The method of obtaining light olefins from a stream of oxygen-containing feedstock
Usage: petrochemistry. Essence: the flow of oxygen-containing materials are in contact in the presence of methane diluent in the reaction zone containing the ELAPO catalyst under conditions selective for the conversion of at least part of the feedstock to light olefins, with the formation of the final reaction products, containing water, methane and light olefins. Preferably the water is removed and the remaining end of the reaction products is separated into a light fraction containing methane and a stream of light olefins. At least part of the light fraction return for mixing with the flow of the feedstock as a diluent. Effect: reduce the water content in the reaction zone. 5 C.p. f-crystals, 1 tab., 1 Il. The technical field Light olefins traditionally was obtained according to the method of using steam, or as a result of catalytic cracking. For reasons of limited availability and high cost of crude oil, the cost of obtaining light olefins from such crude oil currently is constantly increasing. Light olefins are used as feedstock for the production of numerous chemicals. As rising economies developing with Atisa.The search for alternative materials for producing light olefins led to the use of oxygen-containing raw materials, such as alcohols, and more specifically, to the use of methanol, ethanol and higher alcohols or their derivatives. These alcohols can be obtained by fermentation or from synthesis gas. Synthesis gas can be obtained from natural gas, liquid petroleum materials containing carbon, including coal, plastics after recycling, municipal waste water or any organic materials. Thus, the alcohol and alcohol derivatives can be a way to get olefins and other related hydrocarbons, which are not based on the use of oil.Molecular sieves, such as microporous crystalline zeolite and neoreality catalysts, in particular silicon-alumino-phosphate (KAF), a well-known fact that they facilitate the conversion of oxygen-containing molecules in the hydrocarbon mixture. These catalysts in the General case can be used in the presence of one or more diluents which may be present in the oxygen-containing feedstock in the amount of approximately from 1 to 99 molar percent, based on total number of moles of all the comp is up - but are not limited to only these helium, argon, nitrogen, carbon monoxide, carbon dioxide, hydrogen, water, paraffins, hydrocarbons (such as methane and similar compounds, aromatic compounds or mixtures thereof. US-A-4861938 and US-A-4677242 particularly emphasize the use of a diluent in combination with the feedstock to the reaction zone in order to maintain a sufficient selectivity of the catalyst to obtain a product in the form of light olefins, in particular ethylene. One such diluents that was used is steam.US-A-4543435 describes a way of turning oxygen-containing reagents containing methanol, dimethyl ether or similar compounds in the reactor for the conversion of oxygen-containing compounds in liquid hydrocarbons containing olefins With2-C4and a hydrocarbon, C5+. Olefins With2-C4subjected to compression for regeneration gas, enriched with ethylene. Gas enriched in ethylene, were sent to recycling to the reactor for the conversion of oxygen-containing compounds.WO-A-93/13013 relates to an improved method for producing a silicon-alumino-phosphate catalyst, which has greater stability against the e catalysts, used for conversion of methanol to olefins (MBO), lose an active ability to convert methanol to hydrocarbons primarily due to coking in the microporous structure of the crystal, i.e. fill the pores of the carbon-containing compounds with low volatility, which block the porous structure. Carbon compounds can be removed by conventional methods, such as burning in the air.EP A dated 19.05.1993 describes a method of obtaining light hydrocarbons by contacting oxygen-containing feedstock, in particular methanol, dimethyl ether with a catalyst in the form of ELAPO molecular sieves with the possible presence of methane diluent to improve the efficiency of the process.However, in the process, there is no stage transmission of the final reaction products containing methane and light olefins through the separation zone to obtain the fraction of light hydrocarbons, as well as directions on recycling at least part of this fraction into the reaction zone as a diluent.It was found that high concentrations of water in the reaction mixture, which usually requires dilution at the appropriate level have a negative environmenta is wow, water is a byproduct of the reaction, and its receipt increases the amount of water which is taken by the catalyst. Was carried out to find ways that would reduce the water content in the reaction mixture, while maintaining the appropriate