TW201315541A - Hydrogenation catalysts prepared from polyoxometalate precursors and process for using same to produce ethanol - Google Patents

Abstract

The present invention relates to hydrogenation catalysts prepared from polyoxometalate precursors. The polyoxometalate precursors introduce a support modifier to the catalyst. The catalysts are used for hydrogenating alkanoic acids and/or esters thereof to alcohols, preferably with conversion of the ester coproduct. The catalyst may also comprise one or more active metals.

Description

Hydrogenation catalyst prepared from polyoxometallate precursor and process for producing ethanol using the hydrogenation catalyst Cross-references for related applications

The present application claims priority based on U.S. Patent Application Serial No. 13/419,617, filed on March 14, 2012, and U.S. Provisional Patent Application No. 61/583,874, filed on Jan. 6, 2012, and U.S. Application No. 13/267,149, the entire disclosure of which is incorporated herein by reference.

The invention relates to a catalyst, a process for producing a hydrogenation catalyst from a polyoxometallate precursor. The catalyst can be used to produce ethanol from alkanoic acids and/or esters thereof in the presence of the catalyst of the present invention.

Industrial ethanol is conventionally produced from petrochemical sources such as oil, natural gas or coal, or from source intermediates such as syngas or from starchy materials or cellulosic materials such as corn or sugar cane. Conventional methods for producing ethanol from petrochemical sources and from cellulosic materials include ethylene acid catalyzed hydration, methanol homologation, direct alcohol synthesis, and Fischer-Tropsch synthesis. The unstable price of petrochemical sources has caused the price of ethanol produced by the float to fluctuate, which makes it more demanding for alternative sources of ethanol production when the source price increases. Starch materials and cellulosic materials are converted to ethanol by fermentation. However, fermentation is generally used in the manufacture of consumer ethanol, whereby the ethanol produced is suitable for fuel or human consumption. In addition, fermentation of starchy or cellulosic materials competes with food sources and limits the amount of ethanol that can be made for industrial use.

The production of ethanol via reduction reactions of alkanoic acids and/or other carbonyl-containing compounds has been extensively studied, and various combinations of catalysts, supports, and operating conditions are described in the literature. It has been proposed in gold in European Patent EP 0 175 558 and U.S. Patent No. 4,398,039. The genus is oxidized to reduce various carboxylic acids. A summary of the development efforts of hydrogenation catalysts for the conversion of various carboxylic acids is found in Yokoyama et al., "Carboxylic acids and derivatives." in "Fine chemicals through heterogeneous catalysis." 2001, 370-379.

U.S. Patent No. 6,495,730 describes a process for the hydrogenation of carboxylic acids using a catalyst comprising activated carbon to support active metal species including antimony and tin. U.S. Patent No. 6,204,417 describes another process for the preparation of aliphatic alcohols by hydrogenating an aliphatic carboxylic acid or its anhydride or ester or lactone in the presence of a catalyst comprising platinum (Pt) and rhenium (Re). U.S. Patent No. 5,149,680 describes the catalytic hydrogenation of carboxylic acids and their anhydrides in the presence of a catalyst comprising a Group VIII metal such as platinum, a metal alloyable with a Group VIII metal, and at least one metal ruthenium, tungsten or molybdenum. Process for the formation of alcohols and/or their esters. U.S. Patent No. 4,777,303 describes the preparation of alcohols by hydrogenating a carboxylic acid in the presence of a catalyst comprising a first component of molybdenum or tungsten and a noble metal of Group VIII on a high surface area graphitized carbon. The second component. U.S. Patent No. 4,804,791 describes another process for the production of alcohols by hydrogenating carboxylic acids in the presence of a noble metal comprising Group VIII and a catalyst of ruthenium. U.S. Patent No. 4,517,391 describes the preparation of ethanol by hydrogenation of acetic acid at superatmospheric pressure and at elevated temperatures by a process in which a catalyst comprising predominantly cobalt is used.

Existing processes can encounter various problems that hinder commercial viability, including: (i) the lack of catalyst for the necessary selectivity for ethanol; and (ii) the lack of sufficient ethyl ester conversion for the catalyst, which is a hydrogenation of the carboxylic acid. By-product; (iii) the catalyst may be prohibitively expensive and/or non-selective for the formation of ethanol and may produce undesirable by-products; (iv) excessive operating temperatures and pressures are required; / or (v) Catalyst lifetime is not enough.

The present invention relates to a process for producing a catalyst, the process comprising the steps of: impregnating a support modifier from a polyoxometallate precursor onto a support to form a first impregnated support; calcining The first impregnated support forms a calcined support; the one or more active metals from the one or more metal precursors are impregnated onto the calcined support to form a second impregnated support, wherein the one or more active metals Selected from copper, calcium, barium, magnesium, strontium, iron, cobalt, nickel, ruthenium, rhodium, platinum, palladium, rhodium, iridium, titanium, zinc, chromium, molybdenum, tungsten, tin, antimony, bismuth, manganese and gold a group formed; and calcining the second impregnated support to form a catalyst. The polyoxometallate precursor may include a heteropolyoxometalate, an isopolyoxometalate, a hexaxoxometalate, and/or a decahedometallate ( Decaoxometalate). The polyoxometallate precursor may contain a metal atom selected from the group consisting of tungsten, molybdenum, vanadium, niobium, chromium, niobium, and mixtures thereof. In some embodiments, the polyoxometallate precursor comprises a salt selected from the group consisting of ammonium metatungstate ((NH ₄ ) ₆ H ₂ W ₁₂ O ₄₀ .x H ₂ O), ammonium heptamolybdate tetrahydrate ((NH _{4 ) 6} Mo ₇ O ₂₄ .4 H ₂ O), 矽tungstic acid hydrate (H ₄ SiW ₁₂ O ₄₀ .H ₂ O), phosphotungstic acid (H ₃ PW ₁₂ O ₄₀ .n H ₂ O), bismuth molybdenum Acid (H ₄ SiMo ₁₂ O ₄₀ .n H ₂ O), phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ .n H ₂ O), bismuth oxalate hexahydrate ([Nb(HC ₂ O ₄ ) ₅ ]). A compound of the group consisting of 6 H ₂ O), vanadium oxide (V ₂ O ₅ ), ammonium vanadate ((NH ₄ )VO ₃ ), and mixtures thereof. The polyoxometallate precursor can contain at least two different metal atoms. The support modifier is selected from the group consisting of Nb ₂ O ₅ , WO ₃ , MoO ₃ , V ₂ O ₅ , P ₂ O ₅ , P ₄ O ₁₀ , Ta ₂ O ₅ , Bi ₂ O ₃ and mixtures thereof. Group. The one or more active metals may be selected from the group consisting of platinum, palladium, nickel, cobalt, copper, and tin. The one or more metal precursors may be selected from the group consisting of metal halides, amine dissolved metal hydroxides, metal nitrates, and metal oxalates. The second impregnated support can be formed using one or more metal precursors in an aqueous solution of dilute nitric acid and the calcined support. The support material may be selected from the group consisting of cerium oxide, aluminum oxide, titanium oxide, cerium oxide/alumina, calcium metasilicate, pyrolytic cerium oxide, high purity cerium oxide, zirconium oxide, zeolite, carbon and mixtures thereof. . The process may further comprise drying the first impregnated support at a temperature from 50 ° C to 200 ° C and drying the second impregnated support at a temperature from 50 ° C to 200 ° C. The first impregnated support can be calcined at a temperature of from 350 ° C to 850 ° C. The catalyst may comprise from 0.1 to 50% by weight, based on the total weight of the catalyst, of the support modifier, and from 0.1 to 25% by weight, based on the total weight of the catalyst, of the one or more active metals.

In another embodiment, the invention relates to a process for producing ethanol comprising the steps of: passing a gaseous stream comprising hydrogen and a vapor phase alkanoic acid through a hydrogenation catalyst, wherein the hydrogenation catalyst comprises a process comprising the following steps The method comprises: impregnating a support modifier from a polyoxometallate precursor onto a support to form a first impregnation support; calcining the first impregnated support to form a calcined support; One or more active metals of various metal precursors Impregnating the calcined support to form a second impregnated support, wherein the one or more active metals are selected from the group consisting of copper, calcium, barium, magnesium, strontium, iron, cobalt, nickel, ruthenium, rhodium, platinum, palladium, a group consisting of ruthenium, osmium, titanium, zinc, chromium, molybdenum, tungsten, tin, antimony, bismuth, manganese, and gold; and calcining the second impregnated support to form a catalyst. In one embodiment, the support modifier may be impregnated with ammonium metatungstate, ammonium heptamolybdate tetrahydrate or vanadium oxide. The alkanoic acid can be acetic acid and can have a conversion of at least 90% and a selectivity to ethanol of at least 80%. The gaseous stream may in turn comprise ethyl acetate and the conversion of the ethyl acetate may be greater than 0%. The support material may be selected from the group consisting of cerium oxide, aluminum oxide, titanium oxide, cerium oxide/alumina, calcium metasilicate, pyrolytic cerium oxide, high purity cerium oxide, zirconium oxide, zeolite, carbon or a mixture thereof. .

In another embodiment, the invention relates to a catalyst solution for preparing a hydrogenation catalyst comprising ceria and selected from ammonium metatungstate ((NH ₄ ) ₆ H ₂ W ₁₂ O ₄₀ .x H ₂ O ), ammonium heptamolybdate tetrahydrate ((NH ₄ ) ₆ Mo ₇ O ₂₄ .4 H ₂ O), samarium tungstate hydrate (H ₄ SiW ₁₂ O ₄₀ .H ₂ O), phosphotungstic acid (H _{3 )} PW ₁₂ O ₄₀ .n H ₂ O), bismuthmolybdic acid (H ₄ SiMo ₁₂ O ₄₀ .n H ₂ O), phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ .n H ₂ O), bismuth oxalate hexahydrate ([Nb(HC ₂ O ₄ ) ₅ ]). A mixture of aqueous solutions of polyoxometallates of the group consisting of 6 H ₂ O), vanadium oxide (V ₂ O ₅ ), ammonium vanadate ((NH ₄ )VO ₃ ), and mixtures thereof.

The present invention relates to a hydrogenation catalyst prepared using a polyoxometallate precursor. The polyoxometallate precursor introduces one or more support modifiers onto the support. Preferably, the catalyst also includes one or more active metals on the support.

