Carbohydrate pyrolysis process

Abstract

Various processes are described for the pyrolysis of carbohydrates to prepare products such as glycolaldehyde. Also described are various catalysts and processes for preparing catalysts useful in the pyrolysis of carbohydrates.

Description

[Technical field]

[0001] Technical Field The present invention relates to various processes for the pyrolysis of carbohydrates to prepare products such as glycolaldehyde (also known as hydroxyacetaldehyde). The present invention further relates to various catalysts and processes for preparing catalysts useful in the pyrolysis of carbohydrates. [Background technology]

[0002] 2. Background of the Invention For many years, there has been interest in using carbohydrate-rich biomass feedstocks to produce commercially useful chemicals. Pyrolysis of biomass feedstocks is a potentially attractive process that produces a variety of chemical products and intermediates, such as glycolaldehyde, methylglyoxal / pyruvaldehyde, acetol / hydroxyacetone, and formaldehyde. Among these chemicals, glycolaldehyde is a particularly versatile chemical for a variety of valuable strategic products in the nutritional and renewable materials industries. For example, glycolaldehyde is useful as a browning agent and flavoring agent in food applications (e.g., liquid smoke). This compound can also be used as a building block for a variety of amines, polyols, sugars, and sugar alcohols.

[0003] The biomass feedstocks (e.g., cellulose / glucose-containing feedstocks), reaction media (e.g., sand), carrier gases (e.g., nitrogen), and materials of construction used in typical processes and equipment for pyrolysis of biomass are relatively inexpensive. However, pyrolysis of these feedstocks is also an inherently energy-intensive process, typically requiring constant heating at temperatures above 500°C and additional means to facilitate heat transfer. Also, yields of desired products, including glycolaldehyde, have been limited in previous attempts. For example, U.S. Patent No. 7,094,932 reports glycolaldehyde yields in the range of 55% to 70%. Additionally, some pyrolysis processes produce problematic by-products that are difficult to separate and require special handling and disposal. Pyrolysis processes also typically produce char as a by-product. Yields of desired products are limited by the production of char, which can cause operational difficulties and result in reactor shutdowns and / or loss of production. Thus, there remains a need for a carbohydrate pyrolysis process that has lower operating costs, produces more desirable products such as glycolaldehyde, and / or produces fewer by-products and / or char. Summary of the Invention [Means for solving the problem]

[0004] Summary of the Invention Various aspects of the present invention relate to a process for preparing glycolaldehyde. Typically, the process comprises feeding a feed composition comprising a carbohydrate having at least four carbon atoms to a pyrolysis reaction zone and pyrolyzing the carbohydrate in the presence of water and a catalyst in the pyrolysis reaction zone to form a reaction product comprising glycolaldehyde, the catalyst comprising a metal oxide on a catalyst support.

[0005] In some embodiments, the process further comprises at least one of the following conditions: (a) the pyrolysis reaction zone is heated to a temperature of 400° C. or greater; (b) The catalyst carrier is 500m 2 / g or less, 250m 2 / g or less, 100m 2 / g or less, 50m 2 / g or less, 25m 2 / g or less, 10m 2 / g or less, 5m 2 / g or less, or 1m 2 / g or less BET specific surface area, (c) the catalyst support comprises a glass material, a ceramic material, or a refractory material; (d) the pyrolysis reaction zone further comprises a reaction zone medium distinct from the catalyst; and / or (e) the yield of glycolaldehyde is 70% or more, 75% or more, or 80% or more.

[0006] A further aspect of the invention relates to a process for preparing a catalyst useful in the pyrolysis of carbohydrates, in some embodiments, the process for preparing a catalyst comprises mixing a metal oxide, a solvent, and a strong acid to form a sol-gel, depositing the sol-gel on a catalyst support to form a coated catalyst support, and removing the solvent from the coated catalyst support to form the catalyst.

[0007] A further aspect of the invention relates to catalysts prepared by these processes.

[0008] Other objects and features will be in part apparent and in part pointed out hereinafter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Detailed Description of the Preferred Embodiments In general, the present invention relates to various processes for the pyrolysis of carbohydrates to prepare products such as glycolaldehyde, methylglyoxal / pyruvaldehyde, acetol / hydroxyacetone, and formaldehyde. The present invention further relates to various catalysts and processes for preparing catalysts useful in the pyrolysis of carbohydrates. As used herein, "carbohydrate" and / or "carbohydrate feed" will be understood to include any form of biomass feedstock that contains or yields carbohydrates, particularly carbohydrates having 4 or more carbon atoms, from which glycolaldehyde can be obtained under pyrolysis conditions.

[0010] The various processes of the present invention have been found to produce glycolaldehyde with improved yields. Previous attempts to increase the yield of glycolaldehyde have focused mainly on changing feed concentration and reactor conditions, with bed materials and / or pyrolysis catalysts remaining largely unchanged. However, it has been surprisingly discovered that pyrolysis catalysts (typically, but not necessarily, in the form of a fluidizable supported catalyst, combined with conventional bed materials that are fed for heat transfer to the carbohydrate feed) can significantly affect the pyrolysis reaction and overcome the problems encountered in previous processes.

[0011] In particular, as discussed herein, certain metal oxides have been found to be particularly effective in improving the yield of desirable products, such as glycolaldehyde, from the pyrolysis of carbohydrates, particularly sugars such as glucose. The pyrolysis processes described herein incorporating these catalysts can advantageously result in improved process economics and reduced amounts of undesirable products that may require separation from the product mixture and special handling and disposal. For example, pyrolysis processes using these catalysts may use process inputs more productively (e.g., by requiring less energy), produce less undesirable by-products, and / or produce less char in the production of a given amount of glycolaldehyde and other desirable products than would be experienced in the absence of the catalyst. Additionally, the various processes described herein have the advantage of providing stable product yields over extended periods of operation and / or at high reactor throughputs.

[0012] Accordingly, embodiments of the present invention relate to various improved pyrolysis processes for preparing glycolaldehyde. For example, various embodiments relate to a process for preparing glycolaldehyde comprising: feeding a feed composition comprising a carbohydrate having at least four carbon atoms to a pyrolysis reaction zone; and pyrolyzing the carbohydrate in the presence of water and a catalyst in the pyrolysis reaction zone to form a reaction product comprising glycolaldehyde, the catalyst comprising a metal oxide on a catalyst support.

[0013] supply material As previously mentioned, the feed composition includes a carbohydrate having at least four carbon atoms. For example, in some embodiments, the carbohydrate is a C4-C 24The carbohydrates include carbohydrates. Such carbohydrates can be obtained from various conventional biorenewable sources, such as maize, wheat, potato, cassava, and rice, as well as alternative sources, such as energy crops, plant biomass, agricultural waste, forestry residues, sugar processing residues, and plant-derived domestic waste. In various embodiments, the carbohydrates are obtained from grain crops (e.g., corn, wheat, soybeans, rice, barley, rye, millet, sorghum, etc.). More generally, biorenewable sources that can be used include any renewable organic matter, including sources of carbohydrates, such as, for example, switchgrass, miscanthus, trees (broadleaf and coniferous), vegetation, and crop residues (e.g., bagasse and corn stover). Other sources include, for example, waste materials (e.g., post-consumer paper, food waste, municipal waste, etc.). Carbohydrates can be isolated from biorenewable materials using known methods. Carbohydrates can be provided in the form of a carbohydrate solution (e.g., an aqueous glucose solution) or as comminuted solids of such biomass.

