Efficient synthesis of bioetheric fuel additive by combining the reductive and direct etherification of furfural in one-pot over Pd nanoparticles deposited on zeolites

Furfuryl ethers have been considered to be a promising fuel additive.One step reduction etherification of furfural over supported Pd catalysts provides a facile way for the preparation of furfuryl ether.However,the preparation of a reusable Pd catalyst for reductive etherification remains to be a great challenge.In this study,a series of Si O_(2)supported Pd catalysts with particle size ranging from 2.2 nm to 28 nm were prepared.Their textural properties and catalytic performance in furfural reductive etherification have been systematically studied.The results herein shed light on the particle size effect on the competition between hydrogenation/hydrogenolysis of C=O in furfural over Pd surface.We found out that Pd nanoparticles larger than 3 nm are preferred for one step reductive etherification.Based on this finding,we prepared a Pd/ZSM-5 bifunctional catalyst comprising Pd nanoparticles larger than 3 nm and decreased acidity in presence of amino organosilane,which served as a bifunctional catalyst succeeding in one-pot synthesis of ether via reductive-etherification and direct-etherification.This strategy showed significant advantage in efficiently converting furfuryl acohol,a major side-product,into ether,while suppressing the undesired side-reactions.

Etherification of Methanol with Propylene Oxide Catalyzed by Heteropolyacids

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Etherification of HMF to biodiesel additives: The role of NH4+ confinement in Beta zeolites

The role of NH4^+ ion confinement in the catalytic etherification of HMF(5-hydroxymethylfurfural) with ethanol to biodiesel additives was evidenced by studying the catalytic behavior of NH4^+-Beta zeolites with SiO2/Al2O3 ratios of 25 and 75.In order to affect the strength and distribution of the acidic sites, as well as the mobility of NH4^+ ions in the zeolites cages, a secondary level of porosity was introduced in the NH4^+-Beta, presenting a different stability versus alkaline treatment, by using a thermal or an ultrasound assisted method.By analyzing the catalytic behavior in these two series of samples with respect to the changes in porosity by nonlocal density functional theory, structure by XRD, amount of acid sites by FT-IR and mobility of NH4^+ cations by measurements of reversible NH4^+ exchange capacity, was evidenced a decrease in catalytic performances both in terms of rate of HMF depletion and productivity to the main products, when confinement of the ammonium ions is lost due to the introduction of mesoporosity.The high capability of ammonium ions release, associated to the mono-dentate configuration,and the minor confinement effect inside the zeolite pore system, due to the more opened pores structure of mesoporous zeolites, hinders both the direct etherification of HMF to EMF [5-(ethoxymethyl)furan-2-carbaldehyde] and the parallel reaction pathway via acetalization, favoring the rapid desorption of the HMFDEA [5-(hydroxymethyl)furfural diethyl acetal] product out of the crystal and the consequent inhibition of the consecutive reactions to EMFDEA [5-(ethoxymethyl)furfural diethyl acetal] and EMF.

Preparation of Aminated Lignin through Etherification and Amination

A new method for the preparation of aminated lignin （AEL） through etherification and amination reaction was presented. Chlorine atoms were ？rstly introduced into lignin through its etheri？cation with epichlorohydrin. Then, hydrophilic amine groups were grafted to the modi？ed lignin structure through amination with ethylenediamine to obtain AEL. Subsequent acidi？cation of AEL led to the ionized aminated lignin （IAEL）. The results of our analyses showed that the nitrogen content of AEL was 6.9%. Foaming and emulsifying experiments indicated that AEL had better foamability and emulsifying properties than IAEL. Surface tension tests showed that AEL and IAEL had similar critical micelle concentration （CMC）. However, IAEL had lower surface tension （36.33 mN/m） than AEL （42.89 mN/m） at CMC. These results demonstrate the promising applicability of AEL as an emulsi？er and that of IAEL as feedstock in the production of detergent and dispersant.

Methodology for Design of Reactive Distillation Column and Kinetics for Isoamylene Etherification Catalysed by Amberlyst 35

Isoamylene from the Fischer-Tropsch syncrude can be transformed to valuable fuel oxygenate additives through an equilibrium limited etherification reaction with methanol. A reactive distillation process is established to increase isoamylene conversion. Facing the challenge of improving product purity at the same time, an equilibrium stage model based design methodology is proposed and illustrated step-by-step for converting the Fischer-Tropsch C_5 olefins to tert-amyl methyl ether(TAME) process by using Aspen Plus. Under the guide of the proposed methodology, the design leads to a TAME product purity of higher than 95% and an isoamylene conversion of higher than 90%. The etherification kinetics over Amberlyst 35 is also studied within a temperature range of 60 ℃ to 75 ℃ to shed more light on the feasibility of process development. The methodology provides an effective reactive distillation column design to achieve the target reactant conversion and product purity simultaneously.

