Method of producing unsaturated carboxylates

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing unsaturated carboxylates by reacting alkenes containing 2-6 carbon atoms with alkane carboxylic acids containing 1-6 carbon atoms, in the presence of an oxygen-containing gas and a noble metal-based heterogeneous catalyst via a continuous process in a homogeneous gas phase in a reactor. The gas phase is fed into recycling gas and before entering the reactor, is saturated with an alkane carboxylic acid in a saturated designed for this purpose, where before the saturator for saturating with an alkane carboxylic acid (main saturator), there is a pre-saturator in which the recycling gas is saturated with a portion of the alkane carboxylic acid used for saturation, after which the recycling gas is fed into the main saturator and saturated therein with the remaining amount of the alkane carboxylic acid. The invention also relates to an apparatus for realising said method.

EFFECT: use of the presaturator for saturating with acetic acid prolongs the time interval between stoppages of the production process for cleaning the equipment.

10 cl, 1 dwg

 

The present invention relates to a method for producing unsaturated carboxylates (unsaturated esters of carboxylic acids) interaction of alkenes containing from 2 to 6 carbon atoms, with alkenylboronic acids containing from 1 to 6 carbon atoms, in the presence of oxygen-containing gas and a heterogeneous catalyst based on a noble metal by carrying out a continuous process in the homogeneous gas phase.

Obtaining unsaturated carboxylates interaction of alkenes containing from 2 to 6 carbon atoms, with alkenylboronic acids containing from 1 to 6 carbon atoms, in the presence of oxygen-containing gas and a heterogeneous catalyst based on a noble metal by carrying out a continuous process in a homogeneous gas phase is already known. Of particular importance is the obtaining of vinyl acetate by the interaction of ethylene with acetic acid and oxygen or oxygen-containing gases on the fixed layers of the catalysts in the gas phase.

Such reactions are usually carried out at a pressure in the range from 1 to 50 bar, preferably from 5 to 15 bar and at a temperature in the range from 50 to 250°C, preferably from 130 to 200°C. Suitable for use in such reactions, the catalysts contain as a component of the noble metal, and as the other component - the asset is tor (the promoter). As the noble metal is usually used palladium and/or compounds thereof. Often the catalysts optionally also contain gold and/or rhodium or their compounds. As activator use connections of the 1st and/or 2nd main group of the periodic system of elements and/or cadmium. The catalysts can also contain compounds of rhenium and/or zirconium. These components is usually applied to media such as, for example, silicic acid, silicates, titanium dioxide, zirconium dioxide, silicon carbide or aluminum oxide.

Used for the reaction mixture of the olefin, alkene, oxygen) usually contains olefin in multiple molar excess. Therefore, the conversion of ethylene during the reaction is not complete and unreacted olefin must be sent to recycling, i.e. return it to the reaction. Such returned in response registergui gas is called a cycle or working capital. This registergui recycle gas (upon receipt of the vinyl acetate - atlantagay recycle gas) saturate the corresponding carboxylic acid (upon receipt of the vinyl acetate - acetic acid) provided in front of the reactor the saturator (upon receipt of the vinyl acetate - saturator for saturation of acetic acid, below called acetic acid saturator), then saturated with oxygen.

Then reacts the traditional mixture is sent into the reactor. Coming out of the reactor hot reaction mixture, which upon receipt of vinyl acetate consists mainly of unreacted ethylene, unreacted acetic acid, unreacted oxygen, vinyl acetate formed during the reaction are water, carbon dioxide, as well as the original made with oxygen and ethylene inert gases (e.g. nitrogen, ethane, methane, and argon, cooled, if necessary, after a preliminary pass through the drying column. While the prevailing part of the acetic acid, the percentage of vinyl acetate and water are condensed. The resulting condensate is separated into the subsequent stages of its components is isolated and acetic acid (recycle acetic acid) return in the process. Neskondensirovannyh residual gas contains mainly ethylene, CO2and inert components, and after washing from CO2and separation of inert components in the residual gas is sent as recycle gas in acetic acid saturator.

However, the saturation of the recycle gas with acetic acid in the acetic acid saturator has the disadvantage that at the end of the short cycles of acetic acid saturator is pollution. This saturator is usually a column in which the first directly served dry recycle the gas (without acetic acid and water), passing it through the column from the bottom up (upward flow) and adding to it in dosed quantities of acetic acid. Pollution, which reduce productivity and even determine the need to stop production to clean up columns, are formed mainly in the lower part of the column in the feed area it dry and hot recycle gas.

From US 6420595 B1-known equipment of the saturator distillation column, the selection of contaminants together with kubovy residue from the bottom of the column and the separation of impurities from the acetic acid in vacuo to install recovery acid (Acid Recovery Unit (ARU)) with the subsequent return of acetic acid saturator.