[0014] Carbohydrates obtained from these sources can include a variety of monosaccharides, disaccharides, oligosaccharides, and polysaccharides. For example, in some embodiments, carbohydrates include C4 to C6 24 In certain embodiments, the carbohydrate comprises at least one sugar selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, and combinations thereof. In various embodiments, the carbohydrate comprises a monosaccharide. The carbohydrate can also comprise cellulose.

[0015] In some embodiments, the carbohydrate comprises a sugar having at least four carbon atoms. For example, the sugar comprises various aldoses. The aldoses referred to herein include various compounds having an aldehyde group and a hydroxyl group, which can be represented by formula (I): HOCH2(HCOH) w CHO (I) (wherein w can be, for example, an integer from 2 to 10, or in some embodiments, an integer from 2 to 5). In various embodiments, the carbohydrate comprises at least one C4-C7 aldose. In some embodiments, the carbohydrate comprises at least one sugar selected from the group consisting of tetrose, pentose, hexose, heptose, and mixtures thereof. Particular C4-C7 aldoses include, for example, threose, erythrose, xylose, ribose, arabinose, glucose, galactose, mannose, glucoheptose, L-glycero-D-manno-heptose, and mixtures thereof. In various embodiments, the carbohydrate comprises a hexose, such as glucose (dextrose). In some embodiments, the carbohydrate comprises a pentose, such as xylose, ribose, and / or arabinose. The term "aldose" and any particular aldose described herein and defined in formula (I) also includes cyclic forms (hemiacetal forms) of these compounds.

[0016] In some embodiments, the carbohydrate comprises a ketose sugar having at least four carbon atoms. In various embodiments, the carbohydrate comprises at least one ketose sugar selected from the group consisting of ketotetrose, ketopentose, ketohexose, ketoheptose, and mixtures thereof. In certain embodiments, the carbohydrate comprises fructose.

[0017] The feed composition can have a carbohydrate concentration that is 1% or more, 5% or more, 10% or more, 15% or more, or 20% or more by weight. For example, in various embodiments, the feed composition has a carbohydrate concentration that is 1%-50%, 1%-30%, 1%-25%, 5%-50%, 5%-30%, 5%-25%, 10%-50%, 10%-30%, 10%-25%, 15%-50%, 15%-30%, 15%-25%, 20%-50%, 20%-30%, or 20%-25% by weight.

[0018] Pyrolysis Catalyst As previously mentioned, the pyrolysis reaction in the processes described herein is carried out in a catalytic system comprising a metal oxide on a catalyst support. In various embodiments, the metal oxide comprises a transition metal oxide. For example, the metal oxide comprises an oxide of a group 4, 5, 6, 7, 8, 9, 10, or 11 metal, or a mixture thereof. In some embodiments, the metal oxide comprises an oxide of a group 4, 5, or 6 metal, or a mixture thereof. In certain embodiments, the metal oxide comprises an oxide of titanium, molybdenum, tungsten, vanadium, or a mixture thereof. In certain embodiments, the metal oxide comprises an oxide of molybdenum, tungsten, vanadium, or a mixture thereof. In certain embodiments, the metal oxide comprises an oxide of tungsten, molybdenum, or a mixture thereof. Preferred metal oxides typically include those that preferentially catalyze retro-aldol chemistry.

[0019] Molybdenum and tungsten oxides have been found to be particularly effective in pyrolysis catalysts. Thus, in various embodiments, the metal oxide comprises tungsten oxide. For example, the tungsten oxide can comprise tungsten(IV) oxide and / or tungsten(V) oxide. In some embodiments, the metal oxide comprises molybdenum oxide.

[0020] In some embodiments, the tungsten oxide and / or molybdenum oxide constitute a significant portion of the metal oxide on the catalyst support, for example, in some embodiments, the tungsten oxide and / or molybdenum oxide constitutes at least 1 wt%, at least 2 wt%, at least 3 wt%, at least 4 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or at least 99 wt% of the metal oxide on the catalyst support. In various embodiments, the tungsten oxide and / or molybdenum oxide is present in an amount of 1% to 99% by weight, 2% to 99% by weight, 3% to 99% by weight, 4% to 99% by weight, 5% to 99% by weight, 10% to 99% by weight, 15% to 99% by weight, 20% to 99% by weight, 25% to 99% by weight, 30% to 99% by weight, 35% to 99% by weight, 40% to 99% by weight, 45% to 99% by weight, 50% to 99% by weight, 60% to 99% by weight, 70% to 99% by weight, 80% to 99% by weight, 90% to 99% by weight, 95% to 99% by weight, 1 wt%~95wt%, 2wt%~95wt%, 3wt%~95wt%, 4wt%~95wt%, 5wt%~95wt%, 10wt%~95wt%, 15wt%~95wt%, 20wt%~95 Weight%, 25% to 95% by weight, 30% to 95% by weight, 35% to 95% by weight, 40% to 95% by weight, 45% to 95% by weight, 50% to 95% by weight, 60% to 95% by weight Amount%, 70wt%~95wt%, 80wt%~95wt%, 90wt%~95wt%, 1wt%~90wt%, 2wt%~90wt%, 3wt%~90wt%, 4wt%~90wt%, 5wt In one embodiment, the metal oxide on the catalyst support comprises 10% to 90% by weight, 10% to 90% by weight, 15% to 90% by weight, 20% to 90% by weight, 25% to 90% by weight, 30% to 90% by weight, 35% to 90% by weight, 40% to 90% by weight, 45% to 90% by weight, 50% to 90% by weight, 60% to 90% by weight, 70% to 90% by weight, or 80% to 90% by weight of the metal oxide on the catalyst support.In certain embodiments, the metal oxide on the catalyst support comprises tungsten oxide and / or molybdenum oxide.

[0021] The catalyst can have 0.1 wt% or more, 0.5 wt% or more, 1 wt% or more, 2 wt% or more, 5 wt% or more, 10 wt% or more, 20 wt% or more, 30 wt% or more, 40 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, or 99 wt% or more of metal oxide loading. For example, in various embodiments, the catalyst has between 0.1 wt% and 15 wt%, between 0.5 wt% and 15 wt%, between 1 wt% and 15 wt%, between 2 wt% and 15 wt%, between 5 wt% and 15 wt%, between 0.1 wt% and 10 wt%, between 0.5 wt% and 10 wt%, between 1 wt% and 10 wt%, between 2 wt% and 10 wt%, or between 5 wt% and 10 wt% of metal oxide loading.

[0022] In some cases, it has been found that low surface area catalysts and catalyst supports result in greater product yields (e.g., higher yields of glycolaldehyde). Thus, in some embodiments, the catalyst support has a relatively low surface area (e.g., less than 500 m 2 / g or less, 250m 2 / g or less, 100m 2 / g or less, 50m 2 / g or less, 25m 2 / g or less, 10m 2 / g or less, 5m 2 / g or less, or 1m 2 This includes materials having a BET specific surface area of ​​0.1 μm or less (BET specific surface area of ​​0.1 μm or less).

