A method of producing xylitol
(57) Abstract:The invention relates to the production of xylitol. The method is carried out by catalytic reduction of a mixture containing xylose and celonova acid. The mixture is produced either from sulphite cooking liquid and concentrate in respect of xylonic acid, or from the waste formed during crystallization of xylose. The resulting mixture restore at a temperature of 80-130oWith, under pressure from 10000 to 13000 kPa in the presence of a catalyst and a metal hydride reagent. As the catalyst used Ru, Pd, Ni-Raney or Rh, and as a metal hydride reagent is sodium borohydride. Xylitol is separated from the recovered mixture by crystallization or chromatography. The technical result improved method of producing xylitol from sulphite cooking liquid or forestry waste. 17 C.p. f-crystals, 9 PL. The invention relates to a method for producing xylitol.Xylitol is a sugar alcohol found in nature, which is obtained by recovery of xylose and which has a sweetness comparable to "regular sugar, but lower in calories than regular sugar (2, 4 kcal/kg). In a small coliny product of metabolism. Due to certain metabolic, dental and technical properties, xylitol is a very good special sweetener, which is used for various purposes, such as chewing gum, candy, etc. as an example it can be noted that cility metabolism is not dependent on insulin metabolism, and therefore, diabetics can also use xylitol. Xylitol also slows intestinal motility and therefore it can be used in diets. It was also discovered that xylitol not only does not cause tooth decay, but can even prevent its occurrence.Despite the numerous benefits of xylitol, its use was still quite limited. This was due to the relatively high cost of xylitol, which in turn arose due to the difficulty of obtaining xylitol on an industrial scale.Earlier xylitol was obtained by hydrolysis cilostamide material. To receive the mixture of monosaccharides containing, for example, xylose. Xylose is then restored to the xylitol way catalytic reduction (hydrogenation), usually in the presence of Nickel catalyst such as Raney Nickel. In the literature oporow can lead US Patent N 3784408 (Jaffe et al), U.S. patent N 4066711 (Melaja et al), U.S. patent N 4075406 (Melaya et al), U.S. patent N 4008285 (Melaja et al), U.S. patent N 3586537 (Steiner et al).In some plants, most of the hemicellulose is xylan, which can be hydrolyzed into xylose. The main source material for the production of xylan hemicellulose is deciduous trees, which mainly consists of xylan. Recently the object of more attention is the use of xylan and xylose obtained as a by-product of the pulp industry. Xylose is formed, for example, acidic sulfite liquors, where the typical reasons include Mg2+Ca2+, NH4+, Na+. The source material may be a boiling solution of neutral sulfite cooking after calorically of xylan hydrolethalus. In the cooking solutions of the acid sulfite pulping of hemicellulose are already in the form of monosaccharides. The term "cooking solution" in this context refers to the solution used in the process of cooking or received after cooking, or part thereof. Known catalytic methods for recovering xylose used to obtain xylitol, usually require to be recovering xylose atent USA N 4631129, Heikkila and PCT)/FI 95/00224, Heikkila et al.) for example, due to the fact that the catalysts used in the reduction reaction of xylose are very sensitive to impurities (see Harkonen, M. and Nuojua, P., Kemia-Kemi, No. 3 (1980) pp. 98-100). In turn, the purity of the final product largely depends on whether it is possible to allocate the xylitol of the products obtained in the reaction of recovery.When as a raw material for production of xylose to use the liquid obtained during sulfite cooking, the problem is to change the conditions of cooking. Depending on circumstances, hemicellulose of the wood is dissolved in various ways, in this case obtain a larger or smaller amounts of xylose. In terms of cooking, which produce only a small amount of xylose may also produce large amounts of xylonic acid. It is difficult to separate the xylose present in this product, from a solution containing celonova acid, for example by chromatography, when you want to get pure xylose.Present in the solution celonova acid hinders the separation of xylose and therefore reduces the yield of xylose after crystallization. However, it would be preferable to use celonova acid as Syrian acid, obtained from a sulfite cooking liquid, could