Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/132—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group
  • C07C29/136—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH
  • C07C29/14—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of a —CHO group
  • C07C29/141—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group of >C=O containing groups, e.g. —COOH of a —CHO group with hydrogen or hydrogen-containing gases
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/16—Reducing
  • B01J37/18—Reducing with gases containing free hydrogen
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
  • B01J23/46—Ruthenium, rhodium, osmium or iridium
  • B01J23/462—Ruthenium
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/132—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of an oxygen containing functional group
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C31/00—Saturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
  • C07C31/18—Polyhydroxylic acyclic alcohols
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C31/00—Saturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
  • C07C31/18—Polyhydroxylic acyclic alcohols
  • C07C31/26—Hexahydroxylic alcohols
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
  • B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
  • B01J21/08—Silica
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J33/00—Protection of catalysts, e.g. by coating

Definitions

• the present invention relates to a continuous process for the production of sugar alcohols by catalytic hydrogenation of suitable saccharides.
• US 4,380,680, US 4,487,980, US 4,413,152 and US 4,471,144 describe the production of sorbitol by catalytic hydrogenation of glucose, in which catalysts are used which contain ruthenium on a support material which is stable under hydrothermal conditions.
• Alpha-aluminum oxide (US 4,380,680), titanium (IV) oxide (US 4,487,980), aluminum oxide treated with titanium (IV) halide (US 4,413,152) and theta aluminum oxide (US 4,471,144) are proposed as hydrothermal carrier materials.
• No. 4,503,274 discloses catalysts for the hydrogenation of glucose to sorbitol, which are prepared by impregnating a support which is stable under hydrothermal conditions with an aqueous ruthenium halide solution and then hydrogenating the solid at temperatures in the range from 100 to 300.degree.
• No. 3,963,788 describes the hydrogenation of corn starch hydrolyzates to sorbitol over ruthenium catalysts in which the ruthenium was supported with a special zeolite based on an aluminosilicate.
• No. 3,963,789 proposes crystalline aluminosilicate clays, in particular montmorillonite, as supports for ruthenium catalysts.
• FR-A 2526782 describes the use of a ruthenium chloride prepared by reacting sodium chloride and ruthenium via Na 2 RuCI 6 for the production of ruthenium catalysts supported on silicon dioxide for the hydrogenation of mono- and oligosaccharides, for example for the production of sorbitol.
• the present invention is therefore based on the object of providing a continuous process for the production of sugar alcohols by catalytic hydrogenation of the corresponding saccharides which form the desired sugar alcohols during hydrogenation, which avoids the disadvantages mentioned above and in particular the desired sugar alcohols with better space-time - Provides yields in which fewer by-products are obtained and which allows longer catalyst lives.
• This object was surprisingly achieved by a continuous process for the production of sugar alcohols by catalytic hydrogenation of an aqueous solution of a saccharide, which forms the corresponding sugar alcohol on hydrogenation, over a ruthenium catalyst, which is obtainable by:
• step ii) reduction of the solid obtained in i) with hydrogen at a temperature in the range from 100 to 350 ° C., wherein step ii) is carried out immediately after step i), which is characterized in that the aqueous saccharide solution to be hydrogenated is brought into contact with the carrier material before the hydrogenation.
• Suitable saccharides basically include all known tetroses, pentoses, hexoses and heptoses, namely both aldoses and ketoses and their di- and oligosaccharides.
• the monosaccharides which can be used in the process according to the invention include, for example: erythrose, threose, ribose, arabinose, xylose, lyxose, allose, old rose, mannose, gulose, idose, galactose, talose, erythrulose, ribulose, xylulose, psicose , Tagatose, Glucose, Fructose and Gulose both the D-form and the L-form.
• Invert sugar obtained by hydrolysis of sucrose is also suitable.
• disacharides are: maltose, isomaltose, lactose, cellobiose, melobiose and sucrose.
