The method of epoxidation of olefin
(57) Abstract:The epoxides produced by the method comprising the oxidation of a secondary alcohol by molecular oxygen, the branch side of the resulting ketone and epoxidation of the olefin in the presence of titanosilicate catalyst and diluent, in which the crude alcohol stream, resulting from the removal of resin from the mixture of products of the epoxidation, serves as a diluent. Despite the use of the crude alcohol stream that typically contains water, organic acids and glycols, the method provides high selectivity for epoxides such as propylene oxide. 18 C.p. f-crystals, 1 Il. The invention relates to a combined process for the preparation of epoxide. In particular, the invention relates to a method for epoxidation, in which the crude alcohol stream obtained by removing the epoxy from the epoxidation reaction mixture, is used for diluting the concentrated flow of oxidant used as a source of hydrogen peroxide on stage epoxidation.Developed many different ways to obtain epoxides. One such method involves the use of certain titanosilicate Mat, which reveals the way (Example 35) the conversion of propylene to propylene oxide. A mixture of isopropanol/water injected into reaction with oxygen at 135oC to obtain a mixture containing hydrogen peroxide. The mixture is then used directly in the epoxidation reaction of propylene catalyzed by titanosilicates, without intermediate processing or fractionation.U.S. patent No. 5 384 418 describes a combined method of producing epoxide, which also uses hydrogen peroxide obtained in the oxidation of isopropanol, epoxydecane catalyzed by titanosilicates, but indicates that the removal of essentially all of the acetone from isopropanole oxidant before epoxydecane is preferred. Additionally, the patent indicates that isopropanol obtained by hydrogenation of remote acetone, can be used for dilution isopropanole oxidant to achieve the desired concentration of H2O2in the epoxidation reactor. Under certain conditions it is desirable to maintain relatively low (diluted) (for example, 1- > 10 %) the maximum concentration of hydrogen peroxide when epoxydecane, as higher concentrations lead to lower SelectionKey resulting from the removal of the epoxide formed from the reaction mixture, leaving the epoxidation reactor, can also be used for the purpose of dilution of the hydrogen peroxide supplied to the reactor. This result is surprising since it is known that the epoxidation catalyzed by titanium-silicalite, sensitive to the presence of trace impurities. U.S. patent No. 4 824 976, for example, indicates that the addition of certain basic substances to the mixture epoxidation catalyzed by titanosilicates, helps to minimize non-selective reactions disclosure cycle target epoxide catalyzed by acid. Since the above crude alcohol stream typically contains, in addition to isopropanol and water, a measurable amount of relatively heavy (high boiling) organic acids, glycols, and so on, then we should expect that the use of this crude alcohol stream to dilute peroxide of hydrogen supplied to the epoxidation reactor, should lead to a lower yield of epoxide. Instead, it was found that if such dilution to apply, the loss of selectivity to epoxide does not occur or is negligible loss compared with the use of purified or refined isopropanol.The invention ensure the and with molecular oxygen in the liquid phase with formation of a mixture of oxidation products, containing secondary C3-C4-alcohol, aliphatic C3-C4the ketone corresponding to the secondary C3-C4-alcohol, and hydrogen peroxide;
b) separating essentially all C3-C4the ketone from a mixture of oxidation products to produce a concentrated stream containing hydrogen peroxide containing secondary C3-C4-alcohol, hydrogen peroxide and less mass. % C3-C4-ketone;
c) reaction of the concentrated stream containing hydrogen, C2-C4-olefin in the presence of titanosilicate catalyst and diluent to obtain the epoxidation reaction mixture containing C2-C4-epoxide corresponding to C2-C4-olefin, water and secondary C3-C4-spirit;
d) allocation of essentially all C2-C4-epoxide from the reaction mixture epoxidation with the formation of the crude alcohol stream containing water, secondary C3-C4-alcohol and less Mas.% C2-C4-epoxide; and