level of dilution. However, this and other shortcomings of previous versions has been overcome in the present invention and offers a new and improved method for the conversion of oxygen-containing compounds in the hydrocarbon.Disclosure of the invention the present invention uses a combination of stages reduce the water content to reduce the amount of water at the critical point in the case of light olefins. It was found that the use of water or steam as a diluent in the way of conversion of oxygen-containing compounds have a deleterious effect on the metal-alumino-phosphate catalyst. In the method of the present invention, the water content in the conversion zone of oxygen-containing compounds significantly reduced, and can be obtained considerable savings in capital and operating costs. The replacement steam methane as a diluent and as a result produce methane gas as palacerestaurant metal-alumino-phosphate catalyst in the conversion zone of oxygen-containing compounds can be improved. Methane when it is used as a diluent, it has no negative effect on the catalyst activity. The presence of methane in the process reduces the requirements on processing for preparation of the external thread of the diluent to prevent exposure to the catalyst, potentially harmful impurities. Although methane has no thermal advantages and benefits in terms of separation, which has a thinner pair, using methane as the diluent reduces the water concentration in the reaction zone.The invention provides a method for obtaining light olefins which have from 2 to 4 carbon atoms in the molecule of oxygen-containing feedstock. Oxygen-containing feedstock includes at least one representative from the group consisting of alcohol, simple ester, aldehyde, ketone, and mixtures thereof. The method consists of passing the feedstock in the presence of a diluent methane through the reaction zone and thus the contacting of the feedstock with the catalyst in the form of ELAPO molecular sieves, selective regarding the conversion of at least part of the feedstock to light olefins, retrieval is conducted through the separation zone to obtain a light hydrocarbon fraction, containing methane, and the fraction of the product containing light olefins. At least part of the light hydrocarbon fraction is sent to recycling to the reaction zone as methane diluent.The preferred catalyst in the form of ELAPO molecular sieves for use in the reaction zone is a SAPO catalyst, such as SAPO-34 or SAPO-17, and obtain light olefins include ethylene, propylene and butylene.In another variant implementation of the invention relates to a method for producing light olefins containing ethylene and propylene, oxygen-containing feedstock containing at least or methanol, or dimethyl ether. The method consists of passing oxygen-containing feedstock through the reaction zone in the presence of a diluent containing methane. The reaction zone contains a catalyst SAPO, selective regarding the conversion of at least part of the oxygen-containing feedstock to light olefins with getting the flow of the final reaction products, containing water, methane and light olefins. At least part of the water is removed from the stream of the final reaction products, the result is dehydrated stream of the final reaction products. Dehydrated stream coneo the substance does not contain ethylene, and the stream of light olefins. At least part of the stream of light hydrocarbons is returned to the reaction zone as a diluent. The stream of light olefins is recovered. The stream of light olefins may be subjected to additional separation of essentially pure ethylene and propylene. Ethylene and propylene are preferably obtained with a purity of at least about 99.9 mol.%.In another variant implementation of the invention is a process for obtaining light olefins containing ethylene and propylene, from the feedstock. The feedstock contains at least or methanol, or dimethyl ether. The method includes the adulteration of initial raw material methane diluent to obtain a mixture of the feedstock. The mixture of the feedstock is passed through the heat exchanger raw materials/final products for heating a mixture of raw materials to receipt of the heated stream of raw materials. The heated flow of raw material is cooled to obtain a cooled flow of raw materials, and cooling the flow of raw material is directed into the reaction zone. The reaction zone contains a catalyst SAPO, selective regarding the conversion of at least part of the cooled flow of raw materials into light olefins. In the reaction zone produces a stream of final products of the reaction products, and some methane is returned for mixing with the raw material as a diluent.The accompanying diagram (see drawing) represents the sequence of operations of the process of the present invention that