• Suitable mono- and oligosaccharides for the hydrogenation process according to the invention are in particular the monosaccharides mannose for the production of mannitol, galactose for the production of dulcite (galactite) and xylose for the production of xylitol, preferably the D-form of the monosaccharides, and the disaccharides maltose for the production of maltitol, isomaltulose (palatinose) for the production of isomaltitol and lactose for the production of lactitol.
• the preferred starting material for the production of the sugar alcohol sorbitol is glucose and glucose-rich syrups such as hydrolysates of corn starch, wheat starch and potato starch.
• glucose-rich syrups such as hydrolysates of corn starch, wheat starch and potato starch.
• D-sorbitol by hydrogenation of the D-form of the aforementioned monosaccharides is of particular interest.
• the other mono- and oligosaccharides mentioned can also be hydrogenated to the corresponding sugar alcohols in the presence of the ruthenium catalysts according to the invention.
• the hydrogenation of aldoses to sugar alcohols which have the same configuration as the sugar used with regard to the OH groups, and the hydrogenation of furanoses generally leads to mixtures of two diastereomeric sugar alcohols which differ only in the configuration of the C atom, which carries the carbonyl function in furanosis.
• the Isolation of the pure sugar alcohol from this mixture is generally possible without problems.
• the mono- and oligosaccharides can be used as such or as mixtures, the educts preferably being used in pure form.
• the high activity of the catalysts used in the process according to the invention can be attributed to the particularly good distribution of the ruthenium on the surface of the support material and to the substantial absence of halogen in the support material. Due to the production process, the ruthenium is present in the catalysts according to the invention as metallic ruthenium.
• Electron microscopic investigations (TEM) of the catalysts have shown that the ruthenium on the support material is in atomically dispersed form and / or in the form of ruthenium particles which are almost exclusively, i.e. more than 90%, preferably more than 95%, based on the number of visible particles, are present as isolated particles with diameters below 10 nm, in particular below 7 nm.
• the catalyst contains essentially none, i.e. less than 10%, in particular less than 5%, of ruthenium particles and / or agglomerates of ruthenium particles with diameters above 10 nm.
• the use of halogen-free ruthenium precursors and solvents in the production also means that the chlorine content of the catalysts used according to the invention is below 0.05 % By weight ( ⁇ 500 ppm), based on the total weight of the catalyst.
• An essential component of the catalysts used in the process according to the invention is the support material based on amorphous silicon dioxide.
• amorphous means that the proportion of crystalline silicon dioxide phases makes up less than 10% of the carrier material.
• the support materials used to produce the catalysts can have superstructures which are formed by regularly arranging pores in the support material.
• the carrier material can also be another oxidic material, for example MgO, CaO, TiO 2 , ZrO 2 , Fe 2 O 3 or alkali metal oxide.
• the carrier material used is also halogen-free, ie the halogen content is less than 500 ppm.
• the carrier material preferably contains no more than 1% by weight and in particular no more than 0.5% by weight and in particular no detectable amounts ( ⁇ 500 ppm) of aluminum oxide, calculated as Al 2 O 3 .
• support materials are used which contain less than 500 ppm Fe 2 O 3 .
• the proportion of alkali metal oxide generally results from the production of the carrier material and can be up to 2% by weight. It is often less than 1% by weight.
• Alkali metal oxide-free carriers ( ⁇ 0.1% by weight) are also suitable.
• the proportion of MgO, CaO, TiO 2 or ZrO 2 can make up to 10% by weight of the carrier material and is preferably not more than 5% by weight.
• carrier materials which do not contain any detectable amounts of these metal oxides are also suitable.
• carrier materials which have a specific surface area in the range from 50 to 700 m 2 / g, in particular in the range from 80 to 600 m 2 / g and especially in the range from 100 to 600 m 2 / g (BET surface area in accordance with DIN 66131 ).
• specific (BET) surface area is in the range from 200 to 600 m 2 / g.
• specific surface area is in particular in the range from 100 to 300 m 2 / g.
