Synthesis of ethyl acetate by esterification of acetic acid with ethanol over a heteropolyacid on montmorillonite K10

In present work,liquid phase esterification of acetic acid with ethanol over dodecatungestophosphoric acid （DTPA） supported on K10 montmorillonite was systematically studied and optimization of process parameters was carried out.The 20% m/m DTPA/K10 was found to be the optimum catalyst with 90% acetic acid conversion and 100% ethyl acetate selectivity.The study was also explored to see the feasibility of 20% m/m DTPA/K10 as a catalyst for the alkylation of acetic acid with other alcohols like methanol,iso-propanol and n-butanol.The 20% m/m DTPA/K10 has shown increased activity with the increase in carbon number,at the same alcohol reflux.The results are novel.

Pressure Swing Distillation for Separation of Ethyl Acetate and Ethanol in Sub-plateau Region

The pressure swing distillation(PSD)process for separation of ethyl acetate and ethanol mixture in subplateau region was simulated.The pressure of low-pressure column was set at 0.086 MPa,which is in accordance with the atmospheric pressure in the Yunnan-Guizhou region,while the pressure of high-pressure column was determined as 0.304 MPa.Various design parameters,including the plate number,the reflux ratio,and the feeding positions,were optimized,while taking into consideration the total annual cost(TAC).Furthermore,based on the general PSD,the partially heatintegrated pressure swing distillation(PHIPSD)process and the fully heat-integrated pressure swing distillation(FHIPSD)process were also studied.The processes with heat integration showed lower capital cost and lower energy cost,and TACs of the PHIPSD and FHIPSD decreased to 377.21×103$/a and 371.66×103$/a,respectively.Compared with the non-heat integrated process,TACs of the PHIPSD and FHIPSD could be reduced by 27.82%and 28.89%,respectively.The results showed that the FHIPSD process could effectively separate the ethyl acetate-ethanol mixture,and it was more economical and reasonable.This work can provide some technical references for the separation of such azeotropes in the sub-plateau region.

Formation mechanisms of ethyl acetate and organic acids in Kluyveromyces marxianus L1-1 in Chinese acid rice soup

This study aims to explore the formation mechanism of ethyl acetate and organic acids in acid rice soup(rice-acid soup)inoculated with Kluyveromyces marxianus L1-1 through the complementary analysis of transcriptome and proteome.The quantity of K.marxianus L1-1 varied significantly in the fermentation process of rice-acid soup and the first and third days were the two key turning points in the growth phase of K.marxianus L1-1.Importantly,the concentrations of ethyl acetate,ethanol,acetic acid,and L-lactic acid increased from day 1 to day 3.At least 4231 genes and 2937 proteins were identified and 610 differentially expressed proteins were annotated to 30 Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways based on the analysis results of transcriptome and proteome.The key genes and proteins including up-regulated alcohol dehydrogenase family,alcohol O-acetyltransferase,acetyl-CoA C-acetyltransferase,acyl-coenzyme A thioester hydrolase,and down-regulated aldehyde dehydrogenase family were involved in glycolysis/gluconeogenesis pathways,starch and sucrose metabolism pathways,amino sugar and nucleotide sugar metabolism pathways,tricarboxylic acid(TCA)cycle,and pyruvate metabolism pathways,thus promoting the formation of ethyl acetate,organic acids,alcohols,and other esters.Our results revealed the formation mechanisms of ethyl acetate and organic acids in rice-acid soup inoculated with K.marxianus L1-1.

Thermoresistant, Ethanol-Resistant and Acid-Resistant Properties of Acetic Acid Bacteria Isolated from Fermented Mango Alcohol

Vinegar production is seriously affected by the sensitivity of acetic acid bacteria (AAB) to high temperature, high ethanol concentrations, and high acetic acid concentrations. The aim of this study was to investigate the thermo-ethanol-acid tolerance characters of five AAB strains (VMA1, VMA5, VMA7, VMAM, VMAO) previously isolated from fermented mango alcohol and belonging to Gluconoacetobacter genera. As result, the five AAB strains exhibited good growth and acid production at temperatures up to 45°C;they could tolerate and produce acetic acid at ethanol concentrations up to 20% (v/v). In addition, the studied strains showed growth at acetic acid concentrations up to 4.5% (w/v). Strains VMA7 and VMAO showed the highest resistance properties: they demonstrated acid production at 50°C and VMAO could even grow at 60°C;they tolerated and produced acetic acid at 25% (v/v) ethanol concentration;they showed resistance to acetic acid concentrations up to 6% (w/v). Considering all these properties, the use of these strains would seriously contribute to improving the quality of the vinegar produced and help to reduce the cooling water feeds in vinegar production especially in hot countries in the context of global warming.

