Conversion Of Bioethanol Research Articles

Influence of HZSM-5-based catalyst deactivation on the performance of different reactor configurations for the conversion of bioethanol into hydrocarbons

The conversion of bioethanol into hydrocarbons, BTH process, has been simulated in reactors with different catalyst regimes (packed bed, non-circulating fluidized bed and circulating fluidized bed). The production of value-added products, as light olefins (ethylene, propylene and butenes) and gasoline (C4+ hydrocarbons), has been targeted. Different activity profiles have been predicted for packed and fluidized bed reactors, and a circulating fluidized bed reactor has allowed a steady-state operation. The obtained product distribution in this reactor can be easily tuned by modifying the reaction conditions and the mean residence time of the catalyst in the reactor. Maximum yields of olefins (ca. 85%) are predicted to be achieved at low temperature (300 °C), low space time (0.1 gcat h g−1) or high content of water in the feed (75%), whereas the yield of gasoline is otherwise maximized (ca. 70%) at high temperature (400 °C), high space time (1.0 gcat h g−1) or low content of water in the feed (5%, azeotrope mixture). The results highlight the interest of having a useful and versatile simulation model to be used as a tool for the prediction of different reactor performances in processes with complex reaction networks and fast catalyst deactivation as the BTH process.

Биоэтанол – сырье для получения ценных химических соединений

В данном обзоре проведен анализ производства биоэтанола из различных источников биомассы. Были рассмотрены последние данные о производстве биоэтанола в различных странах, включая важность биоэтанола, производимого в нашей стране. Основным сырьем для получения биоэтанола являются сахарный тростник, сахарная свекла, пшеница, рис, маниока, ячмень, сладкое сорго, биомасса водоросли. В процессе получения биоэтанола основное внимание уделяется, прежде всего, природе сырья, различиям в его биохимическом составе и стоимости сырья. Крупнейшими производителями биоэтанола в мире являются США и Бразилия. В Бразилии биоэтанол производят из сахарного тростника, в США основным сырьем для производства биотоплива является кукуруза. В нашей стране биоэтанол получают в основном из пшеницы. 
 Кроме того, в данном обзоре на основании литературных источников анализируются способы каталитической переработки биоэтанола в ценные химические соединения, такие как ацетальдегид, 1,1-диэтоксиэтан, бутанол. Ацетальдегид, полученный из биоэтанола, является важным сырьем для производства других химических веществ, например, уксусной кислоты, уксусного ангидрида и др. 1,1-диэтоксиэтан, бутанол могут использоваться в качестве растворителей, октаноповышающей добавки к топливам. Бутанол также применяется в синтезе многих органических соединений, таких как бутилацетат, бутилакрилат и др. Если учесть, что биоэтанол может быть произведен не только из сельскохозяйственной продукции, но и из различных отходов, содержащих сахара и крахмал, то переработка биоэтанола в продукты с добавленной стоимостью является экономически эффективным и экологически целесообразным.

Conversion of Bioethanol to Diethyl Ether Catalyzed by Sulfuric Acid and Zeolite

Ethoxy ethane, or diethyl ether, has been successfully synthesized through the condensation reaction of bioethanol produced from fruit waste fermentation using acid-activated H-Zeolite, H2SO4/H-Zeolite, and H2SO4 as catalysts. Zeolite activation was carried out using the acidification method with 1 M, 2 M, 4 M, and 6 M H2SO4 for 24 hours. Activated zeolites were characterized using infrared spectroscopy, X-ray diffraction, and NaOH titration. The condensation reaction of bioethanol was carried out by catalysis of H2SO4/H-Zeolite with various concentrations of 1 M, 2 M, 4 M, and 6 M and catalyzed by 2 M, 4 M, and 6 M acid-activated H-Zeolite. The condensation reaction process was carried out with a ratio of bioethanol to catalyst of 2:1 (w/w) using the fractional distillation method. Ethoxy ethane resulting from the condensation reaction was characterized using a GC instrument.

