Preparation method and application of an olefin stream oxygenate purification adsorbent

Abstract

The present application relates to the technical field of adsorbent preparation, in particular to a preparation method and application of an adsorbent for purifying oxygen-containing compounds in an olefin stream. The preparation method comprises the following steps: (1) first, adding alumina to an alkali metal solution to modify it, filtering and drying the modified alumina to obtain modified alumina balls; (2) adding molecular sieves to a solution containing transition metal ions to perform ion exchange modification, filtering, washing, and drying the modified molecular sieves; (3) adding the modified alumina balls into a sugar bowl, then adding the obtained modified molecular sieves, adding a binder and water, and performing ball forming; (4) drying and activating the formed adsorbent to obtain a finished product. Compared with existing adsorbents, the adsorbent has the advantages of simple preparation, high adsorption precision, low adsorption heat, simple regeneration operation, low energy consumption, and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adsorbent preparation, in particular to a preparation method and application of an adsorbent for purifying oxygen-containing compounds in an olefin stream. BACKGROUND

[0002] Olefins are important basic materials for the development of the national economy, and the main sources of olefins such as ethylene and propylene are naphtha cracking, alkane dehydrogenation and coal chemical methanol conversion (MTO, MTP) etc. Due to the differences in raw materials and production processes, the impurity contents of the prepared olefins are different, but there are always trace amounts of oxygen-containing compounds, especially the olefins prepared by coal chemical methanol conversion, which have more types and higher contents of oxygen-containing compounds. These impurities must be purified before they can meet the requirements of polymerization-grade olefins. With the continuous high-endization and functionalization of polymerization materials, and the continuous innovation of polymerization catalysts, higher requirements are put forward for the purity of olefins.

[0003] The main method for removing oxygenates from the mainstream is adsorption, and the key of adsorption method is the selection of adsorbent. Patent EP0229994 uses crystalline molecular sieve adsorbent to remove dimethyl ether in C3-C5 olefins, patent US6111162 reports the use of silica gel as adsorbent to remove oxygenates from hydrocarbon gas stream, and patent US4371718 uses alumina as adsorbent to remove methanol from butene raw material. CN102744035B uses ion exchange molecular sieve and then adds a binder to make a solid adsorbent for removing oxygenates from olefins, solving the problems of low adsorption accuracy, low adsorption capacity and high adsorption heat. CN103495378B uses kaolin as inert matrix, alumina or inorganic silica-aluminum mixture as binder, and sub-micron molecular sieve as active component to prepare microspherical adsorbent with certain particle size distribution for removing oxygenate components in olefin stream, each of which is less than 1 ppm (wt%). CN104549140B uses ion exchange technology to modify molecular sieve by introducing at least one metal cation in Group IIA or Group II A and adding a small amount of other additives, and makes granular adsorbent for removing oxygenates in various olefin raw materials in adsorption purification industrial production, which has the advantages of large adsorption capacity and good regeneration stability. CN105585405A uses SAPO-34 molecular sieve waste catalyst alone or mixed with other adsorbents to remove methanol in olefins, which makes waste reuse. CN109482143A introduces an adsorbent prepared by molecular sieve, alumina, active modifier, etc. by rapid sphere forming for deep removal of various oxygenate impurities in low-carbon olefins. CN102921373B introduces a preparation method of adsorbent for removing impurities in olefin stream, in which zeolite molecular sieve is synthesized on active alumina carrier, and metal oxides are loaded on the adsorbent by ion exchange. The adsorbent is used for removing carbon dioxide, hydrogen sulfide, carbonyl sulfur, methanol, mercaptan, ammonia in ethylene or propylene olefin stream. CN108246249A introduces an adsorbent for removing polar molecules in olefins made of molecular sieve, metal oxide, rare earth oxide and active alumina. CN103523796B introduces a synthesis method of sub-micron X-type molecular sieve and its application. The sub-micron X-type molecular sieve has small crystal grains, which greatly shortens the synthesis time and reduces the production cost. The molecular sieve is applied to hydrocarbon separation and adsorption, especially for olefin purification in methanol-to-olefins (MTO) process, which has the technical characteristics of deep removal of oxygenate impurities. CN105289477B introduces an adsorbent for removing impurities in coal chemical olefin stream and its application, which can reduce the content of oxygenates in olefin stream to ppb level (wt%).CN106512926B introduces a renewable microporous-mesoporous composite adsorbent and its preparation method and application. The renewable microporous-mesoporous composite material is formed into an adsorbent with a certain particle size distribution by tabletting, extrusion or rolling. It has good effect on removing alcohol ethers in olefin stream. CN108126664A provides a modified molecular sieve for purifying olefins and a method for removing oxygen-containing impurities in olefins using the same. The modified molecular sieve is modified by using a metal organic compound. The olefin stream containing water, ether aldehyde, copper, alcohol and other oxygen-containing impurities is passed through the bed of molecular sieve modified by the metal organic compound to obtain a high-purity olefin stream.