The catalyst is particularly useful for catalyzing the hydrogenation of alkanoic acids such as acetic acid and/or its esters such as ethyl acetate to the corresponding alcohols such as ethanol. An ester co-product is also produced when the acetic acid is hydrogenated. It is difficult to limit the amount of ester co-products. Thus the ester co-product must be purged by blowing, which means that the ethanol efficiency is lost or the ester needs to be recycled to the reactor. When the catalyst is recycled, it must be sufficient to consume the ester co-product at a rate sufficient to correspond to the ester co-product formation rate. The catalyst is produced from the polyoxometallate catalyst by introducing a support modifier onto the support to provide a catalyst activity sufficient to convert the ester co-product, ethyl acetate. The conversion of ethyl acetate can be greater than 5%, such as greater than 10%, based on each catalyst pass. Or greater than 15%. In a specific example, the conversion of ethyl acetate may range from 5 to 50%, such as from 5 to 30% or from 5 to 15%, per reference to the catalyst. Once the steady state conditions are reached in the reactor, the ethyl acetate conversion can be 0% or more, indicating that no net production of ethyl acetate is produced. When the ester co-product is consumed, the process recycles the ester co-product and increases the efficiency of ethanol production. In some embodiments, the catalyst of the present invention comprises one or more active metals on a modified support. Preferably, the modified support comprises support particles and a support modifier comprising a metal selected from the group consisting of tungsten, molybdenum, vanadium, niobium, chromium and niobium and mixtures thereof. In most embodiments, the support modifier is present as an oxide. One or more different oxides of each metal or metal mixture can be used as a support modifier. As discussed herein, the support modifier is added to the support from the polyoxometallate precursor.

One or more active metals may be impregnated on the support. In one embodiment, the one or more active metals are selected from the group consisting of copper, calcium, barium, magnesium, strontium, iron, cobalt, nickel, ruthenium, rhodium, platinum, palladium, iridium, osmium, titanium, zinc, chromium, molybdenum, A group of tungsten, tin, antimony, bismuth, manganese and gold. In one embodiment, the catalyst does not contain any defects. In a preferred embodiment, the one or more active metals are selected from the group consisting of platinum, palladium, nickel, cobalt, copper, and tin. The total weight of all active metals present in the catalyst is preferably from 0.1 to 25% by weight, such as from 0.1 to 15% by weight, or from 0.1% to 10% by weight. For the purposes of this specification, unless otherwise indicated, the weight percentages are based on the total weight of the catalyst comprising the metal and the support.

In some embodiments, the catalyst contains at least two active metals in addition to the noble metal. The two active metals may be selected from any of the above listed active metals as long as they are different from or different from the noble metal. Preferably, the metals are a combination of copper, iron, cobalt and tin. Cobalt and tin are examples of catalysts for converting alkanoic acids and their esters to ethanol. The precious metal may be selected from the group consisting of nickel, ruthenium, rhodium, platinum, palladium, rhodium, iridium and gold. The noble metal may be in an elemental state or a molecular state, such as an oxide of a noble metal. The catalyst may comprise a precious metal in an amount of from 0.05 to 10% by weight, such as from 0.1 to 5% by weight or from 0.1 to 3% by weight, based on the total weight of the catalyst. Preferably, the catalyst comprises less than 5% by weight, such as less than 3% by weight or less than 1.5% by weight of the precious metal.

In another embodiment, the catalyst may comprise two active metals or three active metals. The first metal or its oxide may be selected from the group consisting of cobalt, ruthenium, rhodium, platinum, palladium, rhodium, iridium and gold. Into the group. The second metal or oxide thereof may be selected from the group consisting of copper, iron, tin, cobalt, nickel, zinc, and molybdenum. The third metal or an oxide thereof, if present, may be selected from the group consisting of copper, molybdenum, tin, chromium, iron, cobalt, vanadium, palladium, platinum, rhodium, ruthenium, manganese, ruthenium, gold, and nickel. Preferably, the third metal is different from the first metal and the second metal. Furthermore, the first metal and the second metal may be different and the third metal and the second metal may be different.

The metal loadings of the first metal, the second metal, and optionally the third active metal are as follows. The first active metal may be present in the catalyst in an amount from 0.05 to 20% by weight, such as from 0.1 to 10% by weight or from 0.5 to 5% by weight. The second active metal may be present in an amount from 0.05 to 20% by weight, such as from 0.1 to 10% by weight or from 0.5 to 8% by weight. If the catalyst further comprises a third active metal, the third active metal may be present in an amount from 0.05 to 20% by weight, such as from 0.05 to 10% by weight or from 0.5 to 8% by weight. The active metals may be alloyed with one another or may comprise a non-alloyed metal solution, a metal mixture or exhibit one or more metal oxides. For the purposes of this specification, unless otherwise indicated, the weight percentages are based on the total weight of the catalyst including the metal and the support.

Some exemplary catalyst compositions include platinum/tin, platinum/ruthenium, platinum/cobalt, platinum/nickel, palladium/ruthenium, palladium/cobalt, palladium on the support and bimetallic catalysts other than tungsten. Copper, palladium/nickel, ruthenium/cobalt, gold/palladium, ruthenium/iron, ruthenium/iron, ruthenium/cobalt, ruthenium/nickel, cobalt/tin, and bismuth/tin. More preferred bimetallic catalysts include platinum/tin, platinum/cobalt, platinum/nickel, palladium/cobalt, palladium/copper, palladium/nickel, ruthenium/cobalt, ruthenium/iron, ruthenium/iron, ruthenium/cobalt, ruthenium/nickel , cobalt / tin, and antimony / tin.

In some embodiments, the catalyst can be a three-way catalyst that includes three active metals on the support. Exemplary ternary catalysts other than tantalum and tungsten on the support may include palladium/cobalt/tin, platinum/tin/palladium, platinum/tin/iridium, platinum/tin/gold, platinum/tin/ruthenium, platinum. /tin/cobalt, platinum/tin/chromium, platinum/tin/copper, platinum/tin/zinc, platinum/tin/nickel, niobium/nickel/tin, niobium/cobalt/tin and niobium/iron/tin. More preferably, the ternary catalyst comprises three active metals, which may include palladium/cobalt/tin, platinum/tin/palladium, platinum/cobalt/tin, platinum/tin/chromium, platinum/tin/copper, platinum/tin/nickel,铑 / nickel / tin, bismuth / cobalt / tin and bismuth / iron / tin.

The preferred proportion of metal can vary depending on the active metal used in the catalyst. In some embodiments, the first active metal is preferably from 20:1 to 1:20 for the second active metal, such as from 15:1 to 1:15, from 12:1 to 1:12.

In one or more active metals such as one or more first metals, second metals or The third metal is sequentially applied to the catalyst, that is, in the specific example of application in a plurality of impregnation steps, the catalyst may include a plurality of "theoretical layers". For example, when the first metal is impregnated on the support and then impregnated with the second metal, the resulting catalyst may have a first theoretical layer comprising a first metal and a second theoretical layer comprising a second metal. As noted above, in certain aspects, more than one active metal precursor can be simultaneously impregnated onto the support in a single step, and thus the theoretical layer can include more than one metal or metal oxide. On the other hand, the same metal precursor can be impregnated in multiple sequential impregnation steps, resulting in the formation of multiple theoretical layers containing the same metal or metal oxide. In this regard, although the term "layers" is used, it will be understood by those skilled in the art that the multiple layers may or may not be formed on the catalyst carrier, for example, the conditions used in the formation of the catalyst, The amount of metal used in each step depends on the particular metal used.

This catalyst has been found to be particularly effective as a multifunctional hydrogenation catalyst which converts both an alkanoic acid such as acetic acid and an ester thereof such as ethyl acetate to its corresponding alcohol such as ethanol under hydrogenation conditions.

Carrier material

The catalyst of the present invention can be on any suitable support material, preferably on a modified support material. In a specific example, the support material may be an inorganic oxide. In a specific example, the support material may be selected from the group consisting of cerium oxide, aluminum oxide, titanium oxide, cerium oxide/alumina, calcium metasilicate, pyridinium oxide, high purity cerium oxide, zirconium oxide, carbon (such as carbon black ( A group of carbon black) or activated carbon), zeolites, and mixtures thereof. Preferably, the support material comprises cerium oxide. In a preferred embodiment, the support material is present in an amount of from 25% to 99% by weight, such as from 30% to 98% by weight or from 35 to 95% by weight, based on the total weight of the catalyst.

In a preferred embodiment, the support material comprises a enamel support material, such as having a surface area of at least 50 m ² /g (m ² /g), such as at least 100 m ² /g, at least 150 m ² /g, at least 200 m ² /g or at least 250 m ² /g of cerium oxide. When expressed in terms of the range, the enamel support material is preferably from 50 to 600 m ² /g, such as from 100 to 500 m ² /g or from 100 to 300 m ² /g. The high surface area cerium oxide used throughout the specification means cerium oxide having a surface area of at least 250 m ² /g. For the purposes of this specification, surface area means BET nitrogen surface area, meaning surface area as determined by ASTM D6556-04, which is incorporated herein by reference in its entirety.

The preferred enamel carrier material is also preferably an average pore diameter of from 5 to 100 nm (nano) as measured by mercury intrusion porosimetry, such as from 5 to 30 nm, from 5 to 25 nm or from From about 5 to 10 nm, and having an average pore volume of from 0.5 to 2.0 cm ³ /g (cm ³ /g) as measured by a pressure hole meter, such as from 0.7 to 1.5 cm ³ /g or from about 0.8 to 1.3 cm ³ /g.

The morphology of the support material can vary widely and thus the morphology of the resulting catalyst composition can vary widely. In some specific examples, the carrier material and/or the catalyst composition may be in the form of a pellet, an extrudate, a sphere, a spray-dried microsphere, a ring, a pentacyclic, a trilobal, a tetralobal, Multilobal or flaky, but preferably cylindrical granules. Preferably, the enamel support material has a morphology such that the packing density is from 0.1 to 1.0 g/cm ³ (g/cm ³ ), such as from 0.2 to 0.9 g/cm ³ or from 0.5 to 0.8 g/cm ³ . When expressed in terms of size, the cerium oxide support material preferably has an average particle diameter of from 0.01 to 1.0 cm (cm), such as from 0.1 to 0.7 cm or from 0.2 to 0.5 cm, the particle size means for spherical particles The average diameter or for non-spherical particles means the average longest dimension. Since the precious metal and the one or more metals on the support are typically in the form of metal (or metal oxide) particles or crystals that are extremely small relative to the size of the support, such substantially the size of the overall catalyst particles should be Will not have an impact. Thus, the above particle size is typically applied to both the support and the final catalyst particles, but the catalyst particles are preferably processed to form larger catalyst particles, such as extruded to form catalyst particles.

A preferred cerium oxide support material is the SS61138 high surface area (HSA) cerium oxide catalyst carrier available from Saint-Gobain NorPro. Saint-Gobain NorPro SS61138 cerium oxide contains about 95% by weight of high surface area cerium oxide; surface area of about 250 m ² /g; median pore diameter of about 12 nm; average pore volume measured by mercury porosimeter of about 1.0 cm ³ /g; The density is about 0.352 g/cm ³ .