In the US 7202377 B1 the formation of impurities in the acetic acid saturator is attributed to the presence of circulating acetic acid derived from the condensed portion of the reaction mixture and used to saturate the recycle gas along with fresh acetic acid. In this publication it is recommended to clean the recycle gas by passing it through the rectifying section mounted on saturation column, and divide drained from the bottom of saturation of the column the liquid into two streams, one of which is sent to recycling without processing, and the other sent to recycling after separation of high-boiling components and polymers in viscotester the cultural thin-film evaporation apparatus.

The present invention was based on the objective to develop a method of obtaining unsaturated carboxylates, which would allow as effectively to prevent the formation of impurities in the provided before the reactor saturator to saturate the acid that there was no need to conduct is known from the prior art, complicated and expensive purification of the saturator.

With the invention it has been unexpectedly found that pre-saturation of the recycle gas, preferably recycle acetic acid, in a pre-saturator provided in front (main) saturator to saturate the acid can dramatically reduce the formation of impurities in the saturator.

The object of the invention is a method for unsaturated carboxylates interaction of alkenes containing from 2 to 6 carbon atoms, with alkenylboronic acids containing from 1 to 6 carbon atoms, in the presence of oxygen-containing gas and a heterogeneous catalyst based on a noble metal by carrying out a continuous process in a homogeneous gas phase in the reactor, the gaseous phase is sent to recycling (recycle gas) and before entry into the reactor is saturated alkenylboronic acid in the designated saturator, characterized in that before the saturator for having asimenia alkenylboronic acid (the main saturator) provide pre-saturator, in which the recycle gas is saturated part of the total quantity used for saturation alkenylboronic acid, after which the recycle gas is sent to the main saturator and saturate in it the rest of the number alkenylboronic acid.

Below the invention is considered on the example of a vinyl acetate, although in principle proposed in the invention method can be used in General to obtain unsaturated carboxylates. Therefore, in the following description assumes that the implementation discussed below process instead of ethylene in the General case, you can use alkanes containing from 2 to 6 carbon atoms, and instead of acetic acid - other alcancarao acid containing from 1 to 6 carbon atoms.

For use as a pre-saturator, as the (main) saturator, in General, suitable devices with contact between a gas and liquid phases, for example, columns with lattice packings, columns Packed with bodies, columns with plates or other inline elements, as well as Venturi scrubbers, and in the simplest case the pipeline. As a pre-saturator is preferable to use cooling towers or washers without built-in controls, such as scrubbers with spray irrigation, spray washers or scrubbers.

Re illowy gas preferably be submitted in the pre-saturator on top. Together with the recycle gas can also be served in the pre-saturator bottom in countercurrent to the supplied acetic acid. Preferably submit recycle gas in co-current with acetic acid. In one of the preferred options in the saturator use nozzles that are radially spaced evenly in the plane perpendicular to the vertical axis of the saturator, and through which acetic acid is injected in the pre-saturator. Acetic acid is preferable to inject the top.

Atlantagay recycle gas is usually at the entrance to the pre-saturator temperature in the range of from 100 to 170°C, preferably from 120 to 150°C. Acetic acid as the acid, depending on the level of pressure at which carry out the process, served in the pre-saturator temperature in the range from 90 to 200°C, preferably from 100 to 150°C. In contact with recycle gas acetic acid evaporates, and the recycle gas is cooled. Acetic acid should preferably be submitted in such number at which it evaporates not completely. The process of initial saturation is preferably adjusted in such a way that filed for the pre-saturated acetic acid remained in pre-saturator liquid in the amount of at least 5 wt.%, especially before occhialino from 25 to 75 wt.%.

For pre-saturation atlantabased recycle gas, acetic acid, preferably from 20 to 80 wt.%, particularly preferably from 50 to 80 wt.%, of the total number served in pre-saturator and the main saturator. The remaining amount of acetic acid recycle gas is injected in the main saturator. For pre-saturation can be used acetic acid with any of the technological stages. For example, you can use the reverse acetic acid recovered from the effluent from the reactor the reaction mixture, or recycling of acetic acid from the stage of processing the remaining process liquid acetic acid (from the stage of processing residues), fresh acetic acid or acetic acid from the circulation loop of the main saturator. In one of the preferred options for pre-saturation is used, preferably predominantly, i.e. more than 50 wt.%, or exclusively use a circulating acetic acid, recuperated from coming out of the reactor the reaction mixture.

Remaining in a pre-saturator liquid acetic acid is withdrawn from him. This liquid acetic acid from the pre-saturator preferably partially or completely be sent to the bottom of the main saturator. Together with the eating of liquid acetic acid from the pre-saturator can fully or partially be sent directly to the stage of its processing.

The main saturator in the preferred embodiment, is made in the form of columns, for example, in the form of a Packed column or preferably in the form of column trays with some number plates.