together be converted into xylitol.As described above, the recovery of xylose to xylitol is a known technology. Recovery xylonic acid, which is usually in the form of a lactone or salt (see Paperi ja Puu, N 11, so 59 (1977), page 713), until the xylitol is much more difficult. It was found that the simultaneous recovery of xylose and xylonic acid to xylitol difficult for the reason that in the harsh conditions of restoration needed to xylonic acid, xylose decomposes.The present invention concerns a method of producing xylitol. This method is characterized by the fact that restore mixture containing xylose and celonova acid, or concentrated in respect of xylonic acid.Recently it was found that the recovery can be accomplished by catalytic method or using as reagents of metal hydrides, for example sodium borohydride. A suitable method is catalytic reduction, in which the preferred catalysts include catalysts of the type of Raney catalysts and catalysts based on noble metals such is P>oC, preferably 100 to 130oC, and the restoration carried out suitably at a pressure of from 5000 to 20000 kPa, preferably from 10000 to 13000 kPa. the pH of the mixture to be recovered, is preferably from 0.5 to 3.5.Want to rework the mixture may be a mixture obtained from a sulfite cooking liquid by extraction, or represents the fraction obtained by chromatographic separation, preferably by chromatography with pseudopodium layer (SMB) (see WO 94/26380), or flow, formed by the crystallization of xylose fraction. Fractions separated to recovery is clear, for example, by ion exchange. Fraction of xylose and xylonic acid, may require additional purification methods of neutralization/ precipitation/filtration and/or treatment of the carbon adsorbent. You can also use the two-stage hydrogenation, which assumes that the first stage hydrogenation is carried out, for example, Nickel-Raney catalyst, and the second stage with a catalyst, for example, on the basis of precious metal. An embodiment of the invention includes pre-oxidation, in which the separation of the concentrate xileno the part separated from the solution, which is the reaction product recovery, chromatography or preferably by crystallization. The method according to the invention can significantly reduce costs when producing xylitol.The method provides, for example, better use of raw material (enough such quantity of raw material, which is only about twice the amount of xylitol). The following examples explain the invention.Example 1
Hydrogenation acidic fraction obtained by chromatographic separation of sulfite pulping solution.When using pseudopodia layer of sorbent (SMB) (WO 94/26380) fraction allocate chromatography of the liquid obtained by the hydrolysis of beech wood in acid Mg-sulfite pulping solutions, clean granular (Chemviron CPGTM) carbon, strongly acidic cation exchange resin (Dow 88TMin acidic form) and weakly basic anion-exchange resin (Dow 66TMin alkaline form). Conditions of the experimental process as follows: flow rate of 1.0 bv/h/column (bv = bulk volume), temperature 40oC and the content of solids in the feed solution of 23%. The reaction is carried out in a 5-liter autoclave Medimex (batch reactor is de, Engelhard CP 56 x L/R/WW), dosing (Ru/C) so that it was 13% solids solution. The hydrogenation time is four hours. The chemical composition of the feed material and product of hydrogenation are shown in Table 1.Example 2
The hydrogenation product fraction obtained by chromatographic separation. The fraction obtained in Example 1, purified as follows. The fraction is neutralized to pH 5 by the addition of 7.5% of calcium hydroxide based on the dry substance fraction. The precipitate is filtered off. The clear filtrate strong cation exchange resin and a weakly basic anion-exchange resin, as in Example 1. The hydrogenation is carried out in the same conditions as in Example 1. The chemical composition of the feed material and the resulting product is shown in table 1.Example 3
The waste recovery process of crystallization of xylose.Waste is cleaned using a strongly acidic cation exchange resin and a weakly basic anion exchange resin as described in Example 1. The hydrogenation is carried out in the same conditions as in Examples 1 and 2. The chemical composition of the feed material and the resulting product is shown in Table 1.Example 4