PdCu nanoalloy supported on alumina: A stable and selective catalyst for the conversion of bioethanol to linear α-alcohols

PdCu/Al2O3 (Pd = 0.1 wt.%, Cu = 0.1 wt.%) catalyst and its monometallic analogues (Pd/Al2O3 and Cu/Al2O3) were prepared by combination of deposition-precipitation and impregnation methods. The structure of the catalysts was studied by means of XRD, TEM, EDS, TPD-NH3, and DRIFTS. In a standard run (275 ○C, 5 h), Cu/Al2O3 converts 11 % of ethanol to α-alcohols with 0.6 % selectivity, whereas Pd/Al2O3 converts 24 % of ethanol to α-alcohols with 70 % selectivity. The high performance of Pd/Al2O3 was attributed to the catalysis on the Pd°-Al2O3 interfaces. After 3 sequential runs, the activity of Pd/Al2O3 decreases by 98 %. It was explained by blocking of Pd° sites in Pd/Al2O3 by CO molecules produced in side reactions. Modification of Pd/Al2O3 with Cu species results in the formation of PdCu/Al2O3 catalyst containing PdCu alloy particles with the size of 4 nm. This leads to an increased durability of bimetallic sample, because of suppressing CO sorption on Pd° sites in alloy particles. As a result, for the PdCu/Al2O3 catalyst, sustained and high conversion (41 %) accompanied by high selectivity to α-alcohols (91 %) was observed in 20 sequential runs.

A Novel Immobilization Method of <i>Saccharomyces cerevisiae</i> on Fermentation of Nipa Palm Sap for Fuel Grade Bioethanol Production

Nipa palm (Nypa fruticans) spreads abundantly in the mangrove forests of eastern coast of Sumatera Island, Indonesia. Nipa palm sap can be used as a very high-gravity (VHG) substrate for fermentation. In this research, batch fermentation of nipa sap with initial sugar content of 262.713 mg/ml using immobilized Saccharomyces cerevisiae yeast cells was studied. Immobilization of the yeasts in Na-alginate by droplet method and addition of 0.2% v/v Tween 80 and 0.5g/l ergosterol to the immobilized cells were first carried out. Then, the effect of cells weight percentage (5, 10, 15, and 20% w/v) and fermentation time (24, 36, 48, 60, 72, 84, and 96 hrs) on the bioethanol production were investigated. After, the analysis of bioethanol concentration was investigated using Gas Chromatography. The bioethanol production increased with the fermentation time until reaching a maximum value at all cell weights. Except with the 20% w/v, this peak was followed by a decrease in the bioethanol production at cell weights of 5, 10, and 15% w/v. This phenomenon may be explained by degradation of bioethanol into acetic acid resulting in the decreased concentration at the end of fermentation. The formation of acetic acid was characterized by decreases in the pH values of the fermentation medium. On the contrary, the bioethanol level tended to increase until the end of fermentation with the immobilized yeast cells of 20% w/v. High number of available immobilized yeast cells at the end of fermentation, accumulation of bioethanol produced at earlier times, and no further conversion of bioethanol to acetic acid could be the reasons for this increase. The optimum conditions for bioethanol production were 20% w/v cell weight and 96 hr fermentation time, at bioethanol concentration of 17.57% v/v.

Visible-light-driven integrated organic synthesis and hydrogen evolution over 1D/2D CdS-Ti3C2Tx MXene composites

Exploiting solar energy to photocatalyze integrated selective conversion of bioethanol into fine chemicals and hydrogen (H2) is a promising avenue in response to current energy and environmental crises. Herein, we have reported the mild synthesis of a binary heterostructure of CdS-Ti3C2Tx MXene (CdS-MX) combining one-dimensional (1D) CdS nanowires (NWs) with two-dimensional (2D) MXene structure, and its application in photocatalytic coupling redox reaction of H2 evolution and selective conversion of bioethanol into 1,1-diethoxyethane (DEE) under acidic conditions. The results reveal that the synergistic effect of the intimate interfacial contact and matched energy level alignment between electrically conductive 2D MXene and semiconductor 1D CdS NWs benefits the separation and migration of charge carriers. Furthermore, CH(OH)CH3 has been proven to be the pivotal radical intermediate during photoredox process. This work is anticipated to stimulate further interest on rational construction of MXene-semiconductor based composites toward photoredox coupling organic synthesis and H2 evolution in a sustainable manner.