A preferred cerium oxide/alumina support material is KA-160 (Süd Chemie) cerium oxide sphere having a nominal diameter of about 5 mm, a density of about 0.562 g/ml, and an absorption of about 0.583 gram of H ₂ O per gram of support. The ratio, the surface area of about 160 to 175 m ² /g, and the pore volume of about 0.68 ml / g.

Support modifier

The support material is preferably a support modifier which is added to the support material using a polyoxometallate precursor. The bulk modifier can adjust the acidity of the support material. In another embodiment, the support modifier can be an alkaline modifier having low or no volatility. In one embodiment, the support modifier is present in an amount of from 0.1% by weight to 50% by weight, based on the total weight of the catalyst, such as from 0.2% by weight to 25% by weight, from 0.5% by weight to 15% by weight, Or from 1% by weight to 12% by weight.

As shown, the bulk modifier can adjust the acidity of the support. For example, the acid moiety on the support material such as Brinec acid (Br The nsted acid) moiety can be adjusted by the support modifier to favor the selectivity to ethanol during the hydrogenation of acetic acid and/or its ester. The acidity of the support material can be adjusted by optimizing the surface acidity of the support material. The support material can also adjust and change the pKa of the support material by having the support modifier. Unless otherwise stated in the specification, the amount of surface acidity or acid sites thereon may be determined by F. Delannay, Ed., "Characterization of Heterogeneous Catalysts"; Chapter III: Measurement of Acidity of Surfaces, p. 370-404; Marcel Dekker , the technique described by Inc., NY 1984, which is incorporated herein by reference in its entirety. usually. The surface acidity of the support can be adjusted based on the composition of the feed stream to be fed to the hydrogenation process to maximize the production of alcohol, such as ethanol.

In some embodiments, the support material can be an acidic modifier that increases the acidity of the catalyst. Suitable acidic carrier modifiers may be selected from the group IVB metal oxides, the Group VB metal oxides, the Group VIB metal oxides, the Group VIIB metal oxides, the Group VIII metal oxides, a group of alumina and mixtures thereof. The acidic carrier modifier includes those selected from the group consisting of TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , Al ₂ O ₃ , B ₂ O ₃ , P ₂ O ₅ and Sb ₂ O ₃ . . Preferred acidic carrier modifiers include those selected from the group consisting of TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ and Al ₂ O ₃ . The acidic modifier also includes those selected from the group consisting of WO ₃ , MoO ₃ , Fe ₂ O ₃ , Cr ₂ O ₃ , V ₂ O ₅ , MnO ₂ , CuO, Co ₂ O ₃ , P ₂ O ₅ and P ₄ O ₁₀ And a group consisting of Bi ₂ O ₃ . It has been unexpectedly and unexpectedly discovered that the use of such a metal oxide support modifier in combination with a noble metal and one or more active metals produces a versatile catalyst which is suitable for use under hydrogenation conditions. Alkanoic acids such as acetic acid and its corresponding esters such as ethyl acetate are converted to one or more hydrogenation products such as ethanol.

In some embodiments, the acidic support modifier comprises a mixed metal oxide comprising at least one active metal of Group IVB, Group VB, Group VIB, Group VIII such as tungsten, molybdenum, vanadium, niobium or tantalum and oxidation. Anion. The oxide anion can be, for example, in the form of a tungstate, a molybdate, a vanadate or a citrate. Exemplary mixed metal oxides include cobalt tungstate, copper tungstate, iron tungstate, zirconium tungstate, manganese tungstate, cobalt molybdate, copper molybdate, iron molybdate, zirconium molybdate, manganese molybdate, vanadic acid Cobalt, copper vanadate, iron vanadate, zirconium vanadate, manganese vanadate, cobalt ruthenate, copper ruthenate, iron ruthenate, zirconium ruthenate, manganese ruthenate, cobalt ruthenate, copper ruthenate, iron citrate, Zirconium silicate and manganese ruthenate. Catalysts containing such mixed metal support modifiers have been found to provide the desired degree of multifunctionality at increased conversion rates, such as increased ester conversion, and to reduce by-product formation, such as Reduce the formation of diethyl ether.

In one embodiment, the catalyst comprises from 0.25 to 1.25 wt% platinum, from 1 to 10 wt% cobalt, and from 1 to 10 wt% iron on the yttria or yttria-alumina support material. The support material may comprise from 5 to 15% by weight of an acidic support modifier such as WO ₃ , V ₂ O ₃ and/or MoO ₃ . In one embodiment, the acidic modifier may include, for example, cobalt tungstate in an amount of from 5 to 15% by weight.

In some embodiments, the modified support includes one or more active metals in addition to one or more acidic modifiers. The modified support may, for example, comprise one or more metals selected from the group consisting of copper, iron, cobalt, vanadium, nickel, titanium, zinc, chromium, molybdenum, tungsten, tin, antimony, bismuth, and manganese. For example, the support may comprise an active metal, preferably a non-noble metal, and an acidic or alkaline support modifier. Preferably, the support modifier comprises a support modifier metal selected from the group consisting of tungsten, molybdenum, vanadium, niobium and tantalum. In this regard, the final catalyst composition includes a precious metal and one or more active metals on the modified support. In a preferred embodiment, at least one of the active metals in the modified support is the same as the at least one active metal on the support. For example, the catalyst may include a support modified with cobalt, tin, and tungsten (as appropriate, as WO ₃ and/or as cobalt tungstate). In this example, the catalyst further includes a noble metal such as palladium, platinum or rhodium, and at least one active metal such as cobalt and/or tin on the modified support.

Process for manufacturing catalyst

The invention also relates to a process for making the catalyst. Without wishing to be bound by theory, the process of making the catalyst can improve one or more of acetic acid conversion, ester conversion, ethanol selectivity, and overall yield. In one embodiment, the support system is modified with one or more support modifiers and the resulting modified support is substantially impregnated with a noble metal and one or more active metals to form a catalyst composition. For example, the support may be impregnated with a bulk modifier solution comprising a bulk modifier precursor and, optionally, one or more active metal precursors to form a modified support. After drying and calcination, the resulting modified support is impregnated with a second solution comprising a precious metal precursor and, optionally, one or more active metal precursors, followed by drying and calcination to form the final catalyst.

In this embodiment, the support modifier solution may comprise a bulk modifier metal precursor and one or more active metal precursors, more preferably at least two active metal precursors. Preferably, the precursor is comprised of a salt of an individual metal in solution which upon heating converts to an elemental metal state or a metal oxide. In this embodiment, since two or more active metal precursors and the support modifier precursor are simultaneously impregnated on the support material, one or more of the obtained active metals may be formed after the molecular metal and the support The bulk modifier metals interact to form one or more polymetallic crystalline species such as cobalt tungstate. In other embodiments, one or more of the active metals will not interact with the support modifier metal precursor and be deposited separately on the support material, such as as a separate metal nanoparticle or an amorphous metal mixture. Therefore, the support material can be modified with one or more active metal precursors while being modified with the support modifier metal, and the resulting active metal can be formed with or without interaction with the support modifier metal. One or more polymetallic crystalline species.

In some embodiments, the support modifier can be added to the support material as particles. For example, one or more of the support modifier precursors may be added to the support material by mixing the support modifier particles with the support material in water if desired. When mixing, it is preferred to use a bulk modifier such as calcium citrate powder for a certain bulk modifier. When a powdered material is used, the support modifier can be granulated, pulverized, and sieved before being added to the support.

As shown, in most of the specific examples, the support modifier is preferably added via a wet impregnation step. Preferably, the support modifier precursor for the support modifier can be used. Some exemplary support modifier precursors include an alkali metal oxide, an alkaline earth metal oxide, a Group IIB metal oxide, a IIIB metal oxide, a Group IVB metal oxide, a Group VB metal oxide, Group VIB metal oxides, Group VIIB metal oxides, and/or Group VIII metal oxides, and preferably aqueous salts thereof.

Although overwhelming major amounts of metal oxides and polyoxoion salts are insoluble, or have poorly defined or limited solution chemistry, early transition elements are isopoly- and heteropolyoxoions (heteropolyoxoanions) ) Form important exceptions. These complexes can be represented by the following general indication: [M _m O _y ] ^p- isopolyanion (Isopolyanions)

[X _x M _m O _y ] ^q- (x m) Heteropolyanions

Wherein M is selected from the group consisting of tungsten, molybdenum, vanadium, niobium, tantalum and mixtures thereof in the highest (d ⁰ , d ¹ ) oxidation state. This multi-sided oxymetalate anion forms a complex of different structural classes, based primarily on (but not exclusively) quasi-octahedrally-coordinated metal atoms. The element which functions as an additional atom M in the heteropoly- or heteropolyanion may be limited to such an element having both an advantageous combination of an ionic radius and a charge and an ability to form a d _π -p _π MO bond. However, there are very few restrictions on the hetero atom X, which may be substantially selected from any element other than a rare gas. See, for example, MTPope, Heteropoly and Isopoly Oxometalates , Springer Verlag, Berlin, 1983, 180; Chapt. 38, Comprehensive Coordination Chemistry , Vol. 3, 1028-58, Pergamon Press, Oxford, 1987, which is incorporated herein by reference in its entirety.

Polyoxometalates (POMs) and their corresponding heteropolyacids (HPAs) have several advantages that make them economically and environmentally attractive. First, HPAs have a very strong acidity to reach the acidity of the super acid region. In addition, it exhibits rapid reversible multi-electron redox conversion under relatively mild conditions as a potent oxidant. Solid HPAs also have isolated ionic structures, including commonly moving basic structural units such as heteropolyanions and counter cations (H ⁺ , H ₃ O ⁺ , H ₅ O ₂ ^{+ ,} etc.), unlike zeolites and metal oxides. .

Preferably, the support modifier precursor comprises a POM, preferably comprising a metal selected from the group consisting of tungsten, molybdenum, niobium, vanadium and niobium. In some embodiments, the POM comprises a hetero-POM. Non-limiting lists of suitable POMs include ammonium metatungstate ((NH ₄ ) ₆ H ₂ W ₁₂ O ₄₀ .x H ₂ O), ammonium heptamolybdate tetrahydrate ((NH ₄ ) ₆ Mo ₇ O ₂₄ . 4 H ₂ O), samarium tungstate hydrate (H ₄ SiW ₁₂ O ₄₀ .H ₂ O), phosphotungstic acid (H ₃ PW ₁₂ O ₄₀ .n H ₂ O), lanthanum molybdate (H ₄ SiMo ₁₂ O ₄₀ .n H ₂ O), phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ .n H ₂ O), bismuth oxalate hexahydrate ([Nb(HC ₂ O ₄ ) ₅ ].6 H ₂ O), vanadium oxide (V ₂ O ₅ ), ammonium vanadate (NH ₄ ) VO ₃ and mixtures thereof.

