Method for pyrolysis of carbohydrates

Abstract

Various methods for the pyrolysis of carbohydrates to produce products such as glycolaldehyde are described. In addition, various catalysts and methods for making catalysts useful for the pyrolysis of carbohydrates are described.

Description

TECHNICAL FIELD

[0001] The present invention relates to various methods for pyrolysis of carbohydrates to produce products such as glycolaldehyde (also known as hydroxyacetaldehyde). The present invention further relates to various catalysts and methods of making catalysts for pyrolysis of carbohydrates. BACKGROUND

[0003] For many years, there has been interest in using biomass feedstocks rich in carbohydrates to produce commercially useful chemicals. Pyrolysis of biomass feedstocks is a potentially attractive method for producing a range of chemical products and intermediates such as glycolaldehyde, methylglyoxal / pyruvaldehyde, acetol / hydroxypropanone, and formaldehyde. Of these chemicals, glycolaldehyde is a particularly versatile chemical used in a range of valuable and strategic products for the nutrition and renewable materials industries. For example, glycolaldehyde can be used as a browning and flavoring agent in food applications (e.g., smoking liquids). In addition, such a compound can be used as a building block for various amines, polyols, sugars, and sugar alcohols.

[0004] Biomass feedstocks (e.g., cellulose / glucose-containing feedstocks), reaction media (e.g., sand), carrier gases (e.g., nitrogen), and structural materials used in typical methods and apparatuses for pyrolysis of biomass are relatively inexpensive. However, pyrolysis of these feedstocks is also an inherently energy-intensive process, often requiring sustained heating at temperatures in excess of 500 °C, and requiring additional means to facilitate heat transfer. Moreover, in previous attempts, the yield of desired products, including glycolaldehyde, has been limited. For example, U.S. Patent No. 7,094,932 reports a yield of glycolaldehyde ranging from 55% to 70%. In addition, some pyrolysis methods produce problematic byproducts that are difficult to separate and require special handling and disposal. Pyrolysis processes also typically produce char as a byproduct. The yield of desired products is limited by the production of char, and char can cause operational difficulties, leading to reactor shutdown and / or loss of production. Thus, there remains a need for methods of pyrolysis of carbohydrates that have lower operating costs, produce higher yields of desired products such as glycolaldehyde, and / or produce reduced amounts of byproducts and / or char. SUMMARY

[0005] Various aspects of the present invention relate to methods for producing glycolaldehyde. Generally, these methods include 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, wherein the catalyst comprises a metal oxide on a catalyst support.

[0006] In some embodiments, these methods further include at least one of the following conditions:

[0007] (a) the pyrolysis reaction zone is heated to a temperature of 400°C or greater;

[0008] (b) the catalyst support has a BET specific surface area of 500 m 2 / g or less, 250 m 2 / g or less, 100 m 2 / g or less, 50 m 2 / g or less, 25 m 2 / g or less, 10 m 2 / g or less, 5 m 2 / g or less, or 1 m 2 / g or less;

[0009] (c) the catalyst support comprises glass, ceramic, or refractory material;

[0010] (d) the pyrolysis reaction zone further comprises a reaction zone medium that is different from the catalyst; and / or

[0011] (e) the yield of ethanal is 70% or greater, 75% or greater, or 80% or greater.

[0012] Further aspects of the present invention relate to methods for preparing catalysts that can be used for carbohydrate pyrolysis. In some embodiments, a method for preparing a catalyst comprises mixing a metal oxide, a solvent, and a strong acid to form a sol-gel; depositing the sol-gel onto a catalyst support to form a coated catalyst support; and removing the solvent from the coated catalyst support to form a catalyst.

[0013] Further aspects of the present invention relate to catalysts prepared by these methods.

[0014] Other objects and features will be in part apparent and in part pointed out hereinafter. DETAILED DESCRIPTION

[0015] In general, the present invention relates to various methods for carbohydrate pyrolysis to produce products such as ethanal, methylglyoxal / pyruval, propanol / hydroxypropanone, and formaldehyde. The present invention further relates to various catalysts and methods of preparing catalysts for carbohydrate pyrolysis. As used herein, "one or more carbohydrates" and / or "carbohydrate feed" will be understood to include any form of biomass feedstock that contains or provides carbohydrates, especially carbohydrates having four or more carbon atoms, from which ethanal can be obtained under pyrolysis conditions.

[0016] The various methods of the present application have been found to produce glycolaldehyde at improved yields. Previous attempts to improve the yield of glycolaldehyde have primarily focused on improving feed concentrations and reactor conditions, while the bed material and / or pyrolysis catalyst have remained essentially unchanged. However, it has been surprisingly found that the pyrolysis catalyst (typically, but not necessarily, in the form of a fluidizable supported catalyst in combination with conventional bed materials or materials used to provide heat transfer to the carbohydrate feed) can greatly influence the pyrolysis reaction and overcome problems encountered with existing methods.

[0017] Among other things, as discussed herein, it has been found that certain metal oxides are particularly effective at improving the yield of desired products (such as glycolaldehyde) from the pyrolysis of carbohydrates, especially sugars (such as glucose). The pyrolysis methods described herein in combination with these catalysts can advantageously provide improved process economics and reduced amounts of unwanted products that can need to be separated from the product mixture and specially handled and disposed of. For example, the pyrolysis process using these catalysts can more efficiently utilize process inputs (e.g., by requiring less energy), produce reduced amounts of undesirable byproducts, and / or produce less char in producing a given amount of glycolaldehyde and other desired products, as compared to the case without the catalyst. In addition, the various methods described herein have the advantage of providing stable product yields over extended operations and / or at high reactor fluxes.

[0018] Accordingly, embodiments of the present application are directed to various improved pyrolysis methods for preparing glycolaldehyde. For example, various embodiments are directed to a method for preparing glycolaldehyde, the method comprising: feeding a feed composition comprising a carbohydrate having at least four carbon atoms into 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, wherein the catalyst comprises a metal oxide on a catalyst support.

[0019] Feed materials

[0020] As indicated, the feed composition comprises a carbohydrate having at least four carbon atoms. For example, in some embodiments, the carbohydrate includes C4-C 24Carbohydrates. Such carbohydrates can be obtained from a variety of conventional biorenewable sources, such as corn kernel (zea mays), 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 municipal waste. In various embodiments, the carbohydrates are obtained from grain crops (e.g., corn, wheat, soy, rice, barley, rye, millet, sorghum, etc.). More generally, biorenewable sources that can be used include any renewable organic matter, including carbohydrate sources such as, for example, switchgrass, miscanthus, trees (hardwood and softwood), vegetation, and crop residues (e.g., bagasse and corn stover). Other sources include, for example, waste materials (e.g., waste paper, green 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.