[0004] Currently, the main problems in the adsorption removal of oxygen-containing compounds in olefins are large adsorption heat, insufficient adsorption capacity, high regeneration temperature, etc. The above documents generally use molecular sieve hybrid alumina or modified molecular sieve to increase adsorption capacity, reduce adsorption heat, improve purification precision and reduce regeneration energy consumption. All of them are realized by changing the pore of the adsorbent from a micro perspective, and none of them change the structure of the adsorbent from a macro perspective. From the adsorption principle, the adsorption process is divided into diffusion stage, adsorption stage and desorption stage. Diffusion is the first stage, which is the process of moving the adsorbed molecules from the fluid to the surface of the adsorbent. Adsorption is the second stage of the adsorption process, which is the process of adsorbing the adsorbed molecules by the adsorbent. Desorption is the third stage of the adsorption process, in which the adsorbed substances are desorbed from the adsorbent. When the amount of adsorbed molecules is equivalent to that of desorbed molecules, the adsorption reaches equilibrium. At this time, the adsorbed molecules will penetrate the adsorbent, and the adsorbent needs to be regenerated for the next adsorption. Regeneration and adsorption are a reverse process. The stronger the adsorption of the molecules, the longer the energy consumption and time required for regeneration. From a macro perspective, adsorbed substances on the surface or in shallow pores are easy to regenerate, and the heat of adsorption is easy to remove. Adsorbed substances in deep pores and inside the adsorbent are not easy to regenerate, and the heat released by adsorption is not easy to diffuse, which can easily cause a sharp temperature rise. SUMMARY

[0005] The purpose of the present application is to overcome the defects of the prior art, such as difficult diffusion of adsorption heat, high regeneration energy consumption, high regeneration temperature, etc. A preparation method of an adsorbent for purifying oxygen-containing compounds in an olefin stream is provided. The prepared adsorbent can be used for deep removal of oxygen-containing compounds in an olefin stream, and has the advantages of high adsorption precision, low regeneration temperature, small adsorption heat, easy preparation, etc.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0007] A preparation method of an adsorbent for purifying oxygen-containing compounds in an olefin stream, comprising the following steps:

[0008] (1) First, add alumina to an alkali metal solution for modification. After modification, filter and dry to obtain modified alumina balls;

[0009] (2) ion exchange modification by adding molecular sieve into the solution containing transition metal ions, and then filtering, washing and drying the modified molecular sieve;

[0010] (3) adding the modified alumina balls prepared in step (1) into a sugar bowl, then adding the modified molecular sieve prepared in step (2), and then adding a binder and water to perform ball forming by rolling;

[0011] (4) drying and activating the adsorbent formed in step (3) to obtain the finished adsorbent.

[0012] As a preferred embodiment in the present application, the alumina in step (1) is active alumina with a specific surface area of >200 m 2 / g and a particle size of 0.5-2 mm, which can be selected according to requirements.

[0013] As a preferred embodiment in the present application, the alkali metal solution in step (1) is a solution formed by dissolving any one or more of the salts or alkali of sodium, potassium and calcium in water; the alkali metal salt or alkali is one or more of potassium chloride, sodium chloride, calcium chloride, sodium nitrate, potassium nitrate, calcium nitrate, sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate. The weight ratio of the alkali metal solution to the active alumina balls is 1-2, and the mass fraction of the alkali metal contained in the alkali metal solution is 0.5%-10%. The modified alumina balls are filtered and dried, the drying temperature is 80-150°C, and the drying time is 6-12 h, and the modified active alumina balls are prepared after drying.

[0014] As a preferred embodiment in the present application, the molecular sieve in step (2) is one or more of 13X molecular sieve, NaY molecular sieve and USY molecular sieve; the transition metal ion is Ni 2+ , which can be one or more of nickel nitrate, nickel chloride and nickel sulfate, and the Ni 2+ concentration in the solution is 0.3-2 mol / L, the liquid-solid ratio of the salt solution to the molecular sieve is 1.5-10, the exchange temperature is 30-80°C, and the exchange time is 3-12 h.