Hydrogenization and waste from the crystallization of xylose.The mixture is purified strongly acidic cation exchange resin and a weakly basic anion exchange resin as described in Example 1. The hydrogenation is carried out in the same conditions as in Examples 1 to 3. The chemical composition of the feed material and the resulting product is shown in Table 1.Example 5
Recovery of the product fraction obtained by chromatographic separation of sulfite pulping solution using a two-stage hydrogenation.Preliminary hydrogenation is performed on the crude product SMB separation under the following conditions. As catalyst, use of Raney Nickel in an amount of 10% of dry matter solution, Cherncat J 10 GS), temperature 100oC, a pressure of 4000 kPa (at the end of the process the pressure is increased to 8000 kPa), and the duration of the hydrogenation is four hours. Cations are removed from the hydrogenation product by using strongly acidic cation exchange resin (Dow 88, in acidic form), in other words, the acid release from its salts. The flow of feed material 2 bv/h, temperature 40oC and dry matter content in the feed material about 22%. This hydrogenation is carried out in the same conditions as in Examples 1 to 4. The chemical composition is supplied in Table 1.Example 6
Into the autoclave were added 2 g of MgO, 62 g of sulfite pulping solution in accordance with Example 1 and 140 g of a solution SO2(concentration 70-72 g SO2/l). The autoclave was closed and placed in a glycerol bath at 150oC. the Autoclave was kept in the bath for 30 minutes, 1 hour, 2 hours and 4 hours, after which they were cooled. The solution was filtered and was analizirovali. 28% xylose were oxidized to xylonic acid for four hours (table 2).Example 7
The hydrogenation mixture, concentrated in respect of xylonic acid
The hydrogenation is carried out in a five-liter autoclave Medimex (reactor periodic actions) if 110oC and a pressure of 13000 kPa using as the catalyst Ru/carbon (5% Ru on carbon, Engelhard CP 56 x L/R/WW) the amount of which is 18% of dry matter. The hydrogenation time is 3 hours. Table 3 shows the composition of the starting material and the resulting product.Example 8
Hydrogenation using Raney-Nickel mixture, concentrated in respect of xylonic acid.166 g/l xylonic acid in 70% methanol was subjected to hydrogenation in an autoclave with Raney Nickel (2 g) at 122oC and a pressure of 6500 kPa in techenie mixture, concentrated against xylonic acid.166 g/l xylonic acid in water was hydrogenosomal in an autoclave using as catalyst 0.17 g of 5% Rh/2%Mo/Al2O3at 140oC and a pressure of 6500 kPa for 18 hours. The results are presented in table 5.Example 10
Recovery, using sodium borohydride, the oxidized fraction of xylose/celonova acid obtained by chromatographic separation.The recovery is carried out by mixing under conditions of normal pressure and room temperature. The reaction time is 2 hours after the addition of reagents (added gradually). Fraction restore itself and after cation-exchange capacity when the content of dry solids of about 10%. Sodium borohydride is added in a ratio of 3 g/100 g natural weight solution (=10 g dry matter). Sodium borohydride is added in the form of a 4% aqueous solution. The reaction is stopped by acidification of a solution (pH 2) by adding 6 N. hydrochloric acid. The results are presented in Table 6.Example 11
Recovery of synthetic mixtures of xylose/celonova acid using sodium borohydride
Vosstanovlenieplastika mixture of xylose/celonova acid. The results are presented in Table 7.Example 12
Crystallization of xylitol
The source material is xylitol obtained in Example 5. 97 g of xylitol (refractometric dry matter content (RDS) is 11.4% of the feed solution) is subjected to evaporation to content RDS to 91.4% at 60oC. the Mass is transferred into a reaction vessel with a capacity of 1 l, where her strawley 0.06 g of crystals of xylitol at 60oC. to Give effect to 49-hour program linear cooling (60,5oC to 30oC). After cooling the mass is heated for about 3oC and centrifuged. Xilitla purity weight is 77% (based on dry substance. The crystals are separated by centrifugation (drum diameter 22 cm, the size of 0.15 mm sieve) at 4500 rpm for 5 minutes, and the crystals are washed. The yield is 30 g of dry crystals. Xilitla the purity of the crystals is 81,2% (based on dry substance.Example 13
Crystallization of xylitol