e) recycling at least part of the crude alcohol stream for use as at least part of the diluent at the stage (c).The drawing shows in srty, suitable for use include isopropanol (isopropyl alcohol) and second-butanol (sec-butyl alcohol). The secondary alcohol is introduced into the reaction with molecular oxygen (dioxygen) from a suitable source, such as air, with the formation of the oxidation mixture, which usually contains an excess of a secondary alcohol, C3-C4the ketone resulting from oxidation of the secondary alcohol and having the same hydrocarbon skeleton, and alcohol (e.g., acetone or 2-butanone), hydrogen peroxide and water. The source material subject to oxidation, may contain a small amount of ketone and/or water in addition to alcohol. For example, it is advantageous to use the azeotrope of water and isopropanol (87,2 wt.% isopropanol and 12.2 wt.% of water). In one embodiment of the invention the feed oxidant contains 5- > 20.% water, 80-mos.% isopropanol, less Mas.% methanol and less Mas.% of acetone. Generally speaking, the conditions of oxidation adjust so that the oxidizing mixture contained 40-mos.% secondary alcohol from about 5 to 25% hydrogen peroxide, 5-mos.% ketone and 0 MS.% water. Achieved a partial conversion of the secondary alcohol (e.g., 5-50%), so that unreacted secondary alcohol can be used in cachestate time, keeping or reaction from about 0.25 to 4 hours. The oxidation can be either non-catalytic or catalytic (e.g., be performed in the presence of a small amount of peroxide or hydroperoxide such as tert-butylhydroperoxide). To achieve an acceptable rate of oxidation is generally suitable temperature of 50-200oC (more preferably 100-180oC. the Preferred range of partial pressure of oxygen in the incoming gas (which may include inert dilution gas, such as nitrogen, in addition to oxygen) is 0,7104- 176104PA (absolute pressure), preferably 3,5104- 35104PA, most preferably 7104-21104PA. The total pressure in the reaction zone of oxidation must be sufficient to hold the components of the reaction mixture in the liquid phase (usually a good 35 104- 7106PA). You can apply multiple reaction zones of oxidation, supported at various temperatures and pressures. Oxidation of the alcohol can be performed in a continuous manner using, for example, a reactor with continuous stirring.Before using on stage epoxidation of the proposed method substantially the entire ketone CTD is, including fractionation.Preferably, however, the oxidation mixture fractionary, and the ketone is evaporated and removed from the oxidation mixture as the parent thread. The concentrated stream containing hydrogen peroxide obtained in this way, therefore may contain cubic faction. Such fractionation contributes to heating and/or negative (below atmospheric) pressure. For example, removing the acetone, you can use the pressure 3,5104- 21104PA and cubic temperature 90-125oC. the Concentration of ketone in a concentrated stream containing hydrogen peroxide, with this method shall be less mass. % (preferably less than 0.5 wt.%). To minimize the accumulation of any adduct ketone/hydrogen peroxide that has peroxide in nature, this separation is most preferably carried out directly after oxidation by molecular oxygen. Therefore, the oxidation mixture emerging from the oxidation zone, preferably served, avoiding delays or storage, in a distillation column. For quick and complete removal of the ketone from the oxidation mixture preferably also be selected from the top of the column some of the secondary alcohol or harmine) also secondary alcohol and 5-30 mol.% water. However, for security reasons, should be taken precautionary measures against concentration of hydrogen peroxide in the bottom fraction and against the emergence of a significant amount of hydrogen peroxide in the main thread. The residence time in the distillation zone is also important. The residence time must be sufficient to achieve substantial change any content of the reaction products ketone/hydrogen peroxide formed during the oxidation of molecular oxygen or to bring the level of peroxides of aliphatic ketone to less than 0.5 wt.% in General. You should avoid excessive time spent, however, to prevent excessive decomposition of hydrogen peroxide. In a preferred embodiment of the invention applied time 10-45 min (more preferably 15-30 min) at 90-130oC (more preferably 100-120oC). It is found that under these conditions it is desirable to remove the ketone and the transformation of any present peroxides ketone can be easily achieved with minimal loss (<2%) of hydrogen peroxide in the oxidation mixture. The best results can be obtained with careful passivation distillation columns and/or treatment of oxidative mixture to remove and nedow ketone. It is also useful to use the extraction distillation. You can also use other methods of separation, capable of reducing the content of the ketone in the oxidation mixture without substantial loss of hydrogen peroxide, including, for example, absorption, countercurrent extraction, membrane separation, etc. Especially useful multiple fractionation.As a consequence of the removal of the ketone of the oxidant concentration of hydrogen peroxide increases. A concentrated stream of hydrogen peroxide, therefore, usually contains 5 to 30%, H2O2; in one embodiment of the invention the specified stream contains more than > 10 % H2O2. At the stage of epoxidation in the method of the present invention a concentrated stream containing hydrogen peroxide, contact with C2-C4-olefin