[0015] As a preferred embodiment in the present application, the binder in step (3) is one or more of pseudo-boehmite, active clay, kaolin and attapulgite.

[0016] As a preferred embodiment in the present application, when the adsorbent is formed in step (3), the modified alumina accounts for 15-45% by mass percentage, the modified molecular sieve accounts for 50-80% by mass percentage, and the binder accounts for 2-10% by mass percentage, and the total mass percentage is 100%.

[0017] As a preferred embodiment of this application, the drying temperature in step (4) is 80~

[0018] Dry at 150℃ for 4–12 hours.

[0019] As a preferred embodiment of this application, the activation in step (4) is carried out by calcination, with a calcination temperature of 350-500°C and a calcination time of 4-12 hours.

[0020] Another objective of this invention is to protect the oxygen-containing compound purification adsorbent obtained by combining the above methods or steps in an olefin stream.

[0021] Another objective of this invention is to protect the application of an adsorbent for purifying oxygen-containing compounds in olefin streams. This adsorbent is used to remove oxygen-containing compounds from olefin streams. The specific application method is as follows: the adsorbent is placed in a fixed-bed adsorber, adsorbed under low temperature and high pressure, and desorbed under high temperature and low pressure. The oxygen-containing compounds are methanol, propionaldehyde, and dimethyl ether, with a volume concentration of 2 to 1000 ppm. After the oxygen-containing compounds are removed, their concentration is <1 ppm, which meets the requirements for polymerization-grade olefins.

[0022] The adsorbent contacts an olefin stream containing oxide compounds, and under high pressure and low temperature conditions, the oxygen-containing compounds are adsorbed and removed. After removal, the olefin purity meets the requirements for polymerization grade. When adsorption is saturated, it is regenerated using an inert gas under high temperature and low pressure. The regenerated adsorbent can then be used for the next adsorption cycle. Preferably, the olefin stream is C4 or lower olefins, and the preferred oxygen-containing compounds are methanol, dimethyl ether, and propionaldehyde. The concentration of the oxygen-containing compounds is 10–1000 ppm, and the gas hourly space velocity (GHSV) for adsorption is 500–3000 h⁻¹. -1 The liquid space velocity is between 0.5 and 6 h⁻¹. -1 The regeneration temperature is 180–250℃, and the regeneration space velocity is 500–2000 h⁻¹. -1 .

[0023] Compared with existing technologies, the beneficial effects of the present invention are as follows:

[0024] (i) High purification precision

[0025] Molecular sieves modified with transition metal nickel ions were used, utilizing Ni... 2+ Partial Na from the molecular sieve + Swap it out, because of a N i 2+ Two Na can be exchanged + This alters the active center of the cation, reducing the number of atoms, and simultaneously due to Ni 2+ Radius smaller than Na +The radius is modified, the pore and the pore volume are increased, and therefore the adsorption capacity and precision of the adsorbent are improved.

[0026] (ii) The adsorbent is not easy to fly temperature, the regeneration temperature is low, and the energy consumption is low

[0027] The active alumina seed ball is modified by alkali metal, and the transition metal Ni 2+ The modified molecular sieve powder is wrapped outside the active alumina ball, so that the molecular sieve with large adsorption capacity is in the outer layer, and the alumina with small adsorption capacity is in the inner layer. The released heat during adsorption is not easy to accumulate and is easily carried out with the airflow, and the adsorption is not easy to fly temperature. The active alumina is modified by alkali metal, which changes the acidity and alkalinity of the alumina, further reduces the adsorption capacity of the olefin, and reduces the adsorption heat. At the same time, a large amount of adsorbed impurities are on the surface of the adsorbent, so that the desorption during regeneration is relatively easy, and the adsorbent can be regenerated at a relatively low temperature, reducing the energy consumption of desorption. Regeneration at a lower temperature also reduces the carbon deposition of the molecular sieve, prolonging the service life.

[0028] (iii) The adsorbent is simple to prepare and has high strength

[0029] The adsorbent is prepared by rolling ball forming. The steps of rolling ball forming are to make small seed balls first, and then continue to add powder to the appropriate particle size. The strength of the seed ball will directly affect the strength of the finished product. The present application uses finished alumina balls as seeds, which have high strength and save the step of preparing seeds, making the preparation relatively simple. DETAILED DESCRIPTION

[0030] All features disclosed in this specification, or all steps of any method or process disclosed in this specification, can be combined in any combination, except combinations where at least some features and / or steps are mutually exclusive.