uses methane recycling.Detailed description In accordance with the method of the present invention oxygen-containing feedstock is converted under the action of the catalyst in the hydrocarbon-containing aliphatic components, such as but not limited to: methane, ethane, ethylene, propane, propylene, butylene, and limited amounts of other higher aliphatic components in the contact of oxygen-containing feedstock with a pre-selected catalyst. Oxygen-containing feedstock contains derivatives of hydrocarbons containing aliphatic groups, such as - but not limited to: alcohols, halogenated hydrocarbons, mercaptans, sulfides, amines, ethers and carbonyl compounds or their mixtures. Preferable would be if aliphatic group containing from 1 to 10 carbon atoms, and more preferably from 1 to 4 carbon atoms. Representatives of oxygen-containing compounds include, but are not limited tol is Captan, metilsulfate, methylamine, ethyl mercaptan, ethylchloride, formaldehyde, dimethylketone, acetic acid, n-bonds alkylamines, n-alkylhalogenide and n-alkylsulfate, which have alkyl groups of from 1 to 10 carbon atoms, or a mixture thereof. In the preferred implementation as oxygen-containing feedstock is methanol. In the preferred implementation as oxygen-containing feedstock is used dimethyl ether. The term "oxygen-containing feedstock" as used in the present invention and described herein, refers to organic material used as feedstock. Full loading of the feedstock in the reaction zone may contain additional compounds such as thinners.Requires the use of a diluent to maintain the selectivity of the catalyst to obtain light olefins, particularly ethylene and propylene. The use of steam as a diluent provides certain advantages in terms of equipment cost and thermal efficiency. The phase transition between vapor and liquid water can profitably be used to transfer heat between the outcome is Ansatie water in the separation of water from hydrocarbons. Were described relationship of 1 mole of feedstock to 4 moles of water. It was found that these high levels of water in combination with water produced as a by-product of the reaction, lead to rapid loss of catalyst, its activity. Tests on laboratory and pilot plant showed that the activity of the catalyst is greatly reduced due to the actions of combinations of levels of water - diluent - steam and water - a by-product. The use of methane, a by-product of the main reaction, greatly reduces the amount of water in the reaction zone. Preferred is the ratio of moles of the feedstock to the moles of methane diluent in the range from 1:1 to 1:5. To illustrate the main differences in thermal coefficient between the block diagram using a thinner pair and block diagram using diluent methane, we can say that the scheme with the diluent is steam heater requires a feedstock, which is installed after the heat exchanger raw materials/final products, in order to raise the temperature of the combined feedstock to the reaction temperature. In the case of the combined feedstock may be carried out by direct cooling of the combined feedstock after the heat exchanger raw materials/final products or in the use of the fridge in the flow path of the final reaction products to reduce the temperature of the final reaction products before heat exchanger raw materials/final products. Cooling of the feedstock reactor can be carried out by the formation of steam for removing heat process. Preferably, at least part of the heat process would be removed from the combined feedstock before it enters the reactor. Stage of cooling is also used as a control of the refrigerator in order to set the temperature of the cooled end of the reaction products at a value that would allow the cooled end of the reaction products to pass through a water scrubber to remove small particles of catalyst. In that case, if the cooled end products of the reaction will have an excessively high temperature, stage water scrubber will not be effective, and the fine particles of catalyst will reach the compressor end of the reaction products.The concentration of water in the reaction zone can be reduced additionally in the use of raw materials containing dimethyl ether (DME), not methanol. The ratio of methyl groups to the oxygen in the LEED two times greater than that of methanol, which would entail reducing by half the number of the received water for the same amount of received light olefins.The% is Tekirova would be in the vapor phase in the reaction zone with a catalyst in the form of ELAPO molecular sieves under conditions effective to obtain olefinic hydrocarbons, i.e. the effective temperature, pressure, average hourly feed rate of raw material (JCSS) and an effective amount of methane diluent, correlated to obtain olefinic hydrocarbons. The process takes place within a certain period of time