and a catalytically effective amount of titanosilicate at a temperature of 25-120oC (more preferably 40-80oC) for the conversion of the substrate in the target epoxide. Used as a diluent in which the crude alcohol stream is recovered after removal of the epoxide from the epoxidation reaction mixture as at least part of the diluent. Ostasis what risovaniem ketone, remote from the oxidation mixture, or other suitable co-solvent such as methanol. Preferably the diluent contains mainly (for example, 70%), the crude alcohol stream. The amount of diluent used is preferably sufficient to create a concentration of hydrogen peroxide 1- > 10% in the calculation of the total mass of hydrogen peroxide, a secondary alcohol, water and additional components are downloaded to the epoxidation zone (other than the olefin). The diluent is injected in a quantity sufficient to reduce the concentration of hydrogen peroxide up to at least 10% (more preferably at least 20%), based on the level of H2O2in undiluted concentrated stream containing hydrogen peroxide.Suitable C2-C4-olefins include ethylene, propylene, 1-butene, isobutylene, 2-butene, etc.The amount of olefin relative to the amount of hydrogen peroxide is not decisive, but the molar ratio of olefin: hydrogen peroxide may be correspondingly from about 100: 1 to 1:10, preferably from 1:2 to 10:1 (most preferably from 1:1 to 6:1).In one embodiment of the method of the invention, the loading in the reactor epoxydecane. Despite the relatively high content of water present in this embodiment, the selectivity for epoxide surprisingly high with minimal hydrolysis of the epoxide to the glycol.Titanosilicate used as catalyst under epoxidation this way include zeolite substance, in which a portion of the silicon atoms are replaced by titanium in the crystal lattice of the molecular sieve. Such substances are well known in this field. Especially preferred titanosilicate include classes of molecular sieves commonly referred to as "TS-1" (with topology MF1 similar topology aluminosilicate zeolite ZSM-5) "TS-2" (having an MEL topology similar to the topology of aluminosilicate zeolites ZSM-11), and "TS-3" (as described in Belgium patent N 1 001 038). Also suitable for use titanium containing molecular sieve having the structure of a crystal lattice that is isomorphic to the zeolite. Titanosilicate preferably does not contain in the crystal lattice of non-oxygen atoms, other than titanium and silicon, although a small amount of boron, iron, aluminium, gallium, etc. may be present.The epoxidation catalysts suitable for use in the method of nagda x = 0,0001-0,500, more preferably x = 0.01 to 0,125. The molar ratio of Si:Ti in the crystal lattice titanosilicate is preferably from 9.5:1 to 99:1 (most preferably from 9.5:1 to 60:1). The use of silicalite, relatively rich in titanium, preferably.The amount of catalyst is not critical, but should be sufficient to achieve the target epoxidation reaction in a practically short period of time. The optimum amount of catalyst will depend on a number of factors including the reaction temperature, the reactivity of the olefin and its concentration, hydrogen peroxide concentration, type and concentration of organic solvent, and the catalyst activity and the type of reactor or reaction system (for example, periodic or continuous) that were used.Usually, however, in the periodic epoxydecane the amount of the catalyst is 0.001 to 10 g per mol of olefin. In the system with a fixed layer of the optimum amount of catalyst will depend on the speed of flow of the reactants through the fixed layer (typically from about 1 to 100 moles of H2O2per kilogram of catalyst per hour).The catalyst can be used in the form of powder, tablets, useful binders (cogel) or carrier in combination with titanosilicates. Caused or related catalysts can be obtained by known methods, which are effective for zeolite catalysts in General. Preferably use a binder or carrier, which are substantially non-acidic and does not catalyze the selective decomposition of hydrogen peroxide or the ring opening of the epoxide.The catalyst may be treated with a basic substance or silylium reagent in order to reduce the acidity of the surface, as described in U.S. patent No. 4 937 216.The temperature of the epoxidation reaction is preferably 25-120oC (more preferably 40-80oC) that in the method of the present invention was found sufficient to achieve the selective conversion of the olefin to the epoxide acceptable for a short period of time with minimal non-selective decomposition of hydrogen peroxide. It is often useful to carry out the reaction to achieve the highest possible conversion of hydrogen peroxide, preferably at least 50%, more preferably at least 90%, most preferably at least 99%, matching with acceptable selectivity. At the optimum reaction temperature is affected by the concentration and activity of the