• Suitable amorphous carrier materials based on silicon dioxide are familiar to the person skilled in the art and are commercially available (see, for example, OW Flörke, “Silica” in Ullmann's Encyclopedia of Industrial Chemistry 5th ed. On CD-ROM). They can be produced both naturally and artificially Examples of suitable amorphous support materials based on silicon dioxide are diatomaceous earth, silica gels, pyrogenic silica and precipitated silica. In a preferred embodiment of the invention, the catalysts contain silica gels as support materials.
• the carrier material can have different shapes. If the process is designed as a suspension process, it is usual to prepare the catalysts according to the invention. usually use the carrier material in the form of a finely divided powder.
• the particle size of the powder particles is preferably in the range from 1 to 200 ⁇ m and in particular in the range from 10 to 100 ⁇ m.
• shaped bodies made of the carrier material are usually used, which can be obtained, for example, by extrusion, extrusion or tableting and which can have, for example, the shape of spheres, tablets, cylinders, strands, rings or hollow cylinders, stars and the like.
• the dimensions of these moldings usually range from 1 mm to 25 mm. Catalyst strands with strand diameters of 2 to 5 mm and strand lengths of 2 to 25 mm are often used.
• the content of ruthenium in the catalysts can be varied over a wide range. As a rule, it will be at least 0.1% by weight, preferably at least 0.2% by weight, and often will not exceed a value of 10% by weight, in each case based on the weight of the carrier material.
• the ruthenium content is preferably in the range from 0.2 to 7% by weight and in particular in the range from 0.4 to 5% by weight.
• the ruthenium catalysts used in the process according to the invention are generally prepared by first treating the support material with a halogen-free aqueous solution of a low molecular weight ruthenium compound, hereinafter referred to as (ruthenium) precursor, in such a way that the desired amount of ruthenium is absorbed by the carrier material. This step is also referred to below as watering. The carrier thus treated is then dried at the temperatures indicated above. If necessary, the solid thus obtained is then treated again with the aqueous solution of the ruthenium precursor and dried again. This process is repeated until the amount of ruthenium compound taken up by the support material corresponds to the desired ruthenium content in the catalyst.
• ruthenium halogen-free aqueous solution of a low molecular weight ruthenium compound
• the treatment or impregnation of the carrier material can take place in different ways and depends in a known manner on the shape of the carrier material.
• the carrier material can be sprayed or rinsed with the precursor solution or the carrier material can be suspended in the precursor solution.
• the carrier material can be suspended in the aqueous solution of the ruthenium precursor and filtered off from the aqueous supernatant after a certain time.
• the ruthenium content of the catalyst can then be controlled in a simple manner via the amount of liquid taken up and the ruthenium concentration of the solution.
• the support material can also be impregnated, for example, by treating the support with a defined amount of the aqueous solution of the ruthenium precursor which corresponds to the maximum amount of liquid which the support material can hold.
• the liquid can be sprayed onto the carrier material, for example.
• Suitable apparatus for this are the apparatuses usually used for mixing liquids with solids (see Vauck / Müller, Basic Operations of Chemical Process Engineering, 10th edition, German Publisher for Basic Industry, 1994, pp. 405 ff.), For example tumble dryers, water drums, drum mixers, paddle mixers and like.
• Monolithic supports are usually rinsed with the aqueous solutions of the ruthenium precursor.
• the aqueous solutions used for impregnation are halogen-free, ie they contain no or less than 100 ppm halogen. Therefore, only ruthenium compounds that do not contain chemically bound halogen and that are sufficiently soluble in the aqueous solvent are used as ruthenium precursors. These include, for example, ruthenium (III) nitrosyl nitrate (Ru (NO) (NO 3 ) 3 ), ruthenium (III) acetate and the alkali metal ruthenates (IV) such as sodium and potassium ruthenate (IV).
• aqueous denotes water and mixtures of water with up to 50% by volume, preferably not more than 30% by volume and in particular not more than 10% by volume of one or more water-miscible organic solvents, for example mixtures of Water with -CC alkanols such as methanol, ethanol, n- or isopropanol. Water is often used as the sole solvent.