CaY-zeolite Catalyzed Etherification and Alkylation of Substituted Benzyl Alcohols

The reaction of p- and/ α-subtituted benzyl alcohols in CaY-zeolite produced the corresponding dibenzyl ethers and/or benzyl toluenes as the principal products.

STUDY ON ETHERIFICATION OF TERMINAL HYDROXY GROUP OF POLYETHYLENE GLYCOL MONOALKYL ETHERS

In this paper etherification of the terminal hydroxy group of polyethy-lene glycol monoalkyl ethers is studied and a convenient method for the preporation ofpolyethylene glycol dialkyl ethers is propused. Nine methyl , butyl and benzyl deriva-tives are obtained by using Williamson synthetie method. The effect of reaction pa-rameters on the protective ratio is examined by using the optimum seeking method.The protective efficiency is evaluated by cumporing the variation of hydroxy value.The best reaction conditions are found by experiment.It is also found that the protec-tive ratio of methylation is higher than that of butylation while the protective ratio ofbenzylation is the lowest. The protective ratio of AEO9 is equivalant to OP8 and theprotective ratio of AFO3 is much lower.

Study on the Adaptability of Etherification Feedstock to Reactor Type

A reactive C5 olefins and methanol etherification kinetic model based on E-R mechanism was established and three different types of reactors including the adiabatic fixed-bed liquid reactor, the external loop reactor and the mixedphase reactor were constructed by Aspen Plus. The adaptability of reactive C5 olefins to these reactors was studied and simulated using various gasoline fractions with different olefins content. After the theoretical model was validated by the experimental data of the etherification of three C5 light cut fractions from different gasoline sources in different reactors, the simulated isoamylene conversion with reactive C5 olefin contents increasing from 10% to 60% was studied in the three different types of reactors for etherification with methanol, respectively. Test results show that there is an obvious adaptability of the feedstock composition to the reactor type to achieve a high conversion.

Synthesis of Modified β-Zeolite Under Microwave Irradiation and Its Use on Etherification

zeolite was synthesized by using tetraethyl ammonium hydroxide as the template reagent andmicrowave radiation as the heat source. The effect of the sol composition and the radiation temperature onzeolite crystallinity was investigated. The zeolite was tested and compared with the commercial product, whichwas produced by conventional hydrothermal synthesis method. The physico-chemical properties of the syn-thesized samples, the specific surface area of the samples synthesized under microwave irradiation and porevolume measured by X-ray diffraction apparatus, were better than the conventional samples. The etherificationexperiment on FCC light naphtha in the presence of transition metals modified Hβ-zeolite, which was synthe-sized firstly under microwave irradiation, was studied in a fixed-bed reactor. The effect of catalyst preparationconditions on its activity, stability and the effect of reaction temperature, methanol/tertiary-carbon olefin molarratio and liquid hourly space velocity on the etherification reaction were discussed. The experimental resultsshowed that the different metals modified Hβ-zeolite had different etherification performances. And theconversion of tertiary carbon-olefins of the molybdenum modified Hβzeolite, which was loaded at a concen-tration of 3 percents, was higher than that on 6.0 percent of Hβzeolite. The modified Hβzeolite catalystspossessed favorable prospects for its higher stability.

Preparation and Catalytic Properties of Various Oxides and Mesoporous Materials Containing Niobium and Sulfate Ions, in the Etherification Reaction of 2-Naphtol

Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15), using two main preparation methods: the precipitation and the sol-gel methods. Each catalyst was subjected to two types of impregnations: sulfate ions using sulfuric acid as precursor and niobium using niobium oxalate as precursor. These prepared catalysts were tested in the etherification reaction of 2-naphtol, where the catalysts showed both acidic and redox properties. The acidic character was manifested through the formation of 2-butoxynaphtalene (with moderate yields) when oxide is sulfated, and the redox character (when impregnated with niobium) manifested through the formation of the interesting product 2-ethylnaphtofuran (with low yields) and other products that were a result of oxidative coupling of two 2-naphtol molecules (binol and acetal of binol). However despite the effort, several attempts to increase the yield of 2-ethylnaphtofuran did not work. All products prepared were obtained in pure form and characterized by 1H and 13C NMR, GC and MS.