catalyst, reary. Reaction times or stay from about 10 min to 48 h usually applied depending on the above variables.The reaction is usually carried out at atmospheric or elevated pressure (typically 1-100 ATM). For example, if apply olefin, such as propylene, with a boiling point at atmospheric pressure lower than the temperature of the epoxidation use surfmaster pressure sufficient to maintain the desired concentration of propylene in the liquid phase. At the reaction temperature of approximately 60oC, for example, the pressure preferably is supported at approximately 133104- 154104PA.Phase epoxidation of the present invention can be periodic, continuous or semi-continuous manner, using any suitable type of reactor or apparatus, such as the reaction apparatus with a fixed layer, stir suspended layer of the catalyst or CSTR reactor.Known methods for carrying out catalyzed by metal epoxidation using hydrogen peroxide, in General, can also be used. Thus, the reagents can be mixed at once, or sequentially. For example, a concentrated stream containing peroxide in the to, to regulate the addition of various components, so that the concentration of unreacted hydrogen peroxide does not exceed 10 wt.% at any point in the reaction zone. After separation from the epoxidation reaction mixture by any suitable means, such as filtering (for example, when using a reactor with suspended layer), regenerated titanosilicate catalyst can to save re-used in subsequent epoxydecane. If the catalyst is injected in the form of a fixed layer, the product of the epoxidation removed in the form of a stream from the epoxidation zone, substantially does not contain a catalyst, as the catalyst remains in the epoxidation zone. In some embodiments of the present method, in which the epoxide receive a continuous manner, it is desirable to periodically or continuously to regenerate all or part of the used catalyst to maintain optimum activity and selectivity. Suitable methods of regeneration are known and include, for example, annealing and processing solvent.When the olefin and hydrogen peroxide react to the desired degree of conversion, the resulting reaction mixture epoxidation containing water, C2-C4May from the mixture with the formation of the crude alcohol stream containing water, secondary C3-C4-alcohol and less Mas.% C2-C4-epoxide. This separation can be most easily achieved by distillation (e.g., fractional distillation), because the secondary alcohol can be collected so that it has a significantly higher boiling point than the formed epoxide, and could be recovered as a bottom fraction. As the olefin typically has a lower boiling point than epoxide and a secondary alcohol, any unreacted olefin in the reaction mixture epoxidation can be easily removed from the reaction mixture by distillation. In some embodiments, the excess olefin may be removed together with the epoxide single evaporation. Then apply the fractional distillation or condensation to separate olefins from the epoxide. In other embodiments, first remove the olefin from the reaction mixture epoxidation, then the epoxide. If the olefin is propylene, for example, how much of propylene is distilled from the top of the column at a pressure of approximately 192.5 kg PA without exceeding the temperature in the cube approximately 115oC and the aging time of about 10 minutes After this epoxide (e.g., propylene oxide) together with any remaining olefin can otolo 115oC and a pressure of about 24.5 PA.Thus obtained crude alcohol stream is then recycled at least in part, for use as a diluent to the stage epoxidation. An important advantage of this invention is that no additional purification or refining of the crude alcohol stream to achieve a satisfactory result. It is desirable, however, to remove excess quantities of any products C3-C4-ketone formed by epoxydecane; such deletion can be performed, for example, by fractional distillation, If not the entire flow of the crude alcohol is used as solvent, the residue can be recycled for use as raw materials to the stage of oxidation of the secondary alcohol.On stage hydrogenation of a ketone selected from the oxidation mixture, turn back to the corresponding secondary alcohol by reaction with hydrogen in the presence of a transition metal as a catalyst for hydrogenation. Methods of transformation of aliphatic ketones, such as acetone and 2-butanone, in their respective secondary aliphatic alcohols by catalytic hydrogenation using a transition of the EN transition metal, the preferred palladium, platinum, chromium (such as chromite, copper, rhodium, Nickel or ruthenium. If water is present, it is preferable to use Nickel or Raney Nickel promoted molybdenum. The hydrogenation is usually carried out in the liquid or vapor phase.Temperature, pressure and hydrogen concentration of the catalyst during the hydrogenation is chosen in such a way as to achieve substantial (e.g., at