[0021] Carbohydrates obtained from these sources can include a variety of monosaccharides, disaccharides, oligosaccharides, and polysaccharides. For example, in some embodiments, the carbohydrates include C4-C7 aldosaccharides. In various embodiments, the carbohydrates include at least one C4-C7 aldosaccharide. In some embodiments, the carbohydrates include at least one sugar selected from the group consisting of tetrose, pentose, hexose, heptose, and mixtures thereof. Specific C4-C7 aldosaccharides include, for example, tetrose, erythrose, xylose, ribose, arabinose, glucose, galactose, mannose, glucoheptose, L-glycero-D-manno-heptose, and mixtures thereof. In various embodiments, the carbohydrates include a hexose, such as glucose (dextrose). In some embodiments, the carbohydrates include a pentose, such as xylose, ribose, and / or arabinose. The term "aldosaccharide" and any specific aldosaccharides mentioned herein and defined by formula (I) also include cyclic forms (hemiacetal forms) of these compounds. 24 Saccharides. In certain embodiments, the carbohydrates include at least one saccharide selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, and combinations thereof. In various embodiments, the carbohydrates include monosaccharides. The carbohydrates can also include cellulose.

[0022] In some embodiments, the carbohydrates include sugars having at least four carbon atoms. For example, the sugars include a variety of aldoses. As described herein, aldoses include a variety of compounds having an aldehyde and hydroxyl group, which can be represented by formula (I):

[0023] HOCH2(HCOH) w CHO (I)

[0024] where w can be, for example, an integer from 2 to 10, or in some embodiments, from 2 to 5. In various embodiments, the carbohydrates include at least one C4-C7 aldosaccharide. In some embodiments, the carbohydrates include at least one sugar selected from the group consisting of tetrose, pentose, hexose, heptose, and mixtures thereof. Specific C4-C7 aldosaccharides include, for example, tetrose, erythrose, xylose, ribose, arabinose, glucose, galactose, mannose, glucoheptose, L-glycero-D-manno-heptose, and mixtures thereof. In various embodiments, the carbohydrates include a hexose, such as glucose (dextrose). In some embodiments, the carbohydrates include a pentose, such as xylose, ribose, and / or arabinose. The term "aldosaccharide" and any specific aldosaccharides mentioned herein and defined by formula (I) also include cyclic forms (hemiacetal forms) of these compounds.

[0025] In some embodiments, the carbohydrate includes a ketose having at least four carbon atoms. In various embodiments, the carbohydrate includes at least one ketose selected from the group consisting of butanose, pentanose, hexanose, heptanose, and mixtures thereof. In certain embodiments, the carbohydrate includes fructose.

[0026] The feed composition can have a carbohydrate concentration of 1 wt.% or greater, 5 wt.% or greater, 10 wt.% or greater, 15 wt.% or greater, or 20 wt.% or greater. For example, in various embodiments, the feed composition has a carbohydrate concentration of from 1 wt.% to 50 wt.%, from 1 wt.% to 30 wt.%, from 1 wt.% to 25 wt.%, from 5 wt.% to 50 wt.%, from 5 wt.% to 30 wt.%, from 5 wt.% to 25 wt.%, from 10 wt.% to 50 wt.%, from 10 wt.% to 30 wt.%, from 10 wt.% to 25 wt.%, from 15 wt.% to 50 wt.%, from 15 wt.% to 30 wt.%, from 15 wt.% to 25 wt.%, from 20 wt.% to 50 wt.%, from 20 wt.% to 30 wt.%, or from 20 wt.% to 25 wt.%.

[0027] Pyrolysis catalyst

[0028] As noted, the pyrolysis reaction in the processes described herein is conducted in the presence of a catalyst comprising a metal oxide on a catalyst support. In various embodiments, the metal oxide includes a transition metal oxide. For example, the metal oxide includes an oxide of a Group 4, 5, 6, 7, 8, 9, 10, or 11 metal or mixtures thereof. In some embodiments, the metal oxide includes an oxide of a Group 4, 5, or 6 metal or mixtures thereof. In certain embodiments, the metal oxide includes an oxide of titanium, molybdenum, tungsten, vanadium, or mixtures thereof. In particular embodiments, the metal oxide includes an oxide of molybdenum, tungsten, vanadium, or mixtures thereof. In certain embodiments, the metal oxide includes an oxide of tungsten, molybdenum, or mixtures thereof. Preferred metal oxides generally include those that preferentially catalyze the reverse aldol chemistry.

[0029] It has been found that oxides of molybdenum and tungsten are particularly effective for pyrolysis catalysts. Thus, in various embodiments, the metal oxide includes a tungsten oxide. For example, the tungsten oxide can include tungsten (IV) oxide and / or tungsten (V) oxide. In some embodiments, the metal oxide includes a molybdenum oxide.

[0030] In some embodiments, tungsten oxide and / or molybdenum oxide make up a significant portion of the metal oxide on the catalyst support. For example, in some embodiments, tungsten oxide and / or molybdenum oxide make up 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.In various embodiments, the tungsten oxide and / or molybdenum oxide comprises from 1 wt.% to 99 wt.%, from 2 wt.% to 99 wt.%, from 3 wt.% to 99 wt.%, from 4 wt.% to 99 wt.%, from 5 wt.% to 99 wt.%, from 10 wt.% to 99 wt.%, from 15 wt.% to 99 wt.%, from 20 wt.% to 99 wt.%, from 25 wt.% to 99 wt.%, from 30 wt.% to 99 wt.%, from 35 wt.% to 99 wt.%, from 40 wt.% to 99 wt.%, from 45 wt.% to 99 wt.%, from 50 wt.% to 99 wt.%, from 60 wt.% to 99 wt.%, from 70 wt.% to 99 wt.%, from 80 wt.% to 99 wt.%, from 90 wt.% to 99 wt.%, from 95 wt.% to 99 wt.%, from 1 wt.% to 95 wt.%, from 2 wt.% to 95 wt.%, from 3 wt.% to 95 wt.%, from 4 wt.% to 95 wt.%, from 5 wt.% to 95 wt.%, from 10 wt.% to 95 wt.%, from 15 wt.% to 95 wt.%, from 20 wt.% to 95 wt.%, from 25 wt.% to 95 wt.%, from 30 wt.% to 95 wt.%, from 35 wt.% to 95 wt.%, from 40 wt.% to 95 wt.%, from 45 wt.% to 95 wt.%, from 50 wt.% to 95 wt.%, from 60 wt.% to 95 wt.%, from 70 wt.% to 95 wt.%, from 80 wt.% to 95 wt.%, from 90 wt.% to 95 wt.%, from 1 wt.% to 90 wt.%, from 2 wt.% to 90 wt.%, from 3 wt.% to 90 wt.%, from 4 wt.% to 90 wt.%, from 5 wt.% to 90 wt.%, from 10 wt.% to 90 wt.%, from 15 wt.% to 90 wt.%, from 20 wt.% to 90 wt.%, from 25 wt.% to 90 wt.%, from 30 wt.% to 90 wt.%, from 35 wt.% to 90 wt.%, from 40 wt.% to 90 wt.%, from 45 wt.% to 90 wt.%, from 50 wt.% to 90 wt.%, from 60 wt.% to 90 wt.%, from 70 wt.% to 90 wt.%, or from 80 wt.% to 90 wt.% of the metal oxide on the catalyst support. In certain embodiments, the metal oxide on the catalyst support is comprised of tungsten oxide and / or molybdenum oxide.