Conversion of Sugar Cane Bagasse Become Bioethanol Using Variations of Yeast Types and Fermentation Temperatures with Socarification Process

Sugarcane bagasse is a waste of sugar factories and one of its lignocellulosic materials is still of limited use. Sugarcane bagasse consists of three main components, namely cellulose, hemicellulose, and lignin. Sugarcane bagasse can be converted into bioethanol through a hydrolysis process (the process of converting carbohydrates into glucose) which consists of a liquefaction and saccharification process and followed by a fermentation process. The hydrolysis method is carried out enzymatically. This research used alpha amylase and gluco amylase enzymes with various types of yeast including Saccharomyces cereviceae, Rhizopus oryzae, Acetobacter xylinum, Mucor sp., and Aspergilus niger varied with liquefaction temperatures including 80, 85, 90, 95, and 100 °C. Obtained the most optimal yeast is Saccharomyces cereviceae with an optimal temperature of 95 °C resulting in a bioethanol concentration of 4.5%.

Ag- and Cu-Promoted Mesoporous Ta-SiO2 Catalysts Prepared by Non-Hydrolytic Sol-Gel for the Conversion of Ethanol to Butadiene

The direct catalytic conversion of bioethanol to butadiene, also known as the Lebedev process, is one of the most promising solution to replace the petro-based production of this important bulk chemical. Considering the intricate reaction mechanism—where a combination of acid-catalyzed dehydration reactions and metal-catalyzed dehydrogenation have to take place simultaneously—tailor-made bifunctional catalysts are required. We propose to use non-hydrolytic sol-gel (NHSG) chemistry to prepare mesoporous Ta-SiO2 materials which are further promoted by Ag via impregnation. An acetamide elimination route is presented, starting from silicon tetraacetate and pentakis(dimethylamido)tantalum(V), in the presence of a Pluronic surfactant. The catalysts display advantageous texture, with specific surface area in the 600–1000 m² g−1 range, large pore volume (0.6–1.0 mL g−1), an average pore diameter of 4 nm and only a small contribution from micropores. Using an array of characterization techniques, we show that NHSG allows achieving a high degree of dispersion of tantalum, mainly incorporated as single sites in the silica matrix. The presence of these monomeric TaOx active sites is responsible for the much higher dehydration ability, as compared to the corresponding catalyst prepared by impregnation of Ta onto a pristine silica support. We attempt to optimize the butadiene yield by changing the relative proportion of Ta and Ag and by tuning the space velocity. We also demonstrate that Ag or Cu can be introduced directly in one step, during the NHSG process. Copper doping is shown to be much more efficient than silver doping to guide the reaction towards the production of butadiene.

Conversion of hydrous bio-ethanol on ZnxZryOz catalyst to renewable liquid chemicals and additives to gasoline

The conversion of ethanol on the ZnxZryOz catalyst was studied over a wide range of operating conditions to determine the possibility of producing organic liquid (olefins, aromatics and oxygenates). The content of water in the feed was found to be the key parameter. At ≥60 wt% water, no organic liquid is formed. As water content decreased, the yield of organic liquid increased. Furthermore, increasing pressure increased the yield of organic liquids. Experiments conducted at increasing residence time indicated that ethanol was first converted to oxygenates then to aromatics and higher olefins (C5–C11) with propylene, ethylene, carbon dioxide and hydrogen as the main by-products. Increasing temperature at high residence time (WHSV = 0.8 h−1) decreased the yield of liquid oxygenates while increasing the yield of aromatics and higher olefins. A tentative scheme of reactions was proposed considering the special nature of the ZnxZryOz catalyst with balanced basic-acidic sites. The catalyst was stable, tested for >300 h. Tail gas containing light olefins, mainly propylene and ethylene, was converted by oligomerization on a commercial H-ZSM-5 catalyst to higher olefins (>90%) and aromatics at high conversion (>90%). The organic liquid from the two reactors can be used as feedstock for chemicals or as blending stock for gasoline.

Synthesis of 1-Butanol from Ethanol over Calcium Ethoxide: Experimental and Density Functional Theory Simulation

Conversion of bioethanol to 1-butanol has attracted much interest in the field of renewable resource conversion. Development of efficient catalysts is a hot topic for this reaction. In this work, c...

Morphological control of inverted MgO-SiO2 composite catalysts for efficient conversion of ethanol to 1,3-butadiene

In this work, three novel MgO-SiO2 composite catalysts with inverted structure have been synthesized via a facile and scalable strategy by means of the incipient wetness impregnation of the silica sol onto MgO precursors with different morphologies, and evaluated for the one-step conversion of ethanol to 1,3-butadiene. The prepared flower-like MgO-SiO2 composite catalysts exhibited highly enhanced catalytic activity than those catalysts synthesized from MgO precursors with nanodisks and nanosheets morphologies. Characterization results based on XRD, FT-IR, UV–vis, BET, CO2-TPD, NH3-TPD, ethanol-TPD, and 29Si MAS NMR revealed that unique layered flower-like architectures may facilitate the formation of interfacial Mg-O-Si chemical bond in binary MgO-SiO2 composite catalysts which are mainly responsible for the superior activity. This study presents a new strategy to design and develop the catalyst for efficient conversion of bio-ethanol to 1,3-butadiene by morphological control of MgO-SiO2 bifunctional catalysts.