sufficient to obtain the desired product in the form of light olefins. In General, the time required to obtain the desired product may vary from seconds to several hours. It will be appreciated that the residence time will be determined to a significant extent by the reaction temperature selected ELAPO molecular sieves, JCSS, the phase (liquid or gaseous) and selected characteristics of the development process. Consumption of raw materials has an impact on obtaining olefins. The increase in consumption of raw materials (expressed as JCSS) increases the yield of olefin production compared with the output of the receiving paraffins. However, the increase in the yield of olefin production compared with the output of the receiving paraffins offset by reduced conversion of oxygen-containing compounds in the hydrocarbon.The process is effectively carried out in a wide range davlenie) education products light olefins is going to happen, although the optimum amount of product will not necessarily happen at all pressure levels. The preferred pressure is a pressure of between 1 kPa (0.01 atmosphere) and 10.1 MPa (100 ATM). The pressure for the process, to which reference is made in this document represents the pressure solely inert diluent, if present, is present and is associated with a partial pressure of the feedstock, since the quantity of diluent refers to the amount of oxygen-containing compounds and/or mixtures thereof. On the lower and upper edges of the pressure range and outside the range of the selectivity degree of conversion and/or of the speed of olefinic products may not have their optimal values, although a light olefin, such as ethylene, can still be formed.The temperature, which can be used in the process may vary within a wide range depending, at least in part on the selected catalyst in the form of molecular sieves. In General the process can be conducted at an effective temperature in the range between 200oC (392oF) and 700oC (1292oF). On the bottom edge of the temperature range and the TC is noticeably slow. On the top edge of the temperature range and outside the range of the process may not lead to the formation of optimum quantities of produce light olefins.The choice of a particular catalyst for use in the conversion process, where the aliphatic geterosoedineniya turn into light olefins, may be based on the use of any ELAPO molecular sieves, but preferably will be, if the molecular sieve would have relatively small pores. Preferred molecular sieves with small pores are defined as molecular sieves having pores of at least part of the pores, preferably greater part of which have an average effective diameter, characterized by the ability of adsorption (in accordance with the measurement standard method gravimetric adsorption Mac-Bane-Bakr using the specified adsorbate molecules) in such a way that would have occurred adsorption of oxygen (average kinetic diameter of approximately 0,346 nm) and negligibly small adsorption of isobutane (average kinetic diameter of about 0.5 nm). More preferably it would be an average effective diameter to characterize the adsorption of xenon (average kinetic diameter of about 0.4 nm) and negligible aelina of 0.43 nm) and negligible adsorption of isobutane. Slight adsorption of a given adsorbate represents the adsorption of less than three percent in parts by weight from the molecular sieves, and the adsorption of the adsorbate represents the adsorption of more than three percent in parts by weight of the adsorbate on the basis of weight of molecular sieve in the catalyst. Some of the molecular sieves, usable as catalysts used in the present invention have pores with an average effective diameter of less than 5 angstroms. The average effective pore diameter of the preferred molecular sieves is determined in the measurements described in the work of D. W. Beck, ZEOLITE MOLECULAR SIEVES by John Wiley & Sons, New York (1974), this document follows as reference. The term "effective diameter" is used to denote that a random pores have irregular shapes, such as elliptical, and thus the size of the pores are characterized by the size of molecules that can be adsorbed, and not the actual size. Preferably it would be, if the catalysts with small pores had largely homogeneous pore structure, for example, largely pores with a uniform size and a uniform shape. A suitable catalyst may have materials were ELAPO) include molecular sieves, who have the proper effective pore size and which describes an empirical chemical composition not given the hydrated water, expressed by the empirical formula: (ELxAlyPz)O2where EL is an element selected from the group consisting of silicon, magnesium, zinc, iron, cobalt, Nickel, manganese, chromium and mixtures thereof, x represents the mole fraction of EL and is equal at least to 0.005, y