[0031] The catalyst can have a metal oxide loading of 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. For example, in various embodiments, the catalyst has a metal oxide loading of from 0.1 wt.% to 15 wt.%, from 0.5 wt.% to 15 wt.%, from 1 wt.% to 15 wt.%, from 2 wt.% to 15 wt.%, from 5 wt.% to 15 wt.%, from 0.1 wt.% to 10 wt.%, from 0.5 wt.% to 10 wt.%, from 1 wt.% to 10 wt.%, from 2 wt.% to 10 wt.%, or from 5 wt.% to 10 wt.%.

[0032] In some cases, it has been found that low surface area catalysts and catalyst supports provide higher product yields (e.g., higher ethyl glyoxal yields). Thus, in some embodiments, the catalyst support comprises a material having a lower surface area (e.g., 500 m 2 / g or less, 250 m 2 / g or less, 100 m 2 / g or less, 50 m 2 / g or less, 25 m 2 / g or less, 10 m 2 / g or less, 5 m 2 / g or less, or 1 m 2 / g or less.

[0033] In various embodiments, the catalyst support comprises a material selected from the group consisting of glass, ceramic, refractory material, and mixtures thereof. In some embodiments, the catalyst support comprises a glass material. In certain 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 certain embodiments, the catalyst support comprises a material that is substantially non-porous and has a relatively low surface area.

[0034] The catalysts described herein can provide extended time on stream (TOS) segments. 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.

[0035] The catalyst can be prepared according to methods as further described herein. In some embodiments, the catalyst comprises a glass material and a coating comprising a metal oxide, and the coating is deposited on a glass material coated with a sol-gel comprising a metal oxide or a reaction product thereof. In these and other embodiments, the catalyst is an uncalcined catalyst.

[0036] Pyrolysis process features

[0037] As noted, pyrolysis is an energy-intensive process requiring elevated 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 from 400°C to 600°C, from 400°C to 575°C, from 400°C to 550°C, from 400°C to 525°C, from 450°C to 600°C, from 450°C to 575°C, from 450°C to 550°C, from 450°C to 525°C, from 500°C to 600°C, from 500°C to 575°C, from 500°C to 550°C, from 500°C to 525°C, from 525°C to 600°C, from 525°C to 575°C, or from 525°C to 550°C.

[0038] 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 that is distinct from the catalyst. In various embodiments, the reaction zone medium can include any inert material that can combine with the catalyst and be fluidized to provide a generally homogenous distribution of a fluidized bed through which the carbohydrate feed composition and pyrolysis products can be loaded with an inert carrier gas as they are formed, and which can be used to transfer the thermal energy necessary to pyrolyze the carbohydrates in the carbohydrate feed and convert one or more of the carbohydrates into pyrolysis products including at least ethanal. Those of skill in the art will be well able to identify various materials that can perform these necessary functions. In various embodiments, the reaction zone medium comprises a material selected from the group consisting of glass, ceramic, 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.

[0039] As noted, the reaction zone medium is generally different from the catalyst comprising 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 substantially free (e.g., less than 1 wt.% or even less than 0.1 wt.%) of a metal oxide coating. In some embodiments, the reaction zone medium comprises a catalyst support without a metal oxide (i.e., a bare catalyst support).

[0040] The catalyst and the reaction zone medium can constitute the total volume of the medium loaded within the pyrolysis reaction zone, such that the catalyst is from 1 vol.% to 50 vol.%, from 2 vol.% to 25 vol.%, from 3 vol.% to 15 vol.%, or from 4 vol.% to 10 vol.% of the total volume of the medium loaded within the pyrolysis reaction zone.

[0041] In various embodiments, the feed composition is fluidized in the pyrolysis reaction zone in a fluidizing or carrier gas. The fluidizing gas includes, for example, various inert gases or inert gas mixtures. In some embodiments, the fluidizing gas includes nitrogen, water vapor, carbon dioxide, and / or a waste gas (such as a combustion waste gas). In some embodiments, for example, where the carbohydrate is provided in the form of a carbohydrate solution, the method further includes atomizing the feed composition fed to the pyrolysis reaction zone. In certain embodiments, the feed composition can be atomized using a fluidizing gas (e.g., nitrogen, water vapor, etc.).

[0042] 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 from 0.5 seconds to 10, from 0.5 seconds to 5 seconds, from 0.5 seconds to 2 seconds, from 0.5 seconds to 1 second, from 1 second to 10, from 1 second to 5 seconds, or from 1 second to 2 seconds.

[0043] Overall, 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 for 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 methods described herein, the pyrolysis reaction zone includes one or more fluidized bed reactors. It will be appreciated that the feed composition, any fluidizing gas, and the catalyst can be introduced into the appropriate reactor(s) individually or in various combinations.

[0044] It has been found that the various methods of the present application provide improved product yields. For example, as demonstrated herein, using a 20 wt.% aqueous glucose solution as the carbohydrate feed, the various methods described herein provide an ethanolid yield of 70% or greater, 75% or greater, or 80% or greater. In some embodiments, the ethanolid yield is from 70% to 85%, from 70% to 80%, from 75% to 85%, or from 75% to 80%.

[0045] The reaction product can 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, methylglyoxal, 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 ethanolid to formaldehyde is 5: 1 or greater, 6: 1 or greater, 8: 1 or greater, 10: 1 or greater, or 12: 1 or greater.

[0046] In various embodiments, the reaction product further comprises glyoxal. In some embodiments, the reaction product further comprises glyoxal and the molar ratio of ethanolid to glyoxal is 10: 1 or greater, 15: 1 or greater, 20: 1 or greater, or 25: 1 or greater.

[0047] In various embodiments, the reaction product further comprises methylglyoxal. In some embodiments, the reaction product further comprises methylglyoxal and the molar ratio of ethanolid to methylglyoxal is 5: 1 or greater, 6: 1 or greater, 8: 1 or greater, 10: 1 or greater, or 12: 1 or greater.

[0048] In various embodiments, the reaction product further comprises acetol. In some embodiments, the reaction product further comprises acetol and the molar ratio of ethanolid to acetol is 15: 1 or greater, 20: 1 or greater, 25: 1 or greater, or 30: 1 or greater.

[0049] In various embodiments, the reaction product is free or substantially free of ethylene glycol. In some embodiments, the molar ratio of ethanolid to ethylene glycol is 100: 1 or greater; 200: 1 or greater; or 400: 1 or greater.

[0050] The methods of the present application can include various combinations of the features as described herein. For example, the various methods for preparing ethanolid can include:

[0051] feeding a feed composition comprising a carbohydrate having at least four carbon atoms into a pyrolysis reaction zone; and

[0052] pyrolyzing a carbohydrate in the presence of water and a catalyst in a 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:

[0053] (a) the pyrolysis reaction zone is heated to a temperature of 400 °C or greater;

[0054] (b) the catalyst support has a BET specific surface area of 500 m 2 / g or less, 250 m 2 / g or less, 100 m 2 / g or less, 50 m 2 / g or less, 25 m 2 / g or less, 10 m 2 / g or less, 5 m 2 / g or less, or 1 m 2 / g or less;

[0055] (c) the catalyst support comprises a glass material;

[0056] (d) the pyrolysis reaction zone further comprises a reaction zone medium that is different from the catalyst; and / or

[0057] (e) the yield of glycolaldehyde is 70% or greater, 75% or greater, or 80% or greater.