[0031] Any feature disclosed in this specification, unless stated otherwise, can be replaced by any equivalent or similar feature. That is, unless stated otherwise, each feature is one example only of a generic series of equivalent or similar features.

[0032] The features and properties of the present application will be further described with reference to the following examples.

[0033] Example 1

[0034] Take sodium carbonate 1 kg dissolved in 35 kg of deionized water to get solution a, take activated alumina (0.5-1.2 mm) 20 kg into solution a, soak at room temperature for 6 h, then dry at 130 ℃ for 8 h, get modified activated alumina ball. Take 28.7 kg of nickel chloride hexahydrate dissolved in 120 kg of water to get solution b, take 13X molecular sieve 20 kg, take NaY molecular sieve 20 kg, pour into solution b, modify and soak at 60 ℃ for 6 h, then wash, filter, dry at 110 ℃ for 8 h, get modified molecular sieve powder. Take 1.7 kg of pseudoboehmite, 0.8 kg of attapulgite, add to the modified molecular sieve powder and mix well. Put the activated alumina balls into a sugar bowl, spray water to wet, then slowly add the mixed powder of molecular sieve and binder to the sugar bowl while continuously spraying water, so that the molecular sieve powder wraps around the alumina balls, after the addition is completed, screen, take 2-3 mm small balls as the finished product, dry at 120 ℃ for 8 h, calcine at 400 ℃ for 5 h, get sample S1.

[0035] Example 2:

[0036] Take 0.6 kg of sodium hydroxide and 0.6 kg of potassium hydroxide dissolved in 30 kg of deionized water to get solution a, take activated alumina (0.5-1.2 mm) 25 kg into solution a, soak at room temperature for 8 h, then dry at 130 ℃ for 7 h, get modified activated alumina ball. Take 42.18 kg of nickel chloride hexahydrate dissolved in 176 kg of water to get solution b, take 13X molecular sieve 10 kg, take NaY molecular sieve 34 kg, pour into solution b, modify and soak at 50 ℃ for 8 h, then wash, filter, dry at 130 ℃ for 9 h, get modified molecular sieve powder. Take 2.2 kg of activated clay, add to the modified molecular sieve powder and mix well. Put the activated alumina balls into a sugar bowl, spray water to wet, then slowly add the mixed powder of molecular sieve and binder to the sugar bowl while continuously spraying water, so that the molecular sieve powder wraps around the alumina balls, after the addition is completed, screen, take 2-3 mm small balls as the finished product, dry at 120 ℃ for 8 h, calcine at 420 ℃ for 4 h, get sample S2.

[0037] Example 3:

[0038] Take sodium hydroxide 1.6 kg dissolved in 30 kg of deionized water to get solution a, take activated alumina (0.5-1.2 mm) 25 kg into solution a at room temperature for 8 h, then dried at 130 ℃ for 7 h, to get modified activated alumina ball. Take 52.2 kg of nickel nitrate hexahydrate dissolved in 180 kg of water to get solution b, take 13X molecular sieve 25 kg, NaY molecular sieve 10 kg, USY molecular sieve 10 kg, pour into solution b, modified impregnation at 40 ℃ for 8 h, then washed and filtered, dried at 130 ℃ for 8 h, to get modified molecular sieve powder. Take 1.8 kg of high-alumina cement and mix well with the modified molecular sieve powder. Put the activated alumina ball into the sugar pot, spray water to wet, then slowly add the mixed powder of molecular sieve and binder to the sugar pot under continuous water spraying, so that the molecular sieve powder is wrapped outside the alumina ball, after the addition is completed, screen, take 2-3 mm small ball as the product, dried at 120 ℃ for 8 h, calcined at 430 ℃ for 6 h, to get sample S3.