The use of POM-derived support modifiers in the catalyst compositions of the present invention has now unexpectedly and unexpectedly been shown to provide dual- or multi-functional catalyst functionality, resulting in the production of acetic acid and by-product esters such as acetic acid. The conversion of both of the ethyl esters is required, thus giving them a suitable feed for catalyzing a mixed feed comprising, for example, acetic acid and ethyl acetate.

The impregnation of the noble metal and the one or more active metals on the support, such as the modified support, can be carried out simultaneously (commonly impregnated) or sequentially. In simultaneous impregnation, the two or more metal precursors are mixed together and added together to the support, preferably to the modified support, followed by drying and calcination to form the final catalyst composition. . In order to simultaneously impregnate, it may be necessary to utilize a dispersing agent, a surfactant or a dissolving agent such as ammonium oxalate or an acid such as acetic acid or nitric acid to promote the first metal and the second metal when the two precursors are immiscible with a desired solvent such as water. / or dispersion or dissolution of the third metal precursor.

In the sequential impregnation, the first metal precursor may be first added to the support followed by drying and calcination, and the resulting material is then impregnated with a second metal precursor followed by additional drying and calcining steps to form the final catalyst composition. Things. An additional metal precursor (such as a third metal precursor) may be added with one of the first metal and/or the second metal precursor or another third impregnation step followed by drying and calcination.

In the step of upgrading the support, such as a step of impregnating the precursor of the support modifier with the support, it is preferred to use a solvent such as water, glacial acetic acid, a strong acid such as hydrochloric acid, nitric acid or sulfuric acid, or an organic solvent. The support modifier solution comprises a solvent, preferably water, a bulk modifier precursor, and preferably one or more active metal precursors. The solution is stirred and combined with the support material using, for example, incipient wetness techniques, wherein the support modifier precursor is added to the support material having the same pore volume as the solution volume. The impregnation system is carried out by adding (optionally adding) a solution containing one or both of the support modifier and/or the active metal to the dry support material. Then capillary action The modifier is attracted to the pores of the carrier material. Thus the impregnated support can then be dried by drying and optionally under vacuum to drive off the solvent and any volatile components of the support mixture and deposit the support modifier on the support material and/or Formed inside. Drying can be carried out, for example, from 1 to 24 hours, such as from 3 to 15 hours or 6 to 12 hours, from 50 ° C to 300 ° C, such as from 50 ° C to 200 ° C or about 120 ° C. The dry support may optionally be calcined by gradual heating, for example, from 300 ° C to 900 ° C, such as from 350 ° C to 850 ° C, from 400 ° C to 750 ° C, from 500 ° C to 600 ° C or at a temperature of about 550 ° C. The final modified support is formed from 1 to 12 hours, such as from 2 to 10 hours, from 4 to 8 hours, or about 6 hours. After heating and/or applying a vacuum, the metal of the precursor is preferably decomposed into its oxide or elemental state. In some instances, the solvent may not be completely removed prior to use of the catalyst and/or, for example, high temperature calcination during operation. This compound is converted to the catalytically active state of the metal or its catalytically active oxide during the calcination step, or at least during the initial use of the catalyst.

Once formed, the modified calcined support can be shaped into particles having a desired particle size distribution, for example, to form particles having an average particle size in the range of 0.2 to 0.4 cm. The support can be extruded, pelletized, tableted, pressed, comminuted or sieved to the desired particle size distribution. Any known method of shaping the support into a desired particle size distribution can be used. Alternatively, a support granule can be used as a starting material for the manufacture of the modified support and the final catalyst is also a granule.

In one embodiment, the noble metal and one or more active metals are impregnated onto the support, preferably to any of the above modified supports. Preferred in the metal impregnation step is the use of a noble metal precursor such as a water soluble compound or a water dispersible compound/complex containing the relevant precious metal. Similarly, one or more active metal precursors may also be impregnated into the support, preferably impregnated into the modified support. Depending on the metal precursor used, it may be preferred to use a solvent such as water, glacial acetic acid, acetic acid, nitric acid or an organic solvent to aid in dissolving one or more metal precursors.

In one embodiment, individual solutions of the metal precursor are formed which are subsequently blended and impregnated onto the support. For example, a first solution comprising a first metal precursor can be formed, and a second solution comprising a second metal precursor and, optionally, a third metal precursor can be formed. At least one of the first metal, the second metal, and optionally the third metal precursor is preferably a noble metal precursor and He is preferably an active metal precursor (which may or may not include a precious metal). One or both of the solutions preferably include a solvent such as water, glacial acetic acid, acetic acid, hydrochloric acid, nitric acid or an organic solvent.

In one embodiment, a first solution comprising a first metal halide is prepared. The first metal halide optionally includes a tin halide such as tin chloride such as stannous chloride (II) and/or tin (IV) chloride. Optionally, a second metal precursor, either as a solid or as another solution, is combined with the first solution to form a combined solution. The second metal precursor, if used, preferably comprises a second metal oxalate, acetate, halide or nitrate such as cobalt nitrate. The first metal precursor optionally includes an active metal, optionally copper, iron, cobalt, nickel, chromium, molybdenum, tungsten or tin, and the second metal precursor, if present, optionally includes other active metals (also The situation is copper, iron, cobalt, nickel, chromium, molybdenum, tungsten or tin). A second solution comprising a noble metal precursor is also prepared in this embodiment, preferably a halide of a noble metal such as ruthenium, rhodium, platinum or palladium. The second solution is combined with the first solution or the combined solution to form a mixed metal precursor solution depending on whether the second metal precursor is required. The resulting mixed metal precursor solution can then be added to the support, optionally added to the upgrade support, followed by drying and calcination to form the final catalyst composition described above. The resulting catalyst may or may not be washed after the final stage of the calcination step. Since it is difficult to dissolve some of the precursors, it may be desirable to lower the pH of the first and/or second solution by, for example, using an acid such as acetic acid, hydrochloric acid or nitric acid such as 8M HNO ₃ .

In another aspect, a first solution comprising a first metal oxalate, such as copper, iron, cobalt, nickel, chromium, molybdenum, tungsten or tin oxalate, is prepared. In this embodiment, the first solution preferably further comprises an acid such as acetic acid, hydrochloric acid, phosphoric acid or nitric acid, such as 8M HNO ₃ . Optionally, a second metal precursor, either as a solid or as another solution, is combined with the first solution to form a combined solution. The second metal precursor, if used, preferably comprises a second metal oxalate, acetate, halide or nitrate and preferably comprises an active metal, optionally copper, iron, cobalt, nickel, chromium. , molybdenum, tungsten or tin. Also form a second solution comprising a noble metal oxalate such as rhodium, ruthenium, platinum or palladium oxalate, and optionally further comprises an acid such as acetic acid, hydrochloric acid, nitric acid or phosphoric acid, such as 8M HNO _3. The second solution is combined with the first solution or the combined solution to form a mixed metal precursor solution depending on whether the second metal precursor is required. The resulting mixed metal precursor solution can then be added to the support, optionally added to the upgrade support, followed by drying and calcination to form the final catalyst composition described above. The resulting catalyst may or may not be washed after the final stage of the calcination step.

In a specific example, the impregnation support, and optionally the impregnation reforming system, is dried at a temperature of from 100 ° C to 140 ° C, from 110 ° C to 130 ° C or from about 120 ° C, for a period of from 1 to 12 hours, Such as from 2 to 10 hours, from 4 to 8 hours or about 6 hours. If calcination is desired, it is preferred that the calcination temperature used in this step is lower than the calcination temperature used in the above-described reforming support. The second calcination step can be carried out, for example, at a temperature that is at least 50 ° C, at least 100 ° C, at least 150 ° C, or at least 200 ° C lower than the first calcination temperature, such as the calcination step used to form the upgraded support. For example, the impregnating catalyst may be calcined at a temperature of from 200 ° C to 500 ° C, from 300 ° C to 400 ° C, or from about 350 ° C, as the case may be from 1 to 12 hours, such as from 2 to 10 hours, from 4 to 8 Hours or about 6 hours.

In one embodiment, ammonium oxalate is used to promote the dissolution of at least one metal precursor, such as a tin precursor, as described in U.S. Patent Publication No. 2011/0190117 A1, which is incorporated herein by reference in its entirety. In this regard, the first metal precursor optionally includes a noble metal such as oxalate, palladium or platinum oxalate, and the second metal precursor optionally includes tin oxalate. The third metal precursor, if desired, includes a nitrate, halide, acetate or oxalate of chromium, copper or cobalt. In this regard, a solution of the second metal precursor can be made in the presence of the oxalate as a solubilizing agent, and the first metal precursor is added thereto, optionally as a solid or another solution. If a third metal precursor is used, it may be combined with a solution comprising the first metal and the second metal precursor or may be combined with a second metal precursor as a solid or as another solution, adding the first metal precursor . In other specific examples, an acid such as acetic acid, hydrochloric acid or nitric acid may be used in place of ammonium oxalate to promote dissolution of tin oxalate. The resulting mixed metal precursor solution can then be added to the support, optionally added to the upgraded support, followed by drying and calcination to form the final catalyst composition described above.

The particular precursors used in the various embodiments of the invention can vary widely. Suitable metal precursors can include, for example, metal halides, amine dissolved metal hydroxides, metal nitrates or metal oxalates. For example, suitable compounds for the platinum precursor and the palladium precursor include chloroplatinic acid, ammonium chloroplatinate, amine dissolved platinum hydroxide, platinum nitrate, ammonium tetranitrate platinum, platinum chloride, platinum oxalate, palladium nitrate, tetranitrate Ammonium palladium, palladium chloride, palladium oxalate, sodium palladium chloride, sodium platinum chloride and platinum nitrate Pt(NH ₃ ) ₄ (NO ₃ ) ₂ . Generally, an aqueous solution of a soluble compound of platinum and palladium is preferred from the economic and environmental aspects. In one embodiment, the first metal precursor is not a metal halide and is substantially free of metal halides. Without wishing to be bound by theory, such non-(metal halide) precursors are believed to increase the selectivity to ethanol. The preferred precursor of platinum is ammonium nitrate platinum Pt(NH ₃ ) ₄ (NO ₃ ) ₂ . The calcination of the solution containing the support and the activated metal may be carried out, for example, from 250 ° C to 800 ° C, such as from 300 to 700 ° C or about 500 ° C, for a period of from 1 to 12 hours, such as from 2 to 10 hours, From 4 to 8 hours or about 6 hours.

In one aspect, the "accelerator" metal or metal precursor is first added to the support followed by the addition of a "host" or "primary" metal or metal precursor. Of course, the order of addition can also be reversed. Exemplary precursors for promoter metals include metal halides, amine dissolved metal hydroxides, metal nitrates or metal oxalates. As described above, in the subsequent specific examples, it is preferred to carry out drying and calcination after each impregnation step. In the case of the promoted bimetallic catalyst as described above, sequential impregnation may be used to initially add the promoter metal, followed by a second impregnation step involving co-impregnation of two active metals such as Pt and Sn.