[0023] In various embodiments, the catalyst support comprises a material selected from the group consisting of a glass material, a ceramic material, a refractory material, and mixtures thereof. In some embodiments, the catalyst support comprises a glass material. In particular embodiments, the glass material comprises glass beads (e.g., glass spheres, or similar geometric or amorphous shapes). In some embodiments, the catalyst support comprises a ceramic material selected from the group consisting of silicon carbide, yttria-stabilized zirconia, and combinations thereof. In particular embodiments, the catalyst support comprises a material that is substantially non-porous and has a relatively low surface area.

[0024] The catalysts described herein can provide long time on stream (TOS) periods, in some embodiments, the TOS of the catalyst is 1,500 hours or more, 2,000 hours or more, 4,000 hours or more, 6,000 hours or more, 8,000 hours or more, or 10,000 hours or more.

[0025] The catalyst can be prepared according to the processes as further described herein. In some embodiments, the catalyst comprises a glass material and a coating comprising a metal oxide, the coating being deposited on the coated glass material using a sol-gel comprising the metal oxide or a reaction product thereof. In these and other embodiments, the catalyst is an uncalcined catalyst.

[0026] Characteristics of the pyrolysis process As previously mentioned, pyrolysis is an energy intensive process that requires high temperatures in the pyrolysis reaction zone. In various embodiments, the pyrolysis reaction zone is heated to a temperature of 400° C. or more, 450° C. or more, 475° C. or more, 500° C. or more, 525° C. or more, 550° C. or more, 575° C. or more, or 600° C. or more. In some embodiments, the pyrolysis reaction zone is heated to a temperature of 400°C to 600°C, 400°C to 575°C, 400°C to 550°C, 400°C to 525°C, 450°C to 600°C, 450°C to 575°C, 450°C to 550°C, 450°C to 525°C, 500°C to 600°C, 500°C to 575°C, 500°C to 550°C, 500°C to 525°C, 525°C to 600°C, 525°C to 575°C, or 525°C to 550°C.

[0027] In addition to the pyrolysis catalyst comprising a metal oxide on a catalyst support, the pyrolysis reaction zone can further comprise a reaction zone medium distinct from the catalyst. In various embodiments, the reaction zone medium can comprise any inert material that can be combined and fluidized to provide a generally homogeneously distributed fluidized bed through which the carbohydrate feed composition and pyrolysis products can be carried as they are formed by an inert carrier gas, which can be used to carry the heat energy required to pyrolyze the carbohydrates in the carbohydrate feed and convert the carbohydrates into pyrolysis products comprising at least glycolaldehyde. Those skilled in the art will be well able to identify various materials that could perform these essential functions. In various embodiments, the reaction zone medium comprises a material selected from the group consisting of a glass material, a ceramic material, a refractory material, and mixtures thereof. In some embodiments, the reaction zone medium comprises a glass material. In some embodiments, the reaction zone medium comprises a ceramic material selected from the group consisting of silicon carbide, yttria-stabilized zirconia, and combinations thereof. In certain embodiments, the glass material comprises glass beads (e.g., glass spheres, or similar geometric or amorphous shapes) and / or sand.

[0028] As mentioned above, the reaction zone medium is different from the catalyst, which typically comprises a metal oxide on a support. Thus, in various embodiments, the reaction zone medium is uncoated. In certain embodiments, the reaction zone medium is free or essentially free of a metal oxide coating (e.g., less than 1 wt. %, or even less than 0.1 wt. %). In some embodiments, the reaction zone medium comprises a catalyst support that does not comprise a metal oxide (i.e., a bare catalyst support).

[0029] The catalyst and reaction zone media can make up the total volume of media packed in the pyrolysis reaction zone, such that the catalyst is 1 vol.% to 50 vol.%, 2 vol.% to 25 vol.%, 3 vol.% to 15 vol.%, or 4 vol.% to 10 vol.% of the total volume of media packed in the pyrolysis reaction zone.

[0030] In various embodiments, the feed composition is fluidized in a fluidizing gas or carrier gas in the pyrolysis reaction zone. The fluidizing gas includes, for example, various inert gases or inert gas mixtures. In some embodiments, the fluidizing gas includes waste gases such as nitrogen, water vapor, carbon dioxide, and / or combustion off-gases. In some embodiments, for example, when the carbohydrate is provided in the form of a carbohydrate solution, the process further includes atomizing the feed composition provided to the pyrolysis reaction zone. In certain embodiments, the feed composition can be atomized using a fluidizing gas (e.g., nitrogen, steam, etc.).

[0031] The average residence time of the carbohydrate feed in the pyrolysis reaction zone can be relatively fast. For example, in some embodiments, the residence time is 10 seconds or less, 8 seconds or less, 6 seconds or less, 4 seconds or less, 2 seconds or less, 1 second or less, or 0.5 seconds or less. In certain embodiments, the residence time is 0.5 seconds to 10, 0.5 seconds to 5 seconds, 0.5 seconds to 2 seconds, 0.5 seconds to 1 second, 1 second to 10 seconds, 1 second to 5 seconds, or 1 second to 2 seconds.

[0032] In general, the reaction zone can include one or more batch, semi-batch, or continuous reactor designs using fixed bed reactors, trickle bed reactors, slurry phase reactors, moving bed reactors, or any other design that allows catalytic reactions, particularly heterogeneous catalytic reactions. Examples of reactors can be found in Chemical Process Equipment-Selection and Design, Couper et al., Elsevier 1990, which is incorporated herein by reference. In various processes described herein, the pyrolysis reaction zone includes one or more fluidized bed reactors. It should be understood that the feed composition, any fluidizing gas, and catalyst can be introduced into the appropriate reactor separately or in various combinations.

[0033] The various processes of the present invention have been found to result in improved product yields. For example, using a 20 wt. % aqueous glucose solution as the carbohydrate feed, as demonstrated herein, the various processes described herein result in a glycolaldehyde yield of 70% or more, 75% or more, or 80% or more. In some embodiments, the glycolaldehyde yield is 70%-85%, 70%-80%, 75%-85%, or 75%-80%.

[0034] The reaction product may further comprise other minor components. In various embodiments, the reaction product comprises at least one other component selected from the group consisting of formaldehyde, glyoxal, pyruvaldehyde, acetol, and mixtures thereof. In some embodiments, the reaction product further comprises formaldehyde. In certain embodiments, the reaction product further comprises formaldehyde, and the molar ratio of glycolaldehyde to formaldehyde is 5:1 or greater, 6:1 or greater, 8:1 or greater, 10:1 or greater, or 12:1 or greater.

[0035] In various embodiments, the reaction product further comprises glyoxal, hi some embodiments, the reaction product further comprises glyoxal, and the molar ratio of glycolaldehyde to glyoxal is 10:1 or greater, 15:1 or greater, 20:1 or greater, or 25:1 or greater.