[0039] Example 4:

[0040] Take sodium hydroxide 1.6 kg dissolved in 30 kg of deionized water to get solution a, take activated alumina (0.5-1.2 mm) 25 kg into solution a at room temperature for 8 h, then dried at 130 ℃ for 7 h, to get modified activated alumina ball. Take 52.2 kg of nickel nitrate hexahydrate dissolved in 180 kg of water to get solution b, take 13X molecular sieve 25 kg, NaY molecular sieve 10 kg, USY molecular sieve 10 kg, pour into solution b, modified impregnation at 40 ℃ for 8 h, then washed and filtered, dried at 130 ℃ for 8 h, to get modified molecular sieve powder. Take 1.8 kg of high-alumina cement and mix well with the modified molecular sieve powder. Put the activated alumina ball into the sugar pot, spray water to wet, then slowly add the mixed powder of molecular sieve and binder to the sugar pot under continuous water spraying, so that the molecular sieve powder is wrapped outside the alumina ball, after the addition is completed, screen, take 2-3 mm small ball as the product, dried at 120 ℃ for 8 h, calcined at 430 ℃ for 6 h, to get sample S3.

[0041] Comparative Example 1:

[0042] 1.05 kg of sodium hydroxide was dissolved in 35 kg of deionized water to obtain solution a. 25 kg of activated alumina (0.5–1.5 mm) was added to solution a and impregnated at room temperature for 8 hours, then dried at 130°C for 8 hours to obtain modified activated alumina spheres. 50 kg of 13X molecular sieve and 4.28 kg of boehmite were weighed and thoroughly mixed. The activated alumina spheres were added to a coating pan and moistened with water. The mixture of molecular sieve and binder powder was then slowly added to the coating pan while continuously spraying water, so that the molecular sieve powder coated the alumina spheres. After the mixture was formed, it was sieved, and 2–3 mm spheres were taken as the finished product. The spheres were dried at 120°C for 8 hours and calcined at 450°C for 4 hours to obtain sample D1.

[0043] Comparative Example 2:

[0044] 25.44 kg of nickel nitrate hexahydrate and 20.92 kg of nickel chloride hexahydrate were dissolved in 175 kg of water to obtain solution b. 50 kg of 13X molecular sieve was weighed and poured into solution b. The mixture was modified and impregnated at 50℃ for 6 h, then washed and filtered, and dried at 130℃ for 8 h to obtain modified molecular sieve powder. 4.28 kg of boehmite was weighed and added to the modified molecular sieve powder and mixed thoroughly. 25 kg of unmodified activated alumina balls (0.5-1.5 mm) were weighed and added to a coating pan, moistened with water, and then the mixture of molecular sieve and binder powder was slowly added to the coating pan while continuously spraying water, so that the molecular sieve powder coated the alumina balls. After the mixture was fully formed, it was sieved, and small balls of 2-3 mm were taken as the finished product. The balls were dried at 120℃ for 8 h and calcined at 450℃ for 4 h to obtain sample D2.

[0045] Comparative Example 3:

[0046] Weigh 50 kg of 13X molecular sieve and 4.28 kg of pseudoboehmite, and mix them thoroughly. Weigh 25 kg of unmodified activated alumina balls (0.5-1.5 mm) and add them to the coating pan. Spray water to moisten the balls, and then slowly add the mixture of molecular sieve and binder powder to the coating pan while continuously spraying water. Roll the mixture into balls. After the balls are formed, sieve them and take small balls of 2-3 mm as the finished product. Dry the balls at 120℃ for 8 hours and calcine them at 450℃ for 4 hours to obtain sample D3.

[0047] Comparative Example 4:

[0048] Weigh 75 kg of 13X molecular sieve and 6.42 kg of pseudoboehmite, and mix them thoroughly. Then, slowly add the mixture of molecular sieve and binder powder into the coating pan while continuously spraying water. Roll the mixture into balls and, after the addition is complete, sieve them and take small balls of 2-3 mm as the finished product. Dry them at 120℃ for 8 hours and calcine them at 450℃ for 4 hours to obtain sample D4.

[0049] Example 5:

[0050] Take sodium carbonate 1.2 kg, potassium carbonate 1.2 kg dissolved in 36 kg of deionized water to get solution a, take activated alumina (0.5-1.2 mm) 25 kg into solution a, immerse at room temperature for 8 h, then dry at 130℃ for 8 h, get modified activated alumina ball. Take 52.568 kg of nickel sulfate hexahydrate dissolved in 200 kg of water to get solution b, take NaY molecular sieve 25 kg, USY molecular sieve 25 kg, pour into solution b, modify and immerse at 50℃ for 6 h, then wash, filter, dry at 130℃ for 8 h, get modified molecular sieve powder. Take activated clay 1.5 kg, kaolin 1.5 kg, add to the modified molecular sieve powder and mix well. Put the activated alumina ball into the sugar pot, spray water to wet, then slowly add the mixed powder of molecular sieve and binder to the sugar pot under continuous water spraying, so that the molecular sieve powder wraps the outside of the alumina ball, after the addition is completed and the shape is good, screen, take 2-3 mm small balls as finished product, dry at 120℃ for 8 h, calcine at 430℃ for 6 h, get sample S5.

