杂多酸催化剂合成漂白活化剂TAED

探讨了以乙二胺、乙酸、和乙酸酐作为原料，采用两步法在杂多酸（HSiW)催化剂作用下制备活性漂白剂四乙酰乙二胺（TAED）的合成工艺条件。得出两步法的最佳条件是：乙二胺：乙酸（物质的量）＝1：2．5，反应温度约120℃，反应时间1．5h；乙二胺：乙酸酐（物质的量）＝1：4，反应温度为140℃，反应时间4h。TAED的产率与杂多酸催化剂性能的好坏有较紧密的关系。     

二乙酰乙二胺合成工艺研究

以乙二胺和乙酸为原料制备二乙酰乙二胺,综合考虑了催化剂、物料配比、反应时间和反应温度等因素对反应收率、产品品质的影响。优化了二乙酰乙二胺的合成工艺,不仅提高了产品收率,而且大大降低了产品中副产物的生成,有利于下游产品低温漂白活化剂四乙酰乙二胺的合成。     

四乙酰乙胺的合成

四乙酰乙二胺,即ＴＡＥＤ是一种低温型漂白活化剂,本实验以乙二胺、冰乙酸、乙权酐为原料,在同一反应釜内,采用两步法合成四乙酰乙二胺。探讨了产品合成工艺条件,产品产这７５．９％。     

四乙酰乙二胺对过硼酸钠活化作用的研究

研究了四乙酰乙二胺（TAED）对过硼酸钠（SPB）在低温下释氧和漂白的活化作用及影响因素，对特种污布进行了漂白试验。结果表明：由于TAED的存在，SPB可在40℃-60℃内很好地发挥漂白活性。     

漂白活化剂TAED合成工艺的研究

四乙酰乙二胺，即ＴＡＥＤ是一种低温型漂白活化剂，采用二步合成法，在合理工艺条件下合成，产品质量达到国外同类产品水平。     

四乙酰基乙二胺的合成研究

介绍了漂白活性剂四乙酰基乙二胺（TAED）的性能，应用；害比较了各工艺路线的合成方法及合成条件的基础上，进行优化选择。     

合成反应与精馏过程耦合制备四乙酰乙二胺

采用精馏过程与合成反应耦合技术生产四乙酰乙二胺 ,并研究了物料比、反应温度和时间对产率的影响。结果显示最佳工艺条件为 :n(乙二胺 )∶n(乙酸 )∶n(乙酐 ) =1∶2 .5∶6 ,第一步在 1 2 0℃下反应 3h ,第二步在 1 4 0℃下反应 6h。控制合适的精馏回流比 ,总收率可达 79%。     

聚酰乙基苯基次膦酰乙二胺的合成与表征

以羧乙基苯基次膦酸、乙二胺为原料,二甲苯为溶剂,合成膨胀型阻燃剂聚酰乙基苯基次膦酰乙二胺,其最适宜的工艺条件为羧乙基苯基次膦酸与乙二胺的摩尔比为1:1,在140℃下回流反应8h,产品得率为100.8%,用红外、核磁、元素分析仪、热分析仪等对产品结构进行表征,并对其阻燃性能进行了研究。     

漂白活化剂四乙酰乙二胺的制备

以乙二胺、乙酸和乙酸酐为原料，采用两步同釜连续制备工艺，制备漂白活化剂四乙酰乙二胺（ＴＡＥＤ），产率达７５％。     

乙二胺的应用及其下游产品开发

乙二胺是具有化学活性的精细中间体、医药中间体,用它可以开发一系列高附加值产品。综述了乙二胺的应用及其下游产品的合成和开发,主要介绍了咪唑啉、哌嗪、EBS和TAED等。     

四乙酰乙二胺辅助珍珠漂白的研究

为了加快珍珠的漂白过程,探索了采用四乙酰乙二胺(TAED)作为漂白的活化剂.研究结果表明,TAED对珍珠的漂白具有催化漂白效果,可能是TAED与HOO(-)反应生成乙酸根负离子和二乙酰乙二胺(DAED),反应生成的过乙酸具有比H2O2更强的漂白能力所致,TAED浓度对珍珠表面质量有显著影响.     