In the implementation proposed in the invention method pre-rich recycle gas is sent from the pre-saturator in the main saturator. On the entrance temperature of the recycle gas is preferably from 80 to 140°C. In the main saturator cycle gas saturate the residual amount of acetic acid. For this purpose it is preferable to use fresh acetic acid. In principle, however, you can also use fresh acetic acid in combination with liquid acetic acid from the pre-saturator and/or recycling of acetic acid recovered from the effluent from the reactor the reaction mixture and/or at the stage of processing residues. Stream atlantabased, partially saturated acetic acid recycle gas should preferably be submitted in the bottom quarter of the main saturator, particularly preferably at a point on the section between the bottom plate and the level in the main saturator fluid. In another preferred embodiment of this atlantabased saturated with acetic acid in the pre-Satur what the op recycle gas before it enters the main saturator to select the part of the flow, preferably up to 40 vol.%, which kind of bypass flow is served in the main saturator at a point above the point of feed in the main stream of recycle gas.

From the bottom of the main saturator is possible to select CBM product. In one of the preferred options from the bottom of the main saturator select CBM product is heated and returned to the main saturator. In a preferred embodiment, such CBM product that is returned to the main saturator, you can submit it with the distribution of several of his plates. By means of such circulation circuit to regulate the temperature in the main saturator, and thus the saturation process recycle gas with acetic acid. If such circulation circuit described above, the bypass flow is served in the main saturator at a point above the lowest point of the filing of the cubic product in the main saturator through the circulation path.

After saturation, acetic acid, and after saturation with ethylene and oxygen recycle gas is sent into the reactor.

Below proposed in the invention method are considered on the example of one of the variants of its implementation with reference to the accompanying description single drawing, which shows a flow chart, illustrating the proposed invention with the royals.

In the pre-saturator 1 in its upper third of the pipe 2 serves atlantagay recycle gas, and pipeline 3 in parallel serves heated by the heater 4 with acetic acid. On the pipe 5 from the pre-saturator is possible to select a liquid CBM product and fully or partially to send it in the main saturator 7 for saturation acetic acid or stage of processing residues. Saturated acetic acid, atlantagay recycle gas is withdrawn from the lower third of the pre-saturator through the pipeline 6 and send it in the main saturator 7, preferably in its lower third. In a preferred embodiment, from atlantabased saturated acetic acid recycle gas prior to its entrance into the main saturator on line 8 select the part of the flow, which is served in the main saturator 7 at a point above the lowest point of entrance of the inlet pipe 6. The pipe 9 from the main saturator 7 can be selected liquid CBM product. The pipeline 12 with a pump 10 and a heater 11, CBM product after heating it is possible to return to the main saturator 7 (circulation path).

During the process without pre-saturator in the unit for the production of vinyl acetate in an industrial scale (producing what elnett approximately 200,000 tons of vinyl acetate per year) already after about 2-3 months because of the increasing pressure loss in the column and its phenomena "zahlebyvayas", pollution of the main saturator had to reduce the flow rate of the pump material, and later to cut the amount of recycle gas. In addition, there were problems with the release of liquid from the column, which led to fluctuations in the liquid level in the bottom of the column, and in extreme cases - to "drying out" of the flow of the cubic product. With progression of such negative phenomena in the production of vinyl acetate was continuously decreased, and eventually every 3-9 months of the installation had to stop to clean it with the appropriate termination of the output.

The use of pre-saturator for saturation of acetic acid resulted in 2-3 fold increase in the time interval between stops of the production process for the purification installation.

1. The method of obtaining unsaturated carboxylates interaction of alkenes containing from 2 to 6 carbon atoms, with alkenylboronic acids containing from 1 to 6 carbon atoms, in the presence of oxygen-containing gas and a heterogeneous catalyst based on a noble metal by carrying out a continuous process in a homogeneous gas phase in the reactor, the gaseous phase is sent to recycling (recycle gas) and before entry into the reactor is saturated alkenylboronic acid designation is nom the saturator, characterized in that before the saturator for saturation alkenylboronic acid (the main saturator) provide pre-saturator, in which the recycle gas is saturated part of the total quantity used for saturation alkenylboronic acid, after which the recycle gas is sent to the main saturator and saturate in it the rest of the number alkenylboronic acid.

2. The method according to claim 1, characterized in that the pre-saturation use from 20 to 80 wt.% alkenylboronic acid of the total number served in pre-saturator and the main saturator.

3. The method according to claim 1 or 2, characterized in that the pre-saturation predominantly use alcancarao acid recovered from the effluent from the reactor the reaction mixture.

4. The method according to claim 1 or 2, characterized in that the pre-saturation regulate in such a way that filed for the pre-saturation alcantarea acid remains in pre-saturator liquid in the amount of at least 5 wt.%.

5. The method according to claim 1 or 2, characterized in that alkanolamide recycle gas enters the pre-saturator temperature in the range from 100 to 170°C, and alcantarea acid is in the pre-saturator temperature in the range from 90 to 00°C.

6. The method according to claim 1 or 2, characterized in that the main saturator cycle gas saturated with residual alkenylboronic acid, which use fresh alcancarao acid or fresh alcancarao acid in combination with liquid alkenylboronic acid from the pre-saturator and/or working alkenylboronic acid recovered from the effluent from the reactor the reaction mixture and/or at the stage of processing residues.