[0051] Example 6:

[0052] Take sodium hydroxide 0.72 kg, potassium hydroxide 1.1 kg dissolved in 36 kg of deionized water to get solution a, take activated alumina (0.5-1.2 mm) 28 kg into solution a, immerse at room temperature for 9 h, then dry at 140℃ for 8 h, get modified activated alumina ball. Take 27.92 kg of nickel nitrate hexahydrate, 25.2 kg of nickel sulfate hexahydrate dissolved in 240 kg of water to get solution b, take 13X molecular sieve 30 kg, USY molecular sieve 20 kg, pour into solution b, modify and immerse at 50℃ for 10 h, then wash, filter, dry at 140℃ for 8 h, get modified molecular sieve powder. Take kaolin 4 kg, add to the modified molecular sieve powder and mix well. Put the activated alumina ball into the sugar pot, spray water to wet, then slowly add the mixed powder of molecular sieve and binder to the sugar pot under continuous water spraying, so that the molecular sieve powder wraps the outside of the alumina ball, after the addition is completed and the shape is good, screen, take 2-3 mm small balls as finished product, dry at 110℃ for 8 h, calcine at 450℃ for 4 h, get sample S6.

[0053] Example 7:

[0054] Take sodium nitrate 0.8 kg, potassium nitrate 1 kg, calcium nitrate 0.8 kg dissolved in 40 kg deionized water to get solution a, take activated alumina (0.5-1.2 mm) 30 kg into solution a at room temperature for 8 h, then dried at 140 ℃ for 8 h, to get modified activated alumina ball. Take 69.79 kg of nickel nitrate hexahydrate dissolved in 200 kg of water to get solution b, take 50 kg of NaY molecular sieve, pour into solution b, modified immersion at 40 ℃ for 8 h, then washed, filtered, dried at 140 ℃ for 8 h, to get modified molecular sieve powder. Take 3 kg of kaolin and 3 kg of attapulgite and mix well with the modified molecular sieve powder. Put the activated alumina balls into a sugar bowl, spray water to wet, then slowly add the mixture of molecular sieve and binder powder to the sugar bowl while continuously spraying water, so that the molecular sieve powder wraps around the alumina balls, after the addition is completed, screen, take 2-3 mm small balls as the finished product, dry at 110 ℃ for 8 h, calcine at 450 ℃ for 4 h, to get sample S7.

[0055] Example 8:

[0056] Take sodium nitrate 0.8 kg, potassium hydroxide 1 kg dissolved in 40 kg deionized water to get solution a, take activated alumina (0.5-1.2 mm) 25 kg into solution a at room temperature for 8 h, then dried at 140 ℃ for 8 h, to get modified activated alumina ball. Take 25.17 kg of nickel chloride hexahydrate and 13.09 kg of nickel nitrate hexahydrate dissolved in 150 kg of water to get solution b, take 30 kg of 13X molecular sieve, 10 kg of NaY molecular sieve, 10 kg of USY molecular sieve, pour into solution b, modified immersion at 40 ℃ for 8 h, then washed, filtered, dried at 140 ℃ for 8 h, to get modified molecular sieve powder. Take 1.5 kg of high alumina cement and 2 kg of attapulgite and mix well with the modified molecular sieve powder. Put the activated alumina balls into a sugar bowl, spray water to wet, then slowly add the mixture of molecular sieve and binder powder to the sugar bowl while continuously spraying water, so that the molecular sieve powder wraps around the alumina balls, after the addition is completed, screen, take 2-3 mm small balls as the finished product, dry at 110 ℃ for 8 h, calcine at 450 ℃ for 4 h, to get sample S8.