[0058] Catalyst preparation

[0059] The pyrolysis catalyst can be prepared by various techniques. The metal oxide can be deposited onto the catalyst support using procedures including, but not limited to, sol-gel, incipient wetness impregnation, ion exchange, deposition-precipitation, and vacuum impregnation techniques.

[0060] According to aspects of the invention, it has been found that a particularly effective method for preparing the catalyst comprises:

[0061] mixing a metal oxide, a solvent, and a strong acid to form a sol-gel;

[0062] depositing the sol-gel onto a catalyst support to form a coated catalyst support; and

[0063] removing the solvent from the coated catalyst support to form the catalyst.

[0064] In some embodiments, the sol-gel is prepared by mixing a metal oxide, a peroxide source, and a solvent. In further embodiments, the peroxide source comprises hydrogen peroxide and the solvent comprises water.

[0065] The metal oxide, metal oxide loading, and support can be any of those as specified 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).

[0066] In various embodiments, the solvent includes a Ci-C 10 alkanol. For example, the Ci-C 10 alkanol is selected from the group consisting of isopropyl alcohol, ethanol, and mixtures thereof. Further, the strong acid can be selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, and mixtures thereof.

[0067] The sol-gel can be formed in air, or it can be formed in an inert atmosphere. In some embodiments, the sol-gel is formed in an inert atmosphere. For example, the sol-gel can be formed in a nitrogen atmosphere. Further, the sol-gel can be formed in the substantial absence of oxygen. In various embodiments, the sol-gel can be prepared by mixing the metal oxide, the peroxide source, and the solvent. In some embodiments, the peroxide source can be hydrogen peroxide and the solvent can be water.

[0068] During removal of the solvent, the coated catalyst support can be heated to a temperature sufficient to vaporize any solvent on 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 subjected to typical calcination temperatures (e.g., 500°C or more, 750°C or more, or 1000°C or more).

[0069] Having described the application in detail, it will be apparent that modifications and variations are possible without departing from the scope of the application defined in the appended claims. Accordingly, it is intended that all matter contained in the above description and in the following examples be interpreted as illustrative and not in a limiting sense.

[0070] When introducing elements of the present application or the preferred embodiments(s) thereof, the articles "a," "an," "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there can be additional elements other than the listed elements.

[0071] More particularly, as used herein, the term "comprising" is to be read as encompassing both an open and a closed transition, such that the product / method / use comprising the recited elements can also comprise additional elements that are not recited.

[0072] Furthermore, as used herein, the term "comprising" is to be read as encompassing both an open and a closed transition, such that the product / method / use comprising the recited elements can also comprise additional elements that are not recited.

[0073] Unless otherwise indicated, all synthetic methods and parameter measurements are to be understood to be conducted at room / ambient temperature (i.e., at 21 °C ± 1 °C).

[0074] Examples

[0075] The following non-limiting examples are provided to further illustrate the present application.

[0076] Example 1: Preparation of metal oxide coated glass bead catalyst

[0077] To prepare the metal oxide coated glass bead catalyst, a metal oxide sol-gel was first prepared in a nitrogen filled environment to prevent exposure to air. 0.70 mL of tungsten (V) ethanolate, 1,2-dimethoxyethane adduct (99%) was added to 50 mL of isopropanol with stirring. 0.2 mL of 2M hydrochloric acid was then added dropwise to give a light yellow sol with a white precipitate. The mixture was stirred at room temperature for about an hour and allowed to stand overnight.

[0078] Glass beads were prepared by fumigating the beads with isopropanol. 25 ml of the fumigated beads were then added to the sol. The mixture containing the beads was mixed periodically and kept uncovered. The resulting coated glass beads were uniformly coated with the tungsten oxide solution.

[0079] The coated glass beads were then dried at ambient temperature and heated at about 80 °C overnight. The coated glass beads were not subjected to calcination or otherwise modified.

[0080] Each of the coated glass beads contained about 0.25 wt.% tungsten in the form of a thin film coating.

[0081] Example 2: Preparation of metal oxide coated glass bead catalyst

[0082] The procedure of Example 1 was followed except that the coated glass beads were rinsed with acetone prior to heating at about 80 °C overnight. Rinsing the coated glass beads with acetone did not remove any significant amount of the tungsten oxide solution.

[0083] Example 3: Pyrolysis of dextrose using a glass bead catalyst

[0084] Untreated glass bead catalysts were tested for pyrolysis of dextrose using a fluidized bed reactor system. The glass bead catalysts comprised 6% of the total media volume of the reactor bed. A solution of about 20 wt.% dextrose was introduced into the reactor system at a rate of 1.7 mL / min. A nitrogen stream was also introduced into the system at a rate of 4500-5000 mL / min. Tables 1-3 below report the product profiles for different run times at different reaction temperatures. Each reaction listed below had a residence time of 0.98 s.

[0085] Table 1 : Reactions at 525 °C

[0086]

[0087] Table 2: Reactions at 550 °C

[0088]

[0089] Table 3: Reactions at 550 °C

[0090]

[0091] Example 4: Pyrolysis of dextrose using tungsten carbide

[0092] A tungsten carbide sand grit material was mixed with glass beads and used in a fluidized bed reactor system for pyrolysis or cracking of dextrose. The mixture was tested at different reactor temperatures and compared to experiments performed using uncoated glass beads.

[0093] A solution of about 20 wt.% dextrose was introduced into the reactor system at a rate of 1.7 mL / min. A nitrogen stream was also introduced into the system at a rate of 4500-5000 mL / min. Tables 4 and 5 report the temperature, flow rates, residence times, etc. at various points in the reactor system. The "bottom temperature" reported below is the temperature at the fluidized bed reactor feed nozzle. Table 6 reports the product profiles for a given run time.

[0094] Table 4

[0095]

[0096] Table 5

[0097]

[0098] Table 6

[0099]

[0100] A second experiment was performed using tungsten carbide grit material mixed with glass beads under the same conditions. The cracking media contained about 3% tungsten carbide grit and 97% glass beads, by volume. Tables 7 and 8 report the temperatures, flow rates, residence times, etc. at various points in the reactor system. The product slate for this second experiment is reported in Table 9 below.

[0101] Table 7

[0102]

[0103] Table 8

[0104]

[0105] Table 9

[0106]

[0107] Example 5: Pyrolysis of dextrose using a tungsten oxide coated glass bead catalyst

[0108] Several experiments similar to those performed in Example 4 were performed. Tables 10 and 11 report the results using tungsten oxide coated glass bead catalyst at different reactor system temperatures, with the tungsten oxide coated catalyst comprising about 6 wt.% of the total cracking media.

[0109] Table 10: Tungsten Oxide Catalyst

[0110]

[0111] Table 11: Tungsten Oxide Catalyst

[0112]

[0113]

[0114] As demonstrated by the results above, the catalysts comprising metal oxide coated glass beads produced a fairly high ethanal yield compared to the metal carbide catalysts.

[0115] Example 6: Pyrolysis of dextrose using a molybdenum oxide coated glass bead catalyst

[0116] An experiment similar to Example 4 was performed using a molybdenum oxide coated glass bead catalyst, which comprised about 6 wt.% of the total cracking media. The catalyst was tested at different reactor temperatures. The reaction conditions are listed in Table 12, and the results are reported in Table 13.