A Comparative Study of Ultrasound-Guided Intratumoral Acetic Acid and Ethanol Injection Therapy for Liver Tumors in Rats

To compare the therapeutic efficacy of USguided intratumoral injection of acetic acid and ethanol in 77 rats with transplanted Walker256 carcinosarcoma. The rats were divided into three groups: intratumoral acetic acid injection (IAI), intratumoral ethanol injection (IEI), and control group receiving intratumoral saline injection (ISI). Tumor growth rates were measured. Pathologic changes were chronologically observed, and tumor necrosis was quantified as a percentage of the tumor volume using a semiquantitative method. Results: Tumor growth rates were -(37±23)% in the IAI group, (210±174)% in the IEI group and (1 303±473)% in the ISI group (P<0.05). Tumor necrosis rates were (97.4±3.7)%, (79.4±10.9)% and (27.2±10.3)% respectively (P<0.01). In addition, the pathologic results showed that necrosis was more complete and repair of the peripheral tissue of tumor was faster in the IAI group as compared with the IEI group. Conclusion: IAI is more effective than IEI in the local therapy for liver tumors.

Development of <i>α</i>-Amino Acid Detection with Peroxyoxalate Chemiluminescence by Using Water-Acetonitrile-Ethyl Acetate Mixed Solution

Peroxyoxalate chemiluminescence was, for the first time, examined by using ternary mixed solutions of water-hydrophilic/hydrophobic organic solvent. Eosin Y as a model fluorescence compound was dissolved with the ternary solutions of water (1.0 mM carbonate buffer, pH 9.0)-acetonitrile-ethyl acetate, water-rich of 15:3:2 volume ratio and organic solvent-rich of 3:8:4 volume ratio, to which bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide chemiluminescence reagent were added. The chemiluminescence observed with the ternary solutions, especially the organic solvent-rich solution, showed a larger signal than that observed with the water only solution or water-acetonitrile mixed solution. Chemiluminescence in the presence of twenty types of α-amino acid was similarly examined by using the ternary organic solvent-rich solution. The chemiluminescence of three α-amino acids with fluorescence properties was enhanced with the ternary solution. The data reported here may contribute to development of a new, sensitive peroxyoxalate chemiluminescence detection system.

Transformation of Ethanol to Ethyl Acetate over Cu/SiO2 Catalysts Modified by ZrO2

Direct transformation of ethanol to ethyl acetate was investigated on a series of Cu（ZrO2）/SiO2 catalysts. Inductively coupled plasma（ICP）, surface area analysis, X-ray diffraction（XRD）, H2-temperature programmed reduc- tion（H2-TPR）, X-ray photoelectron spectroscopy（XPS）, NH3-temperature programmed desorption（NH3-TPD） and Fourier transform-infrared spectroscopy（FTIR） techniques were used to characterize the catalysts. The results reveal that ZrO2 can improve the dispersion of copper species and increase the acidity of the Cu（ZrO2）/SiO2 catalysts. The Cu0 is responsible for ethanol dehydrogenation to acetaldehyde, and both the Lewis acid and Bronsted acid sites were in favor of the selectivity to ethyl acetate. The synergistic effect of Cu0 and an appropriate amount of acidic sites played an important role in the production of ethyl acetate.

Effects of pomegranate ethyl acetate extract on rat islet cells

Objective The present study investigated the effects of pomegranate ethyl acetate extract(PEE)on cell viability of primary rat islet cells.Methods PEE was extracted by using 95% ethanol and a series of organic solvents.Primary isolated islet cells of rat were cultured in high glucose and/or high fat conditions with or without PEE.Cell viability was determined by MTT assay.Insulin secretion was assessed by using radioimmunoassay.Results Insulin levels were significantly higher in cells treated with high glucose+PEE,palmitic acid+PEE,and olein acid+PEE compared to the cells treated with high glucose,palmitic acid,or oleic acid alone,in which the insulin levels were markedly less than that of the normal control group.Conclusion PEE promotes islet cell growth and insulin secretion,which is suggested that PEE can protect islet cell function in both high glucose and high fatty acid environments.