7. The method according to claim 1 or 2, characterized in that Alcantaras busy alkenylboronic acid in pre-saturator recycle gas prior to its entrance into the main saturator select the part of the flow, which is in the form of bypass flow is served in the main saturator at a point above the point of feed in the main stream of recycle gas.

8. The method according to claim 1 or 2, characterized in that from the bottom of the main saturator select CBM product after the heat return to the main saturator.

9. The method according to claim 1 or 2, characterized in that as alkene use ethylene, and as alkenylboronic acid - acetic acid.

10. A device for implementing the method according to one of claims 1 to 9, characterized in that before the main saturator, established before the reactor, there is a pre-saturator.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of separating vinyl acetate from a gaseous mixture formed from reaction of ethylene with acetic acid and oxygen in gaseous phase over catalysts containing palladium or palladium compounds, involving: a) feeding said gaseous mixture, coming from reactor (5) for vinyl acetate, into a pre-dehydration column (7), b) cooling the gaseous mixture coming from the top part of the pre-dehydration column (7) to temperature lower than 85°C, preferably to temperature lower than 80°C and even more preferably to temperature between 55°C and 75°C in a counter-current heat exchanger (9), c) further cooling of the gaseous mixture or gas-liquid mixture coming from the heat exchange (9) at step b) to temperature ranging from -20°C to 50°C, wherein the obtained condensate is separated into an aqueous phase (17) and an organic phase (18), d) removing the aqueous phase formed at step c), e) recycling all or a portion of the organic phase formed at step c) as reflux into the top part of the pre-dehydration column (7) used at step a), and removing a portion of the organic phase which is not used as reflux, f) wet cleaning of the gas containing vinyl acetate which did not condense at step b) in a gas wet cleaning column (21) through aqueous solution of acetic acid, g) separating vinyl acetate, h) heating the recycled gas coming from the gas wet cleaning column (21), possibly along with fresh ethylene and/or the recycled gas coming from a CO2 removal system (72) and/or blow-out gas in the counter-current heat exchanger (9), thereby reducing temperature of the gaseous mixture coming from the top part of the dehydration column (7), and i) feeding the recycled gas, possibly along with fresh ethylene and/or recycled gas coming from the CO2 removal system (72) and/or blow-out gas pre-heated at step h) into the rector (5) to obtain vinyl acetate.

EFFECT: method significantly reduces power and steam consumption during the entire process of producing vinyl acetate.

13 cl, 1 dwg, 1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemical catalysts for synthesis of vinyl acetate. Described is a catalyst for synthesis of vinyl acetate from acetic acid and acetylene, which contains zinc acetate and a support, wherein the support is Sibunit carbon consisting of microspherical nanoporous particles with size of 200-500 mcm. Described is a method of producing vinyl acetate from acetic acid and acetylene in the presence of the catalyst described above, characterised by that the method is realised at temperature 170-220°C, volume flow rate of acetylene of 0.54-0.84 l/cm3 (cat)·h, mass flow rate of acetic acid of 0.3-0.5 g/cm3 (cat)·h.

EFFECT: described is a catalyst characterised by high mechanical strength and catalytic activity and long service life.

7 cl, 2 tbl, 17 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing vinyl acetate via a gas-phase reaction between ethylene, acetic acid and oxygen with heterogeneous catalysis in continuous mode at pressure 1-30 bars and temperature 130-200°C while tapping reaction heat through heat exchange with water which converts the water into vapour at temperature 120-185°C and pressure 1-10 bars and then separating the gas stream containing the product, said stream mainly consisting of ethylene, vinyl acetate, acetic acid, water, carbon dioxide and other inert gases, and complete or partial return of ethylene into the process with circulation of recycle gas. The water vapour at temperature 120-185°C and pressure 1-10 bars formed during the gas phase reaction as a result of heat exchange is completely or partially compressed with increase of its pressure by at least 0.5 bars and then directed for further use in the vinyl acetate production apparatus.

EFFECT: method enables complete use of vapour formed during exothermic gas-phase reaction during synthesis of vinyl acetate and significantly reduces the volume of supplying heating vapour from external sources.

4 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing vinyl acetate, involving bringing starting material containing ethylene, acetic acid and an oxygen-containing gas into contact with a palladium- or gold-containing catalyst obtained on a calcined and modified carrier material to form vinyl acetate and at least one by-product, where the carrier material is modified with 1) niobium, magnesium, tantalum, yttrium, lanthanum, praseodymium or combinations thereof; or 2) titanium, zirconium or combinations thereof, where the carrier material is selected from zirconium dioxide, titanosilicate or zirconosilicate, and where the modified carrier material is calcined before adding catalyst components. The invention also relates to a method of producing a catalyst which is suitable for producing vinyl acetate, as well as a catalytic composition for catalysis of production of alkenylalkanoates, including carrier material with at least one modifier, palladium and gold, which react to form a catalyst, where the modified carrier material undergoes calcinations in a non-reducing atmosphere, and the modifier includes 1) niobium, magnesium, tantalum, yttrium, lanthanum, praseodymium or combinations thereof; or 2) titanium, zirconium or combination thereof, where the carrier material is selected from zirconium dioxide, titanosilicate or zirconosilicate.