least 80% and more preferably at least 96%) conversion of the ketone to the secondary alcohol for almost a short reaction time (for example, from about 15 min to 12 h) without sverchuvstvovanie ketone. The optimal conditions of hydrogenation will vary depending on the type of catalyst and the reactivity of the ketone, but can be easily identified by experts in the field of technology, has made a series of experiments by hydrogenation of the ketone. Usually use a temperature from about 20 to 175oC and a hydrogen pressure from about 0.5 to 100 ATM, preferably. The molar ratio of H2the ketone is from about 1:1 to 4:1.Apply the amount of catalyst is preferably sufficient for the implementation space velocity sirim, properities, continuous or semi-continuous manner using any suitable reaction vessel or apparatus, which is good contact of the ketone with a hydrogenation catalyst based on a transition metal and hydrogen. Since the catalyst is typically heterogeneous in nature, then use a reactor with a fixed catalyst bed or suspended catalyst. You can also use the system with a stream of the catalyst.The drawing shows a variant of the United way of the invention in which propylene catalytically epoxidized to propylene oxide. A stream containing secondary alcohol, served by line 1 in zone 2 oxidation of alcohol, where the secondary alcohol partially reacts with molecular oxygen with the formation of the oxidation mixture containing hydrogen peroxide, a ketone and an excess of a secondary alcohol. Molecular oxygen is served by line 3 in the form of air or pure, or diluted O2.The oxidation mixture containing hydrogen peroxide, a ketone and a secondary alcohol direct from zone 2 through line 4 zone 5 oxidative distillation. In zone 5 the oxidation mixture is subjected to fractional distillation. Ketone selected from the top (in some cases, aderrasi concentrated hydrogen peroxide), which contains hydrogen peroxide and a secondary alcohol, available on line 8 epoxidation.The olefin to be epoxydecane, is fed to the epoxidation zone 11 along the lines 9 and 10. In the specific embodiment shown in the drawing, lines 8 and 19 also join the line 10 in points, separated from the line 9. However, there may be many other ways of introducing different flows of raw materials in zone 11 epoxidation. For example, the contents of the lines 8 and 19 may be combined into a single line before entering the line 10. Alternatively, the olefin, the crude alcohol stream and a concentrated stream of hydrogen peroxide can be entered separately in the zone 11 epoxidation. Thus, the sequence of the introduction of the various components of the reaction zone epoxidation is not decisive in the present invention, provided that a concentrated stream containing hydrogen peroxide, dilute the crude alcohol stream (in which the concentration of H2O2at all points in the liquid phase epoxidation zone is preferably less than > 10 %). Titanosilicates the catalyst is preferably introduced into zone 11 as a fixed bed, although you can use and suspension. Olefin, a stream containing concentrated perox is cast in district 11 during the time, sufficient to convert at least part of the olefin into the corresponding C3-C4-epoxide, thus, spending most or all of the hydrogen peroxide to form water as a byproduct. Thus obtained reaction mixture epoxidation fed through line 12 into the regeneration zone of the olefin 13, in which the unreacted olefin is separated by suitable means, such as distillation and recycle to the epoxidation zone 11 through line 14 and 10. The rest of the reaction mixture epoxidation taken along the line 15 to the cleaning zone epoxide 16, in which the propylene oxide is separated by suitable means, such as distillation, and is removed by line 17. Removing epoxy and unreacted olefin from the reaction mixture epoxidation get the crude alcohol stream containing isopropanol and heavier substances, such as water, acids, glycols and little, if any, of propylene oxide. You can perform intermediate or advanced treatment, if it is desirable to reduce the level of C3-C4-ketone (if any) generated as a by-product of the secondary alcohol when epoxydecane. The crude alcohol stream is served from the zone 16 cleaning epoxide by l, the rich remnant send in an area of 20 cleaning alcohol on line 21. The method of the invention can be used in conjunction with the method of regeneration of oxygen from the epoxidation reactor, as described in the application U.S. filed 28.12.94 (document N 01-2318A). The crude alcohol stream can enter into contact with a remote from the zone of olefin epoxidation/oxygen purge gas for absorption of the olefin, while inert gas, such as methane, add, to avoid formation of flammable gas compositions containing oxygen. The crude alcohol stream containing absorbed olefin, then recycle and use as a diluent in the reactor epoxidation.Head stream from zone 5 of the