Towards Biorefinery Production of Microalgal Biofuels and Bioproducts: Production of Acetic Acid from the Fermentation of <i>Chlorella</i>sp. and <i>Tetraselmis suecica</i>Hydrolysates

Successful commercialization of microalgal bio-industry requires the design of an integrated microalgal biorefinery system that facilitates the co-production of biofuels, high-value products and industrial chemicals from the biomass. In this study, we investigated the use of sugar hydrolysate obtained from enzymatic saccharification of microalgal biomass (Chlorella sp. and T. suecica) as fermentation feedstock to produce industrially important chemicals, in particular acetic acid and butyric acid. By using hydrolysate with low sugar content as substrate for the anaerobic fermentation (1.5 - 2.4 g/L), we were able to prevent the bacterium C. saccharoperbutylacetonicum from activating its solventogenesis pathway. As a result, the fermentation process generated a product stream that was dominated by organic acids (acetic acid and butyric acid) rather than solvents (butanol, ethanol and acetone). Acetic acid constituted up to 92 wt% of Chlorella’s fermentation products and 80 wt% of T. suecica’s fermentation products. For T. suecica, the fermentation consumed almost all of the sugar available in the hydrolysate (up to 92% of initial sugar) and produced a reasonable yield of fermentation products (0.08 g fermentation products/g sugar). The Gompertz equation was successfully used to predict the formation kinetics of acetic acid and other fermentation products across both species. The results in the study demonstrate the production of industrially important chemicals, such as acetic acid and butyric acid, from the fermentation of microalgal sugar. The process described in the study can potentially be used as a value-adding step to generate biochemicals from cell debris in an integrated microalgal biorefinery system.

Catalytic Hydrogenation of Acetic Acid to Acetaldehyde: Synergistic Effect of Bifunctional Co/Ce-Fe Oxide Solid Solution Catalysts

The large-scale industrial production of acetic acid (HAc) from carbonylation of methanol has enabled intense research interest from direct hydrogenation of HAc to acetaldehyde (AA).Herein,a series of cerium-iron oxide solid solution supported metallic cobalt catalysts were prepared by modified sol-gel method and were applied in gas-phase hydrogenation of HAc to AA.A synergistic effect between the hydrogenation metal cobalt and Ce-Fe oxide solid solution is revealed.Specifically,oxygen vacancies provide the active sites for adsorption of HAc,while highly uniformly dispersed metallic Co adsorbs H2 and activates the reduction of HAc into AA.Moreover,the metallic Co can also assist the cyclical conversion between Fe3+/Fe2+ and Ce3+/Ce4+ on the surface of Ce1.xFexO2-δ supports.The unique effect substantially enhances the ability of the support material to rapidly capture oxygen atoms from HAc.It is found that the catalyst of 5% Co/Ce0.8Fe0.2O2-δ with the highest concentration of oxygen vacancy presents the best catalytic performance (i.e.acetaldehyde yield reaches 49.9%) under the optimal reaction conditions (i.e.623 K and H2 flow rate =10 mL/min).This work indicates that the Co/Ce-Fe oxide solid solution catalyst can be potentially used for the selective hydrogenation from HAc to AA.The synergy between the metallic Co and Ce1-xFexO2-δ revealed can be extended to the design of other composite catalysts.

A Computational Study on Iridium-Catalyzed Production of Acetic Acid from Ethanol and Water Solution

The mechanism for the production of acetic acid from ethanol and water mixture catalyzed by iridium catalyst has been theoretically investigated.The cooperation of the iridium center and bpyO ligand is highlighted,which plays an important role in the catalytic activity.The hydrogen release from the iridium center is the rate-determining step,with an energy barrier of 22.5 kcal/mol.The electronic structure analysis suggests electron-donating substituents could decrease the energy barrier.