is a mole fraction A1 and equals, at least 0.01, z represents the mole fraction of P and is equal to at least about 0.001, and x+y+z= l. When EL is a mixture of elements, x represents the full amount of the mixture of elements. The preferred elements (EL) are silicon, magnesium and cobalt, while silicon is the most preferred.The preparation of various ELAPO well-known experts in their respective fields and can be found in US-A-5191141(ELAPO); US-A-4554143(FeAPO); US-A-4440871(SA-PO); US-A-US-A-4853197 (MAPO, MnAPO, ZnAPO, CoAPO); US-A-4793984(CAPO), US-A-4752651 and US-A-4310440, all these links are provided as reference material. In the General case, ELAPO molecular sieves synthesized by hydrothermal crystallization from a reaction mixture that contains reaction the s metals, such as salt, chlorides or nitrates. When EL is a silicon, a preferred source is small colloidal particles of silica or precipitated silica. Preferred reactive sources of aluminum and phosphorus are the aluminum oxide in pseudoboehmite and phosphoric acid. Preferred matrix agents are the amines and Quaternary ammonium compounds. Particularly preferred matrix material is a hydroxide of tetraethylammonium (TEON).The reaction mixture is placed in a sealed pressure vessel, with the possibility of lining, though not necessarily, from an inert plastic material such as polytetrafluoroethylene and heated, preferably under autogenous pressure to a temperature in the range between 50 and 250oWith, and preferably in the range between 100 and 200oWith in a period of time sufficient to obtain crystals ELAPO molecular sieves. Typically, the time ranges from 2 hours to 30 days, and preferably in the range from 4 hours to 20 days. The desired product is recovered when using the convenient method, such as centrifugation or filtration.It is known that the particle size of Maurice examples) and in the use of TEON as matrix substance. Preferred to ELAPO molecular sieves would consist of particles, at least 50% of which have a particle size less than 1.0 μm and not more than 10% of the particles ELAPO would have a particle size in excess of 2.0 μm.ELAPO, which were synthesized using the process described above, will typically contain some amount of organic matrix substances in your pores. In order ELAPO would be active catalysts, the matrix material should be removed from the pores by heating the powder ELAPO in the atmosphere containing oxygen, at temperatures in the range from 200 to 700oWith up until the matrix substance is removed, usually within a few hours.Preferred implementations of the present invention is one in which the content of metal (EL) ranges from 0.005 to 0.05 mole fraction. In that case, if the EL is more than one item, the total concentration of all metals must be in the range of 0.005 to 0.05 mole fraction. Particularly preferred implementation is one in which EL is silicon (typically, the catalyst is called SAPO). SAPO, which can be used in the present invention are any of those kotomi specific crystallographic structure, described in the patent '871. The structure of SAPO-34 is characterized by the fact that it adsorbs xenon, but not adsorb isobutane, which gives evidence of the fact that it has pore openings of approximatelyAnother SAPO, SAPO -17, as given in Examples 25 and 26 of the patent '871, is also preferred. The structure of SAPO-17 characterized by the fact that it adsorbs oxygen, hexane and water, but not adsorb isobutane, which gives evidence of the fact that it has a pore openings larger thanbut less thanPreferred ELAPO molecular sieves can be, and preferably if it were, embedded in the particles of the solid catalyst, in which the molecular sieves are present in amounts effective for promotion of the desired conversion of derivatives of hydrocarbons. In one aspect, the particles of the solid catalyst contains a catalytically effective amount ELAPO molecular sieves and at least one matrix material, preferably selected from the group consisting of binders, materials, fillers and mixtures thereof, to create the desired property or properties, for example, the desired dilution of the catalyst is often to some extent inherently porous and may or may not be an effective means for promotion of the desired conversion of derivatives of hydrocarbons. Matrix materials can promote the conversion of the flow of raw materials and often provide a lower selectivity for the desired product or products as the catalyst. The filler materials or binders include, for example, synthetic or naturally occurring substances such as metal oxides, clays, silicon oxides, aluminium oxides, silicon oxides of aluminum, silicon oxides of magnesium, oxides of silicon, zirconium, oxides of silicon, thorium oxides of silicon, beryllium, silicon oxides of titanium, oxides of silicon-aluminum-thorium oxides