EFFECT: obtaining catalysts which can be used to produce alkenylalkanoates in general and vinyl acetate in particular, and which are suitable for use in obtaining low ratio of EA/VA while maintaining or improving selectivity of producing CO2.

34 cl

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for synthesis of 2-acetoxy-5-biphenylcarboxylic acid, involving alkylation by adding p-cresol and an alkylation agent into molten pyrophosphoric acid, heating and holding at temperature while stirring, separation of the hydrocarbon layer, washing to a neutral reaction, drying with calcium chloride and rectification under vacuum of 9-10 mm Hg and temperature 151-156°C to obtain 4-methyl-2-cyclohexylphenol and then its dehydrogenation in liquid phase at atmospheric pressure and high temperature on palladium catalysts, with extraction of 5-methyl-2-biphenylol when cooling. Alkylation is carried out at 110-120°C. The alkylation agent used is cyclohexane. Dehydrogenation is carried out at 300-350°C using palladium catalysts in form of palladium catalysts on carbon. After extraction, the 5-methyl-2-biphenylol is acylated in acetic anhydride in the presence of sulphuric acid to 2-acetoxy-5-methylbiphenyl, with subsequent oxidation of the 2-acetoxy-5-methylbiphenyl in a solution of a mixture of glacial acetic acid and acetic anhydride (1:1) with oxygen at temperature 105-110°C in the presence of a soluble cobalt-manganese-bromine catalyst until complete oxidation and extraction of 2-acetoxy-5-biphenylcarboxylic acid crystals from the reaction mixture after cooling.

EFFECT: method increases output of the valuable 2-acetoxy-5-biphenylcarboxylic acid monomer and lowers the cost of the process.

2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved combined methods of producing acetic acid and vinyl acetate involving the following steps: (a) obtaining a first stream of product from the first reaction zone containing acetic acid, where the acetic acid is obtained via an exothermic carbonylation reaction, and where at least part of the heat obtained from the acetic acid is tapped from the first reaction zone and at least part of the heat tapped during production of acetic acid is transferred to a heat exchange system; (b) bringing the reaction stream of acetic acid containing at least a portion of acetic acid from the first stream of product into contact an oxygen-containing gas in a second reaction zone in the presence of a catalyst to obtain a second stream of product which contains vinyl acetate monomer; (c) directing at least a portion of the second stream of product to purification section for purification of at least a portion of vinyl acetate in the second stream of product; and either (d) tapping at least part of heat transferred to the heat exchange system, and delivering at least part of the heat tapped from the heat exchange system to at least one reaction stream of acetic acid and the vinyl acetate purification section, and where the heat exchange system contains a stream of a steam condensate, and where at least part of the heat tapped during production of acetic acid is delivered to the stream of steam condensate which is used to provide at least one reaction stream of acetic acid and the vinyl acetate purification section with heat tapped during production of acetic acid, where the stream of steam condensate containing heat from production of acetic acid is directed to a low-pressure evaporation vessel kept at pressure between 4.0 kg/cm2 and 5.3 kg/cm2, or (d) tapping at least part of the heat transferred to the heat exchange system, and delivering at least part of heat tapped from the heat exchange system to at least one reaction stream of acetic acid and the vinyl acetate purification section, in which a loop is used to cycle the condensate in order to remove most of the heat from production of acetic acid by directing a stream of a hot reaction solution through the heat exchanger for transferring heat to the stream of steam condensate, where the stream of steam condensate which contains heat from production of acetic acid is directed to the low-pressure evaporation vessel kept at pressure between 4.0 kg/cm2 and 5.3 kg/cm2.

EFFECT: proposed methods are useful for lowering expenses and reducing power consumption during vinyl acetate production.

10 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: present invention relates to catalysts, methods of preparing catalysts and methods of producing alkenyl alkanoates. A method is described for preparing a catalyst suitable for use in production of alkenyl alkanoates, involving: deposition of a first carrier material and binding agent on a second carrier material to obtain layered carrier material in form of particles with an inner and an outer layer, where catalyst components in form of palladium, gold or combinations thereof are contained in the outer layer of the layered carrier material. A catalyst is also described for producing alkenyl alkanoates, which contains: layered carrier material in form of particles with at least an outer layer containing a first carrier material and binding agent, and an inner layer containing a second carrier material, where the outer layer contains at least palladium combined with gold which is in contact with it to obtain the catalyst, where the inner layer essentially does not contain palladium and gold. A method is described for producing alkenyl alkanoates, involving: bringing raw material containing alkene, alkanoic acid and oxidising agent into contact with a catalyst prepared using the method described above.

EFFECT: improved production of alkenyl alkanoates, reduced amount of by-products and increased efficiency of production.

44 cl, 6 tbl, 15 ex

FIELD: chemistry.

