties of the obtained copolymers were examined using differential scanning calorimetry. X‐ray diffraction results showed that the synthesized copolymers were amorphous. © 2014 Society of Chemical Industry     

The preparation of polyglycerol esters suitable as low-caloric fat substitutes

Medicinal research has linked dietary fats with such maladies as cancer, heart disease and stroke. The overconsumption of fats has been declared one of the major dietary health concerns in the United States by the Surgeon General. As a result, there is an increased awareness by consumers of their need to reduce the intake of calories derived from fat. The food industry has shown much interest in the development of substitutes for dietary fats and oils. To date, no substitute that can be used as a full fat replacement has entered the marketplace. Linear polyglycerols (LPGs) have been prepared by a proprietary polymerization process. Fatty acid esters prepared from LPGs were found to resist hydrolysis by digestive enzymes and were poorly absorbed in animal feeding tests. When esterified with fatty acids, LPG esters are similar to natural triglycerides in color, odor, taste and other physical characteristics. These properties make LPG oils good candidates for use in nonnutritive edible oil applications, particularly in uses that require stability at high temperatures.     

CeO_2/C有序介孔材料催化甘油转化制碳酸甘油酯

采用溶剂挥发自组装法制备有序介孔CeO_2/C复合材料,利用X射线衍射仪、N_2吸附-脱附仪和透射电子显微镜对样品进行表征,考察催化甘油酯交换制备碳酸甘油脂的催化性能。结果表明,在甘油用2 mmol、碳酸二甲酯10 mmol、有序介孔CeO_2/C复合材料0.1 g、N,N-二甲基乙酰胺5 m L、反应温度140℃和反应时间3 h条件下,CeO_2/C中CeO_2质量分数为16.3%时,甘油转化率和碳酸甘油脂选择性最高,分别为76%和81.8%。     

A review of ionic liquids as catalysts for transesterification reactions of biodiesel and glycerol carbonate production

Biodiesel production has been rapidly increasing due to the strong governmental policies and incentives provided leading to an oversupply of its by-product, glycerol. Therefore, finding ways of utilizing glycerol is essential to increase the net energy and sustainability of biodiesel. Ionic liquids have been used successfully as catalyst for both the production of biodiesel and the conversion of glycerol to glycerol carbonate. These catalysts are relatively environmentally friendly as they have the potential to enable sustainable processes. Herein, the prospect of using ionic liquids to catalyze transesterification triglycerides for the production of biodiesel and the conversion of glycerol to glycerol carbonate will be discussed. Elucidation of the reaction mechanism is expected to provide an in-depth understanding of the process with respect to the effects of cation and anion based on the reactions of interest.     

Synthesis of glycerol carbonate by direct carbonatation of glycerol in supercritical CO2 in the presence of zeolites and ion exchange resins

Glycerol carbonate is a key bifunctional compound employed as solvent, additive, monomer, and chemical intermediate. We have synthesized it on a pilot scale in the laboratory in cyclic or alicyclic organic carbonate medium. In this study, we examined the use of supercritical CO₂ as a reaction medium and as a source of carbonate for carbonatation of glycerol. Glycerol carbonate could be obtained by direct reaction of carbon dioxide with an organic carbonate in the presence of heterogeneous catalysts. Carbonatation of glycerol into glycerol carbonate went to equilibrium in supercritical CO₂ medium. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis of poly(glycerol methacrylate) and its application to dimensional stabilization of wood

The dimensional stabilization of wood is investigated using poly(glycerol methacrylate) (PGMA) prepared from polyglycerol and glycidyl methacrylate instead of the well‐known poly(ethylene glycol). PGMA allows waterborne treatment of wood, which after polymerization leads to the formation of a wood polymer composite with improved dimensional stability. Microscopic observations and a picture analysis permit the location of PGMA in the wood cell walls and explains the dimensional stabilization by its bulking effect. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 743–749, 2003     

甘油法合成缩水甘油

以ZnSO4为催化剂,甘油和尿素反应合成碳酸甘油酯,分别以IR和MS对产物进行了结构表征。碳酸甘油酯在磷酸钠催化下脱掉一分子CO2得到缩水甘油。重点对碳酸甘油酯脱CO2得到缩水甘油的反应时间、反应温度、反应压力、催化剂种类及用量等因素进行了考察。并通过响应面分析法得到了适宜的反应条件为：反应时间4 h、反应温度215 ℃、反应压力2 kPa、催化剂用量2.5%（质量分数）。缩水甘油经旋转蒸发提纯,通过IR、HNMR进行了鉴定,GC测定产率可达到83.8%。