纳米固体超强酸SO_4~(2-)/ZrO_2-Al_2O_3的制备及催化合成乙酸丁酯

研究了以纳米复合固体超强酸SO24-/ZrO2-Al2O3为催化剂,正丁醇和乙酸为原料合成乙酸丁酯,并考察了影响反应的因素。结果表明,醇酸物质的摩尔比为1.5∶1,催化剂用量0.6 g,反应时间3.0 h,带水剂9 mL,反应温度140℃是最适宜的反应条件,其酯化率可达96.5%。     

用玻璃球负载纳米级SO4^2-／TiO2固体超强酸催化合成乙酸正丁酯

用玻璃球负载纳米级SO42-/TiO2固体超强酸催化合成乙酸正丁酯,对催化剂的制备条件和乙酸正丁酯的合成条件进行了研究。在最佳反应条件下,乙酸的转化率为99.3%,催化剂重复使用8次后乙酸的转化率仍高达92.3%。该催化剂选择性好,未发现有副产物生成,看来具有较好的应用前景。     

微波辐射-多相催化合成乙酸丁酯

在微波辐射条件下,研究了HZSM-5为催化剂的多相催化酯化法合成乙酸丁酯的反应。探讨了催化剂用量、微波辐射功率、微波辐射时间和吸水剂用量对反应的影响。在适宜的反应条件下:V(乙酸)/V(正丁醇)=1.6,HZSM-5分子筛为0.094g/mL(以乙酸计),微波辐射功率640W,微波辐射时间30min,吸水剂(氯化钙)0.375g/mL(以乙酸计),酯收率达98.7%。     

Facile Synthesis of Dodecatungstophosphoric Acid @ TiO<Subscript>2</Subscript> Pillared Montmorillonite and Its Effectual Exploitation Towards Solvent Free Esterification of Acetic Acid with <Emphasis Type="Italic">n</Emphasis>-Butanol

Abstract  

An acid activated montmorillonite, treated with organic cationic surfactant, i.e. cetyltrimethylammonium bromide (CTAB), was used as a template to prepare TiO₂ pillared montmorillonite taking titanium ethoxide as titania precursor in hydrochloric acid environment. The pillared montmorillonite was further promoted by dodecatungstophosphoric acid impregnation. The as prepared materials were characterized by various spectroscopic and analytical characterization techniques. The catalyst was employed towards a solvent free esterification of acetic acid with n-butanol. The catalyst showed excellent results with 88% conversion and 100% butyl acetate selectivity. It can be recovered and reused readily, making product isolation and catalyst reuse simple.     

蒙脱石负载铝基固体酸的制备及其催化性能

采用浸渍法制备了蒙脱石负载铝基固体酸(SO_4~(2-)/Al-O-MMT),用FTIR、XRD、TG/DSC、SEM、BET和PyFTIR对其结构进行表征与分析。以乙酸-正丁醇、柠檬酸-正丁醇的酯化反应为探针,研究了焙烧温度、浸渍液浓度对SO_4~(2-)/Al-O-MMT固体酸催化性能的影响,并测定SO_4~(2-)/Al-O-MMT固体酸的重复使用性。结果表明:蒙脱石负载铝基固体酸大大地提高了其催化活性。当焙烧温度为400℃,浸渍液浓度为0.75 mol/L时,SO_4~(2-)/Al-OMMT固体酸表现出最佳的催化活性,其催化合成乙酸正丁酯和柠檬酸三丁酯的酯化率分别可达到99.7%和96.1%。同时,SO_4~(2-)/Al-O-MMT固体酸表现出较好的重复使用稳定性,重复使用6次后,对于上述两个反应的酯化率分别保持在89.0%和84.6%。     

The use of dilute acetic acid for butyl acetate production in a reactive distillation: Simulation and control studies

The recovery of dilute acetic acid, which is widely found as a by-product in many chemical and petrochemical industries, becomes an important issue due to economic and environmental awareness. In general, separation of acetic acid in aqueous solution by conventional distillation columns is difficult, requiring a column with many stages and high energy consumption. As a result, the primary concern of the present study is the application of reactive distillation as a potential alternative method to recover dilute acetic acid. The direct use of dilute acetic acid as reactant for esterification with butanol to produce butyl acetate in the reactive distillation is investigated. Simulation studies are performed in order to investigate effect of the concentration of dilute acetic acid and key process parameters on the performance of the reactive distillation in terms of acetic acid conversion and butyl acetate production. In addition, three alternative control strategies are studied for the closed loop control of the reactive distillation. The control objective is to maintain the butyl acetate in a bottom product stream at the desired purity of 99.5 wt%.     