[0036] In various embodiments, the reaction product further comprises pyruvaldehyde, hi some embodiments, the reaction product further comprises pyruvaldehyde, and the molar ratio of glycolaldehyde to pyruvaldehyde is 5:1 or greater, 6:1 or greater, 8:1 or greater, 10:1 or greater, or 12:1 or greater.

[0037] In various embodiments, the reaction product further comprises acetol, hi some embodiments, the reaction product further comprises acetol, and the molar ratio of glycolaldehyde to acetol is 15:1 or greater, 20:1 or greater, 25:1 or greater, or 30:1 or greater.

[0038] In various embodiments, the reaction product is free or essentially free of ethylene glycol, hi some embodiments, the molar ratio of glycolaldehyde to ethylene glycol is 100:1 or greater, 200:1 or greater, or 400:1 or greater.

[0039] The processes of the present invention can include various combinations of the features described herein. For example, various processes for preparing glycolaldehyde include: providing a feed composition to a pyrolysis reaction zone, the feed composition comprising a carbohydrate having at least four carbon atoms; pyrolyzing the carbohydrate in the presence of water and a catalyst in the pyrolysis reaction zone to form a reaction product comprising glycolaldehyde; wherein the catalyst comprises a metal oxide on a catalyst support and at least one of the following conditions is met: (a) the pyrolysis reaction zone is heated to a temperature of 400° C. or greater; (b) The catalyst carrier is 500m 2 / g or less, 250m 2 / g or less, 100m 2 / g or less, 50m 2 / g or less, 25m 2 / g or less, 10m 2 / g or less, 5m 2 / g or less, or 1m 2 / g or less BET specific surface area, (c) the catalyst support comprises a glass material; (d) the pyrolysis reaction zone further comprises a reaction zone medium distinct from the catalyst; and / or (e) the yield of glycolaldehyde is 70% or more, 75% or more, or 80% or more.

[0040] Preparation of catalyst Pyrolysis catalysts can be prepared by a variety of techniques. Metal oxides can be deposited on catalyst supports using procedures including, but not limited to, sol-gel, incipient wetness, ion exchange, deposition-precipitation, and vacuum impregnation techniques.

[0041] According to an aspect of the invention, one process for preparing a catalyst that has been found to be particularly effective comprises the steps of: mixing a metal oxide, a solvent, and a strong acid to form a sol-gel; depositing the sol-gel on a catalyst support to form a coated catalyst support; removing the solvent from the coated catalyst support to form the catalyst; Includes.

[0042] In some embodiments, the sol-gel is prepared by mixing a metal oxide, a peroxide source, and a solvent, hi further embodiments, the peroxide source comprises hydrogen peroxide and the solvent comprises water.

[0043] The metal oxide, metal oxide filler, and support can be any of those identified herein for the pyrolysis catalyst. For example, in some embodiments, the metal oxide can include tungsten oxide and / or molybdenum oxide, and the support can include a low surface area material such as glass (e.g., glass beads).

[0044] In various embodiments, the solvent is selected from the group consisting of C1-C 10 Contains alkanols, e.g., C1-C 10 The alkanol is selected from the group consisting of isopropanol, ethanol, and mixtures thereof. Additionally, the strong acid can be selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, and mixtures thereof.

[0045] The sol-gel may be formed in air or in an inert atmosphere. In some embodiments, the sol-gel is formed in an inert atmosphere. For example, the sol-gel may be formed in a nitrogen atmosphere. Additionally, the sol-gel may be formed in the substantial absence of oxygen. In various embodiments, the sol-gel may be prepared by mixing a metal oxide, a peroxide source, and a solvent. In some embodiments, the peroxide source may be hydrogen peroxide and the solvent may be water.

[0046] During solvent removal, the coated catalyst support can be heated to a temperature sufficient to evaporate any solvent in the coated catalyst. In various embodiments, the coated catalyst support is heated to a temperature of 80° C. or more, 90° C. or more, or 100° C. or more to remove the solvent. However, in various embodiments, the catalyst is not exposed to temperatures typical of calcination (e.g., 500° C. or more, 750° C. or more, or 1000° C. or more).

[0047] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention as defined in the appended claims. It is therefore intended that all matter contained in the above description or in the specific examples given below should be interpreted as illustrative and not in a limiting sense.

[0048] When introducing elements of the invention or preferred embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0049] More specifically, as used herein, the term "comprising" should be understood to encompass the alternative that the product / method / use in relation to which the term "comprising" is used may "consist only of" the elements set forth below.

[0050] Also, as used herein, the term "comprising" should be understood to similarly encompass alternatives that the product / method / use in relation to which the term "comprising" is used may "consist essentially of" the elements set forth below.

[0051] Unless otherwise stated, it should be understood that all synthetic processes and parameter measurements were conducted at room / ambient temperature, i.e., 21±1 degrees Celsius. EXAMPLES

[0052] Working Example The following non-limiting examples are provided to further illustrate the present invention.

[0053] Example 1: Preparation of metal oxide coated glass bead catalyst To prepare the metal oxide coated glass bead catalysts, the metal oxide sol-gel was first prepared in a nitrogen filled environment to prevent exposure to oxygen. 0.70 mL of tungsten(V) ethoxide, 1,2-dimethoxyethane adduct, 99% was added to 50 mL of isopropanol with stirring. 0.2 mL of 2 M hydrochloric acid was then added dropwise, resulting in a pale yellow sol with a white precipitate. The mixture was stirred at room temperature for approximately 1 hour and left overnight.

[0054] Glass beads were prepared by fuming the glass beads with isopropanol. 25 ml of the fumed glass beads were then added to the sol. The mixture containing the glass beads was mixed periodically and left uncovered. The resulting coated glass beads were then uniformly coated with the tungsten oxide solution.

[0055] The coated glass beads were then dried at ambient temperature and heated overnight at about 80° C. The coated glass beads were not subjected to calcination or other modification.

[0056] Each coated glass bead contained approximately 0.25% by weight tungsten in the form of a thin film coating.

[0057] Example 2: Preparation of metal oxide coated glass bead catalyst The experiment was carried out according to the procedure of Example 1, except that the coated glass beads were rinsed with acetone before being heated overnight at about 80° C. Rinsing the coated glass beads with acetone did not remove a significant amount of the tungsten oxide solution.

[0058] Example 3: Thermal decomposition of dextrose using glass bead catalyst The untreated glass bead catalyst was tested for the thermal decomposition of dextrose utilizing a fluidized bed reactor system. The glass bead catalyst comprised 6% of the total media volume of the reactor bed. Approximately 20% by weight of dextrose solution was introduced into the reactor system at a rate of 1.7 mL / min. A nitrogen gas stream was also introduced into the system at a rate of 4500-5000 mL / min. Tables 1-3 below report the product profiles at various times during the run for various reaction temperatures. The residence time for each reaction shown below was 0.98 seconds.

[0059] [Table 1]

[0060] [Table 2]

[0061] [Table 3]

[0062] Example 4: Pyrolysis of dextrose using tungsten carbide Tungsten carbide grit material was mixed with glass beads and utilized in a fluidized bed reactor system for the pyrolysis or cracking of dextrose. The mixture was tested at various reactor temperatures and compared to experiments performed with uncoated glass beads.