The source material is xylitol obtained according to Example 2. The solution of xylitol filtered through a 12 μm membrane. 170 g (dry matter) xylitol (RDS 19.7% of the feed solution) is evaporated to content RDS of 91.3% at 60oC. the Mass is transferred into the reaction vessel Amman cooling (60,5oC to 30oC). After cooling the temperature of the mass increases approximatelyoC and the mass is centrifuged. Xilitla purity mass is 64.3% of dry matter. The crystals are separated by centrifugation (diameter of bowl 22 cm, the size of 0.15 mm sieve) at 4500 rpm for 5 minutes and washed. Obtain 54 g of dry crystals. Xilitla the purity of the crystals is 93,3% (based on dry substance.Example 14
Crystallization of xylitol
The source material is xylitol, obtained as described in Example 3. The solution of xylitol filtered through a 12 μm membrane. 185 g (dry matter) xylitol (RDS 20.9% of the supplied solution is evaporated to content RDS of 92.2% at 60oC. the Mass is transferred into a reaction vessel with a capacity of 1 l, where her strawley 0.05 g of crystals of xylitol when 56,5oC. trigger 69-hour program linear cooling (57oC to 30oC). After cooling the temperature of the mass increases approximatelyoC and the mass is centrifuged. Xilitla purity mass is 56.5% of dry matter. The crystals are separated by centrifugation (diameter of bowl 22 cm, the size of 0.15 mm sieve) at 4500 rpm for 5 minutes and washed. Get 55 g of dry crystals. Xilitla number is Lanovoy acid from Ca sulfite cooking liquor by extraction with ethanol.Commercially available dry powder product Ca-sulfite pulping of hardwood, the composition of which is presented in Table 8 (1), extracted with ethanol. The amount of powder for extraction is 1500 g, and the amount of 95% ethanol 15 L. the Mixture was stirred at 50oC for 4 hours, after which it is filtered and the resulting cake is dried. The amount of dissolved solids is 32%. The filtrate is evaporated in a rotary evaporator under reduced pressure.The resulting after evaporation the residue is dissolved in about 8 liters of water. The composition of the solution is presented in Table 8 (2). The yield of xylose is about 78%, and the output of xylonic acid is about 43%. The outputs of these products increase to 95% and 56%, respectively, by repeating the extraction with ethanol.Example 16
Pretreatment fraction of xylose/celonova acid.The feed solution is a fraction of xylose/celonova acid continuous chromatographic separation process. Faction serves on a number of ion exchangers, including strongly acidic cation exchange resin (Dow 88TM) and two weakly basic anion exchange resin (Dow 66TM). Cations prilipaemost.The content of dry solids in the feed solution is 32%, temperature 40oC, the feed speed of the material 2bv /h/column.In this experiment, the number of solution approximately corresponds to the total amount of resin.In this experiment, the number of xylonic acid, which has stuck to both anion-exchange resins is: 22 g/l of resin for the first resin and 63 g/l of resin to the second resin. The chemical composition of the source material and the resulting product is shown in Table 9.Example 17
Pretreatment fraction of xylose/celonova acid
Chromatographic separation of Mg-sulfite cooking liquid is performed with the use of weakly acidic cation exchange resin, Finex Ca 24 GCTM. Temperature 65oC, the flow rate is 0.19 m/hour. the pH of the feed solution is 1.2 and the content of xylose is 9.8%. Performance in respect of xylose fraction with a purity of 25% is 9.6 kg of dry matter/m3per hour, and the maximum purity xylose when splitting amounts to 31.4%. The content of xylonic acid in the feed solution is 5.5% dry substance (RDS) and in the fraction of xylose 16,7% /dry matter. Order elwer the lot later).Example 18
Pretreatment fraction of xylose/celonova acid
Chromatographic separation of Mg-sulfite cooking liquid is performed with the use of weakly acidic cation exchange resin Purolite WITH 105TMat a temperature of 65oC and flow velocity of 0.7 m/h.the pH of the feed solution 4.5 and xylose content of 10.9%. Performance in relation to the fraction of xylose in the purity of 25% is 19 kg of dry matter/m3/h and when the purity of 40% is 7.8 kg of dry matter/m3per hour, and the maximum purity xylose when the separation is 42.7 percent. The content of xylonic acid in the feed solution is 5.6% dry substance (RDS). Purity xylonic acid in the fraction of xylose in the purity 25%/ dry matter xylose is 11.7% /dry matter, and in a fraction of xylose with a purity of 40% /dry matter xylose purity xylonic acid is 18.5% /dry matter. Elution salts, xylose and xylonic acid occurs almost simultaneously (celonova acid later).Example 19
Pretreatment fraction of xylose/celonova acid