of silicon-aluminum-zirconium aluminophosphate, mixtures thereof and similar substances.In that case, if the matrix materials, such as binder and/or filler material included in the composition of the catalyst, then neoreality molecular sieve preferably approximately from 1 to 99%, and more preferably from about 5 to 90%, and even more preferably from about 10 to 80% by weight of the total composition. Preparation of solid particles containing the catalyst and a matrix material, the conventional and well known to experts in the relevant field and does not require a detailed discussion in this doylei on the drawing, which illustrates various aspects of the method.Referring to the drawing, oxygen-containing feedstock containing at least one representative from the group consisting of alcohol, simple ester, aldehyde, ketone, and mixtures thereof on the line 10 is mixed with the methane diluent 52, and this mixture is passed by line 12 to the first heat exchanger 100 for preliminary heating of the mixture of the feedstock/solvent in the transverse heat transfer and to obtain a pre-heated mixture stream of the feedstock 14. Pre-heated mixture stream of the feedstock 14 is passed through the second heat exchanger 101, in which the pre-heated mixture stream of the feedstock is involved in heat exchange with a stream of the final reaction products 20 for receiving the heated flow of the feedstock 16 and the cooled stream of the final reaction products 22. The heated flow of the feedstock 16 is passed through the fridge reactor 102 for cooling the flow of feedstock to the reactor 18 to reaction conditions comprising a reaction temperature in the range from 350 to 525oC and a pressure in the range of 101,3 to 506,5 kPa (1 to 5 atmospheres). The mixture of the flow of raw materials reacto least part of the flow of feedstock to the reactor 18 in olefins With2-C4to obtain flow of the final reaction products 20. Thread the end of the reaction product 20 is cooled in the heat exchanger 112, and the resulting cooled stream 20, which contains methane, water and light olefins, is directed to the second heat exchanger 101 for receiving the cooled stream of the final reaction products 22. In alternative implementations, the flow of the final reaction products 20 may be passed through a steam boiler 112 for cooling the final reaction products in the selection part of the heat process and the final products of the reaction after the first cooling line 20'. Final products of the reactions after the first cooling 20' is passed through the second heat exchanger 101, which cools the final reaction products, and the result is a chilled stream of the final reaction products 22.The cooled stream of the final reaction products 22 passes through an area of water scrubber 104, in which the cooled stream of the final reaction products 22 in contact with wash water stream 24 to remove all small particles of catalyst from the cooled stream of final products 22 with their paretooptimal until further compression of the cooled stream of the final reaction products when preparing for separation of the individual components. The water stream 28 is selected for further processing (not shown). Stream after passing through a water scrubber 26 is withdrawn from zone water scrubber 104 and then passes through the compressor end of the reaction products 105 to increase the pressure of the flow after passing through a water scrubber 26 and to receive the compressed stream of final products 30. Compressed stream of the final reaction products 30 undergoes transverse heat exchange with the mixture of the feedstock/solvent 12 in the first heat exchanger 100 for pre-heating of the mixture 12 and the first cooling the compressed stream of final products 30 for receiving the compressed stream of final products after the first cooling 32. This allows you to recover low-grade heat in the heat exchanger 100. The compressed stream of final products after the first cooling 32 is further cooled in the condenser 106 to condense at least part of the water in the stream end products 32 and to receive the stream of the final products after condensation 34. The flow of final products after condensation 34 is passed through a zone of rapid distillation 107 to separate the flow of final products after condensation 34 to the flow of hydrocarbons 38 and the second water stream 36.Second body light olefins and methane, passed through the compressor 108 to receive the compressed stream of hydrocarbons 40. Preferable would be if a compressed stream of hydrocarbons 40 would have a pressure in the range from 2000 kPa to 4000 kPa, and more preferably, if the flow pressure of 40 would be in the pressure range from 3000 to 4000 kPa. Compressed stream of hydrocarbons 40 is passed through the zone to remove water 109, which contains