[0063] A dextrose solution of about 20 wt. % was introduced into the reactor system at a rate of 1.7 mL / min. A stream of nitrogen gas was also introduced into the system at a rate of 4500-5000 mL / min. Tables 4 and 5 report the temperatures, flow rates, residence times, etc. at various locations in the reactor system. The "bottom temperature" reported below is the temperature at the feed nozzle of the fluidized bed reactor. Table 6 reports the product profile at specific times during the run.

[0064] [Table 4]

[0065] [Table 5]

[0066] [Table 6]

[0067] A second experiment utilizing tungsten carbide grit material mixed with glass beads was conducted under the same conditions. The cracking media contained approximately 3% tungsten carbide grit and 97% glass beads by volume. Tables 7 and 8 report the temperatures, flow rates, residence times, etc. at various locations in the reactor system. The product profile for this second experiment is reported in Table 9.

[0068] [Table 7]

[0069] [Table 8]

[0070] [Table 9]

[0071] Example 5: Thermal decomposition of dextrose using tungsten oxide coated glass beads catalyst Several experiments similar to those conducted in Example 4 were conducted. Tables 10 and 11 report the results of using a tungsten oxide coated glass bead catalyst at various temperatures in a reactor system where the tungsten oxide coated catalyst comprised approximately 6% by weight of the total cracking media.

[0072] [Table 10]

[0073] [Table 11]

[0074] As demonstrated by the results above, the catalysts comprising metal oxide coated glass beads produced significantly higher yields of glycolaldehyde compared to the metal carbide catalysts.

[0075] Example 6: Thermal decomposition of dextrose using molybdenum oxide coated glass beads catalyst A similar experiment to Example 4 was carried out using a molybdenum oxide coated glass bead catalyst, which accounted for about 6% by weight of the total cracking media. The catalyst was tested at various reactor temperatures. The reaction conditions are shown in Table 12 and the results are reported in Table 13.

[0076] [Table 12]

[0077] [Table 13]

[0078] [Table 14]

[0079] [Table 15]

[0080] Example 7: Thermal decomposition of dextrose using vanadium oxide coated glass beads catalyst A similar experiment to Example 4 was carried out using a 5 wt% vanadium oxide coated glass bead catalyst. This catalyst was used in a reaction at a set temperature of 525° C. After 50 hours of operation, coking of the reactor was observed.

[0081] The reaction conditions are listed in Table 14 below. Table 15 reports the temperatures at various locations in the reactor during the reaction. The "Bottom Temperature" below is the temperature at the feed nozzle. Table 16 reports the production profile of the reaction products.

[0082] [Table 16]

[0083] [Table 17]

[0084] [Table 18]

[0085] Example 8: Pyrolysis of dextrose using molybdenum-coated quartz sand catalyst An experiment similar to Example 4 was conducted using a cracking media that was about 5 wt. % molybdenum coated quartz sand catalyst and 95 wt. % untreated quartz sand. The reaction was conducted at a set temperature of 525° C. The reaction conditions are listed below in Tables 17 and 18. The "bottom temperature" reported below is the temperature at the feed nozzle. Table 19 reports the results of the experiment.

[0086] After 3 hours on stream, the reaction was stopped and the reactor was inspected. Coking was observed and solid lumps had formed in the reactor.

[0087] [Table 19]

[0088] [Table 20]

[0089] [Table 21]

[0090] Example 9: Pyrolysis of dextrose using titania-coated glass beads catalyst Titania oxide coated glass beads were prepared according to the procedure of Example 1, and the thermal decomposition of dextrose using this catalyst was tested according to the procedure of Example 4. The reaction product profile is reported in Table 20 below.

[0091] The entire reactor body and all gas handling lines were properly cleaned prior to running the reaction. The reactor was unable to operate for more than 30 hours before being completely sealed. Investigation revealed that a mass of solids had formed within the reactor and the gas handling lines had become sealed with a mixture of char and pyrolysis oil. It was hypothesized that after injection, the feed reacted with the glass beads to form a mass of solids, increasing the amount of char. This buildup eventually caused the reactor to shut down and pressure to increase.

[0092] [Table 22]

[0093] When introducing elements of the invention or preferred embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0094] In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

[0095] item: 1. providing a feed composition comprising a carbohydrate having at least four carbon atoms to a pyrolysis reaction zone; pyrolyzing the carbohydrate in the presence of water and a catalyst in the pyrolysis reaction zone to form a reaction product comprising glycolaldehyde; 1. A process for preparing glycolaldehyde, comprising: the catalyst comprising a metal oxide on a catalyst support, the process comprising: (a) the pyrolysis reaction zone is heated to a temperature of 400° C. or greater; (b) The catalyst carrier is 500m 2 / g or less, 250m 2 / g or less, 100m 2 / g or less, 50m 2 / g or less, 25m 2 / g or less, 10m 2 / g or less, 5m 2 / g or less, or 1m 2 / g or less BET specific surface area, (c) the catalyst support comprises a glass material, a ceramic material, or a refractory material; (d) the pyrolysis reaction zone further comprises a reaction zone medium distinct from the catalyst; and / or (e) A process in which at least one of the following yields is satisfied: the yield of glycolaldehyde is 70% or more, 75% or more, or 80% or more.

[0096] 2. The carbohydrate is C4 to C 24 The process of item 1, including carbohydrates.

[0097] 3. The process of claim 1 or 2, wherein the carbohydrate comprises at least one sugar selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, and combinations thereof.

[0098] 4. The process of any one of items 1 to 3, wherein the carbohydrate comprises a monosaccharide.

[0099] 5. The process of any one of items 1 to 4, wherein the carbohydrate comprises cellulose.

[0100] 6. The process of any one of items 1 to 5, wherein the carbohydrate comprises at least one sugar selected from the group consisting of tetrose, pentose, hexose, heptose, and mixtures thereof.

[0101] 7. The process of any one of items 1 to 6, wherein the carbohydrate comprises at least one ketose sugar selected from the group consisting of ketotetrose, ketopentose, ketohexose, ketoheptose, and mixtures thereof.

[0102] 8. The process of any one of items 1 to 7, wherein the carbohydrates include glucose (dextrose) and / or fructose.

[0103] 9. The process of any one of items 1 to 8, wherein the feed composition comprises an aqueous solution containing the carbohydrate.

[0104] 10. The process of item 9, wherein the feed composition comprises an aqueous solution containing glucose.

[0105] 11. The process of any one of items 1 to 10, wherein the feed composition comprises a solid comprising the carbohydrate.

[0106] 12. The process of any one of items 1 to 11, wherein the feed composition comprises a biomass feedstock.

[0107] 13. The process of any one of items 1 to 12, wherein the feed composition comprises comminuted biomass solids.

[0108] 14. The process of any one of items 1 to 13, wherein the metal oxide comprises a transition metal oxide.

[0109] 15. The process of any one of items 1 to 14, wherein the metal oxide comprises an oxide of a Group 4, 5, 6, 7, 8, 9, 10, or 11 metal or a mixture thereof.

[0110] 16. The process of any one of items 1 to 15, wherein the metal oxide comprises an oxide of a Group 4, 5, or 6 metal or a mixture thereof.