distillation of oxidant serves then line 7 in the hydrogenation zone 6, in which the stream is introduced into reaction with hydrogen (supplied on line 22) in the presence of a suitable hydrogenation catalyst, such as promoted by ruthenium or molybdenum Nickel Raney (which is preferably introduced as a fixed bed in zone 6) in order to transform at least a portion or preferably essentially all (e.g., more than 95% recycled ketone to the secondary alcohol. The flow hydrogenation allocated from the zone is directly back into the zone 2 oxidation of alcohol.Zone 20 cleaning alcohol acts so that the purified secondary alcohol (or azeotrope of ethanol with water) taken from the top of the column and an aqueous stream containing at least a portion of the water formed as a by-product of the epoxidation of hydrogen peroxide, as well as more serious side epoxidation products (acids, glycols) as a distillation fraction is removed by line 24. Purified secondary alcohol or its azeotrope recycle zone 2 oxidation of alcohol by lines 25 and 1. The resulting secondary alcohol injected into a stream of purified secondary alcohol on line 26.From the above description, any person skilled in the art can easily set the essential features of the invention and, keeping its spirit and scope, can make various changes and modifications to adapt it for various applications, conditions and options.EXAMPLES
Coming on the epoxidation of propylene material containing hydrogen peroxide, receive combining 820 g of isopropanol, 120 g of water, 60 g of H2O2(50% aqueous solution), 5.0 g of aqueous ammonium acetate (1 wt.% solution), 2.0 g of acetic acid and 0.26 g of formic acid. Epoxidation is conducted using propylene (5 equivalents) at operasie 60 cm3quartz fragments. Raw materials containing hydrogen peroxide, served with a speed of 70 ml/h the Analysis of the product by gas chromatography and iodometric titration showed 99% conversion of hydrogen peroxide, 89% selectivity to propylene oxide and 6% selectivity to products with open loop (glycol, glycolether) and 5% selectivity for oxygen. The propylene oxide and the excess propylene was removed by distillation. Distillation distillation residues containing 80% isopropanol, 18% water, 2% of products with open loop and 15 ppm NH4+use as recycled raw material (crude alcohol stream) in the following examples.Prepared additional raw materials similar with isopropanole oxidizing mixture after removal of the acetone by distillation by combining 46 g of isopropanol, 27 g of H2O2(50% aqueous solution), and 0.37 g of acetic acid and 0.13 g of formic acid. Containing raw materials of 18.45% H2O2by iodometric titration was used as fresh oxidant in the following examples.EXAMPLE 1
The reactor Parr", has an internal pocket thermocouple and inclined tube attached to the cylinder with propylene, was downloaded: 24,0 g above recyclery the lyst and 0,384 g of 1% aqueous solution of ammonium acetate (5,010-5mol; 34 ppm NH4+). The reactor was purged with helium, and then downloaded 16 ml of propylene (0.20 mol). The reactor was immersed in an oil bath and the reaction mixture was stirred at 56oC for 1 hour. The reactor was cooled to 18oC and then the gas produced in the gas bag, which was analyzed for oxygen and organic products. The remaining solution was analyzed by gas chromatography and iodometric titration. The conversion of hydrogen peroxide was 98%. Selectivity were: 88% propylene oxide, 6% in the acetone, 3% oxygen and 3% for products with open loop (after amendments for entry-level products with open loop in recycled raw materials). Despite the use of untreated recycled raw materials as a diluent, the selectivity for the target epoxy product was substantially identical to the selectivity obtained with fresh oxidant (see Comparative Examples 5 and 6 below).EXAMPLE 2
Example 1 was repeated using 0,121 g of 1% aqueous solution of ammonium acetate (1,610-5mole; 11 ppm NH4+) and 14 ml of 0.17 mol) of propylene. The conversion of hydrogen peroxide 98%. Selectivity were: 86% propylene oxide, 5% to acetone, 2% oxygen and 7% of the products revealed the I (5,010-5mole; 47 ppm Na+instead of ammonium acetate. The conversion of hydrogen peroxide was 97%. Selectivity were: 87% propylene oxide, 5% to acetone, 3% oxygen and 5% for products with open loop.EXAMPLE 4
Example 2 was repeated using 0,816 g of 1% aqueous solution of lithium nitrate (1,210-4mole; 27 ppm Li+instead of ammonium acetate. The conversion of hydrogen peroxide was 94%. Selectivity were: 84% propylene oxide, 4% in the acetone, 2% oxygen and 10% for products with open loop.COMPARATIVE EXAMPLE 5