Rapid microwave-assisted liquid phase conversion of bio-ethanol to n-butanol over a heterogeneous catalyst

A sustainable bio-based fuel industry is dependent on finding efficient technologies for the production of biofuels. A microwave-assisted method to produce bio-butanol from bio-ethanol in liquid phase was investigated using a 2-level factorial design with catalyst type and loading, reaction temperature and reaction time as variables. A combined severity factor (CSF) was used to quantify the combined effect of all reaction conditions on ethanol conversion and butanol selectivity. From the results, it could be qualitatively deduced that the reaction initially followed the Guerbet mechanism for formation of butanol, but gradually shifted toward the direct coupling mechanism as reaction conditions became more severe with 50% of the butanol produced at a CSF of 6, produced through the direct coupling mechanism. The overall reaction order and observed specific reaction rate was determined as 1.54 ± 0.26 and 2.91·10−6 ± 2.36·10−7 g.0.54.L−0.54.s−1 respectively. Both high ethanol conversions (76.6 wt%) and high butanol selectivity (60 wt%) could be obtained in a very short reaction time (60 minutes). The results represent an improvement in reaction time, ethanol conversion and butanol selectivity of 300%, 47% and 16.7% respectively compared to previously reported data. This represents a significant step towards realizing an affordable low-carbon drop-in fuel for a low carbon economy.

Sc2O3-promoted composite of In2O3 and Beta zeolite for direct conversion of bio-ethanol to propylene

A series of Sc2O3-modified (1–5%) In2O3/Beta composites were prepared by the deposition-precipitation method. These catalysts were characterized by X-ray diffraction, N2 adsorption, temperature-programmed desorption of NH3 and CO2, temperature-programmed reduction, X-ray photoelectron spectroscopy and 27Al magic-angle spinning nuclear magnetic resonance. The incorporation of Sc2O3 into In2O3/Beta results in enhanced catalyst stability for the conversion of ethanol to propylene, which is due to inhibition of the reduction of In3+ to In0 upon Sc2O3 modification.

Conversion of bioethanol over oxide catalysts

The conversion of bioethanol over supported oxide catalysts (CuO, ZnO, Cr2O3,CeO2) was studied, among which the most active in the production of hydrogenis 3% CuO / γ-Al2O3. Modification of 3% CuO / γ-Al2O3 catalyst with Cr2O3, ZnOand CeO2 promotes the growth of hydrogen yield. The highest concentrationof hydrogen at 300° C and a space velocity of 1 h-1 on CuO-ZnO / γ-Al2O3 was48% by volume. The acidity of catalysts for adsorption-desorption of pyridine byinfrared spectroscopy (ITI Matson FTIR) was determined. When the content ofCuO in the catalyst is increased from 1 to 3%, the amount of Lewis acidic centers(LAS) increases from 58 to 82 µmol/ gcat. Modification with chromium oxide ofthe copper catalyst increases the number of LAS from 82 to 156 µmol/ gcat byadsorption of pyridine at 150° C and from 79 to 120 µmol/ gcat with pyridineadsorption at 250° C. It has been established that an increase in the number ofLewis acid sites has a positive effect on the yield of hydrogen in the conversion ofbioethanol. According to electron microscopy, the modification of catalysts leadsto an increase in the dispersity of the catalyst and to a uniform distribution ofparticles on the surface of the catalyst, which also contributes to its greater activityin the production of hydrogen.