Liquid Etherification of Alkoxybenzyl Alcohols, Cinnamyl Alcohols and Fluorinated Phenylalkenols with Platinum on Carbon (Pt/C) and Palladium on Carbon (Pd/C)

In the presence of either Pd/C or Pt/C, 4-alkoxybenzyl alcohols, 4-alkoxy-phenylalkyl alcohols and cinnamyl alcohols undergo liquid etherification to bis(4-alkoxybenzyl) ethers, bis[(4-alkoxybenzyl)alkyl] ethers and bis(cin-namyl) ethers at temperatures of 100°C - 135°C. In a number of cases, Pt/C and Pd/C as catalysts, also when they are doped with Ru, show distinct differences when the reactions run in air, with an oxidative dehydrogenation of the alcohols as side-reaction, yielding the corresponding ketones and aldehydes as by-products. Also, the reactivity of fluorinated phenylalkenols under these conditions has been investigated. Furthermore, the immobilization of alkyl aryl ethers on silica within a column with passage of hexane as solvent was found to lead to the formation and elution of styrenes from the column in fair yield.

Etherification of Alkali-pretreated Sugarcane Bagasse Cellulose in Tetrahydrofuran

Sugarcane bagasse(SCB)is an important by-product in the sugar industry.It is a source of cellulose fibers or cellulose for paper mills and textiles factories.In this study,SCB was ethyl etherified in tetrahydrofuran(THF)after alkali pretreatment.The alkali concentration for the pretreatment,the ratio of ethyl bromide(EtBr)to dried SCB in the reaction,reaction time,and temperature were investigated for the etherification of SCB.The ethoxyl content and characterization of the product were determined using headspace gas chromatography(HS-GC),Fourier Transform Infrared(FT-IR)and 13C-NMR spectroscopy,respectively.It was found that SCB was well-etherified with EtBr in alkali-THF.Upon ethylation of SCB,the ethoxyl content of the product was high when the alkali concentration and the ratio of EtBr to dried SCB were controlled from 50%to 75%and 4:1(V/w)to 6:1(V/w),respectively.The reaction occurred optimally when the temperature was controlled below 110℃;above this temperature,the degree of etherification decreased.The thermal stability of ethylated SCB was higher than that of SCB but slightly lower than that of commercial ethyl cellulose.Ethylated SCB has the potential to form composites with many materials because it is soluble in a wide variety of solvents.

催化轻汽油醚化装置长周期平稳运行优化措施

目的对催化轻汽油醚化装置运行过程中出现的叔戊醇在甲醇回收塔内积聚、甲醇萃取塔塔底出料带油问题进行分析,并提出解决措施。方法对于叔戊醇在甲醇回收塔内积聚的问题,主要采取以下措施进行处理:①降低甲醇回收塔进料塔板与塔顶之间的温差;②将叔戊醇自甲醇回收塔侧线抽出;③降低甲醇回收塔进料中叔戊醇质量分数。对于甲醇萃取塔塔底出料带油的问题,主要采取以下措施进行处理:①降低含醇轻汽油进料中的有害物含量;②降低甲醇萃取塔内有害物含量;③优化轻汽油进料分布器结构。结果采取相应措施后,大幅度降低了因叔戊醇在塔内积聚而引起的甲醇回收塔液泛和冲塔事故的发生,副产物生成量降低,产品质量提高;有效降低了甲醇萃取塔塔底出料带油量,避免了因大量轻汽油通过甲醇回收塔回流罐排至火炬而造成的产品损失和环境污染问题。结论对相关流程和操作条件进行优化,可有效降低叔戊醇在塔内积聚及甲醇萃取塔塔底出料带油事故的发生,确保装置长周期平稳运行。

轻汽油醚化装置工艺流程模拟

利用稳态流程模拟软件PRO/Ⅱ,对0.4 Mt/a轻汽油醚化装置主要工艺流程进行了系统的模拟计算,介绍了软件建模的热力学方法选择、重要设备的模块选择、工艺建模过程及其主要设置。模型验证结果表明,所建模型具有较高的准确性和适用性。为实现活性烯烃最大转化率,保证碳五组分质量,利用所建模型对醚化分馏塔甲醇加注量和回流比,甲醇回收单元萃取水量、循环甲醇中水含量及萃取水中甲醇含量等参数进行了优化。结果表明,醚化分馏塔甲醇加注量控制在进料甲醇量的8.8%,醚化分馏塔回流比控制在2.0,萃取水量控制在10~11t/h,萃取水中甲醇质量分数控制在0.04%,循环甲醇中水质量分数控制在0.016%为宜。