a desiccant to reduce the water content in the flow of hydrocarbons to less than about 1 millionth volume fraction, and to obtain a dry stream of hydrocarbons 42. Dry stream of hydrocarbons 42 is passed through the zone for the removal of acid gas 110, which contains an adsorbent selective for the removal of acidic gases, such as CO2from dry stream of hydrocarbons 42, to receive the stream with a reduced content of acid gas 44. Stream with a reduced content of acid gas 44 is passed into a column for distillation of methane 111, where methane is recovered at the top of the thread 46, and light olefins containing From2-C4that is regenerated in the lower stream 48. Preferable would be if the upper stream 46, which contains the fraction of light hydrocarbons, containing from about 75 to 99.9% methane; therefore, the current should preferably be less than 5 mol %, and more preferable if the content of ethylene in the upper stream would be less than 1%. The bottom stream 48 is passed through the installation of additional fractionation (not shown) for regeneration of essentially pure ethylene and propylene with a purity greater than about 99%, and more preferably a purity in excess of 99.9%. At least part of the upper stream 46 and 52 is returned to the mixing to the original raw material 10 as the diluent, and the upper part of the thread 46 is withdrawn in line 50, typically for use as a fuel stream. Preferred is a molar ratio of diluent in the mixture of the feedstock in the range from 1.8 to 2.3.Example I.There was a series of cycles to determine the effect of accelerated hydrothermal treatment of the catalyst of the present invention. A sample of catalyst SAPO-34 size 40 grams was located in a tubular reactor made of Monel metal with an inner diameter of 2.2 cm (7/8 inch), thus creating in him a substrate of the catalyst. The reactor was equipped ricami of the sintered stainless steel in the lower part of the substrate of the catalyst and at the exit of the reactor above the catalyst substrate. Air blowing from nebylo increased to 793 kPa(100 psig), a temperature was increased from room temperature to 460oC. when the temperature stabilized, the air flow was replaced water with a flow rate of 90 g/HR steam Treatment of the catalyst in such a way that continued for a number of specific times in the range from 5 to 200 hours. At the end of this time the water flow was replaced by an air stream, and the reactor was cooled to approximately 100oWith, and it was stravovaci pressure.Part of the fresh and hydrothermally treated catalyst, about 10 grams each, were separately placed in a reactor made of stainless steel with a lining made of porcelain with an inner diameter of 2.2 cm (7/8 inch). A sample of the catalyst was pre-treated using a stream of nitrogen at 435oC for about 1 hour for drying the catalyst and increasing the substrate temperature of the catalyst. The nitrogen was replaced with a mixture of methanol and water containing about 80 wt.% methanol at a flow rate of the feedstock approximately equal to 12.5 grams per hour at a pressure approximately equal to 138 kPa (5 psig). Time, or time in the stream, from the beginning of the reaction up to the point at which the conversion of methanol (IDMA) reached 99%, were recorded. Experience, measuring the composition of the final reaction products. The results of this accelerated hydrothermal treatment are shown in Table 1. Hydrothermal treatment of the catalyst SAPO-34 has detected a progressive loss of catalytic activity in the range from approximately 4.8 hours for the fresh catalyst to 3.5 h for a sample of the catalyst after 100 h steam treatment.Tests hydrothermal treatment of SAPO-34, watch the stream by conversion of >99%: Fresh catalyst - 4,8 5 hours steam treatment is 4.5
25 hours steam treatment is 4.3
100 hours steam treatment - 3,5
Example II.Continued assessment of the impact of accelerated hydrothermal treatment on the conversion for samples of fresh catalyst and the catalyst after 100 hours of steaming in example 1. The conversion was recorded as a function of time from the introduction of the feedstock. Effect of long-term hydrothermal treatment of the catalyst are presented in the table. For the fresh catalyst and the catalyst after 100 hours of processing, the conversion decreased to approximately 20% after days of flow in the range from 5 to 6.3 hours, the catalyst is treated with steam, showed a more pronounced decrease in conversion at early times in the stream compared to stalinator ferry entail the permanent loss of catalytic activity, this steam treatment was evaluated at levels far exceeding the levels of water, which usually deal when using methane as a diluent. The use of methane diluent dramatically reduces the effective speed of hydrothermal processing of this catalyst is SAPO-34.