[0117] Table 12

[0118]

[0119]

[0120] Table 13

[0121]

[0122]

[0123] Example 7: Pyrolysis of dextrose using a vanadium oxide coated glass bead catalyst

[0124] An experiment similar to Example 4 was performed using a 5 wt.% vanadium oxide coated glass bead catalyst. The catalyst was used in a reaction with a set temperature of 525°C. After 50 hours of operation, coking of the reactor was observed.

[0125] Reaction conditions are listed in Table 14 below. Table 15 reports the temperatures at various points in the reactor during the reaction. The "bottom temperature" reported below is the temperature at the feed nozzle. Table 16 reports the product slate of the reaction products.

[0126] Table 14

[0127]

[0128] Table 15

[0129]

[0130] Table 16

[0131]

[0132] Example 8: Pyrolysis of dextrose using a molybdenum coated quartz sand catalyst

[0133] An experiment similar to Example 4 was performed using a 5 wt.% vanadium oxide coated glass bead catalyst. The catalyst was used in a reaction with a set temperature of 525°C. After 50 hours of operation, coking of the reactor was observed.

[0134] After 3 hours of operation, the reaction was stopped and the reactor was inspected. Coking was observed and a solid mass was formed in the reactor.

[0135] Table 17

[0136]

[0137] Table 18

[0138]

[0139] Table 19

[0140]

[0141] Example 9: Pyrolysis of dextrose using a titanium dioxide coated glass bead catalyst

[0142] Titanium dioxide-coated glass beads were prepared according to the procedure of Example 1 and pyrolysis experiments of dextrose using this catalyst were tested according to the procedure of Example 4. The reaction product profiles are reported in Table 20 below.

[0143] Prior to running the reaction, the entire reactor body and all gas handling lines were properly cleaned. The reactor failed to operate for more than 30 hours before being completely shut down. Upon inspection, a solid mass was formed in the reactor and the gas handling lines were sealed with a mixture of carbon and pyrolysis oil. It is hypothesized that upon dosing, the feed reacted with the glass beads to form the solid mass and increased amounts of carbon. This buildup eventually led to the reactor being shut down due to pressure buildup.

[0144] Table 20

[0145]

[0146] When introducing an element of the application or the embodiments thereof, the articles "a," "an," "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including" and "having" are intended to be inclusive and mean that there can be additional elements other than the listed elements.

[0147] In light of the above, it will be seen that the several objects of the application are achieved and other advantageous results attained.

[0148] Item:

[0149] 1. A process for making glycolaldehyde, the process comprising:

[0150] feeding a feed composition comprising a carbohydrate having at least four carbon atoms into a pyrolysis reaction zone; and

[0151] 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:

[0152] (a) the pyrolysis reaction zone is heated to a temperature of 400°C or greater;

[0153] (b) the catalyst support has a BET specific surface area of 500 m 2 / g or less, 250 m 2 / g or less, 100 m 2 / g or less, 50 m 2 / g or less, 25 m 2 / g or less, 10 m 2 / g or less, 5 m 2 / g or less, or 1 m 2 / g or less;

[0154] (c) the catalyst support comprises glass, ceramic, or refractory material;

[0155] (d) the pyrolysis reaction zone further comprises a reaction zone medium different from the catalyst; and / or

[0156] (e) the yield of ethanodial is 70% or more, 75% or more, or 80% or more.

[0157] 2. The method of item 1, wherein the carbohydrate comprises C4-C 24 carbohydrate.

[0158] 3. The method of item 1 or item 2, wherein the carbohydrate comprises at least one saccharide selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, and combinations thereof.

[0159] 4. The method of any one of items 1 to 3, wherein the carbohydrate comprises a monosaccharide.

[0160] 5. The method of any one of items 1 to 4, wherein the carbohydrate comprises cellulose.

[0161] 6. The method of any one of items 1 to 5, wherein the carbohydrate comprises at least one saccharide selected from the group consisting of tetruloses, pentuloses, hexuloses, heptuloses, and mixtures thereof.

[0162] 7. The method of any one of items 1 to 6, wherein the carbohydrate comprises at least one ketose selected from the group consisting of tetrose, pentulose, hexulose, heptulose, and mixtures thereof.

[0163] 8. The method of any one of items 1 to 7, wherein the carbohydrate comprises glucose (dextrose) and / or fructose.

[0164] 9. The method of any one of items 1 to 8, wherein the feed composition comprises an aqueous solution comprising the carbohydrate.

[0165] 10. The method of item 9, wherein the feed composition comprises an aqueous solution comprising glucose.

[0166] 11. The method of any one of items 1 to 10, wherein the feed composition comprises a solid comprising the carbohydrate.

[0167] 12. The process of any of items 1 to 11, wherein the feed composition comprises a biomass feedstock.

[0168] 13. The process of any of items 1 to 12, wherein the feed composition comprises a comminuted biomass solid.

[0169] 14. The process of any of items 1 to 13, wherein the metal oxide comprises a transition metal oxide.

[0170] 15. The process of any 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 mixtures thereof.

[0171] 16. The process of any of items 1 to 15, wherein the metal oxide comprises an oxide of a Group 4, 5, or 6 metal or mixtures thereof.

[0172] 17. The process of any of items 1 to 16, wherein the metal oxide comprises an oxide of titanium, molybdenum, tungsten, vanadium, or mixtures thereof.

[0173] 18. The process of any of items 1 to 17, wherein the metal oxide comprises an oxide of molybdenum, tungsten, or mixtures thereof.

[0174] 19. The process of any of items 1 to 18, wherein the metal oxide comprises tungsten (IV) oxide.

[0175] 20. The process of any of items 1 to 19, wherein the metal oxide comprises tungsten (V) oxide.

[0176] 21. The process of any of items 1 to 20, wherein the metal oxide comprises a molybdenum oxide.

[0177] 22. The process of any of items 17 to 21, wherein tungsten oxide and / or molybdenum oxide comprises 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.