Chromatographic separation of Mg-sulfite cooking liquid osushestvlyaetsya structure, this resin activate the acid. Temperature is 65oC, the flow velocity of 1.8 m/hour. the pH of the feed solution of 2.2, the xylose content of 8.9%. Maximum purity xylose in the division of 23.4%. The content of xylonic acid in the feed solution of 5.1% dry substance (RDS) and maximum clarity at a fraction of xylose 15,0% /dry matter. The order of elution of the following: most of the salt, and xylose and celonova acid together.Example 20
Pretreatment fraction of xylose/celonova acid
Chromatographic separation of Mg-sulfite cooking liquid is performed with the use of strongly acidic cation exchange resin Finex CS 11 GCTM. Temperature is 65oC, the flow velocity of 0.7 m/h. the pH of the feed solution of 1.0 and xylose content of 11.9%. Performance in respect of xylose fraction with a purity of 40% to 11.2 kg of dry matter/m3/h and the maximum purity xylose in the division 44,8%. The content of xylonic acid in the feed solution of 5.5% dry substance (RDS) and in the fraction of xylose 25% /dry matter. The order of elution of the following: salt, xylose and celonova acid. The last two fractions partially overlap. 1. A method for production of xylitol is mu restoration is subjected to the mixture, containing xylose and celonova acid, or a mixture, concentrated in respect of xylonic acid, and this mixture is obtained from a sulfite cooking liquid or waste is generated during the crystallization of xylose, and recovered from the mixture produce xylitol.2. The method according to p. 1, characterized in that when the catalytic reduction using a catalyst made of noble metal.3. The method according to p. 2, characterized in that the catalyst is Ru, Rd, Ni-Raney or Rh.4. The method according to p. 3, characterized in that the catalyst is Ru.5. The method according to any preceding paragraph, wherein the restoring is performed at a temperature of from 80 to 130oC.6. The method according to any preceding paragraph, wherein the restoring is performed under a pressure of from 10 000 to 13 000 KPa.7. The method according to any preceding paragraph, wherein the restoring spend a pH of from 0.5 to 3.5.8. The method according to p. 1, characterized in that the recovery is carried out using a metal hydride reagent.9. The method according to p. 8, characterized in that the metal hydride reagent is sodium borohydride.10. is a fraction, obtained from the cooking liquid sulfite cooking by chromatographic separation.11. The method according to p. 10, characterized in that the chromatographic separation is performed using pseudopodia layer (S).12. The method according to any of paragraphs.1-9, characterized in that the regenerated mixture is a mixture obtained from the cooking liquid sulfite cooking by extraction, for example, ethanol.13. The method according to any of paragraphs.10-12, characterized in that the sulfite cooking is magnesium or calcium sulfite cooking.14. The method according to any preceding paragraph, wherein the regenerated mixture was concentrated in relation to xylonic acid by ion exchange.15. The method according to any preceding clause, characterized in that the xylose and want to restore the mixture to at least partially oxidize to xylonic acid.16. The method according to p. 15, characterized in that the regenerated mixture oxidizes bisulfite.17. The method according to any preceding paragraph, wherein the xylitol is separated by crystallization.18. The method according to any of paragraphs.1-16, distinguishing the
FIELD: organic chemistry, in particular production of high oxoalcohols.
SUBSTANCE: invention relates to method for production of high oxoalcohol from isomeric olefin mixture containing from 5 to 24 of carbon atoms. Claimed method includes hydroformylation in presence of catalyst at elevated temperature and elevated pressure. Hydroformylation in carried out in one step, and ones-through olefin conversion is limited in range of 40-90 %. Obtained reaction mixture after catalyst separation is preferably transferred to selective hydration carrying out at 120-220°C and pressure of 5-30 bar in presence of supported catalyst containing copper, nickel and chromium as active ingredients. Hydration product mixture is separated by distillation, and olefin fraction is recycled into hydroformylation step. As starting materials for hydroformylation mixtures of C8-, C9-, C12- or C16-olefins are used.
EFFECT: high olefin conversion ratio, selectivity, and capability.