SUBSTANCE: proposed is a method of oxidising alkane from C2 to C4, obtaining the corresponding alkene and carboxylic acid and/or oxidising alkene from C2 to C4, obtaining the corresponding carboxylic acid. The method involves addition into the reaction zone of the above mentioned alkane and/or alkene, containing molecular oxygen gas, carbon monoxide and optionally water, in the presence of a catalyst, effective for oxidising the alkane to the corresponding alkene and carboxylic acid and/or effective for oxidising the alkene to the corresponding carboxylic acid at temperature between 100 and 400 °C. Concentration of carbon monoxide is kept between 1 and 20% of the total volume of the initial material added to the oxidation reaction zone. The method can optionally involve further reaction in a second reaction zone.

EFFECT: new oxidation method for producing carboxylic acids and alkenes.

30 cl, 3 ex, 1 tbl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of producing methanol, acetic acid and optionally vinyl acetate, which includes integrated stages: separation of hydrocarbons source into first and second hydrocarbons flows; vapour reforming of first hydrocarbons flow with vapour in order to obtain subjected to reforming flow; autothermal reforming of mixture of subjected to reforming flow and second hydrocarbons flow with oxygen and carbon dioxide in order to obtain synthesis-gas flow; separation of smaller part of synthesis-gas flow into flow with higher carbon dioxide content, flow with higher hydrogen content and flow with higher content of carbon oxide; recirculation of flow with higher carbon dioxide content to autothermal reforming; compression of remaining part of synthesis-gas flow, CO2 flow, not necessarily from associated process, and at least part of flow with higher hydrogen content for supplying feeding flow to circuit of methanol synthesis in order to obtain methanol product, whose stoichiometric coefficient is determined as [(H2-CO2)/(CO+CO2)], and stoichiometric coefficient of feeding flow constitutes from 2.0 to 2.1; acetic acid synthesis from at least part pf methanol product and flow with higher content of carbon oxide, and optionally synthesis of vinyl acetate from at least part of synthesised acetic acid.

EFFECT: elaboration of improved method of producing methanol, acetic acid, characterised by highly economical indices and low intensity of CO2 emission.

23 cl, 2 ex, 2 dwg

FIELD: chemistry.

SUBSTANCE: reaction of alkene with molecular oxygen is carried out in reactor with pseudoliquefied layer in presence of catalytically active pseudoliquefied layer of solid particles, which lies in the following: gas, containing molecular oxygen, concentration of oxygen in which exceeds its concentration in air, is introduced into pseudoliquefied layer simultaneously supporting turbulent mode in pseudoliquefied layer. Invention also relates to method of obtaining vinylacetate by reaction of ethylene and acetic acid with molecular oxygen in reactor with pseudoliquefied layer in presence of catalytically active pseudoliquefied layer of solid particles, which have diameter in range from 20 to 300 mcm, distribution according to particle diameter constitutes at least 20 mcm; at to method of carrying out reaction of molecular oxygen with ethane, ethylene or their mixture obtaining acetic acid and optionally ethylene in reactor with pseudoliquefied layer in presence of catalytically active pseudoliquefied layer of solid particles.

EFFECT: elaboration of safer method of carrying out reaction.

45 cl, 2 tbl, 3 ex,4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of separating vinyl acetate from a gaseous mixture formed from reaction of ethylene with acetic acid and oxygen in gaseous phase over catalysts containing palladium or palladium compounds, involving: a) feeding said gaseous mixture, coming from reactor (5) for vinyl acetate, into a pre-dehydration column (7), b) cooling the gaseous mixture coming from the top part of the pre-dehydration column (7) to temperature lower than 85°C, preferably to temperature lower than 80°C and even more preferably to temperature between 55°C and 75°C in a counter-current heat exchanger (9), c) further cooling of the gaseous mixture or gas-liquid mixture coming from the heat exchange (9) at step b) to temperature ranging from -20°C to 50°C, wherein the obtained condensate is separated into an aqueous phase (17) and an organic phase (18), d) removing the aqueous phase formed at step c), e) recycling all or a portion of the organic phase formed at step c) as reflux into the top part of the pre-dehydration column (7) used at step a), and removing a portion of the organic phase which is not used as reflux, f) wet cleaning of the gas containing vinyl acetate which did not condense at step b) in a gas wet cleaning column (21) through aqueous solution of acetic acid, g) separating vinyl acetate, h) heating the recycled gas coming from the gas wet cleaning column (21), possibly along with fresh ethylene and/or the recycled gas coming from a CO2 removal system (72) and/or blow-out gas in the counter-current heat exchanger (9), thereby reducing temperature of the gaseous mixture coming from the top part of the dehydration column (7), and i) feeding the recycled gas, possibly along with fresh ethylene and/or recycled gas coming from the CO2 removal system (72) and/or blow-out gas pre-heated at step h) into the rector (5) to obtain vinyl acetate.

EFFECT: method significantly reduces power and steam consumption during the entire process of producing vinyl acetate.