For example, PtSnCo/WO _{3 is} supported on SiO ₂ by first impregnating the WO ₃ precursor, preferably the POM precursor of WO ₃ on SiO ₂ , followed by platinum oxalate, oxalic acid Tin and cobalt nitrate are preferably prepared by co-impregnation in the presence of an acid such as acetic acid, hydrochloric acid or nitric acid. Again, the drying and calcining steps may be carried out after each impregnation step, while the second calcination temperature is preferably lower than the first calcination step. In other embodiments, the second metal and a third metal body prior to of WO ₃ on a common carrier body is impregnated, and WO ₃ optionally form a mixed oxide, such as tungsten, cobalt, followed by drying and firing. Preferably, the resulting modified support is impregnated with one or more of the first metal, the second metal, and the third metal in a single impregnation step, followed by a second drying and calcination. In this way, cobalt tungstate can be formed on the modified support. Again, the second calcination temperature is preferably lower than the first calcination step.

Using a catalyst to hydrogenate acetic acid

One of the advantages of the catalyst of the present invention is that the catalyst is used to produce the stability or activity of ethanol. Accordingly, it will be appreciated that the catalyst of the present invention is fully useful for commercial scale industrial applications of hydrogenated acetic acid, particularly for the manufacture of ethanol. In particular, it is achieved that the catalyst activity will have a production attenuation of less than 6% per 100 hours of use of the catalyst, such as less than 3% per 100 hours or less than 1.5% of production degradation per 100 hours. Preferably, the production attenuation rate is achieved by the catalyst. Determined under steady state conditions.

In one embodiment, the process of the present invention for producing ethanol is such that a feed comprising selected from the group consisting of acetic acid, ethyl acetate, and mixtures thereof is hydrogenated in the presence of any of the above catalysts. A particularly good reaction is the production of ethanol from acetic acid. The hydrogenation reaction can be expressed as follows: HOAc + 2 H ₂ → EtOH + H ₂ O

In some embodiments, the catalyst is characterized by a multifunctional catalyst that is effective to catalyze the reaction of hydrogenation of acetic acid to ethanol and the conversion of ethyl acetate to one or more products, preferably ethanol. The multifunctional catalyst does not produce ethyl acetate under steady state conditions, but consumes the ethyl acetate cycle at a rate substantially equal to the rate of ethyl acetate formation in the reactor.

The feedstock acetic acid and hydrogen fed to the hydrogenation reactor for use in the process of the present invention may be derived from any suitable source, including natural gas, petroleum, vehicle carbon, biomass materials, and the like. For example, acetic acid can be produced by methanol carbonylation, acetaldehyde oxidation, ethane oxidation, oxidative fermentation, and anaerobic fermentation. Methanol carbonylation processes suitable for the manufacture of acetic acid are described in U.S. Patent Nos. 7,208,624, 7,115, 772, 7,005, 541, 6, 657, 078, 6, 627, 770, 6, 143, 930, 5, 599, 976, 5, 144, 068, 5, 026, 908, 5, 001, 259, and 4, 994, 608, the entire disclosures of each of which are incorporated herein by reference. Ethanol production can be integrated with the methanol carbonylation process, as appropriate.

As oil and natural gas prices become expensive or cheaper, methods for producing acetic acid and intermediates such as methanol and carbon monoxide from alternative carbon sources are gaining attention. In particular, when petroleum is relatively expensive, it would be advantageous to produce acetic acid from a synthesis gas ("synthesis gas") derived from more available carbon sources. A method for retrofitting a methanol plant for the manufacture of acetic acid is taught, for example, in U.S. Patent No. 6,232,352, the entire disclosure of which is incorporated herein by reference. By retrofitting the methanol plant, the significant cost associated with carbon monoxide production in new acetic acid plants can be significantly reduced or substantially eliminated. All or part of the synthesis gas system is derived from a methanol synthesis loop and is supplied to a separator unit to recover carbon monoxide, which is then used to make acetic acid. In a similar manner, hydrogen from the hydrogenation step can be supplied from the syngas.

In some embodiments, some or all of the starting materials for the acetic acid hydrogenation process may be derived in part or in whole from the syngas. For example, acetic acid can be formed from methanol and carbon monoxide, both derived from syngas. The syngas can be formed by partial oxidation reforming or steam reforming, and carbon monoxide can be separated from the syngas. Similarly The hydrogen used in the step of hydrogenating acetic acid to form a crude ethanol product can be separated from the synthesis gas. This syngas can in turn be derived from a variety of carbon sources. The carbon source may, for example, be selected from the group consisting of natural gas, oil, petroleum, coal, biomass materials, or combinations thereof. Syngas or hydrogen can also be obtained from biologically derived methane gas such as biologically derived methane gas produced from waste landfill or agricultural waste.

In another embodiment, the acetic acid used in the hydrogenation step can be formed by fermentation from a biomass material. Preferably, the fermentation process utilizes a homoacetogenic process or a homoacetogenic microorganism to ferment the sugar to acetic acid and produce a very small amount, if any, of carbon dioxide as a by-product. The carbon efficiency of the fermentation process is preferably greater than 70%, greater than 80% or greater than 90% compared to conventional yeast processes which generally have a carbon efficiency of about 67%. Depending on the case, the microorganism used in the fermentation process is a genus of the genus Clostridium, Lactobacillus, Moorella, Thermoanaerobacter, C. a group consisting of Propionibacterium, Propionispera, Anaerobiospirillum, and Bacteriodes, and in particular, the species is selected from the group consisting of onychomycosis Clostridium formicoaceticum, Clostridium butyricum, Moorella thermoacetica, Thermoanaerobacter kivui, Lactobacillus delbrueckii, Propionibacterium acidipropionici ), a group consisting of Propionispera arboris, Anaerobiospirillum succinicproducens, Bacteriodes amylophilus, and Bacteroides ruminicola. Optionally, in the present process, the unfermented residue of all or part of the autologous material (e.g., lignan) can be gasified to form hydrogen which can be used in the hydrogenation step of the present invention. The exemplified fermentation process for the formation of acetic acid is described in U.S. Patent Nos. 6,509,180, 6,927,048, 7,074,603, 7,507,562, 7, 351, 559, 7, 601, 865, 7, 682, 812, and 7, 888, 082, incorporated herein by reference. See also U.S. Patent Publication Nos. 2008/0193989 and 2009/0281354, the entire contents of each of which are hereby incorporated by reference.

Examples of biomaterials include, but are not limited to, agricultural waste, forest products, turf and Other cellulosic materials, lumber residues in wood yards, cork sheets, hardwood chips, branches, trunks, leaves, bark, sawdust, substandard pulp, corn, corn stalks, wheat shavings, rice shavings, sugar cane bagasse, switchgrass, miscanthus, Animal waste, municipal waste, municipal sewage, commercial waste, grape pumice, apricot shell, large walnut shell, coconut shell, coffee grounds, grass, hay, wood, cardboard, paper, plastic and cloth. See, for example, U.S. Patent No. 7,884,253, the disclosure of which is incorporated herein by reference in its entirety. Other sources of biomass material are straw black liquor, a thick black liquid that is a by-product of the kraft pulp process used to convert wood into pulp, which is then dried for papermaking. The straw black liquor is an aqueous solution of lignin residues, hemicellulose and inorganic chemicals.

U.S. Reissue Patent No. RE 35,377, which is incorporated herein by reference in its entirety, is incorporated herein by reference. The process includes hydrogasification of a solid and/or liquid carbonaceous material to obtain a process gas that is cracked with other natural gas vapor to form a syngas. The syngas is converted to methanol which can be further carbonylated to acetic acid. This method also produces hydrogen which can be used in the above invention. U.S. Patent No. 5,821,111 discloses a process for the conversion of waste biomass material to syngas via gasification, and U.S. Patent No. 6,685,754 discloses a process for the manufacture of a hydrogen-containing gas composition such as a synthesis gas comprising hydrogen and carbon monoxide, which are incorporated herein by reference. reference.

The acetic acid fed to the hydrogenation reactor also includes other carboxylic acids and anhydrides as well as aldehydes and/or ketones such as acetaldehyde and acetone. Preferably, the feed comprises acetic acid and ethyl acetate. Suitable acetic acid feed streams include one or more compounds selected from the group consisting of acetic acid, acetic anhydride, acetaldehyde, ethyl acetate, diethyl acetal, diethyl ether, and mixtures thereof. These other compounds may also be hydrogenated in the process of the invention. In some embodiments, the presence of a carboxylic acid such as propionic acid or an anhydride thereof may be advantageous for the manufacture of propanol. Water can also be present in the acetic acid feed.

Alternatively, the acetic acid in the vapor state can be obtained directly as a crude product from a flash vessel of a methanol carbonylation unit as described in U.S. Patent No. 6,657,078, the disclosure of which is incorporated herein in its entirety. The crude steam product can, for example, be fed directly into the hydrogenation reactor without the need to condense or remove water from the acetic acid and light hydrocarbons, thereby saving overall processing costs.

The acetic acid can be vaporized at the reaction temperature, and then the vaporized acetic acid can be fed together with an undiluted state or hydrogen diluted with a relatively inert carrier such as nitrogen, argon, helium, carbon dioxide or the like. In. For the reaction operation in the vapor phase, the temperature in the system should be controlled so as not to fall below the dew point of the acetic acid. In one embodiment, acetic acid can be vaporized at a specific pressure at the boiling point of acetic acid, and then the vaporized acetic acid can be further heated to the reactor inlet temperature. In another embodiment, the acetic acid is mixed with other gases prior to vaporization, and the mixed steam is then heated to the reactor inlet temperature. Preferably, the acetic acid is transferred to the vapor state by passing hydrogen and/or a recycle gas through the acetic acid at a temperature of 125 ° C or less, followed by heating the combined gas stream to the reactor inlet temperature.

The reactors in some embodiments may include various configurations using fixed bed reactors or fluid bed reactors. In many embodiments of the invention, a "adiabatic" reactor can be used, i.e., there is little or no need to pass an internal conduit into the reaction zone to add or remove heat. In other embodiments, a radial flow reactor or reactors may be utilized, or a set of reactors in series may be utilized, whether or not with or without heat exchange, quenching or introduction of additional feed materials. Alternatively, a shell with a heat transfer medium and a tubular reactor can be used. In many instances, the reaction zone can be contained in a single vessel or in a tandem vessel having a heat exchanger therebetween.