对甲苯磺酸催化合成乙酸丁酯的研究

研究了以对甲苯磺酸为催化剂 ,乙酸和正丁醇为原料合成乙酸丁酯 ,并考察了影响反应的因素。结果表明 ,醇酸摩尔比为 1 2∶1,催化剂用量为 0 8g(乙酸为 0 2mol的情况下 ) ,带水剂环己烷为 5ml,反应时间为 2 0h是最适宜的反应条件 ,酯化率达 96 9%     

硅胶固载氧化镓非均相催化合成乙酸丁酯

在氧化镓固载量为20%,500℃焙烧2 h的条件下制备了硅胶固载氧化物型非均相酯化催化剂Ga2O3/S iO2,用于催化合成乙酸丁酯,考察了催化剂用量、n(正丁醇)∶n(乙酸)、环己烷用量、反应时间、带水剂用量和催化剂重复使用性等因素对酯化率的影响。结果表明,该催化剂催化合成乙酸丁酯的适宜反应条件为:乙酸0.2 mol,n(正丁醇)∶n(乙酸)=1.8,催化剂1.25 g,回流反应1 h,酯化率达99.62%。     

Study on the Synthesis of n‐Butyl Acetate by Catalytic Rectification

With Hβ zeolite as the catalyst and θ rings as the fillings, the technological process of synthesizing n‐butyl acetate with acetic acid and n‐butanol in a Φ 30 mm and 2 m tall catalytic rectifying column was studied. The influence of factors such as catalyst loading height, material feed site, reflux ratio and feed rate on the esterification reaction and the rectification effect was investigated. The study results suggested that the appropriate conditions of n‐butyl acetate synthesis by catalytic rectification include: The height ratio of the rectifying section, the reaction section and the stripping section is 1:1:1; acetic acid and n‐butanol are fed in upside and downside of the reaction section, respectively; the reflux ratio is 2.5; the liquid hourly space velocity of n‐butanol is 0.64 h^–1. Under these conditions, the mass fraction of n‐butyl acetate in the column bottom is 98.64 %, and the total yield of n‐butyl acetate is 91.5 %.     

Preparation,Characterization of Dawson-type Heteropoly Acid Cerium (III) Salt and Its Catalytic Performance on the Synthesis of n-Butyl Acetate

A novel cerium (III) salt of Dawson type tungstophosphoric acid (Ce₂P₂W₁₈O₆₂·16H₂O) was prepared by doping cerous nitrate in H₆P₂W₁₈O₆₂·13H₂O powder and characterized by thermogravimetry and differential thermal analyses (TG/DTA), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), pyridine infrared spectroscopy (Py-IR) and scanning electron microscopy (SEM). Its catalytic activity was evaluated by the probe reaction of synthesis of n-butyl acetate with acetic acid and n-butanol. The effects of various parameters such as molar ratio of n-butanol to acetic acid, reaction temperature, reaction time, and catalyst amount have been studied by single factor experiment. The results show that Ce₂P₂W₁₈O₆₂·16H₂O behaved as an excellent heterogeneous catalyst in the synthesis of n-butyl acetate. The optimum synthetic conditions were determined as follows:molar ratio of n-butanol to acetic acid at 2.0:1.0, mass of the catalyst being 1.44% of the total reaction mixture, reaction temperature of 120 ℃ and reaction time of 150 min. Under above conditions, the conversion of acetic acid was above 97.8％. The selectivity of n-butyl acetate based on acetic acid was, in all cases, nearly 100%. The catalysts could be recycled and still exhibited high catalytic activity with 90.4% conversion after five cycles of reaction. It was found by means of TG-DTA and Py-IR that the catalyst deactivation was due to the adsorption of a complex of by-product on the active sites on catalysts surface or the catalyst loss in its separation from the products. Compared with using sulfuric acid as catalyst, the present procedure with Ce₂P₂W₁₈O₆₂·16H₂O is a green productive technology due to simple process, higher yield, catalyst recycling and no corrosion for the production facilities.     

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes,structural characterization and catalytic activity on esterification reaction

In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl₂]·2H₂O (1), [Co(L)Cl₂(H₂O)₂] (2) and [Ni(L)Cl₂(H₂O)₂] (3), having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1. The esterification of butanol gave butyl acetate with 100% selectivity.     

氧化铌负载型催化剂的制备及催化性能研究

以乙酸和正丁醇催化酯化合成乙酸丁酯为探针反应 ,对氧化铌负载型催化剂的制备与催化活性进行了一系列研究 ,得出了优惠工艺条件。正丁醇的转化率达 95% ,乙酸丁酯选择性 1 0 0 %。     

纳米HZSM-5分子筛催化剂制备及其在乙酸丁醇酯化反应中的应用

以四丙基氢氧化铵为模板剂,碱性有机生物分子L-Lysine为添加剂,水热合成系列不同硅铝物质的量比的纳米HZSM-5分子筛,结合XRD、SEM、Py-FTIR和N2吸附-脱附技术,探讨分子筛结构形态、酸性与其在乙酸和丁醇酯化反应中的催化性能关系。结果表明,纳米HZSM-5分子筛催化剂的酸性位与比表面积、孔径和孔容等结构形态间存在协同作用,共同决定最终的催化效果;在反应温度125℃、乙酸用量0.125 mol、醇酸物质的量比2∶1、带水剂苯用量为10 m L、催化剂用量0.4 g和反应时间4.5 h条件下,乙酸转化率93.65%,乙酸丁酯选择性大于97%。催化剂重复使用6次,乙酸转化率仍大于90%,重复使用性能较好。     