• the aqueous solvent will often additionally contain at least one halogen-free acid, for example nitric acid, sulfuric acid, phosphoric acid or acetic acid, preferably a halogen-free mineral acid, in order to stabilize the ruthenium precursor in the solution. In many cases, therefore, a halogen-free mineral acid, e.g. B.
• the concentration of the ruthenium precursor in the aqueous solutions naturally depends on the amount of ruthenium precursor to be applied and the absorption capacity of the carrier material for the aqueous solution and is generally in the range from 0.1 to 20% by weight.
• Drying can be carried out using the customary methods of drying solids while maintaining the above-mentioned temperatures. Compliance with the upper limit of the drying temperatures according to the invention is important for the quality, i.e. the activity of the catalyst is important. Exceeding the drying temperatures given above leads to a significant loss of activity. Calcining the support at higher temperatures, e.g. Above 300 ° C or even 400 ° C, as proposed in the prior art, is not only superfluous but also has a disadvantageous effect on the activity of the catalyst.
• the drying of the solid impregnated with the ruthenium precursor usually takes place under normal pressure. A reduced pressure can also be used to promote the drying. Often, to promote drying, a gas stream will be passed over or through the material to be dried, e.g. Air or nitrogen.
• the drying time naturally depends on the desired degree of drying and the drying temperature and is generally in the range from 2 h to 30 h, preferably in the range from 4 h to 15 h.
• the treatment of the treated carrier material is preferably carried out to such an extent that the content of water or volatile solvent components before the reduction ii) is less than 5% by weight, in particular not more than 2% by weight and particularly preferably not more than 1% by weight .-%, based on the total weight of the solid.
• the stated weight fractions relate to the weight loss of the solid, determined at a temperature of 300 ° C., a pressure of 1 bar and a duration of 10 min. In this way, the activity of the catalysts according to the invention can be increased further.
• Drying is preferably carried out by moving the solid treated with the precursor solution, for example by drying the solid in a rotary motion. tube furnace or a rotary kiln. In this way, the activity of the catalysts according to the invention can be increased further.
• the solid obtained after drying is converted into its catalytically active form by hydrogenating the solid at the temperatures indicated above in a manner known per se.
• the carrier material is brought into contact with hydrogen or a mixture of hydrogen and an inert gas at the temperatures indicated above.
• the hydrogen partial pressure is of minor importance for the result of the reduction and can be varied in the range from 0.2 bar to 1.5 bar.
• the hydrogenation of the catalyst material often takes place at normal hydrogen pressure in the hydrogen stream.
• the hydrogenation is preferably carried out by moving the solid obtained in i), for example by hydrogenating the solid in a rotary tubular furnace or a rotary ball furnace. In this way, the activity of the catalysts according to the invention can be increased further.
• the catalyst can be passivated in a known manner to improve handling, e.g. by briefly using the catalyst with an oxygen-containing gas, e.g. Air, but preferably treated with an inert gas mixture containing 1 to 10% by volume of oxygen.
• an oxygen-containing gas e.g. Air
• an inert gas mixture containing 1 to 10% by volume of oxygen
• the saccharide is preferably hydrogenated by hydrogenating an aqueous solution of the respective saccharide or, in the case of invert sugar, as the starting material, the saccharide mixture.
• aqueous is to be understood here in the manner defined above.
• Water is expediently used as the sole solvent, which may contain small amounts of a preferably halogen-free acid for adjusting the pH.
• the monosaccharide is used as an aqueous solution which has a pH in the range from 4 to 10, and especially in the range from 5 to 7.
• the concentration of saccharide in the liquid phase can in principle be chosen freely and is frequently in the range from 10 to 80% by weight and preferably in the range from 15 to 50% by weight, based on the total weight of the solution.
• the saccharide solution is brought into contact with the support material before the hydrogenation, ie before it comes into contact with the ruthenium catalyst. The purpose of this is that the saccharide solution becomes saturated on the support material, ie above all on silicon dioxide, and as a result less support material is released from the catalyst, which has an advantageous effect on the service life (service life) of the catalyst.