In a preferred embodiment, a catalyst is used in a fixed bed reactor, such as a straight tube or a tubular reactor, where the generally gaseous reactant passes over or within the catalyst. Other reactors such as fluid or ebullient bed reactors can be used. In some instances, the hydrogenation catalyst can be combined with an inert material to adjust the pressure drop of the reactant stream through the catalyst bed and the contact time of the reactant compound with the catalyst particles. In some embodiments, multiple catalyst beds are used in the same reactor or in different reactors, such as different reactors in series. For example, in one embodiment, the first catalyst functions as a catalyst for hydrogenating an alkanoic acid such as acetic acid to its corresponding alcohol such as ethanol in the first catalyst stage, and the second multifunctional catalyst is used in The second stage is used to convert unreacted acetic acid to ethanol and to convert by-product esters such as ethyl acetate to additional products, preferably to ethanol. The catalyst of the present invention can be used in one or both of the first and/or second stages of such a reaction system.

The hydrogenation reaction in the reactor can be carried out in the liquid phase or in the vapor phase. Preferably, the reaction is carried out in the vapor phase under the following conditions. The reaction temperature may range from 125 ° C to 350 ° C, such as from 200 ° C to 325 ° C, from 225 ° C to 300 ° C, or from 250 ° C to 300 ° C. The pressure can range from 10 kPa to 3000 kPa, such as from 50 kPa to 2300 kPa, or from 100 kPa to 2000 kPa. The reaction may be greater than 500 hr ^-1 (h ^-1), 1000hr ^-1, for example, greater than, greater than, or even greater than 2500 hr ^-1 gas hourly space velocity of 5000 hr ^-1 (a GHSV) fed into the reactor. When expressed in a range of GHSV may range from 50,000hr ^-1 to 50hr ^-1, the self-500hr ^-1 to 30,000hr ^-1, from 1000hr ^-1 to 10,000hr ^-1, or from 1000hr ^-1 to 6500hr ^1- .

The hydrogenation reaction can be carried out at a pressure just sufficient to overcome the pressure drop across the catalyst bed at the selected GHSV, although higher pressures are not excluded, but should be understood at high space velocity, such as 5000 hr ^-1 or 6,500. A pressure drop across the reaction bed at hr ^-1 may experience considerable pressure drop.

Although the reaction consumes two moles of hydrogen per mole of acetic acid to produce one mole of ethanol, the actual molar ratio of hydrogen to acetic acid in the feed stream can vary from about 100:1 to 1:100, such as from 50. : 1 to 1:50, from 20:1 to 1:2, or from 12:1 to 1:1. Preferably, the molar ratio of hydrogen to acetic acid is greater than 2:1, such as greater than 4:1 or greater than 8:1. In the case of a mixed source, the molar ratio of hydrogen to ethyl acetate can be greater than 5:1, such as greater than 10:1, or greater than 15:1.

Contact or residence times can also vary widely, depending on various variables such as the amount of feed (acetic acid and / or ethyl acetate), catalyst, reactor, temperature and pressure. When a catalyst system is used instead of a fixed bed, the typical contact time ranges from a few milliseconds to over several hours, and at least the preferred contact time for the vapor phase reaction is from 0.1 to 100 seconds, for example from 0.3 to 80 seconds or from 0.4 to 30 seconds.

In particular, by utilizing the catalyst of the present invention, hydrogenation of acetic acid and/or ethyl acetate in the reactor can achieve favorable conversion and advantageous selectivity and yield to ethanol. For the purposes of the present invention, the term "conversion" means the net change in the flow of acetic acid or ethyl acetate into the reactor as compared to acetic acid or ethyl acetate. The conversion is expressed as a percentage of acetic acid or ethyl acetate in the feed. The acetic acid conversion can be at least 20%, more preferably at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 99%.

Ethyl acetate may also be produced as a by-product during the hydrogenation of acetic acid. Any ethyl acetate in the mixed vapor phase reactant is not consumed and the conversion of ethyl acetate will be considered a negative value. Catalysts with negative conversion rates may result in the accumulation of ethyl acetate required in the system, especially for systems that use one or more streams recycled to the reactor.

However, the catalyst of the present invention is multifunctional, which can effectively catalyze the conversion of acetic acid to ethanol. And catalyzing the conversion of an alkyl acetate such as ethyl acetate to one or more products other than the alkyl acetate. Preferably, the multifunctional catalyst is effective for consuming ethyl acetate at a rate large enough to at least offset the rate of ethyl acetate production, thereby resulting in a non-negative ethyl acetate conversion, which is also understood to be acetic acid. The net value of the ester did not increase. The use of such a catalyst can result in, for example, an ethyl acetate conversion of effectively 0% or greater than 0%. In some embodiments, the catalyst of the present invention is effective to provide at least 5%, such as at least 10%, at least 15%, at least 20%, or at least 35% ethyl acetate conversion per pass.

In a continuous process, the ethyl acetate to be added (e.g., recycled) to the hydrogenation reactor and the ethyl acetate in the crude product leaving the reactor is preferably at a certain amount after the process reaches equilibrium. The use of a multifunctional catalyst that catalyzes the conversion of ethyl acetate and acetic acid results in a reduction in the amount of ethyl acetate added to the reactor and the production of less ethyl acetate. In a preferred embodiment, the ethyl acetate concentration in the mixed feed and the crude product is less than 40% by weight, less than 25% by weight, or less than 15% by weight after equilibrium. In a preferred embodiment, the process forms a crude product comprising ethanol and ethyl acetate, and the crude product has from 0.1 to 40% by weight, such as from 0.1 to 20% by weight or from 0.1 to 10% by weight of ethyl acetate. concentration.

While a catalyst having a high acetic acid conversion is desirable, such as at least 60%, in some embodiments, low conversion but high selectivity to ethanol is acceptable. It should of course be understood that in many cases it may be possible to compensate for conversion by appropriate recycle streams or by using larger reactors, but poor selectivity is more difficult to compensate.

The selectivity is expressed as the percentage of moles based on converted acetic acid and/or ethyl acetate. It will be appreciated that each compound converted from acetic acid and/or ethyl acetate has an independent selectivity and that the selectivity and conversion are also independent of each other. For example, if 60 mole % of converted acetic acid is converted to ethanol, the ethanol selectivity is said to be 60%. For the purposes of the present invention, the overall selectivity is based on the combined converted acetic acid and ethyl acetate. Preferably, the total selectivity to ethanol is at least 60%, such as at least 70%, or at least 80%, at least 85%, or at least 88%. Preferred embodiments of the hydrogenation process also have low selectivity for undesirable products such as methane, ethane and carbon dioxide. The selectivity for these undesirable products is preferably less than 4%, such as less than 2% or less than 1%. More preferably, the undesired products are present in a non-detectable amount. The formation of alkanes may be lower and ideally less than 2%, less than 1% or less than 0.5% of acetic acid through the catalyst. It is converted to alkanes, which have only a very low value except for use as a fuel.

As used herein, the term "yield" means based on the kilogram of catalyst used per hour being more than the grams of a particular product formed during hydrogenation, such as ethanol. Preferably, the production is at least 100 grams of ethanol per kilogram of catalyst per hour, such as at least 400 grams of ethanol per kilogram of catalyst per hour or at least 600 grams of ethanol per kilogram of catalyst per hour. When expressed in terms of range, the production volume is preferably from 100 to 3,000 grams of ethanol per kilogram of catalyst per hour, such as from 400 to 2,500 grams of ethanol per kilogram of catalyst per hour, or from 600 per kilogram of catalyst per hour. Up to 2,000 grams of ethanol.

Operation under the conditions of the present invention can produce an ethanol production of at least 0.1 ton per hour, such as at least 1 ton of ethanol per hour, at least 5 tons of ethanol per hour, or at least 10 tons of ethanol per hour. Larger industrial scale ethanol production, depending on the size, should typically produce at least 1 ton of ethanol per hour, such as at least 15 tons of ethanol per hour, or at least 30 tons of ethanol per hour. In terms of ranges, the process of the present invention can produce from 0.1 to 160 tons of ethanol per hour for larger ethanol manufacturing industries, such as 15 to 160 tons of ethanol per hour, or 30 to 80 tons of ethanol per hour. Ethanol Production by Fermentation Due to the economic scale, generally a single plant ethanol production cannot achieve a scale that can be achieved by using a specific example of the present invention.

In various embodiments of the invention, the crude ethanol product produced by the reactor generally includes unreacted acetic acid, ethanol, and water prior to any subsequent processing, such as purification and separation. An exemplary composition range of the crude ethanol product is shown in Table 1. The definitions of "others" in Table 1 may include, for example, esters, ethers, aldehydes, ketones, alkanes, and carbon dioxide.

In one embodiment, the crude ethanol product can include acetic acid in an amount of less than 20% by weight, such as less than 15% by weight, less than 10% by weight, or less than 5% by weight. When expressed in terms of ranges, the acetic acid concentration in Table 1 may be from 0.1% by weight to 20% by weight, such as from 0.1% by weight to 15% by weight, from 0.1% by weight to 10% by weight or from 0.1% by weight to 5% by weight. In a specific example having a lower amount of acetic acid, the conversion of acetic acid is preferably greater than 75%, such as greater than 85% or greater than 90%. In addition, the selectivity for ethanol is also higher, and preferably greater than 75%, such as greater than 85% or greater than 90%. Further, the conversion of ethyl acetate may be greater than 0%, preferably greater than 5%.

The ethanol product can be recovered from the crude ethanol product produced from the reactor using the catalyst of the present invention using several different separation techniques.

The ethanol product may be an industrial grade ethanol comprising from 75 to 96% by weight ethanol, such as from 80 to 96% by weight or from 85 to 96% by weight ethanol, based on the total weight of the ethanol product. In some embodiments, when further water separation is used, the ethanol product preferably contains ethanol in an amount greater than 96% by weight, such as greater than 98% by weight or greater than 99.5% by weight ethanol. The ethanol product in this aspect preferably comprises less than 3% by weight water, such as less than 2% by weight or less than 0.5% by weight water.

The finished ethanol composition prepared by the specific examples of the present invention can be used for various purposes, including as a fuel, a solvent, a chemical raw material, a pharmaceutical product, a detergent, a disinfectant, hydrogen transport or consumption. In fuel applications, the finished ethanol composition can be blended with gasoline for vehicles such as automobiles, boats, and small piston engine aircraft. For non-fuel applications, the finished ethanol composition can be used as a solvent for hygiene and cosmetic preparations, detergents, disinfectants, coatings, inks, and pharmaceuticals. The finished ethanol composition can also be used as a processing solvent in the manufacturing process of pharmaceutical products, food preparations, dyes, photochemicals, and latex processing.

The completed ethanol composition can also be used as a chemical raw material to manufacture other chemicals such as vinegar, ethyl acrylate, ethyl acetate, ethylene, glycol ethers, ethylamines, ethylbenzene, aldehydes, butadiene and advanced Alcohols are especially butanol. In the manufacture of ethyl acetate, the finished ethanol composition can be esterified by acetic acid. In other applications, the finished ethanol composition can be dehydrated to produce ethylene. Any of the known dehydration catalysts can be used to dehydrate the ethanol, as described in the unexamined U.S. Patent Publication Nos. 2010/0030002 and 2010/0030001, the entire contents of which are incorporated herein by reference. Revealed and incorporated herein by reference. For example, a zeolite catalyst can be used as the dehydration catalyst. Preferably, the zeolite has a pore diameter of at least about 0.6 nm, and preferably the zeolite comprises a dehydration catalyst selected from the group consisting of mordenite, ZSM-5, zeolite X and zeolite Y. Zeolite X is described in, for example, U.S. Patent No. 2,882,244, the disclosure of which is incorporated herein by reference.