Therapeutic potential of ethyl acetate fraction of Tephrosia purpurea Linn.leaves in a rat model of gout

Objective: The present study is to determine the potential treatment effects of ethyl acetate fraction of Tephrosia purpurea Linn. leaves(EATP) against gout.Methods: Gout in experimental rats was induced with potassium oxonate at the dose of 250 mg/kg(intraperitoneal injection) for 7 consecutive days;EATP was administered 1 h after administration of the potassium oxonate on each day of experiment. Potassium oxonate was discontinued on the 8 th day;thereafter allopurinol(10 mg/kg, p.o.) and EATP(200 and 400 mg/kg, p.o.) were continued until day 14. The uric acid level was measured from serum and urine during the experiment. Other biochemical parameters were assessed, including blood and urine creatinine, erythrocyte sedimentation rate, and total protein. Blood urea nitrogen, serum aspartate aminotransferase serum alanine aminotransferase and alkaline phosphatase were also measured. The blood was analyzed for levels of malondialdehyde and the antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase.Histopathological and radiological changes in the ankle of rats were observed after completion of the experiment.Results: EATP was able to decrease serum uric acid and creatinine level;it also reduced inflammation,oxidative stress and lysosomal enzyme level, which has a role in acute inflammation. EATP increased uric acid excretion through urine due to its uricosuric effect.Conclusion: EATP lowered the serum uric acid level and increased the urine uric acid level through excretion, which is useful in the treatment of gout. Hence the EATP was found to be helpful in the treatment of gout.

Effect of thermal pretreatment on the surface structure of PtSn/SiO2 catalyst and its performance in acetic acid hydrogenation

The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO2 catalyst in acetic acid （AcOH） hydrogenation was investigated in this article. The catalysts were characterized by N2 physical adsorption, X-ray diffraction, transmission electron microscopy, pyridine Fourier-transform infrared spectra, and H2-O2 titration on its physicochemical properties. The results showed that Pt species were formed primarily in crystalline structure and no PtSnx alloy was observed. Meanwhile, with the increment of thermal pretreatrnent temperature, Pt dispersion showed a decreas- ing trend due to the aggregation of Pt particles. Simultaneously, the amount of Lewis acid sites was remarkably influenced by such thermal pretreatment owning to the consequent physicochemical property variation of Sn species. Interestingly, the catalytic activity showed the similar variation trend with that of Lewis acid sites, confirming the important roles of Lewis acid sites in AcOH hydrogenation. Moreover, a balancing effect between exposed Pt and Lewis acid sites was obtained, resulting in the superior catalytic performance in AcOH hydrogenation.

The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

The catalytic hydrogenation of carboxylic acid to alcohols is one of the important strategies for the conversion of biomass.Herein,a series of Ni-doped PtSn catalysts were prepared,characterized and studied in the hydrogenation of acetic acid.The Ni dopant has a strong interaction with Pt,which promotes the hydrogen adsorption,providing an activated hydrogen-rich environment for the hydrogenation.Meanwhile,the presence of Ni also improves the Pt dispersion,giving more accessible active sites for hydrogen activation.The cooperation of Pt and Ni significantly promotes the catalytic activity of the hydrogenation of acetic acid to ethanol.As a result,the catalyst with 0.1%Ni exhibits the best reaction activity,and its space time yield is twice as that of the PtSn/SiO2 catalyst.It provides a meaningful instruction on the catalyst design for the carboxylic acid hydrogenation.

Impact of Ionic Liquid 1-Ethyl-3-Methylimidazolium Acetate Mediated Extraction on Lignin Features

This study aims at investigating the impact of ionic liquid extraction on lignin structure by studying the mechanism of lignin depolymerization in 1-ethyl-3-methylimidazolium acetate EMIM[OAc]) and comparing it with that of organosolv and milled wood methods. Ionic liquid mediated lignin (ILL) using EMIM[OAc]), ethanol organosolv lignin (EOL) and milled wood lignin (MWL) were isolated from Typha capensis (TC) and subjected to several analytical characterizations. Experimental data shows that ILL exhibited a relatively lower degree of condensation, lower aromatic C-C structures and a higher aliphatic OH with values of 0.42/Ar, 1.94/Ar and 1.33/Ar moieties compared with EOL values of 0.92/Ar, 2.22/Ar and 0.51/Ar moieties respectively. The ILL was depolymerized under mild conditions giving relatively higher β-aryl ether linkages content, higher molecular mass, and exhibited closer structures and reactivity to native lignin than EOL. These insights on TC lignin depolymerization in EMIM[OAc]) acetate may contribute to better value-addition of lignocellulosic biomass.