1. The method of obtaining light olefins having from 2 to 4 carbon atoms in the molecule of oxygen-containing feedstock selected from the group consisting of alcohol, simple ester, aldehyde, ketone, and mixtures thereof by passing an oxygen-containing raw material through a reaction zone where it is in contact in the presence of methane diluent with a catalyst in the form of ELAPO molecular sieves under conditions selective for the conversion of at least part of the feedstock in these light olefins and water with the formation of the final reaction products containing methane and these olefins, characterized in that the removed at least part of the water from the final reaction products pass these end products of the reaction through the separation zone to obtain a light hydrocarbon fraction containing methane, and the fraction of the product, soteriou zone as specified diluent.2. The method according to p. 1, characterized in that the said ELAPO molecular sieves have an empirical formula, not taking into account the hydrated water
where EL is an element selected from the group consisting of silicon, magnesium, zinc, iron, cobalt, Nickel, manganese, chromium and mixtures thereof;
x represents the mole fraction of EL and equal, at least 0,005;
y represents a molar fraction A1 and equal, at least 0.01;
z represents the mole fraction of P and is equal to, at least 0.01,
and x + y + z = 1.3. The method according to p. 1 or 2, characterized in that the catalyst in the form of ELAPO molecular sieves are selected from the group consisting of SAPO-34, SAPO-17, and mixtures thereof.4. The method according to p. 1 or 2, characterized in that the fraction of light hydrocarbons contain from about 75 to 99.9 mol. % methane.5. The method according to p. 1 or 2, characterized in that the oxygen-containing feedstock contains at least one of methanol or dimethyl ether.6. The method according to p. 1 or 2, characterized in that the ratio of feedstock to methane diluent, expressed in moles, leaves from 1 : 1 to 1 : 5.
the cerium oxide - 3,0
the oxide of lanthanum - 65,0
the oxide of neodymium - 21,0
the oxide of praseodymium - Rest
moreover, each value of silicon oxide to aluminum oxide in the crystalline aluminosilicate type pentasil corresponds to a certain range of values of the content of sodium oxide, in the following ratio of catalyst components, wt.%:
Crystalline aluminosilicate type pentasil - 63,0-70,0
The sodium oxide - 0,12-0,30
Zinc oxide - 0,5-3,0
The oxide of rare earth elements in the specified composition - 0,1-3,0
Binding - Rest
This catalyst has a higher activity
FIELD: regeneration of heat and extraction of impurities.
SUBSTANCE: the invention is pertaining to the method of regeneration of heat and extraction of impurities from the area of the heat-producing reaction in the fluidized flow, conducted for conversion into light olefins of oxygenates present in the flow of the oxygenate (oxygen-containing) raw. raw. The offered method includes the new system of a two-stage quick chilling intended for extraction at the first stage of water from the outgoing from the reactor flow and regeneration of heat of this flow for the purpose, at least, of the partial evaporation of the raw flow due to indirect heat-exchange between the oxygenated raw and the flow of the upper product of the first stage or the flow of recirculation of the first stage. The flow of purification being withdrawn from the first stage, contains the large share of impurities and the high-boiling oxygenates. In the second stage besides conduct extraction of water from the products flow containing light olefins, and produce the flow of the purified water, which requires only the minimum evaporation of the water for production of the water flow of the high degree purification. The method allows to concentrate the impurities in a rather small flow and ensures the significant saving of power and money resources at production of a flow of the vaporous raw guided into the area of realization of the heat-exchange reaction in the fluidized flow.
EFFECT: the invention ensures concentration of the impurities in a rather small flow and the significant saving of power and money at production of the flow of the vaporous raw directed into the area of realization of the heat-exchange reaction in the fluidized flow.
19 cl, 3 tbl, 4 dwg, 5 ex