[0111] 17. The process of any one of items 1 to 16, wherein the metal oxide comprises an oxide of titanium, molybdenum, tungsten, vanadium, or a mixture thereof.

[0112] 18. The process of any one of items 1 to 17, wherein the metal oxide comprises an oxide of molybdenum, tungsten, or a mixture thereof.

[0113] 19. The process of any one of items 1 to 18, wherein the metal oxide comprises tungsten(IV) oxide.

[0114] 20. The process of any one of items 1 to 19, wherein the metal oxide comprises tungsten(V) oxide.

[0115] 21. The process of any one of items 1 to 20, wherein the metal oxide comprises molybdenum oxide.

[0116] 22. The process of any one of items 17 to 21, wherein tungsten oxide and / or molybdenum oxide constitute 1 wt% or more, 2 wt% or more, 3 wt% or more, 4 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, or 99 wt% or more of the metal oxide on the catalyst support.

[0117] 23. Tungsten oxide and / or molybdenum oxide are 1% by weight to 99% by weight, 2% by weight to 99% by weight, 3% by weight to 99% by weight, 4% by weight to 99% by weight, 5% by weight to 99% by weight, 10% by weight to 99% by weight, 15% by weight to 99% by weight, 20% by weight to 99% by weight, 25% by weight to 99% by weight, 30% by weight to 99% by weight, 35% by weight to 99% by weight, 40% by weight to 99% by weight, Weight%, 45% to 99% by weight, 50% to 99% by weight, 60% to 99% by weight, 70% to 99% by weight, 80% to 99% by weight, 90% to 99% by weight, 95% to 99% by weight , 1wt%~95wt%, 2wt%~95wt%, 3wt%~95wt%, 4wt%~95wt%, 5wt%~95wt%, 10wt%~95wt%, 15wt%~95wt%, 20wt%~95 Weight%, 25% to 95% by weight, 30% to 95% by weight, 35% to 95% by weight, 40% to 95% by weight, 45% to 95% by weight, 50% to 95% by weight, 60% to 95% by weight , 70% to 95% by weight, 80% to 95% by weight, 90% to 95% by weight, 1% to 90% by weight, 2% to 90% by weight, 3% to 90% by weight, 4% to 90% by weight, 5% to 90% by weight 22. The process of any one of items 17 to 21, wherein the composition comprises 10% by weight, 10% by weight to 90% by weight, 15% by weight to 90% by weight, 20% by weight to 90% by weight, 25% by weight to 90% by weight, 30% by weight to 90% by weight, 35% by weight to 90% by weight, 40% by weight to 90% by weight, 45% by weight to 90% by weight, 50% by weight to 90% by weight, 60% by weight to 90% by weight, 70% by weight to 90% by weight, or 80% by weight to 90% by weight.

[0118] 24. The process of any one of items 1 to 23, wherein the metal oxide in the catalyst support comprises tungsten oxide and / or molybdenum oxide.

[0119] 25. The process of any one of items 1 to 24, wherein the catalyst has at least 0.1 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 5 wt%, at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or at least 99 wt% metal oxide filling.

[0120] 26. The process of any one of items 1 to 25, wherein the catalyst has 0.1% to 15% by weight, 0.5% to 15% by weight, 1% to 15% by weight, 2% to 15% by weight, 5% to 15% by weight, 0.1% to 10% by weight, 0.5% to 10% by weight, 1% to 10% by weight, 2% to 10% by weight, or 5% to 10% by weight of a metal oxide filling.

[0121] 27. The catalyst carrier is 500m 2 / g or less, 250m 2 / g or less, 100m 2 / g or less, 50m 2 / g or less, 25m 2 / g or less, 10m 2 / g or less, 5m 2 / g or less, or 1m 2 27. The process of any one of items 1 to 26, wherein the yttrium-containing fluorine-containing polymer has a BET specific surface area of ​​0.1 to 0.2 μm / g or less.

[0122] 28. The process of any one of items 1 to 27, wherein the catalyst support comprises a material selected from the group consisting of a glass material, a ceramic material, a refractory material, and mixtures thereof.

[0123] 29. The process of any one of items 1 to 28, wherein the catalyst support comprises a glass material.

[0124] 30. The process of item 29, wherein the glass material comprises glass beads.

[0125] 31. The process of any one of items 28 to 30, wherein the catalyst comprises a catalyst support comprising a glass material and a coating comprising a metal oxide, the coating being deposited on the coated glass material using a sol-gel comprising the metal oxide or a reaction product thereof.

[0126] 32. The process of any one of items 1 to 28, wherein the catalyst support comprises a ceramic material.

[0127] 33. The process of item 33, wherein the ceramic material is selected from the group consisting of silicon carbide, yttria-stabilized zirconia, and combinations thereof.

[0128] 34. The process of any one of items 1 to 28, wherein the catalyst support comprises a refractory material.

[0129] 35. The process of item 34, wherein the refractory material comprises silicon, aluminum, magnesium, calcium, zirconium, or a combination thereof.

[0130] 36. The process of any one of items 1 to 35, wherein the catalyst is an uncalcined catalyst.

[0131] 37. The process of any one of items 1 to 36, wherein the feed composition has a carbohydrate concentration that is 1 wt.% or more, 5 wt.% or more, 10 wt.% or more, 15 wt.% or more, or 20 wt.% or more.

[0132] 38. The process of any one of items 1 to 37, wherein the feed composition has a carbohydrate concentration of 1 wt% to 50 wt%, 1 wt% to 30 wt%, 1 wt% to 25 wt%, 5 wt% to 50 wt%, 5 wt% to 30 wt%, 5 wt% to 25 wt%, 10 wt% to 50 wt%, 10 wt% to 30 wt%, 10 wt% to 25 wt%, 15 wt% to 50 wt%, 15 wt% to 30 wt%, 15 wt% to 25 wt%, 20 wt% to 50 wt%, 20 wt% to 30 wt%, or 20 wt% to 25 wt%.

[0133] 39. The process of any one of items 1 to 38, wherein the pyrolysis reaction zone is heated to a temperature of 400°C or more, 450°C or more, 475°C or more, 500°C or more, 525°C or more, 550°C or more, 575°C or more, or 600°C or more.

[0134] 40. The process of any one of items 1 to 39, wherein the pyrolysis reaction zone is heated to a temperature of 400°C to 600°C, 400°C to 575°C, 400°C to 550°C, 400°C to 525°C, 450°C to 600°C, 450°C to 575°C, 450°C to 550°C, 450°C to 525°C, 500°C to 600°C, 500°C to 575°C, 500°C to 550°C, 500°C to 525°C, 525°C to 600°C, 525°C to 575°C, or 525°C to 550°C.

[0135] 41. The process of any one of items 1 to 40, wherein the yield of glycolaldehyde is 70% or more, 75% or more, or 80% or more.

[0136] 42. The process of any one of items 1 to 41, wherein the yield of glycolaldehyde is 70% to 85%, 70% to 80%, 75% to 85%, or 75% to 80%.

[0137] 43. The process of any one of items 37 to 42, wherein the feed composition comprises an aqueous glucose solution and the yield of glycolaldehyde is 70% or more, 75% or more, or 80% or more.