This example shows that the method of the invention using as diluent stream recycled from the stage epoxidation, provides selectivity to epoxide, comparable with selectively obtained with fresh oxidant isopropanol. Fresh oxidizing mixture is produced by mixing 67 grams of isopropanol, 10 g of H2O2, 23 g of water, 0.20 g of acetic acid and 0.025 g of formic acid. The oxidizing mixture contained 5,11% H2O2according to the iodometric titration. The reactor Parr", has an internal pocket thermocouple and inclined tube attached to the cylinder with propylene, download 33,0 g fresh oxidizing mixture (0,050 mol H2+). The reactor is rinsed with helium and injected into 20 ml of propylene (0,25 mol). The reactor is immersed in an oil bath and stirred at 53oC for one hour. The reactor is cooled to 18oC and the gas release bag for gas. The conversion of hydrogen peroxide was 95%. Selectivity were 89% propylene oxide, 5% to acetone, 2% oxygen and 3% for products with open loop.COMPARATIVE EXAMPLE 6
Comparative example 5 was repeated using 0,298 g of 1% aqueous solution of ammonium acetate (3,910-5mole; 27 ppm NH4+). The conversion of hydrogen peroxide was 94%. Selectivity were: 87% propylene oxide, 6% in the acetone, 1% oxygen and 6% for products with open loop. 1. The way epoxidation C2-C4olefins, comprising: (a) the interaction of secondary C3-C4alcohol and molecular oxygen in the liquid phase with the formation of the oxidation mixture containing secondary C3-C4alcohol, aliphatic C3-C4the ketone corresponding to the secondary C3-C4alcohol, and the first oxide hydrogen; (b) the Department of practically all C3-C4ketone from the oxidation mixture to produce a concentrated stream containing hydrogen peroxide containing secondary tarirovannogo thread containing the first oxide hydrogen, C2-C4the olefin in the presence of titanosilicate catalyst and diluent with the formation of the epoxidation reaction mixture containing C2-C4epoxide corresponding to C2-C4the olefin, water and secondary C3-C4alcohol and d) separation of almost all C2-C4epoxide from the reaction mixture epoxidation with obtaining the crude alcohol stream containing water and secondary C3-C4alcohol, characterized in that the crude alcohol stream contains less than 1 wt.% C2-C4epoxide and at least part of the crude alcohol recycle stream for use as at least part of the diluent at the stage (C).2. The method according to p. 1, characterized in that C3-C4ketone isolated from the oxidation mixture in stage (b), hydronaut to secondary C3-C4spirit.3. The method according to p. 2, characterized in that the hydrogenation is carried out in the presence of a hydrogenation catalyst containing a transition metal selected from palladium, platinum, ruthenium, chromium, rhodium, and Nickel at a temperature of from 20 to 175oand a hydrogen pressure of 0.5 to 100 ATM.4. The method according to any is .4, characterized in that the molar ratio of propylene: hydrogen peroxide stage (C) is from 1:2 to 10:1.6. The method according to p. 4 or 5, characterized in that there is an excess of propylene relative to the hydrogen peroxide stage (C) and the excess propylene is separated from the epoxidation reaction mixture after stage C) and before stage (e).7. The method according to any one of paragraphs. 1-6, characterized in that the secondary C3-C4alcohol is isopropanol.8. The method according to any one of the preceding paragraphs, wherein the concentrated stream containing hydrogen, contains from 5 to 30 mass % of hydrogen peroxide.9. The method according to any one of the preceding paragraphs, characterized in that the diluent is present in a quantity sufficient to provide a concentration of hydrogen peroxide is less than 10 mass%, based on the total weight of the concentrated stream containing hydrogen peroxide and diluent on stage).10. The method according to any of the preceding paragraphs, characterized in that the diluent is present in a quantity sufficient to provide a concentration of hydrogen peroxide in stage C) at least 1% but less than 10 wt.%, in racetab according to any one of the preceding paragraphs, characterized in that titanosilicate has the topology MF1, MEL or topology etazolate.12. The method according to any of the preceding paragraphs, characterized in that titanosilicate has a composition corresponding to the chemical form xTiO2:(1-x)SiO2where x is in the range from 0.01 and 0.125.13. The method according to any one of the preceding paragraphs, characterized in that titanosilicate used in the form of a fixed layer.14. The method according to any one of the preceding paragraphs, characterized in that titanosilicate used in combination with a carrier.15. The method according to any one of the preceding paragraphs, characterized in that stage b) of the Department carry out the distillation, with almost all of C3-C4the ketone is evaporated and removed from the oxidation mixture as head of the stream.16. The method according to any of the preceding paragraphs, characterized in that stage a) is carried out at a temperature of from 50 to 200o.17. The method according to any one of the preceding paragraphs, wherein stage C) is carried out at temperatures from 25 to 120o.18. The method according to any one of the preceding paragraphs, characterized in that stage a) is carried out at partial Yes the eat, that includes: (a) interaction isopropanol and molecular oxygen in the liquid phase at a temperature of from 50 to 200owith the formation of the oxidation mixture containing isopropanol, acetone and hydrogen peroxide; (b) distillation of the oxidation mixture, whereby almost all of the acetone is evaporated and removed from the oxidation mixture as a head stream in order to obtain a concentrated stream containing hydrogen peroxide containing isopropanol, from 10 to 30 wt.