15 cl, 1 dwg, 1 tbl, 2 ex
FIELD: methods of production of 1.3 alkandiol.
SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to production of 1.3 alkandiol by hydrogenation of the raw material, containing 3-hydroxyaldehyde at presence of a catalyst and a source of hydrogen, where as a source of hydrogen use a synthesis gas, and the catalyst represents a heterogeneous catalyst containing copper on the carrier; and also to the method of production of 1.3-alkandiol by conversion of an oxide in the process including a hydroformylation and hydrogenation. At that it is not obligatory to realize the indicated phases simultaneously in one reaction vessel. The reached technical result consists in essential reduction of the fixed value of equipment and in bringing to a "single-phase" production of 1.3-propandiol (or a similar 3-alcandil) from ethylene oxide (or a corresponding oxide).
EFFECT: the invention ensures essential reduction of the fixed value of equipment and reduction to a "single-phase" process of the propandiol or alkandiol production.
9 cl, 2 tbl, 2 ex
FIELD: industrial organic synthesis and catalysts.
SUBSTANCE: invention relates to a method for processing of butanol-butyl formate fraction obtained in propylene hydroformylation process, which method comprises reduction of butanol-butyl formate fractions with hydrogen at 200-280°C, pressure 1-30 atm, and volumetric feedstock and hydrogen supply rate 0.1-0.5 and 50-500 h-1, respectively. Reaction is carried out on catalyst having following chemical analysis, wt %: copper oxide 48.0-63.0, zinc oxide 9.0-18.1, chromium oxide 19.0-34.8, graphite 1.0-5.1 and activity index below 40 to form butyl alcohols and carbon oxide as final products. Method allows using real non-diluted butanol-butyl formate fractions and achieving following results: conversion of butyl formates 94.5-99.5%, content of methanol and high-boiling products in hydrogenate 0.8-1.5 and 2.9-3.5%, respectively.
EFFECT: enhanced process efficiency.
4 tbl, 2 ex
FIELD: chemical technology.
SUBSTANCE: invention relates to a method for synthesis of 1,3-propanediol involving the following steps: (a) formation of aqueous solution of 3-hydroxypropanal; (b) hydrogenation of 3-hydroxypropanal to form crude mixture of 1,3-propanediol, water and cyclic acetal of molecular mass 132 Da (MW 132 cyclic acetal) and/or cyclic acetal of molecular mass 176 Da (MW 176 cyclic acetal); (c) distillation (drying) of indicated crude mixture of 1,3-propanediol for water removing and formation of the second crude mixture of 1,3-propanediol (the first flow of residues after distillation) containing 1,3-propanediol and MQ 132 cyclic acetal and/or MW 176 cyclic acetal; (d) contact of the flow containing MW 132 cyclic acetal and/or MW 176 cyclic acetal with acid-base cation-exchange resin or with acid zeolite, or with soluble acid, and (e) removal of MW 132 cyclic acetal. Method provides enhancing effectiveness for extraction and purification of 1,3-propanediol.
EFFECT: improved method of treatment.
10 cl, 9 tbl, 1 dwg, 6 ex
FIELD: hydrogenation-dehydrogenation catalysts.
SUBSTANCE: invention relates to novel ruthenium catalysts, method for preparation thereof, and to employment thereof for catalytic hydrogenation of mono- and oligosaccharides in production of corresponding sugar alcohols. Ruthenium hydrogenation catalyst contains ruthenium supported by amorphous silica-based carrier, content of ruthenium being 0.2 to 7% of the weight of carrier, while carrier contains at least 90% silica and less than 10% of crystalline silicon dioxide phases. Catalyst is prepared by single or multiple treatment of carrier material with halogen-free solution of low-molecular weight ruthenium compound and subsequent drying of treated material at temperature not lower than 200°C immediately followed by reduction of dried material with hydrogen at 100 to 350°C. Herein disclosed is also a process for liquid-phase production of sugar alcohols (excepting sorbitol) via catalytic hydrogenation of corresponding mono- and oligosaccharides in presence of proposed catalysts.
EFFECT: increased activity and selectivity of catalysts.
16 cl, 4 tbl, 7 ex