[0138] 44. The process of any one of items 1 to 43, wherein the reaction product further comprises at least one other component selected from the group consisting of formaldehyde, glyoxal, pyruvaldehyde, acetol, and mixtures thereof.

[0139] 45. The process of any one of items 1 to 44, wherein the reaction product further comprises formaldehyde.

[0140] 46. ​​The process of any one of items 1 to 45, wherein the reaction product further comprises formaldehyde, and the molar ratio of glycolaldehyde to formaldehyde is 5:1 or greater, 6:1 or greater, 8:1 or greater, 10:1 or greater, or 12:1 or greater.

[0141] 47. The process of any one of items 1 to 46, wherein the reaction product further comprises glyoxal.

[0142] 48. The process of any one of items 1 to 47, wherein the reaction product further comprises glyoxal, and the molar ratio of glycolaldehyde to glyoxal is 10:1 or greater, 15:1 or greater, 20:1 or greater, or 25:1 or greater.

[0143] 49. The process of any one of items 1 to 48, wherein the reaction product further comprises pyruvaldehyde.

[0144] 50. The process of any one of items 1 to 49, wherein the reaction product further comprises pyruvaldehyde, and the molar ratio of glycolaldehyde to pyruvaldehyde is 5:1 or more, 6:1 or more, 8:1 or more, 10:1 or more, or 12:1 or more.

[0145] 51. The process of any one of items 1 to 50, wherein the reaction product further comprises acetol.

[0146] 52. The process of any one of items 1 to 51, wherein the reaction product further comprises acetol, and the molar ratio of glycolaldehyde to acetol is 15:1 or greater, 20:1 or greater, 25:1 or greater, or 30:1 or greater.

[0147] 53. The process of any one of items 1 to 52, wherein the reaction product is free or essentially free of ethylene glycol.

[0148] 54. The process of any one of items 1 to 53, wherein the molar ratio of glycolaldehyde to ethylene glycol is 100:1 or more, 200:1 or more, or 400:1 or more.

[0149] 55. The process of any one of items 1 to 54, wherein the pyrolysis reaction zone further comprises a reaction zone medium different from the catalyst.

[0150] 56. The process of any one of items 1 to 55, wherein the catalyst and the reaction zone medium constitute a total volume of the medium packed in the pyrolysis reaction zone, and the catalyst is 1 vol.% to 50 vol.%, 2 vol.% to 25 vol.%, 3 vol.% to 15 vol.%, or 4 vol.% to 10 vol.% of the total volume of the medium packed in the pyrolysis reaction zone.

[0151] 57. The process of any one of items 1 to 56, wherein the reaction zone medium comprises a material selected from the group consisting of a glass material, a ceramic material, a refractory material, and mixtures thereof.

[0152] 58. The process of any one of items 1 to 57, wherein the reaction region medium comprises a glass material.

[0153] 59. The process of item 58, wherein the glass material comprises glass beads.

[0154] 60. The process of any one of items 1 to 59, wherein the reaction zone medium is uncoated.

[0155] 61. The process of any one of items 1 to 60, wherein the reaction zone medium is free or essentially free of a metal oxide coating.

[0156] 62. The process of any one of items 1 to 61, wherein the reaction zone medium comprises a support for the catalyst that does not contain a metal oxide.

[0157] 63. The process of any one of items 1 to 62, wherein the pyrolysis reaction zone comprises at least one fluidized bed reactor.

[0158] 64. The process of any one of items 1 to 63, wherein the feed composition is fluidized in a fluidizing gas in the pyrolysis reaction zone.

[0159] 65. The process of item 64, wherein the fluidizing gas comprises nitrogen, steam, carbon dioxide, and / or combustion off-gas.

[0160] 66. The process of any one of items 1 to 65, further comprising atomizing the feed composition provided to the pyrolysis reaction zone.

[0161] 67. The process of any one of items 1 to 66, wherein the residence time is 10 seconds or less, 8 seconds or less, 6 seconds or less, 4 seconds or less, 2 seconds or less, 1 second or less, or 0.5 seconds.

[0162] 68. The process of any one of items 1 to 67, wherein the residence time is 0.5 seconds to 10 seconds, 0.5 seconds to 5 seconds, 0.5 seconds to 2 seconds, 0.5 seconds to 1 second, 1 second to 10 seconds, 1 second to 5 seconds, or 1 second to 2 seconds.

[0163] 69. The process of any one of items 1 to 68, wherein the catalyst has a time on stream (TOS) period of 1,500 hours or more, 2,000 hours or more, 4,000 hours or more, 6,000 hours or more, 8,000 hours or more, or 10,000 hours or more.

[0164] 70. The catalyst comprises: mixing a metal oxide, a solvent, and a strong acid and / or peroxide source to form a sol-gel; depositing the sol-gel on the catalyst support to form a coated catalyst support; removing the solvent from the coated catalyst support to form the catalyst; 69. The process of any one of items 1 to 69, wherein the process comprises:

[0165] 71. The solvent is C1 to C 10 The process of item 70, which includes an alkanol.

[0166] 72. The process of item 70, wherein the peroxide source comprises hydrogen peroxide and the solvent comprises water.

[0167] 73. The process of any one of items 69 to 72, wherein the strong acid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, and mixtures thereof.

[0168] 74. A process for preparing a catalyst comprising: mixing a metal oxide, a solvent, and a strong acid to form a sol-gel; depositing the sol-gel on a catalyst support to form a coated catalyst support; and removing the solvent from the coated catalyst support to form the catalyst. 1. A process for preparing a catalyst comprising:

[0169] 75. The process of item 74, wherein the metal oxide comprises an oxide of a transition metal oxide.

[0170] 76. The process of claim 74 or 75, wherein the metal oxide comprises an oxide of a Group 4, 5, 6, 7, 8, 9, 10, or 11 metal or a mixture thereof.

[0171] 77. The process of any one of items 74 to 76, wherein the metal oxide comprises an oxide of a Group 4, 5, or 6 metal or a mixture thereof.

[0172] 78. The process of any one of items 74 to 77, wherein the metal oxide comprises an oxide of titanium, molybdenum, tungsten, vanadium, or a mixture thereof.

[0173] 79. The process of any one of items 74 to 78, wherein the metal oxide comprises an oxide of molybdenum, tungsten, or a mixture thereof.

[0174] 80. The process of any one of items 74 to 79, wherein the metal oxide comprises tungsten(IV) oxide.

[0175] 81. The process of any one of items 74 to 80, wherein the metal oxide comprises tungsten(V) oxide.

[0176] 82. The process of any one of items 74 to 81, wherein the catalyst has at least 0.1 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 5 wt%, at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or at least 99 wt% metal oxide filling.

[0177] 83. The process of any one of items 74 to 82, wherein the catalyst has 0.1% to 15% by weight, 0.5% to 15% by weight, 1% to 15% by weight, 2% to 15% by weight, 5% to 15% by weight, 0.1% to 10% by weight, 0.5% to 10% by weight, 1% to 10% by weight, 2% to 10% by weight, or 5% to 10% by weight of a metal oxide filling.