% of hydrogen peroxide and less than 1 wt.% acetone; (C) the interaction of concentrated flow containing hydrogen peroxide with propylene at a temperature of 25 - 120oWith the presence titanosilicate catalyst and diluent to obtain epoxidation reaction mixture containing water, propylene oxide and isopropanol; (d) the Department of practically all of the propylene oxide from the epoxidation reaction mixture by distillation to obtain the cubic stream containing water, isopropanol and less than 1 wt.% of propylene oxide; (e) recycling at least part of the cubic stream for use as at least part of the diluent at the stage (C); (f) hydrogenation of acetone, separated from the oxidation mixture at the stage b), to isopropanol and (g) recircu
R1-CC--CHH-R2where R1is phenyl; R2is hydrogen or lower alkyl
FIELD: chemical industry; production of hydrogen peroxide and oxiranes.
SUBSTANCE: the invention is dealt with a method of production of hydrogen peroxides and oxiranes. The invention provides for conductance of reaction of olefin with hydrogen peroxide at the presence of a catalyst and organic thinner. At that hydrogen peroxide is present as a water solution of hydrogen peroxide extracted mainly with the help of purified water out of a mixture produced as a result of oxidation at least of one alkylanthrahydroquinone without aftertreatment with a cleansing water and-or purification. The technical result is an increase of an output and selectivity of oxirane.
EFFECT: the invention ensures increased output and selectivity of oxirane.
17 cl, 5 tbl, 10 ex
FIELD: chemical industry; production of a catalyst carrier material and the catalyst.
SUBSTANCE: the invention is dealt with the field of chemical industry. The method of production of a catalyst carrier material includes the following stages: (a) treatment of the utilized catalyst of titanium dioxide-on-silicon dioxide to clear from coke; (Ь) washing of the catalyst cleared from the coke by a flushing fluid chosen from a water solution of an inorganic acid, a water solution of an ammonium salt and their combinations; (c) drying and calcination of the catalyst washed out and cleared from the coke with production of the catalyst carrier material. The technical effect - the material produced this way is fit for use as the carrying agent material for titanium dioxide in a heterogeneous catalyst for epoxidation of olefines in alkylene oxide.
EFFECT: the invention ensures production of the material fit for use as the carrying agent material for titanium dioxide in a heterogeneous catalyst for epoxidation of olefines in alkylene oxide.
12 cl, 4 ex, 1 tbl
FIELD: petrochemical industry; production of zeolite.
SUBSTANCE: the invention offers the method of production of titanium-containing zeolite by: (a) combining a capable to be hydrolyzed silicon compound and a capable to be hydrolyzed titanium compound; (b) adding a basic quaternary ammonium compound in a water medium into the mixture from a stage (a) and a hydrolysis of a reaction mixture at the temperature within the interval from 0 up to 100°C with production of a synthesis sol; and then (c) the synthesis sol aging at the temperature within the interval from 150 up to 190°C and (d) crystallizations of the synthesis sol at this temperature, differing by the fact, that aging duration at the increased temperature at the stage of (c) makes less than 240 minutes. The method ensures production of zeolite with a catalytic activity in reactions of epoxidation of olefins by hydrogen peroxide.
EFFECT: the invention ensures production of zeolite with a catalytic activity in reactions of epoxidation of olefins by hydrogen peroxide.
8 cl, 1 tbl
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing oxyrane. Method involves reaction of olefin with peroxide compound in the presence of catalyst and a solvent in at least two reactors arranged in series and each reactor contains part of catalyst. Peroxide compound is added to the first reactor only and the next or the following reactors are fed with peroxide compound presenting in medium preparing from the preceding reactor but not with fresh peroxide compound or used in this preceding reactor. Method provides enhancing output and reducing formation of by-side products.
EFFECT: improved method for preparing.
10 cl, 1 dwg, 2 ex