13 cl, 1 dwg, 1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method involves cyanoethylation of solid polymers of vinyl alcohol with liquid acrylonitrile in the presence of a sodium hydroxide catalyst at temperature (50-70)°C to obtain a solution of cyanoethyl ether, followed by precipitation of the polymer with a liquid precipitation agent. Cyanoethylation is carried out in excess acrylonitrile in molar ratio of acrylonitrile: vinyl alcohol polymer equal to (1.2-1.5):1, until an ether solution in acrylonitrile with viscosity (75-450) Pa·s is obtained. Said value of viscosity of the solution is maintained by adding acetone until complete dissolution of the polymer. The precipitation agent used is (0.4-1.3)% aqueous solution of a copolymer of vinyl alcohol with vinyl acetate containing (8-12) wt % acetate groups.

EFFECT: obtaining cyanoethyl ethers with good dielectric and vibration-absorbing properties.

3 cl, 14 ex, 2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing vinyl acetate, involving bringing starting material containing ethylene, acetic acid and an oxygen-containing gas into contact with a palladium- or gold-containing catalyst obtained on a calcined and modified carrier material to form vinyl acetate and at least one by-product, where the carrier material is modified with 1) niobium, magnesium, tantalum, yttrium, lanthanum, praseodymium or combinations thereof; or 2) titanium, zirconium or combinations thereof, where the carrier material is selected from zirconium dioxide, titanosilicate or zirconosilicate, and where the modified carrier material is calcined before adding catalyst components. The invention also relates to a method of producing a catalyst which is suitable for producing vinyl acetate, as well as a catalytic composition for catalysis of production of alkenylalkanoates, including carrier material with at least one modifier, palladium and gold, which react to form a catalyst, where the modified carrier material undergoes calcinations in a non-reducing atmosphere, and the modifier includes 1) niobium, magnesium, tantalum, yttrium, lanthanum, praseodymium or combinations thereof; or 2) titanium, zirconium or combination thereof, where the carrier material is selected from zirconium dioxide, titanosilicate or zirconosilicate.

EFFECT: obtaining catalysts which can be used to produce alkenylalkanoates in general and vinyl acetate in particular, and which are suitable for use in obtaining low ratio of EA/VA while maintaining or improving selectivity of producing CO2.

34 cl

FIELD: chemistry.

SUBSTANCE: invention relates to novel compounds of formula (I), where each R1, R2 and R3 is independently selected from a group comprising H, OH, F, Cl, Br, a methoxy group and an ethoxy group; or R1 and R2 together form -OCH2O-, and R3 is selected from a group comprising H, OH, methoxy group, ethoxy group and halogens; R4 denotes OH or o-acetoxybenzoyloxy nicotinoyloxy or iso-nicotinoyloxy; R5 denotes or , and at least one of R1, R2 and R3 is not hydrogen.

EFFECT: method for synthesis of a compound of formula (I) and use of the compound of formula (I) in preparing medicinal agents for preventing or treating cerebrovascular diseases.

17 cl, 14 tbl, 5 dwg, 12 ex

FIELD: chemistry.

SUBSTANCE: invention relates to method of oxidising alkane from C2 to C4 with the obtaining of corresponding alkene and carboxylic acids. The method includes the following stages: (a) contact in the oxidation reaction zone of the alkane, which contains molecular oxygen gas, not necessarily corresponding to the alkene and not necessarily water in the presence of at least one catalyst, effective with the oxidation of the alkane to the corresponding alkene and carboxylic acid, alkane, oxygen and water; (b) separation in the first separating agent at least part of the first stream of products in a gaseous stream, which includes alkene, alkane and oxygen, and a liquid stream, which includes carboxylic acid; (c) contact of the mentioned gaseous stream with the solution of a salt of metal, capable of selectively chemically absorbing alkene, with the formation of a liquid stream rich in chemically absorbed alkene; (d) isolation from the flow of the solution of salt of the metal. The invention also relates to combined methods of obtaining alkyl-carboxylate or alkenyl-carboxylate (for example vinyl acetate), moreover these methods include oxidising of alkane from C2 to C4 with the obtaining of corresponding alkene and carboxylic acid, isolation of alkene from the mixture of alkene, alkane and oxygen by absorption using the solution of the salt of metal and extraction of the stream rich in alkene from the solution of the salt from metal for using when obtaining alkyl-carboxylate and alkenyl-carboxylate.

EFFECT: improved method of oxidising alkane from C2 to C4 with the obtaining of corresponding alkene and carboxylic acids.

46 cl, 1 dwg

FIELD: organic chemistry, medicine, pharmacy.

SUBSTANCE: invention describes derivatives of hyperforin and adhyperforin of the formula (I): wherein R represents methyl or ethyl; R2 represents hydrogen atom, lithium or dicyclohexyl ammonium cation, direct or branched (C2-C5)-acyl residue wherein alternatively: (a) R1 represents 3-methylbut-1-yl, and oxo groups are in 1- and 10-positions; (b) R2 represents 3-methyl-2-butene-1-yl, and hydroxy groups are in 1- and 10-positions; (c) R1 represents 3-methylbut-1-yl, and hydroxy groups are in 1- and 10-positions. Compounds are used in preparing drugs for using in treatment of depression and Alzheimer's disease. Also, invention describes a pharmaceutical composition possessing anti-depressant effect.