[0178] 84. The catalyst carrier is 500m 2 / g or less, 250m 2 / g or less, or 100m 2 The process of any one of items 74 to 83, wherein the sintered body has a BET specific surface area of ​​not more than 1 / g.

[0179] 85. The process of any one of items 74 to 84, wherein the catalyst support comprises a material selected from the group consisting of a glass material, a ceramic material, a refractory material, and mixtures thereof.

[0180] 86. The process of any one of items 74 to 85, wherein the catalyst support comprises a glass material.

[0181] 87. The process of any one of items 74 to 86, wherein the glass material comprises glass beads.

[0182] 88. The process of any one of items 74 to 87, wherein the catalyst is not subjected to calcination.

[0183] 89. The solvent is C1-C 10 The process of any one of items 74 to 88, which includes an alkanol.

[0184] 90.C1~C above 10 89. The process of item 89, wherein the alkanol is selected from the group consisting of isopropanol, ethanol, and mixtures thereof.

[0185] 91. The process of any one of items 74 to 90, wherein the strong acid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, and mixtures thereof.

[0186] 92. The process of any one of items 74 to 91, wherein the sol-gel is formed in a nitrogen atmosphere.

[0187] 93. The process of any one of items 74 to 92, wherein the sol-gel is formed in the substantial absence of oxygen.

[0188] 94. The process of any one of items 74 to 93, wherein the coated catalyst support is heated to a temperature of 80° C. or more, 90° C. or more, or 100° C. or more to remove the solvent.

[0189] 95. A process for preparing a catalyst comprising: mixing a metal oxide, a solvent, and a peroxide source to form a sol-gel; depositing the sol-gel on a catalyst support to form a coated catalyst support; removing the solvent from the coated catalyst support to form the catalyst; 1. A process for preparing a catalyst comprising:

[0190] 96. The process of item 95, wherein the peroxide source comprises hydrogen peroxide.

[0191] 97. The process of item 95 or 96, wherein the solvent comprises water.

Claims

1. providing a feed composition to a pyrolysis reaction zone, the feed composition comprising a carbohydrate having at least four carbon atoms; pyrolyzing the carbohydrate in the presence of water and a catalyst in the pyrolysis reaction zone to form a reaction product comprising glycolaldehyde; 1. A process for preparing glycolaldehyde, comprising: the catalyst being an uncalcined catalyst comprising a metal oxide on a catalyst support, the process comprising: (a) the pyrolysis reaction zone is heated to a temperature of 400° C. or greater; (b) The catalyst carrier is 500 m ２ / g or less, 250m ２ / g or less, 100m ２ / g or less, 50m ２ / g or less, 25m ２ / g or less, 10m ２ / g or less, 5m ２ / g or less, or 1m ２ / g or less BET specific surface area, (c) the catalyst support comprises a glass material, a ceramic material, or a refractory material; (d) the pyrolysis reaction zone further comprises a reaction zone medium distinct from the catalyst; and / or (e) the yield of glycolaldehyde is 70% or more, 75% or more, or 80% or more.

2. The carbohydrate is C ４ ~C ２４ The process of claim 1 , comprising:

3. The carbohydrate comprises at least one C sugar selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, and combinations thereof. ４ ~C ２４ 2. The process of claim 1 comprising sugar.

4. The process according to any one of claims 1 to 3, wherein the carbohydrates comprise glucose, dextrose and / or fructose.

5. The process of claim 2 , wherein the feed composition comprises an aqueous solution containing the carbohydrate.

6. 6. The process of claim 5, wherein the feed composition comprises an aqueous solution containing glucose.

7. The process of claim 1 or 6, wherein the metal oxide comprises a transition metal oxide.

8. 8. The process of claim 7, wherein the metal oxide comprises an oxide of a Group 4, 5, 6, 7, 8, 9, 10, or 11 metal or a mixture thereof.

9. 9. The process of claim 8, wherein the metal oxide comprises an oxide of a Group 4, 5, or 6 metal or a mixture thereof.

10. 10. The process of claim 9, wherein the metal oxide comprises an oxide of titanium, molybdenum, tungsten, vanadium, or mixtures thereof.

11. 11. The process of claim 10, wherein the metal oxide comprises an oxide of molybdenum, tungsten, or a mixture thereof.

12. 12. The process of claim 11, wherein the metal oxide comprises tungsten (IV) oxide.

13. 12. The process of claim 11, wherein the metal oxide comprises tungsten (V) oxide.

14. The process of claim 11 , wherein the metal oxide comprises molybdenum oxide.

15. 12. The process of claim 11, wherein tungsten oxide and / or molybdenum oxide constitute 1 wt% or more, 2 wt% or more, 3 wt% or more, 4 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, or 99 wt% or more of the metal oxides in the catalyst support.

16. 12. The process of claim 11, wherein the metal oxide in the catalyst support comprises tungsten oxide and / or molybdenum oxide.

17. 17. The process of claim 16, wherein the catalyst has at least 0.1 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 5 wt%, at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or at least 99 wt% of tungsten oxide and / or molybdenum oxide filling.

18. 18. The process of claim 17, wherein the catalyst has 0.1 wt% to 15 wt%, 0.5 wt% to 15 wt%, 1 wt% to 15 wt%, 2 wt% to 15 wt%, 5 wt% to 15 wt%, 0.1 wt% to 10 wt%, 0.5 wt% to 10 wt%, 1 wt% to 10 wt%, 2 wt% to 10 wt%, or 5 wt% to 10 wt% of a metal oxide loading of tungsten and / or molybdenum.

19. The catalyst carrier is 500 m ２ / g or less, 250m ２ / g or less, 100m ２ / g or less, 50m ２ / g or less, 25m ２ / g or less, 10m ２ / g or less, 5m ２ / g or less, or 1m ２ 20. The process of claim 11 or 18, wherein the SiO2 has a BET specific surface area of ​​0.1 to 1.0 μm / g or less.

20. 20. The process of claim 19, wherein the catalyst support comprises a material selected from the group consisting of a glass material, a ceramic material, a refractory material, and mixtures thereof.

21. The process of claim 20 , wherein the catalyst support comprises a glass material.

22. 21. The process of claim 20, wherein the catalyst support comprises a ceramic material.

23. 23. The process of claim 22, wherein the ceramic material is selected from the group consisting of silicon carbide, yttria stabilized zirconia, and combinations thereof.

24. 21. The process of claim 20, wherein the catalyst support comprises a refractory material.

25. 25. The process of claim 24, wherein the refractory material comprises silicon, aluminum, magnesium, calcium, zirconium, or combinations thereof.

26. The process of claim 1, wherein when condition (d) is met, the reaction region medium comprises a material selected from the group consisting of a glass material, a ceramic material, a refractory material, and mixtures thereof.

27. 27. The process of claim 26, wherein the reaction region medium comprises a glass material.

28. 30. The process of claim 27, wherein the reaction region medium is uncoated.

29. 27. The process of claim 26, wherein the reaction region medium is uncoated.

30. 30. The process of claim 28, wherein the reaction zone medium is free or essentially free of a metal oxide coating.

31. 30. The process of claim 29, wherein the reaction zone medium is free or essentially free of a metal oxide coating.

Images