[0057] Example 9:

[0058] Take potassium chloride 1 kg, sodium hydroxide 2.5 kg dissolved in 42 kg of deionized water to get solution a, take activated alumina (0.5-1.5 mm) 25 kg into solution a, immerse at room temperature for 8 h, then dry at 140℃ for 8 h, to get modified activated alumina ball. Take 56.08 kg of nickel chloride hexahydrate dissolved in 165 kg of water to get solution b, take 13X molecular sieve 40 kg, NaY molecular sieve 15 kg, pour into solution b, modify and immerse at 40℃ for 8 h, then wash, filter, dry at 140℃ for 8 h, to get modified molecular sieve powder. Take pseudoboehmite 3.92 kg, kaolin 1.65 kg, add to the modified molecular sieve powder and mix well. Put the activated alumina ball into a sugar bowl, spray water to wet, then slowly add the mixture of molecular sieve and binder powder to the sugar bowl under continuous water spraying, so that the molecular sieve powder is wrapped outside the alumina ball, after the addition is completed, screen, take 2-3 mm small balls as the product, dry at 110℃ for 8 h, calcine at 450℃ for 4 h, to get sample S9.

[0059] Example 10:

[0060] Take potassium carbonate 1.35 kg, sodium hydroxide 0.9 kg dissolved in 45 kg of deionized water to get solution a, take activated alumina (0.5-1.5 mm) 25 kg into solution a, immerse at room temperature for 9 h, then dry at 140℃ for 8 h, to get modified activated alumina ball. Take 57.57 kg of nickel nitrate hexahydrate dissolved in 220 kg of water to get solution b, take 13X molecular sieve 25 kg, NaY molecular sieve 25 kg, pour into solution b, modify and immerse at 40℃ for 8 h, then wash, filter, dry at 140℃ for 8 h, to get modified molecular sieve powder. Take activated clay 1.5 kg, kaolin 1.5 kg, attapulgite 1.5 kg, add to the modified molecular sieve powder and mix well. Put the activated alumina ball into a sugar bowl, spray water to wet, then slowly add the mixture of molecular sieve and binder powder to the sugar bowl under continuous water spraying, so that the molecular sieve powder is wrapped outside the alumina ball, after the addition is completed, screen, take 2-3 mm small balls as the product, dry at 110℃ for 8 h, calcine at 450℃ for 4 h, to get sample S10.

[0061] Performance test of adsorbent

[0062] The samples prepared in the examples and comparative examples were tested for strength using an intelligent particle strength tester, 25 particles of each sample were randomly measured, and the average strength results are shown in Table 1 below.

[0063] Table 1 Strength test results

[0064]

[0065] The samples prepared in the examples and comparative examples were respectively loaded into a fixed bed reactor, and the temperature change during adsorption, the removal accuracy of oxygen-containing compounds, the adsorption time, and the repeated regeneration adsorption were continuously measured. The adsorbent loading amount was 50 g, the adsorption gas composition was ethylene containing methanol 100 ppm, dimethyl ether 100 ppm, and propyl aldehyde 100 ppm. The adsorption temperature was 40°C, the adsorption pressure was 0.5 MPa, and the adsorption volume space velocity was 3000 h -1 , the concentration in the tail gas was analyzed online by gas chromatography, the regeneration temperature was 200°C, the regeneration time was 8 h, and the regeneration used nitrogen with a volume space velocity of 1000 h -1 . The gas phase ethylene adsorption performance results are shown in Table 2 below.

[0066] Table 2 Adsorption performance table of oxygen-containing compounds in gas phase ethylene

[0067]

[0068]

[0069] Several samples were selected for testing the adsorption and removal performance of oxygen-containing compounds in liquid propylene. The adsorption liquid composition was propylene containing methanol 100 ppm, dimethyl ether 100 ppm, and propyl aldehyde 100 ppm, where the content was a mass ratio. The adsorption liquid volume space velocity was 3 h -1 , the adsorption pressure was 2.0 MPa, the time of dimethyl ether breakthrough 1 ppm was taken as the adsorption end point, the concentration in the tail gas was analyzed online by gas chromatography, the regeneration temperature was 200°C, the regeneration time was 8 h, and the regeneration used nitrogen with a volume space velocity of 1000 h -1 . The liquid phase propylene adsorption performance results are shown in Table 3 below.