[0178] 23. The method of any of items 17 to 21, wherein tungsten oxide and / or molybdenum oxide comprises from 1 wt.% to 99 wt.%, from 2 wt.% to 99 wt.%, from 3 wt.% to 99 wt.%, from 4 wt.% to 99 wt.%, from 5 wt.% to 99 wt.%, from 10 wt.% to 99 wt.%, from 15 wt.% to 99 wt.%, from 20 wt.% to 99 wt.%, from 25 wt.% to 99 wt.%, from 30 wt.% to 99 wt.%, from 35 wt.% to 99 wt.%, from 40 wt.% to 99 wt.%, from 45 wt.% to 99 wt.%, from 50 wt.% to 99 wt.%, from 60 wt.% to 99 wt.%, from 70 wt.% to 99 wt.%, from 80 wt.% to 99 wt.%, from 90 wt.% to 99 wt.%, from 95 wt.% to 99 wt.%, from 1 wt.% to 95 wt.%, from 2 wt.% to 95 wt.%, from 3 wt.% to 95 wt.%, from 4 wt.% to 95 wt.%, from 5 wt.% to 95 wt.%, from 10 wt.% to 95 wt.%, from 15 wt.% to 95 wt.%, from 20 wt.% to 95 wt.%, from 25 wt.% to 95 wt.%, from 30 wt.% to 95 wt.%, from 35 wt.% to 95 wt.%, from 40 wt.% to 95 wt.%, from 45 wt.% to 95 wt.%, from 50 wt.% to 95 wt.%, from 60 wt.% to 95 wt.%, from 70 wt.% to 95 wt.%, from 80 wt.% to 95 wt.%, from 90 wt.% to 95 wt.%, from 1 wt.% to 90 wt.%, from 2 wt.% to 90 wt.%, from 3 wt.% to 90 wt.%, from 4 wt.% to 90 wt.%, from 5 wt.% to 90 wt.%, from 10 wt.% to 90 wt.%, from 15 wt.% to 90 wt.%, from 20 wt.% to 90 wt.%, from 25 wt.% to 90 wt.%, from 30 wt.% to 90 wt.%, from 35 wt.% to 90 wt.%, from 40 wt.% to 90 wt.%, from 45 wt.% to 90 wt.%, from 50 wt.% to 90 wt.%, from 60 wt.% to 90 wt.%, from 70 wt.% to 90 wt.%, or from 80 wt.% to 90 wt.% of the metal oxide on the catalyst support.

[0179] 24. The method of any of items 1 to 23, wherein the metal oxide on the catalyst support is comprised of tungsten oxide and / or molybdenum oxide.

[0180] 25. The method of any of items 1 to 24, wherein the catalyst has a metal oxide loading of 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.

[0181] 26. The method of any of items 1 to 25, wherein the catalyst has a metal oxide loading of from 0.1 wt.% to 15 wt.%, from 0.5 wt.% to 15 wt.%, from 1 wt.% to 15 wt.%, from 2 wt.% to 15 wt.%, from 5 wt.% to 15 wt.%, from 0.1 wt.% to 10 wt.%, from 0.5 wt.% to 10 wt.%, from 1 wt.% to 10 wt.%, from 2 wt.% to 10 wt.%, or from 5 wt.% to 10 wt.%.

[0182] 27. The method of any of items 1 to 26, wherein the catalyst support has a BET specific surface area of 500 m2 / g or less, 250 m2 / g or less, 100 m2 / g or less, 50 m2 / g or less, 25 m2 / g or less, 10 m2 / g or less, 5 m2 / g or less, or 1 m2 / g or less. 2 2 2 2 2 2 2 2

[0183] 28. The method of any of items 1 to 27, wherein the catalyst support comprises a material selected from the group consisting of glass, ceramic, refractory material, and mixtures thereof.

[0184] 29. The method of any of items 1 to 28, wherein the catalyst support comprises a glass material.

[0185] 30. The method of item 29, wherein the glass material comprises glass beads.

[0186] 31. The method of any of items 28 to 30, wherein the catalyst comprises a catalyst support comprising a glass material and a coating comprising the metal oxide, and the coating is deposited on the glass material using a sol-gel coating comprising the metal oxide or reaction products thereof. ​​​​​​​​

[0187] 32. The method of any of items 1 to 28, wherein the catalyst support comprises a ceramic material.

[0188] 33. The method of item 33, wherein the ceramic material is selected from the group consisting of silicon carbide, yttria-stabilized zirconia, and combinations thereof.

[0189] 34. The method of any of items 1 to 28, wherein the catalyst support comprises a refractory material.

[0190] 35. The method of item 34, wherein the refractory material comprises silicon, aluminum, magnesium, calcium, zirconium, or combinations thereof.

[0191] 36. The method of any of items 1 to 35, wherein the catalyst is an uncalcined catalyst.

[0192] 37. The method of any of items 1 to 36, wherein the feed composition has a carbohydrate concentration of 1 wt.% or greater, 5 wt.% or greater, 10 wt.% or greater, 15 wt.% or greater, or 20 wt.% or greater.

[0193] 38. The method of any of items 1 to 37, wherein the feed composition has a carbohydrate concentration of from 1 wt.% to 50 wt.%, from 1 wt.% to 30 wt.%, from 1 wt.% to 25 wt.%, from 5 wt.% to 50 wt.%, from 5 wt.% to 30 wt.%, from 5 wt.% to 25 wt.%, from 10 wt.% to 50 wt.%, from 10 wt.% to 30 wt.%, from 10 wt.% to 25 wt.%, from 15 wt.% to 50 wt.%, from 15 wt.% to 30 wt.%, from 15 wt.% to 25 wt.%, from 20 wt.% to 50 wt.%, from 20 wt.% to 30 wt.%, or from 20 wt.% to 25 wt.%.

[0194] 39. The method of any of items 1 to 38, wherein the pyrolysis reaction zone is heated to a temperature of 400°C or greater, 450°C or greater, 475°C or greater, 500°C or greater, 525°C or greater, 550°C or greater, 575°C or greater, or 600°C or greater.

[0195] 40. The process of any of items 1 to 39, wherein the pyrolysis reaction zone is heated to a temperature from 400 °C to 600 °C, from 400 °C to 575 °C, from 400 °C to 550 °C, from 400 °C to 525 °C, from 450 °C to 600 °C, from 450 °C to 575 °C, from 450 °C to 550 °C, from 450 °C to 525 °C, from 500 °C to 600 °C, from 500 °C to 575 °C, from 500 °C to 550 °C, from 500 °C to 525 °C, from 525 °C to 600 °C, from 525 °C to 575 °C, or from 525 °C to 550 °C.

[0196] 41. The process of any of items 1 to 40, wherein the glycolaldehyde yield is 70% or more, 75% or more, or 80% or more.

[0197] 42. The process of any of items 1 to 41, wherein the glycolaldehyde yield is from 70% to 85%, from 70% to 80%, from 75% to 85%, or from 75% to 80%.

[0198] 43. The process of any of items 37 to 42, wherein the feed composition comprises an aqueous solution of glucose and the glycolaldehyde yield is 70% or more, 75% or more, or 80% or more.

[0199] 44. The process of any of items 1 to 43, wherein the reaction product further comprises at least one additional component selected from the group consisting of formaldehyde, glyoxal, methylglyoxal, acetol, and mixtures thereof.

[0200] 45. The process of any of items 1 to 44, wherein the reaction product further comprises formaldehyde.

[0201] 46. The process of any of items 1 to 45, wherein the reaction product further comprises formaldehyde and the molar ratio of glycolaldehyde to formaldehyde is 5: 1 or more, 6: 1 or more, 8: 1 or more, 10: 1 or more, or 12: 1 or more.

[0202] 47. The process of any of items 1 to 46, wherein the reaction product further comprises glyoxal.

[0203] 48. The process of any of items 1 to 47, wherein the reaction product further comprises glyoxal and the molar ratio of glycolaldehyde to glyoxal is 10: 1 or more, 15: 1 or more, 20: 1 or more, or 25: 1 or more.

[0204] 49. The process of any of items 1 to 48, wherein the reaction product further comprises methylglyoxal.

[0205] 50. The method of any of items 1 to 49, wherein the reaction product further comprises methylglyoxal and the molar ratio of glycolaldehyde to methylglyoxal is 5: 1 or greater, 6: 1 or greater, 8: 1 or greater, 10: 1 or greater, or 12: 1 or greater.