Fractionation of Carboxylic Acids Mixture Obtained by Succinic Fermentation using Reactive Extraction

Formic, acetic, and succinic acids have been selectively separated from their mixture obtained by A. succinogenes fermentation using reactive extraction with tri-n-octylamine (TOA) dissolved in three solvents with different polarities (n-heptane, butyl acetate, and dichloromethane) without and with 1-octanol addition. This technique allows recovering formic and acetic acids from the mixture, the raffinate containing only succinic acid. The extractant concentration and organic phase polarity control the selectivity of acids extraction. Thus, at pH = 1, the selectivity factor increased from 92, in the absence of 1-octanol; to 148, in the presence of this alcohol in organic phase. The corresponding optimum concentrations of TOA in the solvent were 30 and 50 g/l, respectively. The total separation of monocarboxylic acids from the mixture with succinic acid is possible by a multi-stage extraction process, adjusting the extractant concentration in each stage to that stoechiometrically needed for reactions with formic and acetic acids only. The addition of 1-octanol reduces the number of required extraction stages.     

改性树脂催化剂催化浆态鼓泡床合成乙酸正丁酯

以改性D001型阳离子交换树脂为催化剂,以乙酸和正丁醇为原料,在浆态鼓泡床多相反应器反应回流条件下催化酯化反应制备乙酸正丁酯,研究了反应器的技术优势及催化剂的特性和催化剂类型、用量对酯化反应的影响及其使用寿命. 结果表明,最佳反应条件为：正丁醇:乙酸=1.2:1(摩尔比),催化剂用量占乙酸量的40%(w),反应温度110℃,反应时间75 min,该条件下乙酸正丁酯产率达98%以上,纯度达99.5%,催化剂经洗涤活化、再生,可重复使用6次.     

反应精馏合成乙酸丁酯的实验和模拟(英文)

In this paper, a reactive distillation (RD) column was applied for synthesis n-butyl acetate from n-butanol and acetic acid. The Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model and an equilibrium stage model for separation were employed to study the RD process. The results obtained from the equilibrium stage model agreed well with the experiments. The effects of operating variables on the n-butanol conversion and n-butyl acetate purity were further investigated. The optimal column configuration for the production of n-butyl acetate was designed with 5 rectifying stages, 8 reaction stages and 13 stripping stages by the simulation study. According to the simulation results, n-butanol conversion and n-butyl acetate purity all reached greater than 96%.     

过硫酸铵催化合成乙酸正丁酯的研究

以过硫酸铵为催化剂,以冰乙酸和正丁醇为原料,合成了乙酸正丁酯。结果表明,反应的最佳条件为:酸醇物质的量比为1∶2.8,催化剂用量为酸醇总质量的9%,反应时间为40min,乙酸的酯化率为91.79%。     

新型Nb_2O_5催化剂的制备及催化性能的研究

以乙酸和正丁醇催化酯化合成乙酸正丁酯为探针反应 ,对Nb2 O5型催化剂的制备与催化活性进行了一系列的研究 ,得出了优惠的工艺条件。正丁醇的转化率达 95 % ,乙酸正丁酯的选择性 10 0 %。并对催化剂进行了一系列的表征 ,发现其与催化活性能很好地关联。     

磺化硅胶催化合成乙酸正丁酯的研究

磺化硅胶是一种以化学键键合而成,性能稳定的固体酸催化剂。本文以冰醋酸和正丁醇为原料,磺化硅胶为催化剂,合成了乙酸正丁酯,并获得了最佳合成条件:催化剂用量为反应物总质量的1.0%,n(乙酸)∶n(正丁醇)=1∶1.5,回流时间为45 min,乙酸正丁酯的酯化率可达98.5%,催化剂重复使用10次后的酯化率仍达81.3%。磺化硅胶对乙酸正丁酯的合成具有良好的催化活性。     

固体酸S_2O_8~(2-)/Fe_2O_3-SiO_2催化合成乙酸丁酯的研究

本文研究了以S2 O82 -/Fe2 O3 -SiO2 固体酸为催化剂 ,以乙酸、丁醇为原料合成乙酸丁酯 ,考察了影响反应的因素 ,结果表明最佳工艺条件是 :固体酸催化剂前驱体经微波陈化处理 ,醇酸摩尔比为1.2∶1,催化剂用量为 0 .8g(乙酸用量为 0 .2mol的情况下 ) ,带水剂为 10mL ,反应时间为 3.0h ,酯化可达到97.7% ,可重复利用 6次以上