[0070] Table 3 Performance table of oxygen-containing compounds in liquid phase propylene

[0071] Sample No. Adsorption Max. Temp. Rise °C First Adsorption Time h Adsorption Time After 5 Times of Continuous Adsorption and Regeneration h S1 35 100 80 S4 35 101 80 D1 46 92 74 D2 40 96 76 D3 51 88 70 D4 73 120 82 S8 34 101 80

[0072] The sample S4 was loaded into a fixed bed reactor for testing the adsorption performance of oxygen-containing compounds in ethylene. The adsorbent loading amount was 50 g, the adsorption gas composition was ethylene containing methanol 150 ppm, dimethyl ether 150 ppm, and propyl aldehyde 150 ppm. The adsorption temperature was 40°C, the adsorption pressure was 0.5 MPa, and the adsorption volume space velocity was 3000 h -1 , the concentration in the tail gas was analyzed online by gas chromatography, the regeneration temperature was 200°C, the regeneration time was 8 h, and the regeneration used nitrogen with a volume space velocity of 1000 h -1 . After 50 times of adsorption and regeneration, the adsorption accuracy of impurities could still meet the requirements of polymerization grade olefins, and the adsorption time did not decrease significantly. The adsorption operation time is shown in Table 4 below.

[0073] Table 4 Adsorption Regeneration Schedule for Continuous Adsorption-Regeneration

[0074]

[0075]

[0076] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

[0077] This background section is provided to generally present the context of the invention. The work of the currently named inventors, the work to the extent described in this background section, and aspects of this section that did not constitute prior art at the time of application are neither expressly nor impliedly acknowledged as prior art to the invention.

Claims

1. A process for the preparation of an adsorbent for the purification of oxygenates in an olefin stream, characterized in that The method comprises the following steps: (1) first, the alumina is added into the alkali solution to modify it, and the modified alumina is filtered and dried to obtain modified alumina balls; (2) adding molecular sieve into solution containing transition metal ions to carry out ion exchange modification, and after modification, filtering, washing and drying, modified molecular sieve is obtained; the transition metal ions are Ni 2+ , and the source is its soluble salt. (3) the modified alumina balls prepared in step (1) are added into a sugar bowl, then the modified molecular sieve obtained in step (2) is added, and then the binder and water are added to perform ball forming; (4) the adsorbent formed in step (3) is dried and activated to obtain a finished adsorbent; the adsorbent is used for removing oxygen-containing compounds in an olefin stream; The alkali metal solution in step (1) is a solution formed by dissolving any one or more of sodium, potassium or their salts or bases in water; the alumina in step (1) is active alumina ball with specific surface area > 200 m 2 / g and particle size of 0.5-2 mm; the weight ratio of the alkali metal solution to the active alumina ball is 1-2, and the mass fraction of the alkali metal contained in the alkali metal solution is 0.5%-10%.

2. The method of claim 1, wherein the olefin stream is a C5 stream. In step (1), the drying temperature is 80-150℃, and the drying time is 6-12h.

3. The method of claim 1, wherein the olefin stream is a C5 stream. The molecular sieve in step (2) is one or more of a mixture of 13X molecular sieve, NaY molecular sieve, and USY molecular sieve; the solution concentration of Ni 2+ The solution concentration of Ni is 0.3-2 mol / L, the liquid-solid ratio of the salt solution and the molecular sieve is 1.5-10, the exchange temperature is 30-80°C, and the exchange time is 3-12 h; the drying temperature in step (2) is 80-150°C, and the drying time is 4-12 h.

4. The method of claim 1, wherein the olefin stream is a C5 stream. In step (3), the binder is one or more of pseudo-boehmite, activated clay, kaolin, attapulgite and high-alumina cement.

5. The method of claim 1, wherein the olefin stream is a C5 stream. In step (3), when the adsorbent is formed, the mass percentage of the modified alumina is 15-45%, the mass percentage of the modified molecular sieve is 50-80%, and the mass percentage of the binder is 2-10%, and the total mass percentage is 100%.

6. The method of claim 1, wherein the olefin stream is a C5 stream. In step (4), the drying temperature is 80-150℃, and the drying time is 4-12h.

7. The method of claim 1, wherein the olefin stream is a C5 stream. In step (4), the activation is performed by calcination, the calcination temperature is 350-500℃, and the calcination time is 4-12h.

8. The olefin stream containing oxygen-containing compound purification adsorbent obtained by the method according to any one of claims 1-7.

9. Use of an olefin stream oxygenate purifying adsorbent according to claim 8, characterized in that, The adsorbent is used for removing oxygen-containing compounds in an olefin stream; the specific application method is that the adsorbent is loaded into a fixed bed adsorber, and is adsorbed at low temperature and high pressure, and is desorbed at high temperature and low pressure; the oxygen-containing compounds are methanol, propyl aldehyde and dimethyl ether, the volume concentration of the oxygen-containing compounds is 2-1000ppm, and the concentration of the oxygen-containing compounds after removal is less than 1ppm, and the precision meets the requirements of polymerization grade olefin.

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