[0206] 51. The method of any of items 1 to 50, wherein the reaction product further comprises acetol.

[0207] 52. The method of any 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.

[0208] 53. The method of any of items 1 to 52, wherein the reaction product is free or substantially free of ethylene glycol.

[0209] 54. The method of any of items 1 to 53, wherein the molar ratio of glycolaldehyde to ethylene glycol is 100: 1 or greater; 200: 1 or greater; or 400: 1 or greater.

[0210] 55. The method of any of items 1 to 54, wherein the pyrolysis reaction zone further comprises the reaction zone media that is different from the catalyst.

[0211] 56. The method of any of items 1 to 55, wherein the catalyst and reaction zone media make up the total volume of media loaded within the pyrolysis reaction zone, and the catalyst is from 1 vol. % to 50 vol. %, from 2 vol. % to 25 vol. %, from 3 vol. % to 15 vol. %, or from 4 vol. % to 10 vol. % of the total volume of media loaded within the pyrolysis reaction zone.

[0212] 57. The method of any of items 1 to 56, wherein the reaction zone media comprises a material selected from the group consisting of glass, ceramic, refractory material, and mixtures thereof.

[0213] 58. The method of any of items 1 to 57, wherein the reaction zone media comprises a glass material.

[0214] 59. The method of item 58, wherein the glass material comprises glass beads.

[0215] 60. The method of any of items 1 to 59, wherein the reaction zone media is uncoated.

[0216] 61. The method of any of items 1 to 60, wherein the reaction zone medium is free or substantially free of a metal oxide coating.

[0217] 62. The method of any of items 1 to 61, wherein the reaction zone medium comprises a support without a metal oxide catalyst.

[0218] 63. The method of any of items 1 to 62, wherein the pyrolysis reaction zone comprises at least one fluidized bed reactor.

[0219] 64. The method of any of items 1 to 63, wherein the feed composition is fluidized in a fluidization gas in the pyrolysis reaction zone.

[0220] 65. The method of item 64, wherein the fluidization gas comprises nitrogen, water vapor, carbon dioxide, and / or combustion exhaust.

[0221] 66. The method of any of items 1 to 65, further comprising atomizing the feed composition fed to the pyrolysis reaction zone.

[0222] 67. The method of any 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 or less.

[0223] 68. The method of any of items 1 to 67, wherein the residence time is from 0.5 seconds to 10, from 0.5 seconds to 5 seconds, from 0.5 seconds to 2 seconds, from 0.5 seconds to 1 second, from 1 second to 10, from 1 second to 5 seconds, or from 1 second to 2 seconds.

[0224] 69. The method of any of items 1 to 68, wherein the time on stream (TOS) segment 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.

[0225] 70. The method of any of items 1 to 69, wherein the catalyst is formed by a method comprising:

[0226] mixing a metal oxide, a solvent, and a strong acid and / or a peroxide source to form a sol-gel;

[0227] depositing the sol-gel onto the catalyst support to form a coated catalyst support; and

[0228] removing solvent from the coated catalyst support to form a catalyst.

[0229] 71. The method of item 70, wherein the solvent comprises a Ci-C 10 alkanol.

[0230] 72. The method of item 70, wherein the peroxide source comprises hydrogen peroxide and the solvent comprises water.

[0231] 73. The method 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.

[0232] 74. A method for preparing a catalyst, the method comprising:

[0233] mixing a metal oxide, a solvent, and a strong acid to form a sol-gel;

[0234] depositing the sol-gel onto a catalyst support to form a coated catalyst support; and

[0235] removing the solvent from the coated catalyst support to form a catalyst.

[0236] 75. The method of item 74, wherein the metal oxide comprises an oxide of a transition metal oxide.

[0237] 76. The method of item 74 or item 75, wherein the metal oxide comprises an oxide of a Group 4, 5, 6, 7, 8, 9, 10, or 11 metal or mixtures thereof.

[0238] 77. The method of any one of items 74 to 76, wherein the metal oxide comprises an oxide of a Group 4, 5, or 6 metal or mixtures thereof.

[0239] 78. The method of any one of items 74 to 77, wherein the metal oxide comprises an oxide of titanium, molybdenum, tungsten, vanadium, or mixtures thereof.

[0240] 79. The method of any one of items 74 to 78, wherein the metal oxide comprises an oxide of molybdenum, tungsten, or mixtures thereof.

[0241] 80. The method of any one of items 74 to 79, wherein the metal oxide comprises tungsten (IV) oxide.

[0242] 81. The method of any one of items 74 to 80, wherein the metal oxide comprises tungsten (V) oxide.

[0243] 82. The method of any of items 74 to 81, wherein the catalyst has a metal oxide loading of 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.

[0244] 83. The method of any of items 74 to 82, wherein the catalyst has a metal oxide loading of from 0.1 wt.% to 15 wt.%, from 0.5 wt.% to 15 wt.%, from 1 wt.% to 15 wt.%, from 2 wt.% to 15 wt.%, from 5 wt.% to 15 wt.%, from 0.1 wt.% to 10 wt.%, from 0.5 wt.% to 10 wt.%, from 1 wt.% to 10 wt.%, from 2 wt.% to 10 wt.%, or from 5 wt.% to 10 wt.%.

[0245] 84. The method of any of items 74 to 83, wherein the catalyst support has a BET specific surface area of 500 m 2 / g or less, 250 m 2 / g or less, or 100 m 2 / g or less.

[0246] 85. The method of any of items 74 to 84, wherein the catalyst support comprises a material selected from the group consisting of glass, ceramic, refractory material, and mixtures thereof.

[0247] 86. The method of any of items 74 to 85, wherein the catalyst support comprises a glass material.

[0248] 87. The method of any of items 74 to 86, wherein the glass material comprises glass beads.

[0249] 88. The method of any of items 74 to 87, wherein the catalyst is not subjected to calcination.

[0250] 89. The method of any of items 74 to 88, wherein the solvent comprises a C1-C 10 alkanol.

[0251] 90. The method of item 89, wherein the C1-C 10 alkanol is selected from the group consisting of isopropyl alcohol, ethanol, and mixtures thereof.

[0252] 91. The method of any 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.

[0253] 92. The method of any of items 74 to 91, wherein the sol-gel is formed in a nitrogen atmosphere.

[0254] 93. The method of any of items 74 to 92, wherein the sol-gel is formed in the substantial absence of oxygen.

[0255] 94. The method of any of items 74 to 93, wherein the coated catalyst support is heated to a temperature of 80°C or greater, 90°C or greater, or 100°C or greater to remove solvent.

[0256] 95. A method for preparing a catalyst, the method comprising:

[0257] mixing a metal oxide, a solvent, and a peroxide source to form a sol-gel;

[0258] depositing the sol-gel onto a catalyst support to form a coated catalyst support; and

[0259] removing solvent from the coated catalyst support to form a catalyst.

[0260] 96. The method of item 95, wherein the peroxide source comprises hydrogen peroxide.

[0261] 97. The method of item 95 or 96, wherein the solvent comprises water.