The following examples describe the catalysts and processes of the present invention.

I. Examples 1-8

Eight platinum/tin/cobalt catalysts of Examples 1-8 were prepared using different support modifiers. The resulting catalyst was then tested in a hydrogenation unit as a mixed feed. The catalyst compositions of Examples 1-8 are shown in Table 2.

Catalyst preparation overview

A commercially available high surface area (HAS) SiO _{2 support} (HSA SS #61138, 3 mm pellet, NorPro) was used as the starting material for the transition metal oxide upgrading support. Typically, the catalyst system is prepared by impregnating the SiO ₂ extrudates with an aqueous solution of a corresponding W, Mo, Nb or V polyoxometalate (POM) precursor (see experimental paragraph), It was then dried at 120 ° C and calcined at 550 ° C in air. The catalyst for supporting the metal is carried out by a single-step incipient wetness method using Sn, Co, and Pt in an aqueous solution of dilute nitric acid and a metal oxide-modified cerium oxide support.

A [SiO ₂ -MO _x (n)] catalyst carrier (M = W, Mo, Nb, V) was prepared using the molar amount of the transition metal M described above. The corresponding amount of oxide n is therefore provided in parentheses in % by weight. The preparation of individual catalysts and supports is detailed in the experimental paragraphs. The catalyst preparation method is shown in Figure 1. The catalytic activity of the corresponding catalyst holding {PtCoSn} is summarized in Table 3.

experiment

Materials: Metal precursor tin(II) oxalate SnC ₂ O ₄ and cobalt (II) nitrate hexahydrate Co(NO ₃ ) ₂ . The 6H ₂ O system was purchased from Aldrich and used without further purification. Ammonium metatungstate (NH ₄ ) ₆ H ₂ W ₁₂ O ₄₀ . H ₂ O (AMT), ammonium hexaaminate tetrahydrate (NH ₄ ) ₆ Mo ₇ O ₂₄ . 4 H ₂ O(AHM), samarium tungstate hydrate H ₄ SiW ₁₂ O ₄₀ . H ₂ O, phosphotungstic acid H ₃ PW ₁₂ O ₄₀ . n H ₂ O(H-PW ₁₂ ), bismuth molybdate H ₄ SiMo ₁₂ O ₄₀ . nH ₂ O (H-SiMo ₁₂ ), phosphomolybdic acid H ₃ PMo ₁₂ O ₄₀ . nH ₂ O(H-PMo ₁₂ ), bismuth oxalate hexahydrate [Nb(HC ₂ O ₄ ) ₅ ]. 6 H ₂ O (NbOX), and vanadium oxide (V) V ₂ O ₅ were purchased from Aldrich. The oxalic acid platinum (II) PtC ₂ O ₄ solution (about 10% by weight Pt) was obtained from Heraeus and used directly after it was obtained. The cerium oxide catalyst support (HSA SS #61138, SA = 250 m ² /g; 3 mm pellet; SiO ₂ ) was used in the state obtained from the supplier. Acetic acid and nitric acid were obtained from Fisher Scientific.

Analytical procedure (organic product) . The reactor effluent was collected periodically and product analysis was performed using a sample-corrected GC off-line analytical method. Temperature flow: T _initially = 60 ° C (for 2.5 minutes); increasing (20 ° C / min) to 245 ° C (for 5.5 minutes). The total operating time is 17.25 minutes (the highest oven temperature is 280 ° C).

Catalyst Preparation : A commercially available SiO _{2 support} (HAS SS #61138) was used as a 3 mm pellet unless otherwise indicated. Typically, the upgrading system is prepared by impregnating the SiO ₂ extrudate with an aqueous solution of the corresponding W, Mo, Nb or V precursor, followed by drying at 120 ° C and calcination at 550 ° C in air. Catalyst preparation was carried out by a single step incipient wetness impregnation method using Sn, Co and Pt in an aqueous solution of dilute nitric acid and a modified cerium oxide support.

The [SiO ₂ -MO _x (n)] catalyst support (M = W, Mo, Nb, V) was prepared while maintaining the same molar amount of M, so that the corresponding amount of oxide n was provided in brackets in % by weight. The preparation of individual catalysts and supports is detailed in the following paragraphs. The catalytic activity of the catalyst holding {PtCoSn} is summarized in Table 4.

Example 1 : SiO ₂ -WO ₃ (12). For this preparation, 176.0 g of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 25.504 grams (8.63 millimoles) of ammonium metatungstate hydrate (AMT) in 250 milliliters of deionized water. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: about 200 grams of light yellow extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Example 2 : SiO ₂ -Si (1/12) WO ₃ (12). For this preparation, 22.0 g of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 3.104 g (1.08 mmol) of tungstic acid hydrate in 32 ml of deionized water. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: about 25 grams of light yellow extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Example 3 : SiO ₂ -P (1/12) WO ₃ (12). For this preparation, 22.0 g of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 3.106 g (1.08 mmol) of phosphotungstic acid hydrate in 32 ml of deionized water. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: about 25 grams of light yellow extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Example 4 : SiO ₂ -MoO ₃ (7.4). For this preparation, 23.14 g of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 2.284 grams (1.85 millimoles) of ammonium heptamolybdate tetrahydrate in 33.5 milliliters of deionized water. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: about 25 grams of yellow extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Example 5 : SiO ₂ -Si(1/12)MoO ₃ (7.4). For this preparation, 23.14 grams of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 1.996 g (1.09 mmol) of hydrazine molybdate hydrate in 33.5 ml of deionized water. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: about 25 grams of yellow extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Example 6 : SiO ₂ -P(1/12)MoO ₃ (7.4). For this preparation, 23.14 g of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 1.968 g (1.09 mmol) of phosphomolybdic acid in 33.5 ml of deionized water. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: about 25 grams of yellow extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Example 7 : SiO ₂ -Nb ₂ O ₅ (6.9). For this preparation, 23.28 g of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 3.921 g (6.07 mmol) of ruthenium (V) oxalate hexahydrate in 34 ml of deionized water. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: about 25 grams of white extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Example 8 : SiO ₂ -V ₂ O ₅ (4.8). For this preparation, 23.14 g of SiO _{2 support} (NorPro, 3 mm pellets) was used. An impregnated aqueous solution was prepared by dissolving 1.177 grams (6.47 millimoles) of vanadium oxide (V) in 30 milliliters of deionized water. Next, 2.0 ml of aqueous ammonia (30% by weight) was added and the oxide was dissolved at room temperature with stirring. The support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The dried material was then calcined at 550 ° C / air for 6 hours. Yield: Approximately 25 grams of yellow orange extrudate. The precious metal and the active metal are then impregnated onto the modified support according to the following catalyst preparation procedure.

Catalyst preparation: [SiO ₂ -MO _x (n)]-Pt(1.0)-Co(4.8)-Sn(4.1); M= W, Mo, Nb, V

The catalyst preparations of Examples 1-8 were carried out using the following general procedure and 9.775 grams of each modified cerium oxide support from Examples 1-8. The metal impregnation solution was prepared as follows. First, 3.5 ml of 8 M HNO _{3 was} added to a glass vessel containing a Teflon coated stir bar. Next, 0.7770 g (3.76 mmol) of solid tin (II) oxalate was slowly added with stirring. The solution was then diluted by the addition of 2.5 ml of deionized water and 2.5530 g (8.77 mmol) of solid cobalt (II) nitrate hexahydrate was added with stirring. Separately, 1.1673 g of PtC ₂ O ₄ solution (10.12 wt% Pt) was diluted to a total volume of 2.0 ml by adding deionized water. The diluted platinum solution was then added to a solution containing tin and cobalt, and the mixture was stirred at room temperature for another 5 minutes. The [SiO ₂ -(MO _x )] support was then impregnated using an incipient wetness technique and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 ° C overnight. The final material was then calcined in flowing air at 350 ° C for 6 hours. Yield: Approximately 10 grams of finished catalyst (dark/black extrudate).

II. Comparative Example 9-10 Catalyst preparation

Example 9: SiO ₂ -W(10)-Re(5)-Ru(1) . The catalyst was prepared by impregnating a preformed cerium oxide support (3 mm pellet, SA = 250 m ² /g; NorPro Saint-Gobain) with an aqueous solution containing a soluble precursor for W, Re and Ru. It is true that the catalyst is prepared as follows. An impregnated aqueous solution was prepared by adding 3.351 grams of ammonium metatungstate and 1.8007 grams of ammonium perrhenate to 20 milliliters of water. This solution was heated to 50 ° C and stirred at this temperature for 5 minutes. Next, 0.7774 g of Ruthenium nitrosylnitrate was added and dissolved under stirring. This solution was then added to 21 grams of yttrium oxide support (incipient wetness impregnation technique) and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The material is then finally calcined in flowing air at 500 °C.

Example 10 : SiO ₂ -W(10)-Re(5)-Rh(1). The catalyst was prepared by impregnating a preformed cerium oxide support (3 mm pellet, SA = 250 m ² /g; NorPro Saint-Gobain) with an aqueous solution containing a soluble precursor for W, Re and Ru. It is true that the catalyst is prepared as follows. An impregnated aqueous solution was prepared by adding 3.351 grams of ammonium metatungstate and 1.8007 grams of ammonium perrhenate to 20 milliliters of water. This solution was heated to 50 ° C and stirred at this temperature for 5 minutes. Next, 0.6458 g of cerium (III) chloride hydrate was added with stirring and dissolved. This solution was then added to 21 grams of yttrium oxide support (incipient wetness impregnation technique) and the material was dried using a rotary evaporator followed by drying in a circulating air at 120 °C overnight. The material is then finally calcined in flowing air at 500 °C.

The catalysts of Examples 9 and 10 were both pretreated and tested under the same conditions as used in Examples 1-8. The highest conversion of acetic acid was seen for the catalyst containing ruthenium. This material also exhibits a high conversion of ethyl acetate. However, the selectivity for ethanol is low and a mixture of various hydrocarbons is the main reaction product.

Reactor system and catalytic test conditions

The test unit consists of four separate tubular fixed bed reactor systems with a general temperature controller, pressure and gas and liquid feed. The reactor was made from a 3/8 inch (0.95 cm) 316 SS tube and was 12 and 1/8 inch (30.8 cm) in length. The vaporizer is made of 3/8 inch (0.95 cm) 316 SS tube and has a length of 12 and 3/8 inch (31.45 cm). The reactor, vaporizer and its individual effluent transfer lines are electrically heated (heating belt).