Catalytic Ethylene Oligomerization over Ni/Al-HMS: A Key Step in Conversion of Bio-Ethanol to Higher Olefins

Al-modified hexagonal mesoporous silica (HMS) materials were synthesized using dodecylamine as a template according to the methods reported in the literature. FT-IR spectra proved that Al3+ ions entered in the HMS framework in Al-HMS (prepared by sol-gel reaction) but Al3+ ions existed in the extra-framework in Al/HMS (prepared by post-modification). NH3-TPD indicated that either Al-HMS or Al/HMS had solid acid sites on the surface, and the acidic strength of Al/HMS was stronger than that of Al-HMS. For ethylene oligomerization at 200 °C under 1 MPa, Ni/Al-HMS showed an ethylene conversion of 96.3%, which was much higher than that over Ni/Al/HMS (45.6%). The selectivity for C4H8, C6H12, C8H16, and C8+ was 37.7%, 24.5%, 24.0%, and 9.1% for ethylene oligomerization over Ni/Al-HMS, respectively. Ni/Al-MCM-41, which has been reported as an effective catalyst for ethylene oligomerization in the literature, showed a high ethylene conversion (95.2%) similar to that of Ni/Al-HMS in this study. However, the selectivity for C8H16 over Ni/Al-MCM-41 (16.3%) was lower than that over Ni/Al-HMS (24.0%) in the ethylene oligomerization. For ethanol dehydration at 300 °C under 1 MPa, a commercial H-ZSM-5 catalyst showed a high ethylene yield (91.2%) after reaction for 24 h using a feed containing 90 wt.% ethanol and 10 wt.% water. In this study, a two-step process containing two fixed-bed reactors and one cold trap was designed to achieve the direct synthesis of higher olefins from bio-ethanol. The cold trap was used to collect the water formed from ethanol dehydration. By using H-ZSM-5 as a catalyst for ethanol dehydration in the first reactor and using Ni/Al-HMS as a catalyst for ethylene oligomerization in the second reactor, higher olefins were continuously formed by feeding a mixture containing 90 wt.% ethanol and 10 wt.% water. The yields of higher olefins did not decrease after reaction for 8 h in the two-step reaction system.

Pd/carbon paper electrodes modified with polyaniline as co-support for sustainable energy conversion of bioethanol from Salicornia bigelovii

The production of sustainable and renewable fuels for energy conversion is vital for designing green technologies to supply the energy needs of the population. In this work, bioethanol was obtained from Salicornia bigelovii as a salt-tolerant plant watered with seawater, converting it in an interesting sustainable energy source for clean and renewable technologies, such as fuel cells. Thus, Bioethanol (BioEOR) and ethanol (EOR) electro-oxidation reactions were evaluated using polyaniline (PANI) as a co-support in Pd/carbon paper electrodes in alkaline medium (0.3 M KOH). PANI was growth electrochemically on carbon paper (PANI-T) for the further electrodeposition of Pd on both, carbon paper (T) and PANI-T. Physicochemical characterization by XRD, TEM, EDX mapping, and XPS indicated that PANI promoted differences in the properties of Pd/PANI-T compared to Pd/T as the reference material. It decreased crystallite and particle sizes to 8.29 nm and 15 ± 3 nm. PANI improved particle homogeneity and prevented the formation of microsized Pd agglomerates. PANI promoted shifts in binding energies of Pd due to their metal/support interaction. Electrocatalytic evaluation of Pd/PANI-T for EOR resulted in a maximum current density of 295.88 mA cm−2, and an oxidation potential of −0.41 V vs. NHE at 5 M ethanol. This current was 110 mA cm−2 higher to that achieved by Pd/T. In addition, Pd/PANI-T presented higher current density for BioEOR (146.41 mA cm−2 at 3 M bioethanol) than Pd/T. However, this current density was lower to that found for EOR due to the presence of impurities like toluene. According to a spectroelectrochemical analysis by surface-enhanced Raman spectroscopy, the differences in activity for BioEOR of Pd/PANI-T and Pd/T were associated with changes in the reaction pathway: Pd/PANI-T promoted the formation of formates and carbonates (12e−), while Pd/T formed mainly acetates (4e−). Thus, Pd/PANI-T enabled a higher electron transfer per bioethanol molecule.

Purification, characterization, and stabilization of alcohol oxidase from Ogataea thermomethanolica

Alcohol oxidase (AOX) functions in oxidation of primary alcohols into the corresponding aldehydes with potential on catalyzing synthesis reactions in chemical industry. In this study, AOX from a thermotolerant methylotrophic yeast, Ogataea thermomethanolica (OthAOX) was purified to high homogeneity using a single step chromatographic separation on a DEAE-Sepharose column. The purified OthAOX had a specific activity of 15.34 U/mg with 77.5% recovery yield. The enzyme worked optimally at 50 °C in an alkaline range (pH 9.0). According to kinetic analysis, OthAOX showed a higher affinity toward short-chain aliphatic primary alcohol with the Vmax, Km, and kcat of 0.24 nmol/min, 0.27 mM, and 3628.8 min−1, respectively against methanol. Addition of alginic acid (0.35%) showed a protective effect on enhancing thermal stability of the enzyme, resulting in 72% increase in its half-life at 40 °C under the operational conditions. This enzyme represents a promising candidate for conversion of bioethanol to acetaldehyde as secondary chemical in biorefinery.