Mineral carbonation accelerated by dicarboxylic acids as a disposal process of carbon dioxide

Mineral carbonation is based on the reaction of carbon dioxide with metal-oxide bearing minerals, usually containing magnesium or calcium silicate, to form hardly soluble carbonates and other solid byproducts. The concept is based on acceleration of the naturally occurring rock weathering process. In the present work the calcium silicate is present in the mineral, wollastonite. To accelerate the process and make it potentially useful for practical applications, mineral carbonation is conducted here using an indirect two-step route in which the reactive component (Ca²⁺ ions in considered case) is first extracted from the mineral matrix and afterwards carbonated. Two solid byproducts are formed in this process: silica in the extraction step and calcium carbonate in the carbonation step. In the experimental part of this work, both stages of mineral carbonation are investigated using three extraction media: acetic acid and two dicarboxylic acids, succinic and adipic. To interpret the extraction stage of the mineral carbonation process the shrinking core - shrinking shell model is proposed. In the model, the change of the unreacted core size is due to surface reaction that is affected by the porous layer diffusion, with the porous layer subject to abrasion. The model of abrasion is based on the theory of turbulence. Results of investigations show that succinic acid is most effective, followed by adipic acid and acetic acid when both stages of the process are considered in detail.     

Transesterification of supercritical ethyl acetate by higher alcohol

The transesterification of supercritical ethyl acetate by a higher alcohol occurred at 573 K without the further addition of catalysts. The transesterification by a primary alcohol apparently obeyed zero-order kinetics with respect to ethyl acetate and the primary alcohol during most of the reaction. The transesterification was assumed to be a two-step reaction. The initial step is the hydrolysis of the supercritical ethyl acetate to acetic acid by the small amount of water in the reaction system. The later step is the esterification of the generated acetic acid with the higher alcohol. When a primary alcohol was used as the reaction partner for the supercritical ethyl acetate, a high yield of the transesterified product was obtained. On the other hand, when a secondary alcohol was used, a moderate yield was obtained. The moderate yield with a secondary alcohol would be due to the transformation of the transesterified product into unknown products.     

Wet air oxidation of polyether solutions

This paper studied the characteristics of wet air oxidation (WAO) on polyether as non-ionic surfactant and analyzed its main intermediates. The results showed that, WAO was an effective method to treat non-ionic surfactants like polyether; temperature played a decisive role throughout the process: the COD removal percentage within 2 h was only 33.5% at 160 °C, 57.2% at 200 °C, and 94.4% at 240; fatty acid was the major intermediate, and oxidation of acetic acid was the key rate-determining step during fatty acid oxidation, and the oxidation of fatty acid could be accelerated by rising the temperature as well as elongating the reaction time. Meanwhile, oxidative decomposition of polyether and oxidation on fatty acid were the rate-determining steps to the whole WAO process, the oxidation of polyether was relatively more limited at lower temperature; on the contrary, the oxidation of fatty acid and other organics was obviously more limited at higher temperature.     

Electrooxidation of ethanol at polycrystalline and platinum stepped single crystals: A study by differential electrochemical mass spectrometry

The electrooxidation of adsorbed and bulk solution of 10⁻² M ethanol and D₆-ethanol at polycrystalline platinum, smooth, roughened and Ru modified Pt(3 3 2), Pt(3 3 1) and Pt(1 1 1) electrodes was studied by on-line differential electrochemical mass spectroscopy (DEMS) using a dual thin layer flow through cell.On polycrystalline Pt, the main (or even single) product is acetaldehyde; due to the flow through conditions the amount of acetaldehyde further oxidized to acetic acid is negligible. At stepped single crystals with (1 1 1) terraces (Pt(s)[n(1 1 1) × (1 1 1)], acetic acid is produced at a lower potential than acetaldehyde. This demonstrates that in addition to the reaction path involving C-C bond splitting leading to CO₂ (via adsorbed CO and CH_x) and the reaction path leading to acetaldehyde there is a third, direct reaction path leading to the formation of acetic acid.Step decoration by Ru does not lead to an increased reactivity. This is different from the strong cocatalytic effect of Ru at step sites on the oxidation of CO. Furthermore, Ru does not influence the relative amount of acetaldehyde formed.     