The reactor effluent is directed to a cooling water condenser and knock-out pots. The condensed liquid is automatically collected and then manually discharged from the dispensing pot if necessary. The non-condensing gas is passed through a manual negative pressure regulator (BPR) and then through the water and discharged to a fume hood. For each example, 15 ml of catalyst (3 mm pellets) was loaded into the reactor. Both the inlet and the outlet of the reactor were filled with glass beads (3 mm) to form a fixed bed. The following operating conditions were used for catalyst screening: T = 275 ° C, P = 300 psig (2068 kPag), [feed] = 0.138 ml / min (pump rate) and [H ₂ ] = 513 sccm (standard cubic centimeters), gas Time-space velocity (GHSV) = 2246hr ^-1 . The composition of the mixed feed used for the test is summarized in Table 3.

Catalytic results. [SiO ₂ -MO _x (n)]-Pt(1)- was investigated using a test unit consisting of four separate tubular fixed-bed reactors as described above with general temperature controller, pressure and gas and liquid feeds. Co(4.8)-Sn(4.1) (M=W, Mo, Nb, V) and the catalytic performance of Comparative Examples 9 and 10. The condensed liquid is collected automatically and then manually discharged from the dispensing pan if necessary and analyzed by sampling calibration GC (gas chromatography).

Acetic acid conversion rate and ethanol selectivity

All eight materials showed acetic acid conversion of 80% and higher. The highest conversion (>99%) was observed for both tungsten modified supports (AMT, H-SiW ₁₂ ) and for vanadium oxide (V ₂ O ₅ ) modified materials. High ethanol selectivity was also observed for all three materials. Therefore all three materials increase the ethanol selectivity to greater than 90%. The catalytic properties of the materials obtained from AMT and H-SiW ₁₂ are almost the same. Comparative Examples 9 and 10 have low ethanol selectivity and low acetic acid conversion, respectively. The catalytic results for acetic acid conversion and ethanol selectivity are summarized in Figure 2 and Table 4. The catalysts obtained from Examples 1, 2 and 8 unexpectedly and unexpectedly showed a net reduction of ethyl acetate, indicating that the catalyst was multifunctional for both acetic acid and ethyl acetate conversion.

Ethanol yield

Both tungsten-modified materials exhibited an ethanol yield of greater than 600 g/kg/h, and the vanadium-promoted support also had a yield close to this value. All other materials showed significantly lower yields, mainly due to the lower selectivity for ethanol (see Figure 2). Again, the yields seen for the catalysts prepared using AMT and H-SiW ₁₂ precursors are nearly identical, emphasizing the similarity of the resulting support materials. Comparative Example 9 gave a low ethanol yield. The catalytic results for ethanol yield are summarized in Figure 3.

Ethyl acetate conversion

In order to maximize the amount of ethanol produced in the acetic acid hydrogenation reaction, it is desirable to minimize ethyl acetate production. An apparent and stable ethyl acetate conversion that is sustained over the life of the catalyst is desired to avoid accumulation of the co-product in the recycle loop. Hydrogenation of ethyl acetate to ethyl acetate hydrogenated per mole gave two moles of ethanol. This will further increase the ethanol selectivity and overall process effectiveness.

To investigate the combined catalytic conversion of acetic acid and ethyl acetate, the product mixture of Table 2 was used as the reactor feed. Of the eight materials studied, three showed ethyl acetate conversion, as indicated by the positive values in Figure 4 (negative values indicate an increase in ethyl acetate production). Both the tungsten and vanadium-modified supports increased the net consumption of ethyl acetate. The three materials unexpectedly and unexpectedly provide functionality to both acetic acid and ethyl acetate. Comparative Example 10 gave a low ethyl acetate conversion. Catalytic data on ethyl acetate conversion is summarized in Figure 4.

Example 11 - Catalyst Preparation

A modified catalyst was prepared by adding WO ₃ and CaSiO ₃ to a SiO ₂ catalyst support followed by a combination of Pt/Sn binary metals.

An aqueous suspension of CaSiO ₃ (≦200 mesh) was prepared and stirred with SiO ₂ for 2 hours at room temperature. In addition, a soluble WO ₃ precursor (NH ₄ ) ₆ H ₁₂ W ₁₂ O ₄₀ was added dropwise to the SiO ₂ in the bottle. The solution of n H ₂ O (AMT), the amount of CaSiO ₃ and WO ₃ varies with each catalyst depending on the molar ratio. The catalyst was dried overnight at 120 ° C followed by calcination at 500 ° C for 6 hours. After the modified support is produced, the precursor is added to the binary metal and calcined. The metal loading of the binary metal is less than 5% by weight based on the total weight of the catalyst, and is the same for each catalyst. The following three catalysts were produced in accordance with this embodiment.

11A) SiO ₂ -CaSiO ₃ (6 wt.%)-Pt-Sn

11B) SiO ₂ -CaSiO ₃ (6 wt.%)-WO ₃ (8 wt.%)-Pt-Sn

11C) SiO ₂ -CaSiO ₃ (6 wt.%)-WO ₃ (12 wt.%)-Pt-Sn

The molar ratio of Ca to W in the catalyst 11B was 13:1, and the catalyst 11C was 1:1. The catalyst 11A contains only the CaSiO _{3 support} modifier and does not contain any WO ₃ .

Example 12 - Hydrogenation

The vaporized acetic acid and hydrogen were passed through the respective catalysts produced in Example 11. The reaction conditions are the same for each reaction. The results are shown in Table 5.

Catalysts 11B and 11C demonstrated a better yield and acetic acid conversion than catalyst 11A. When the amount of WO ₃ is increased by more than 12% by weight, the acetic acid conversion rate and the ethanol selectivity are generally maintained similar to that of the catalyst 11C.

Although the invention has been described in detail, it will be apparent to those skilled in the art All of the above publications and references are incorporated herein by reference. In addition, it should be understood that the objects and various aspects of the invention and various features may be combined or interchanged in whole or in part. In the foregoing description of the specific examples, the specific examples of the other specific examples may be appropriately combined with one or more other specific examples, which are known to those skilled in the art. In addition, those skilled in the art will understand that the foregoing description is by way of example only and is not intended to limit the invention.

The invention will be better understood by reference to the appended non-limiting drawings, in which FIG. 1 provides a non-limiting flow diagram of a process for forming a catalyst in accordance with an embodiment of the present invention.

Fig. 2 is a graph showing the conversion ratio and selectivity of various catalysts for ethanol according to several specific examples of the present invention.

Fig. 3 is a graph showing the ethanol yield of various exemplary catalysts in accordance with several specific examples of the present invention.

Fig. 4 is a graph showing the ethyl acetate conversion rate of various exemplary catalysts according to several specific examples of the present invention.

Claims (15)

A process for producing a catalyst, the process comprising the steps of: impregnating a support from a polyoxometalate precursor onto a support to form a first impregnation support; calcining the first impregnation support Forming a calcined support; impregnating one or more active metals from one or more metal precursors onto the calcined support to form a second impregnated support, wherein the one or more active metals are selected from the group consisting of copper, Groups of calcium, barium, magnesium, strontium, iron, cobalt, nickel, ruthenium, rhodium, platinum, palladium, rhodium, iridium, titanium, zinc, chromium, molybdenum, tungsten, tin, antimony, bismuth, manganese and gold And calcining the second impregnated support to form a catalyst. The process of claim 1, wherein the polyoxometallate pre-system is selected from the group consisting of heteropolyoxometalate, isopolyoxometalate, and hexaoxometalate. And a group consisting of decaoxometalate. The process of claim 1 or 2 wherein the polyoxometallate precursor comprises a metal atom selected from the group consisting of tungsten, molybdenum, vanadium, niobium, chromium, niobium, and mixtures thereof. The process of claim 1, wherein the polyoxometallate precursor comprises a compound selected from the group consisting of ammonium metatungstate ((NH ₄ ) ₆ H ₂ W ₁₂ O ₄₀ .x H ₂ O), Ammonium molybdate tetrahydrate ((NH ₄ ) ₆ Mo ₇ O ₂₄ .4 H ₂ O), samarium tungstate hydrate (H ₄ SiW ₁₂ O ₄₀ .H ₂ O), phosphotungstic acid (H ₃ PW ₁₂ O ₄₀ .n H ₂ O), hydrazine molybdate (H ₄ SiMo ₁₂ O ₄₀ .n H ₂ O), phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ .n H ₂ O), bismuth oxalate hexahydrate ([Nb (HC ₂ O ₄ ) ₅ ]). a group consisting of 6 H ₂ O), vanadium oxide (V ₂ O ₅ ), ammonium vanadate ((NH ₄ )VO ₃ ), and mixtures thereof. The process of any one of claims 1 to 4 wherein the polyoxometallate precursor contains at least two different metal atoms. The process of any one of claims 1 to 4, wherein the support modifier is selected from the group consisting of Nb ₂ O ₅ , WO ₃ , MoO ₃ , V ₂ O ₅ , P ₂ O ₅ , P ₄ O ₁₀ , a group consisting of Ta ₂ O ₅ , Bi ₂ O ₃ and mixtures thereof. The process of any one of claims 1 to 6, wherein the one or more active metals are selected from the group consisting of platinum, palladium, nickel, cobalt, copper, and tin. The process of any one of claims 1 to 7, wherein the one or more pre-metal systems are selected from the group consisting of metal halides, amine-dissolved metal hydroxides, metal nitrates, and metal oxalates. group. The process of any one of claims 1 to 8, wherein the second impregnation system is formed using one or more metal precursors in an aqueous solution of dilute nitric acid and the calcined support. The process of any one of claims 1 to 9, wherein the support material is selected from the group consisting of cerium oxide, aluminum oxide, titanium oxide, cerium oxide/alumina, calcium metamorphic acid, pyrolytic cerium oxide, high purity. A group consisting of cerium oxide, zirconium oxide, zeolite, carbon, and mixtures thereof. The process of any one of claims 1 to 10, wherein the first impregnated support is dried at a temperature of from 50 ° C to 200 ° C and the second impregnated support is dried at a temperature of from 50 ° C to 200 ° C. . The process of any one of claims 1 to 11, wherein the first impregnated support is calcined at a temperature of from 350 ° C to 850 ° C. The process of any one of claims 1 to 12, wherein the catalyst comprises from 0.1 to 50% by weight based on the total weight of the catalyst, the support modifier, and 0.1% based on the total weight of the catalyst. 25% by weight of the one or more active metals. A process for producing ethanol, comprising the steps of: passing a gaseous stream comprising hydrogen and a vapor phase alkanoic acid through a hydrogenation catalyst, wherein the hydrogenation catalyst is as claimed in any one of claims 1 to 13 Made by the process. The process of claim 14, wherein the gaseous stream further comprises ethyl acetate.