• the saccharide solution can be brought into contact with the carrier material in a number of ways, for example by suspending the powdery carrier material in the saccharide solution or by passing the saccharide solution through shaped bodies made of carrier material.
• the passage of the saccharide solution through silica strands is a particularly preferred embodiment of the method according to the invention, in particular if the solution is pressed under pressure through tubes filled with silica strands.
• Another advantage of the method according to the invention results from the fact that when the saccharide solution is pressed through the silica strands, any oligomeric sugars still present in the saccharide solution are retained and the purity of the sugar alcohol formed is thus increased. This can be observed particularly when using starch hydrolyzates as saccharides.
• the actual hydrogenation is usually carried out in analogy to the known hydrogenation processes for the production of sugar alcohols, as described in the prior art mentioned at the beginning.
• the liquid phase containing the saccharide is brought into contact with the catalyst in the presence of hydrogen.
• the catalyst can either be suspended in the liquid phase (suspension mode) or the liquid phase is passed over a fluidized catalyst bed (fluidized bed mode) or a fixed catalyst bed (fixed bed mode).
• the hydrogenation can be carried out either continuously or batchwise.
• the process according to the invention is preferably carried out in trickle-bed reactors according to the fixed bed procedure.
• the hydrogen can be passed both in cocurrent with the solution of the starting material to be hydrogenated and in countercurrent over the catalyst.
• Suitable apparatus for carrying out a hydrogenation according to the suspension procedure and also for hydrogenation on a fixed catalyst bed are known from the prior art, for example from Ulimann's Encyclopedia of Industrial Chemistry, 4th edition, volume 13, p. 135 ff. And from PN Rylander, “Hydrogenation and Dehydrogenation "in Ullmann's Encyclopedia of Industrial Chemistry, 5th ed. on CD-ROM.
• the hydrogenation is carried out at elevated hydrogen pressure, e.g. at a hydrogen partial pressure of at least 10 bar, preferably at least 20 bar and in particular at least 40 bar.
• the hydrogen partial pressure will not exceed a value of 500 bar, in particular 350 bar.
• the hydrogen partial pressure is particularly preferably in the range from 40 to 200 bar.
• the reaction temperatures are usually at least 40 ° C and will often not exceed 250 ° C.
• the hydrogenation process is carried out at temperatures in the range from 80 to 150 ° C.
• the starting material is hydrogenated in an amount of 0.05 to 2 kg / (l (catalyst) * h), in particular in an amount of 0.07 to 0.7 kg / (l (catalyst) * h) over the Lead catalyst.
• the sugar alcohol can be obtained, for example, by evaporation with subsequent crystallization (DE-A 2350690, EP-A 32288, EP-A 330352) or spray drying (DK 133603, DD 277176) the catalyst is separated off by customary processes and the reaction solution is subjected to decolorization with suitable filter aids and / or treatment with ion exchange to remove metal ions, gluconates or other organic acids.
• sorbitol can be obtained from the reaction mixtures obtained in this way by selective crystallization.
• the process according to the invention is distinguished on the one hand by the high space-time yields achieved and, when using glucose as the starting material, also by a high product selectivity.
• the process according to the invention is distinguished by a particularly long service life of the ruthenium catalysts, which makes the process particularly economically attractive.
• the catalysts used in this process can of course be regenerated according to the methods known to those skilled in the art for noble metal catalysts such as ruthenium catalysts.
• treatment of the catalyst with oxygen as described in BE 882279 treatment with dilute, halogen-free mineral acids as described in US 4,072,628, or treatment with hydrogen peroxide, e.g. in the form of aqueous solutions with a content of 0.1 to 35% by weight, or the treatment with other oxidizing substances, preferably in the form of halogen-free solutions.
• the catalyst is reactivated with a solvent, e.g. Water, rinse.
