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 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.

Etherification of Methanol with Propylene Oxide Catalyzed by Heteropolyacids

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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.

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.

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.

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.

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.

Copper-Catalyzed Oxidative Dearomatization of 2-Naphthols via Etherification

Copper-catalyzed intermolecular oxidative-etherification type dearomatization reaction of 2-naphthols was developed.With air as the terminal oxidant,the reaction proceeded in excellent yields under mild conditions.In addition,the reaction between two different naphthol substrates occurred smoothly.A series of multifunctionalized β-naphthalenones,important scaffold existed widely in natural products and biologically active molecules,were synthesized efficiently.

Highly Stereocontrolled Total Syntheses of Cedrane Sesquiterpenes via Cascade [5+2] Cycloaddition/Etherification

Cedrane sesquiterpenes possess common tricyclo[5.3.1.0^(1,5)]undecane core structure.The varied oxa-five-membered ring decorating their core structure to form 8-oxa-tetracyclo[7.2.2.0^(1,5).0^(6,13)]tridecane framework,containing six consecutive chiral centers(including two all-carbon quaternary centers and one oxygenated quaternary carbon center),has proven to be a synthetic challenge and a biosynthetic mystery to date.

Walking Cations: Transition-Metal Free Benzyl Cation-Triggered sp^(2) C—H Phosphorylation and Etherification

A novel benzyl cation-triggered site-selective sp^(2) C—H phosphorylation and etherification was developed. This reaction was conducted under the transition metal-free conditions through cation migration via dearomatization. Under the reaction conditions, the derivatives of naphthalenes, benzofurans and benzo[b]thiophenes all can be transformed into the corresponding products in good to excellent yields. It provides a method to construct sp^(2) C—P and sp^(2) C—O bonds as well as a new strategy for benzylic activation-triggered sp^(2) C—H functionalization.

Expected and unexpected etherification of 2-per(poly)fluoroethyl 4-substitutedphenol with β-haloethanol

Under different reaction conditions, the expected and unexpected reaction products (of which X-ray crystallographic structure was presented) of etherification of 2-per(poly)fluoroethyl 4-substituted phenol with β-haloethanol can be obtained respectively.

Regioselective etherification of 1,2-O-isopropylidene-4,6-di-O-benzyl myo-inositol

During the etherification of 1,2-O-isopropylidene-4,6-di-O-benzyl myo-inositol, the specific regioselectivity on 3- or 8-hydroxyl group was showed to be determined by the nature of the O-alkylating agents used. As demonstrated by MM and MNDO calculation, the regioselectivity of the reaction mentioned can be rationalized by steric and/or electronic effect.

Concise synthesis of xanthones by the tandem etherification——Acylation of diaryliodonium salts with salicylates

An efficient synthetic method for multi-substituted xanthones was developed. The reaction of diaryliodonium salts and salicylates was employed for the preparation of the xanthones. This method proceeded through an intermolecular etherification-acylation to give target heterocycles in good yields（up to 91%）. Multi-substituted xanthones were gained by shifting the substituent of salicylates or diaryliodonium salts

Surface Properties and Etherification in Microemulsion Systems of Novel Bronsted Acid Surfactants

Novel Bronsted acid-surfactants with different alkyl chains were synthesized via a two-step process, and their surface properties were studied. The critical micelle concentration（cmc）, surface tension at the cmc（γcmc）, and ability of these compounds to lower the surface tension by 0.02 N/re（C20 and pC20） were investigated at 25 and 40 ℃. The molecular architecture of the compounds strongly influenced these physicochemical parameters. The ability of these compounds to lower surface tension was found to be good. Etherification in microemulsions formed by these surfactants as well as dodecylbenzenesulfonic acid（DBSA） was performed; surfactants 3a and 3b were found to be much more efficient than dodecylbanzenesulfonic acid（DBSA）.

Conversion of Cellulose to 5-Hydroxymethylfurfural in Water- Tetrahydrofuran and Byproducts Identification

Conversion of cellulose into platform chemical 5-hydroxymethylfurfural （HMF） in water-tetrahydrofuran （THF） co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentration of 2.4wt%, but levulinic acid （LA） and solid humins became the main products with high cellulose concentration. The soluble byproducts were analyzed by high performance liquid chromatography/multiple stage tandem mass spec-trometry, and chemicals with formula of C9H16O4、 C10H14O4、 C11H12O4、C12H10O5 and C12H16O8 were detected. THF could participate in the reaction via ring-opening into 1,4-butanediol followed by esterification with LA into C9H16O4 or etherification with HMF into C10H14O4. C11H12O4 was formed by esterification of HMF with LA, C12H10O5 was formed by self-etherification of HMF, while C12H16O8 was formed by acetalization of HMF with glucose. Self-etherification of HMF and etherification of HMF with 1,4-butanediol were identified as two main side reactions.