EFFECT: valuable medicinal properties of substances and pharmaceutical composition.

8 cl, 2 tbl, 6 ex

FIELD: organic synthesis.

SUBSTANCE: invention relates to A-ring precursors of vitamin D having formula I:

in which A represents -CH2OH, -CH2-OCOR', -COR", or ethynyl; R represents hydrogen or C1-C6-alkyl; R1 hydrogen, C1-C6-alkyl, or (CH2)nOP; R2 hydrogen or -OP; R' is phenyl; R" hydrogen, hydroxyl, C1-C6-alkoxy; P hydrogen or group -Si(R3)3, wherein each R3 independently represents C1-C6-alkyl or phenyl; n = 0 or 1, provided that, when compound I has configuration 2S,3aS,4aS, A is formyl, hydroxymethyl, ethynyl, or methoxycarbonyl, and R and R2 are both hydrogen atoms, then R1 is not -OSi(R3)3.Preparation of compounds I comprises: (i) interaction of compounds having general formula 1:

,

in which A represents C1-C6-alkoxycarbonyl or C1-C3-alkylaminocarbonyl, with lipase in vinyl alkanoate or acid anhydride and (ii) conversion of resulting compound of formula 2: (2) or 2': (2'), where Z represents alkyl, preferably C1-C3-alkyl, into corresponding compound I via formation of a leaving group and cyclization caused by treatment with a base to form desired bicyclo[3.1.0]hexane, said conversion comprising: protection of hydroxy groups, hydrolysis of ester, inversion of 3- or 5-hydroxy group, and converting carboalkoxy or carbamoyl group into desired substituent A.

EFFECT: optimized synthesis conditions allowing more effective larger-scale preparation of precursors.

8 cl, 4 dwg, 45 ex

The invention relates to the discovery, before this time is appreciated that in the preparation of vinyl acetate using supported on a carrier catalyst containing palladium, gold and copper in which copper is essentially mixed with palladium or gold or both of these metals, the copper content in the catalyst during the lifetime of the catalyst tends essentially to decline, it is necessary previously to replace or regenerate the catalyst, the durability of which can approach or exceed two years

Multicore bisazide // 2067572
The invention relates to new compounds of General formula I

< / BR>
Z=-SO2-, -X--Y--X-

X=O,S

Y=0, S, SO2; CO.,

which can be used as light-sensitive components of photoresists

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of separating vinyl acetate from a gaseous mixture formed from reaction of ethylene with acetic acid and oxygen in gaseous phase over catalysts containing palladium or palladium compounds, involving: a) feeding said gaseous mixture, coming from reactor (5) for vinyl acetate, into a pre-dehydration column (7), b) cooling the gaseous mixture coming from the top part of the pre-dehydration column (7) to temperature lower than 85°C, preferably to temperature lower than 80°C and even more preferably to temperature between 55°C and 75°C in a counter-current heat exchanger (9), c) further cooling of the gaseous mixture or gas-liquid mixture coming from the heat exchange (9) at step b) to temperature ranging from -20°C to 50°C, wherein the obtained condensate is separated into an aqueous phase (17) and an organic phase (18), d) removing the aqueous phase formed at step c), e) recycling all or a portion of the organic phase formed at step c) as reflux into the top part of the pre-dehydration column (7) used at step a), and removing a portion of the organic phase which is not used as reflux, f) wet cleaning of the gas containing vinyl acetate which did not condense at step b) in a gas wet cleaning column (21) through aqueous solution of acetic acid, g) separating vinyl acetate, h) heating the recycled gas coming from the gas wet cleaning column (21), possibly along with fresh ethylene and/or the recycled gas coming from a CO2 removal system (72) and/or blow-out gas in the counter-current heat exchanger (9), thereby reducing temperature of the gaseous mixture coming from the top part of the dehydration column (7), and i) feeding the recycled gas, possibly along with fresh ethylene and/or recycled gas coming from the CO2 removal system (72) and/or blow-out gas pre-heated at step h) into the rector (5) to obtain vinyl acetate.

EFFECT: method significantly reduces power and steam consumption during the entire process of producing vinyl acetate.

13 cl, 1 dwg, 1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing catalysts and use thereof. Described is a method of producing a palladium-gold catalyst on a support, involving: (a) increasing mercury penetration volume of a titanium dioxide support to 0.31 ml/g or higher by mixing two titanium dioxides with different particle size or by mixing sintered titanium dioxide with non-sintered titanium dioxide or by mixing spray dried titanium dioxide with non-spray dried titanium dioxide, and saturating the support with a palladium salt, a gold salt and, optionally, an alkali metal or ammonium compound; and (b) reducing the saturated support to obtain a palladium-gold catalyst on a support. Described is a method of producing vinyl acetate, involving oxidation of ethylene in the presence of acetic acid and the palladium-gold catalyst described above.

EFFECT: described palladium-gold catalysts on supports have high activity during acetoxylation.

15 cl, 2 tbl, 7 ex

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