• a defined amount of the respective carrier material was impregnated with the maximum amount of a solution of ruthenium (III) nitrosyl nitrate in water that could be absorbed by the respective carrier material.
• the maximum amount absorbed by the respective carrier material was previously based on an authentic sample. been agreed.
• the concentration of the solution was measured such that the desired concentration of ruthenium in the support material resulted.
• the solid obtained in this way was then dried in a rotary ball oven at 120 ° C. for 13 h.
• the residual water content was below 1% by weight.
• the solid obtained in this way was reduced in a rotary kiln for 4 h at 300 ° C. in a stream of hydrogen at normal pressure. After cooling and inerting with nitrogen, the catalyst was passivated by passing 5% by volume of oxygen into nitrogen over a period of 120 min.
• the preparation was carried out analogously to regulation A, but the solid obtained after drying was heated to 400 ° C. in an air stream for 4 h before the hydrogenation.
• a defined amount of cylindrical support material strands (diameter 4 mm, length 3 to 10 mm) was impregnated with the maximum amount of a solution of ruthenium (III) nitrosyl nitrate in water which could be taken up by the respective support material.
• the maximum amount absorbed by the respective carrier material had previously been determined on the basis of an authentic sample.
• the concentration of the solution was measured such that the desired concentration of ruthenium in the support material resulted.
• the soaked, soaked strands were then dried for 13 hours at 120 ° C. in a rotary ball oven.
• the residual water content was less than 1% by weight.
• the dried strands obtained in this way were reduced in a rotary kiln for 4 h at 300 ° C. in a stream of hydrogen at normal pressure.
• the catalyst obtained in this way was passivated by passing 5% by volume of oxygen into nitrogen over a period of 120 min. »
• the preparation was carried out analogously to regulation D, but ruthenium (III) chloride was used instead of ruthenium (III) nitrosyl nitrate.
• a reaction unit consisting of a main reactor with circulation and a post-reactor is charged with the ruthenium catalyst prepared under I.
• aqueous solution of corn starch hydrolyzate with a glucose concentration of 40% is passed under pressure through a tube filled with silica strands. This solution is then fed into the main reactor, which had a top temperature of 80 to 130 ° C., and then passed through the post-reactor, the top temperature of which was adjusted to the bottom temperature of the main reactor. The hydrogenation was carried out at a pressure of 140 bar.
• the process delivers a conversion of 99.8% and a selectivity based on sorbitol of 99.3%.
• a reaction unit consisting of a main reactor with circulation and a post-reactor is charged with the ruthenium catalyst prepared under I.
• aqueous solution of xylose (source: Aldrich, purity 99.6%) with a concentration of 30% is passed under pressure through a tube filled with silica strands hazards. This solution is then fed into the main reactor, which had a top temperature of 80 to 130 ° C., and then passed through the post-reactor, the top temperature of which was adjusted to the bottom temperature of the main reactor. The hydrogenation was carried out at a pressure of 90 bar.
• the process delivers a conversion of 99.8% and a selectivity based on xylitol of 98.5%.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Catalysts (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Applications Claiming Priority (5)

Publications (1)

Family

ID=32509752

Family Applications (1)

Country Status (7)

Families Citing this family (18)

Family Cites Families (11)

• 2003
  • 2003-12-03 WO PCT/EP2003/013632 patent/WO2004052813A1/de not_active Application Discontinuation
  • 2003-12-03 KR KR1020057010587A patent/KR20050085536A/ko not_active Application Discontinuation
  • 2003-12-03 EP EP03780110A patent/EP1572607A1/de not_active Withdrawn
  • 2003-12-03 AU AU2003288219A patent/AU2003288219A1/en not_active Abandoned
  • 2003-12-03 JP JP2005502311A patent/JP2006509833A/ja not_active Withdrawn
  • 2003-12-03 BR BR0316829-8A patent/BR0316829A/pt not_active IP Right Cessation
  • 2003-12-03 US US10/538,265 patent/US20060009661A1/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events