双乙烯酮的环保生产

以醋酸为原料经催化、裂解脱水是目前国内外制取双乙烯酮、醋酐等产品的主要生产方法,由于醋酸裂解生成-分子的水致使生产过程中会有大量稀醋酸产生,为了回收利用稀醋酸,稀醋酸提浓将会产生较大量的废水。目前国内双乙烯酮产品收率基本上维持在80％左右（以醋酸计）．损失的20％中约50％为双乙烯酮精馏残渣,另有50％为醋酸裂解的副反...     

醋酸装置催化剂循环使用周期短的原因及对策

根据乙醛氧化反应催化剂的循环使用机理对湘维醋酸装置催化剂循环使用周期短的原因进行了分析，找出了反应温度偏高、氧醛比偏大、醋酸锰循环使用流程不合理、用工业水溶解醋酸锰等四项原因，并提出了改进措施，实施后使湘维醋酸装置催化剂循环使用周期达到了国内先进水平。     

Energy saving in acetic acid process using an azeotropic distillation column with a side stripper

Dilute acetic acid is obtained primarily from fermentation and synthesis processes and cannot be produced by simple distillation due to relatively low volatility of acetic acid compared to water. Instead, an azeotropic distillation is applied to increase the concentration of dilute acetic acid. When acetic acid is extracted from a dilute aqueous solution using a solvent mixture of ester and alcohol, its recovery requires an energy-intensive azeotropic distillation. In the water stripping process that follows azeotropic distillation, two distillation columns handle the acetic acid and water mixture in similar composition. Therefore, the two columns can be combined as a side stripper connected to the azeotropic distillation column. The energy-saving effect is examined with the HYSYS (Aspentech Corporation) evaluation of the process. Compared to the conventional process, the modified process suggests 39% reduction in heating duty and 24% coolant savings. The economic analysis shows 32% decrease in investment and 36% utility savings. Based on heat utilization analysis, the thermodynamic efficiency is enhanced by 11%.     

羰基合成醋酐反应中催化剂的作用

对醋酸甲酯羰基化制备醋酐的反应机理作了分析,对主催化剂和助催化剂的作用作了描述。在整个催化循环中,碘甲烷氧化加成到二碘二羰基铑是反应的控制步之一,由于碱金属的参与,改变了反应历程,可以认为反应仅受限于铑和碘甲烷的浓度。     

Acetic Acid Recovery from Fast Pyrolysis Oil. An Exploratory Study on Liquid-Liquid Reactive Extraction using Aliphatic Tertiary Amines

Abstract

Flash pyrolysis oil or Bio-oil (BO), obtained by flash pyrolysis of lignocellulosic biomass, is very acidic in nature. The major component responsible for this acidity is acetic acid, present in levels up to 2–10 wt%. Here, we report an exploratory study on BO upgrading by reactive extraction of acetic acid using long-chain tertiary amines in a batch set-up. Factors affecting the extraction efficiency, such as the type and concentration of tertiary amine and co-solvents, were investigated. More than 90 wt% of the acetic acid could be extracted in a single equilibrium step (BO diluted in THF (26 wt% BO), trioctylamine (TOA) in octane as the extractant phase, T = 20°C). However, the amine has considerable affinity for the BO phase and about 10 wt% on initial intake was transferred to the BO. A considerable improvement was obtained when using the aqueous phase of a thermally treated BO containing 6 wt% acid of acetic acid. In a single extraction step, acetic acid extraction efficiencies up to 75 wt% were achieved without significant amine transfer to the aqueous phase.