Influence of different precursors on isobutene production from bio-ethanol over bifunctional Zn1Zr10Ox catalysts

The effects of zinc precursors on the performance of bifunctinal Zn1Zr10Ox catalysts were investigated for direct conversion of bio-ethanol into isobutene (ETIB). The catalyst derived from zinc acetate precursor exhibited full ethanol conversion and 50% isobutene yield at a WHSV of 0.38 gethanol gcat−1 h−1 at 450 °C. Characterization results based on XRD, FT-IR, UV–vis, Raman, BET, CO2-TPD, NH3-TPD, H2-TPR, and XPS revealed that Zn1Zr10Ox catalyst prepared by zinc acetate precursor with large anion size possessed the highest zinc dispersion and the strong ZnO-ZrO2 interaction, and presented the highest ethanol reaction rate and isobutene yield under kinetic control regime. The beneficial effect of larger anion size was rationalized by the shielding effect in the incorporation model dominated by the size of capping anion in zinc precursors. Further durability test showed that the catalyst exhibited slow deactivation against coking formation while isobutene yield was maintained above 45% for 18 h.

A combined experimental and theoretical study on ethanol conversion to propylene over Y/ZrO2 catalyst

ZrO2-based catalysts doped with Y were prepared by co-precipitation method. The effect of yttrium modification on the selective conversion of bio-ethanol to propylene over ZrO2 catalysts was investigated. The physical and chemical properties of the catalysts were characterized by N2 adsorption-desorption method, temperature programmed desorption and X-ray diffraction. The maximum yield of propylene reached 44.0% over 0.03Y/ZrO2 catalyst. A coordination of acid-base properties accounts for the remarkable improvement of reaction activities over Y-doped ZrO2 catalysts in this investigation. On the basis of calculation results, it can be concluded that significant charge transfer occurs as a result of introduction of Y or O-vacancy. The adsorption of ethanol and propylene on perfect t-ZrO2 (1 0 1), defect t-ZrO2 (1 0 1) and Y/ZrO2 (1 0 1) surfaces were investigated with density functional theory (DFT). The adsorption for ethanol on Y/ZrO2 (1 0 1) and defect t-ZrO2 (1 0 1) surfaces are more stable than that on perfect t-ZrO2 (1 0 1). On the defect t-ZrO2 (1 0 1) surface, ethanol dominantly absorbs at the O-vacancy site, indicating that O-vacancy becomes the favorable adsorption site. On the Y/ZrO2 (1 0 1) and defect t-ZrO2 (1 0 1) surfaces, the adsorption energy of propylene decreases, which makes propylene desorb quickly after formation.

ZnO-Al2O3-promoted CuO/ZrO2 catalyst prepared by oxalate gel-coprecipitation for the conversion of water-bearing materials

Generally, ZrO2 facilitates the reactions of O-containing species, which result in the loss of activity or the sintering of Cu species via intimate interaction between water and CuO/ZrO2 catalysts. Indeed, the CuO/ZrO2 catalysts (CZo) prepared by oxalate gel-coprecipitation technique possessed a high dispersion of Cu and a certain degree of alkalinity. Unfortunately, it exhibited inferior catalytic activity in conversion of bio-ethanol (37.6% conversion). In contrast, the CuO–ZnO–Al2O3–ZrO2 catalysts (CZAZo) with extra addition of ZnO and Al2O3 showed a good catalytic performance and stability (>600 h on line). For example, the 92.5% selectivity of ethyl acetate based on 62.2% conversion of ethanol, was achieved. Besides, it performed better in hydrogenation of hydrous ethyl acetate than CZo. Evidently, the excellent performance in conversion of water-bearing materials was mainly due to the addition of ZnO and Al2O3 to CuO/ZrO2 catalysts. Besides, the uniform combination of each component could be achieved successfully by the employment of oxalate gel-coprecipitation. As a result, the surface electronic properties are tuned effectively and the affinity for water decreases sharply. Most importantly, the associated loss of active sites could be effectively avoided because of the reduced water coverage over CZAZo.