Amberlyst-15催化木糖醇醚化反应研究

以酸性离子交换树脂Amberlyst-15(A-15)为催化剂,通过跟踪测定产物羟值,研究了木糖醇的醚化脱水规律。考察了反应时间、催化剂用量、反应温度对木糖醇醚化过程的影响。采用傅里叶变换红外光谱法(FTIR)和气相色谱-质谱联用法(GC-MS)分析了木糖醇醚化产物的结构。结果表明,当A-15用量为体系质量的0.4%~0.5%、反应温度为140~155℃、真空度为-0.1MPa、反应时间为1.5~2h时,可以将醚化产物的羟值控制在1250~1450mg KOH·g^(-1)范围内。

红霉素肟硅醚化绿色工艺研究

研究了红霉素肟硅醚化绿色合成工艺。以红霉素A肟为原料,盐酸甲醇为催化剂,进行硅醚化反应,并优化了反应条件。优化条件下,硅醚化反应收率96.4%,产品纯度94.4%。该工艺可以替代现有盐酸吡啶为催化剂的硅烷化反应,达到绿色合成、降低原辅料成本、并减少三废的目的,适合工业化生产。

D-山梨醇醚化过程的热力学计算与分析

D-山梨醇在酸催化下会发生醚化反应,生成失水山梨醇的混合物。为便于了解各反应特性,采用Benson法、Myrdal-Krzyzaniak-Yalkowsky法、Joback法等基团贡献法和Marrero-Pardillo键贡献法估算了D-山梨醇醚化反应中所涉及物质的标准摩尔生成焓、标准摩尔熵和摩尔定压热容等热力学参数。并根据估算数据计算了不同温度下各反应的标准摩尔反应焓变、标准摩尔反应Gibbs自由能变和平衡常数。计算结果表明:D-山梨醇醚化过程中,各个反应均为吸热反应,升高温度有利于醚化反应进行,标准摩尔反应Gibbs自由能变均小于0,反应为自发过程,反应能正向完全进行。产物中1,4-失水山梨醇的平衡常数较大,会进一步生成异山梨醇。这些数据为失水山梨醇的高效制备提供理论参考。

虾青素合成工艺研究

虾青素是一种含氧类胡萝卜素,是目前已实现工业化合成类胡萝卜素产品中的最高级别产物,合成难度最大,价值也最高。虾青素具有极强的抗氧化和淬灭活性氧作用,具有调节免疫系统和提高免疫力等功能,是维护人类和动物机体健康不可或缺的营养素,被广泛应用于食品、饲料、化妆品以及医药保健等领域,市场前景广阔。本文以4-氧代乙烯基-β-紫罗兰醇为起始原料,先硅醚化保护链上羟基,接着用三乙酸锰进行乙酰氧基化,之后进行脱保护和皂化,再进行溴代和Wittig反应制得虾青素,并考察了硅醚化反应中缚酸剂的选择,乙酰氧基化的反应溶剂、温度、催化剂等因素对反应收率的影响。

RS码的Step-by-step译码及软件实现

RS码以其强大的纠正随机错误和突发错误的能力,被广泛地应用于各种数字通信系统中。其译码算法是实现RS码的核心,Step-by-step算法与传统的译码算法相比,不用计算错误位置多项式,可以大大地节省译码时间。文章在分析RS码的基本原理及Step-by-step译码算法的基础上,介绍了一种用软件来实现Step-by-step译码算法的方案,并且给出了流程图。

汽油池烯烃影响因素及管控措施

自2023年7月1日起,史上最严的国六B排放标准开始实施。国六B标准相对于国六A标准,对烯烃含量提出了更高的要求,由原来18 vol%降低至15 vol%,给汽油调和带来较大难度。随着95号汽油供应量扩大,以及92号和95号汽油价格差扩大,提高95号汽油的产量,对提高炼油厂收益越来越重要。因此,炼油厂厂部从全局出发,优化上游装置操作,从源头降低烯烃含量,降低调和高标号汽油难度,采用多种调和方案,提高汽油产量,有效提高了炼油厂经济效益。主要阐述炼油厂汽油池烯烃影响因素,根据实际调整情况,对汽油池调整效果进行总结和分析并给出合理的建议。