Claims

1. A process for the production of glycolaldehyde, the process comprising: a feed composition comprising C4-C 24 a feed composition comprising C4-C a feed composition comprising C4-C C4-C 24 saccharide is pyrolyzed in the presence of water and a catalyst in the pyrolysis reaction zone to form a reaction product comprising ethanol aldehyde, wherein the catalyst is a metal oxide on a catalyst support; the metal oxide comprises an oxide of molybdenum, an oxide of tungsten, or a mixture thereof; and the yield of ethanol aldehyde is 75% or more; and at least one of the following conditions is met: (a) heating the pyrolysis reaction zone to a temperature of 400°C or greater; (b) the catalyst support has a BET specific surface area of 500 m 2 / g or less; (c) the catalyst support is selected from the group consisting of glass, ceramic, refractory material, and mixtures thereof; and / or (d) the pyrolysis reaction zone further comprises a reaction zone medium that is different from the catalyst.

2. The method of claim 1, wherein, said C4-C 24 saccharide is glucose and / or fructose.

3. The method of claim 1, wherein, said C4-C 24 saccharide is dextrose and / or fructose.

4. The method of claim 1, wherein, The feed composition is a C4-C 24 aqueous solution of a sugar.

5. The method of claim 4, wherein, The feed composition is an aqueous solution comprising glucose.

6. The method of claim 1 or claim 5, wherein, The metal oxide further comprises a transition metal oxide other than molybdenum or tungsten.

7. The method of claim 6, wherein, The metal oxide further comprises an oxide of a Group 4, 5, 6, 7, 8, 9, 10, or 11 metal or mixtures thereof.

8. The method of claim 7, wherein, The metal oxide further comprises an oxide of a Group 4, 5, or 6 metal or mixtures thereof.

9. The method of claim 8, wherein, The metal oxide further comprises an oxide of titanium, vanadium, or mixtures thereof.

10. The method of claim 1, wherein, The yield of glycolaldehyde is 80% or greater.

11. The method of claim 1, wherein, The metal oxide is tungsten oxide, the tungsten being in the +4 oxidation state.

12. The method of claim 1, wherein, The metal oxide is tungsten oxide, the tungsten being in the +5 oxidation state.

13. The method of claim 1, wherein, The metal oxide is a molybdenum oxide.

14. The method of claim 1, wherein, The tungsten oxide and / or molybdenum oxide comprises 1 wt.% or more of the metal oxide on the catalyst support.

15. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 2 wt.% or more of the metal oxide on the catalyst support.

16. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 3 wt.% or more of the metal oxide on the catalyst support.

17. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 4 wt.% or more of the metal oxide on the catalyst support.

18. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 5 wt.% or more of the metal oxide on the catalyst support.

19. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 10 wt.% or more of the metal oxide on the catalyst support.

20. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 15 wt.% or more of the metal oxide on the catalyst support.

21. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 20 wt.% or more of the metal oxide on the catalyst support.

22. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 25 wt.% or more of the metal oxide on the catalyst support.

23. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 30 wt.% or more of the metal oxide on the catalyst support.

24. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 35 wt.% or more of the metal oxide on the catalyst support.

25. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 40 wt.% or more of the metal oxide on the catalyst support.

26. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 45 wt.% or more of the metal oxide on the catalyst support.

27. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 50 wt.% or more of the metal oxide on the catalyst support.

28. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 60 wt.% or more of the metal oxide on the catalyst support.

29. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 70 wt.% or more of the metal oxide on the catalyst support.

30. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 80 wt.% or more of the metal oxide on the catalyst support.

31. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 90 wt.% or more of the metal oxide on the catalyst support.

32. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 95 wt.% or more of the metal oxide on the catalyst support.

33. The method of claim 14, wherein, The tungsten oxide and / or molybdenum oxide comprises 99 wt.% or more of the metal oxide on the catalyst support.

34. The method of claim 1, wherein, The metal oxide on the catalyst support consists of tungsten oxide and / or molybdenum oxide.

35. The method of claim 34, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 0.1 wt.% or more.

36. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 0.5 wt.% or more.

37. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 1 wt.% or more.

38. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 2 wt.% or more.

39. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 5 wt.% or more.

40. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 10 wt.% or more.

41. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 20 wt.% or more.

42. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 30 wt.% or more.

43. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 40 wt.% or more.

44. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 50 wt.% or more.

45. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 60 wt.% or more.

46. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 70 wt.% or more.

47. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 80 wt.% or more.

48. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 90 wt.% or more.

49. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 95 wt.% or more.

50. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum oxide of 99 wt.% or more.

51. The method of claim 35, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 15 wt.%.

52. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 15 wt.%.

53. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 15 wt.%.

54. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 15 wt.%.

55. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 15 wt.%.

56. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 10 wt.%.

57. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 10 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 10 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 10 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 10 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 0.5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 0.5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 0.5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 0.5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 0.5 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 0.1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 0.1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 0.1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 0.1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 0.1 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 0.01 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 0.01 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 0.01 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 0.01 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 0.01 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 0.001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 0.001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 0.001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 0.001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 0.001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 0.0001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 0.0001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 0.0001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 0.0001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 5 wt.% to 0.0001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.1 wt.% to 0.00001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 0.5 wt.% to 0.00001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 1 wt.% to 0.00001 wt.%. The catalyst has a loading of tungsten and / or molybdenum metal oxide of from 2 wt.% to 0.00001 wt.% 58. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide from 1 wt.% to 10 wt.%.

59. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide from 2 wt.% to 10 wt.%.

60. The method of claim 51, wherein, The catalyst has a loading of tungsten and / or molybdenum metal oxide from 5 wt.% to 10 wt.%.

61. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 500 m 2 / g or less.

62. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 250 m 2 / g or less.

63. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 100 m 2 / g or less.

64. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 50 m 2 / g or less.

65. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 25 m 2 / g or less.

66. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 10 m 2 / g or less.

67. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 5 m 2 / g or less.

68. The method of claim 1 or claim 51, wherein, The catalyst support has a BET specific surface area of 1 m 2 / g or less.

69. The method of claim 1, wherein, The catalyst support is a glass material.

70. The method of claim 1, wherein, The catalyst support is a ceramic material.

71. The method of claim 70, wherein, The ceramic material is selected from the group consisting of silicon carbide, yttria-stabilized zirconia, and combinations thereof.

72. The method of claim 1, wherein, The catalyst support is a refractory material.

73. The method of claim 72, wherein, The refractory material is selected from the group consisting of silicon, aluminum, magnesium, calcium, zirconium, and combinations thereof.

74. The method of claim 1, wherein, The catalyst is an uncalcined catalyst.

75. The method of any one of claims 1, 4, and 5, wherein, The reaction zone medium is selected from the group consisting of glass, ceramic, refractory material, and mixtures thereof.

76. The method of claim 75, wherein, The reaction zone medium is a glass material.

77. The method of claim 76, wherein, The reaction zone medium is uncoated.

78. The method of claim 75, wherein, The reaction zone medium is uncoated.

79. The method of claim 77, wherein, The reaction zone medium is free or substantially free of a metal oxide coating.

80. The method of claim 78, wherein, The reaction zone medium is free or substantially free of a metal oxide coating.

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