Synthesis, Spectroscopic and Crystal Structure Studies on Ethyl 5,7-Dimethyl Coumarin-4-Acetate

Ethyl ester of 5,7-dimethyl coumarin-4-acetic acid has been synthesized from 3,5-Xylenol in a two step sequence of reaction involving Pechmann cyclisation and acid catalyzed esterification. The title compound 2 crystallizes in Monoclinic form, space group P 1 21/c 1, with a = 8.6248(4) ?, b = 18.9103(8) , c = 8.4204(4)?, β = 101.241(2)?, V = 1347.00(11) ?, D cal = 1.283 Mg/cm3, Z = 4. The molecule is stabilized by intermolecular C-H … O bonds.

糖醋酒液诱捕核桃园小黄鳃金龟的效果

为研究核桃园中小黄鳃金龟Pseudosymmachia flavescens(Brenske)成虫的发生规律,探讨糖醋酒液对小黄鳃金龟的诱捕效果,本研究采用正交试验筛选糖醋酒液最佳配方,并于2020年-2022年在陕西省商洛市镇安县核桃园开展不同配方糖醋酒液及诱捕器悬挂不同高度诱捕小黄鳃金龟成虫试验。结果表明,糖∶乙酸∶乙醇∶水为3 g∶4 mL∶3 mL∶20 mL的配方对小黄鳃金龟成虫诱捕效果最佳。商洛市镇安县核桃园小黄鳃金龟成虫的发生期为5月上旬至9月中旬,盛发期为6月中旬至7月中旬。糖醋酒液诱捕器在距地面0.5~1.5 m范围内诱捕量随高度升高增加,当高度升至2.0 m时诱捕量明显下降,悬挂高度1.5 m时诱捕量570头/年、占比50.04%,显著高于其他高度处理。糖醋酒液3∶4∶3∶20配方(m∶V∶V∶V)既可准确监测核桃园小黄鳃金龟成虫种群发生动态,亦可高效诱杀用于防治。

二元磁性S_(2)O_(8)^(2-)/Fe_(3)O_(4)-ZrO_(2)固体超强酸催化合成乙酸乙酯工艺研究

以无水氯化锆、过硫酸铵、硫酸亚铁、硝酸铁为原料,采用共沉淀-浸渍法制备了二元磁性S_(2)O_(8)^(2-)/Fe_(3)O_(4)-ZrO_(2)固体酸催化剂,利用IR、XRD、BET、NH_(3)-TPD对二元磁性固体酸进行表征,并用于乙酸乙酯的合成反应。实验结果表明:催化剂制备条件为Fe_(3)O_(4)的添加量35%,过硫酸铵的浸渍浓度0.5 mol/L;适宜的酯化条件为醇酸摩尔比3∶1,酯化时间2 h,固体超强酸的用量0.5 g。以S_(2)O_(8)^(2-)/Fe_(3)O_(4)-ZrO_(2)为催化剂乙酸乙酯酯化率90.25%,重复4次后,乙酸乙酯的酯化率可达62.5%。

适合青梅醋酿造的醋酸菌选育

以腐烂的青梅为筛菌对象,采用平板分离、产酸定性和青梅果醋发酵实验筛选出一株产酸能力强的热带醋酸杆菌(Acetobacter tropicalis)J-27。进一步采用常压室温等离子体(atmosphericand room temperature plasma,ARTP)诱变技术和高通量筛选(high-throughput screening,HTS)相结合的方法,获得了1株具有高耐酸性且酿造后具有典型青梅醋风味的醋酸菌J-2736。用该菌株进行青梅醋发酵实验,发酵结束时总酸质量浓度为62.47 g/L,且菌株对乙醇、乙酸耐受性良好,可以耐受体积分数10%的乙醇和40 g/L的乙酸。对青梅醋中的风味物质进行分析,其中醇类物质、酯类物质和羧酸类物质质量分数较高,分别占挥发性风味物质的11.7%、36.0%和45.9%。因此选育的热带醋酸杆菌J-2736能够较好适应青梅的高酸特性,具有工业应用的可行性。

Q[6]-PW_(12)自组装体制备及其催化合成乙酸乙酯

以六元瓜环(Q[6])及Keggin型磷钨酸(PW_(12))为原料,制备Q[6]-PW_(12)自组装体。将Q[6]-PW_(12)自组装体作为催化剂应用于乙酸与乙醇酯化反应合成乙酸乙酯。结果表明,Q[6]与PW_(12)发生了自组装作用,且Q[6]-PW_(12)自组装体具有多孔结构特征;Q[6]-PW_(12)自组装体对酯化反应合成乙酸乙酯具有催化作用,且自组装体催化剂经过多次循环使用后依然效果良好。