A kind of magnetic ceramsite catalyst loaded with heteropoly acid and preparation method of sec-butyl acetate

Abstract

The present invention relates to a magnetic ceramsite catalyst loaded with heteropolyacid and a preparation method of sec-butyl acetate. The preparation method of sec-butyl acetate comprises: preheating a carbon four fraction after etherification and glacial acetic acid to 90-100 degrees Celsius respectively, controlling the space velocity of the carbon four fraction after etherification to be 1.0-2.0h ‑1 The invention relates to a process for preparing a esterification reaction vessel comprising a first step of preparing a first esterification reaction vessel and a second step of preparing a second esterification reaction vessel. The first step is to prepare a first ... esterification reaction vessel and a second esterification reaction vessel.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and particularly relates to a heteropolyacid-loaded magnetic ceramsite catalyst and a preparation method of sec-butyl acetate. Background Art

[0002] Sec-butyl acetate, one of the four isomers of butyl acetate, is widely used in coatings, inks, pharmaceuticals, flavors and fragrances, metal cleaning, adhesives, and other fields. Compared to other isomers, sec-butyl acetate has a lower boiling point and faster evaporation rate, making it more suitable for applications where slow drying is strictly required.

[0003] At present, in the industrial production of sec-butyl acetate, etherified mixed carbon tetrahydrate is usually used as a raw material and acetic acid is reacted with it in the presence of an ion exchange resin catalyst to produce it. The ion exchange resin catalyst used is the most widely used catalyst for the industrial synthesis of sec-butyl acetate due to its good selectivity. However, the following problems still exist: 1) the resin particles have low strength and are easily broken, which leads to catalyst deactivation; 2) poor heat resistance and low conversion rate of cis-butene (cis-2-butene) and trans-butene (trans-2-butene): Since this type of catalyst has poor heat resistance, high temperature easily causes the active groups of the catalyst to fall off and the catalyst to deactivate. Therefore, when using this type of catalyst, the reaction temperature is usually low, generally 70-100 degrees Celsius. Under this temperature condition, the conversion rate of n-butene (1-butene) is high, but due to the poor heat resistance of the catalyst, the conversion rate of n-butene (1-butene) is high. The C4 fraction used contains not only n-butene, but also cis-butene and trans-butene, and the reactivity of cis-butene, trans-butene and n-butene is quite different, n-butene>cis-butene>trans-butene, and a relatively low reaction temperature is not conducive to the conversion of cis-butene and trans-butene, resulting in a low total conversion rate of n-butene, cis-butene and trans-butene; 3) when the C4 fraction is used as a raw material, not only n-butene, cis-butene and trans-butene are prone to polymerization, but the isobutylene remaining in the etherified C4 fraction is more prone to polymerization to generate dimerization and trimerization, thereby causing catalyst blockage, and the catalyst bed temperature will increase after blockage. When its temperature rises to a temperature exceeding its operating temperature, the catalyst will be deactivated. In addition, this type of resin-type catalyst has the defect of being difficult to regenerate and can only be professionally treated as solid waste, increasing waste disposal costs.

[0004] In order to solve the problem of low conversion of cis-butene and trans-butene in the carbon four fraction after etherification, two methods are usually adopted at present: 1) increasing the feeding amount of acetic acid to make it seriously excessive, that is, increasing the acid-olefin ratio, which will inevitably lead to a great waste of acetic acid and an increase in production cost; 2) improving the heat resistance of the catalyst, and then promoting the conversion of cis-butene and trans-butene by increasing the reaction temperature to achieve the purpose of improving the total conversion rate of n-butene, cis-butene and trans-butene. For this reason, heat-resistant porous carrier-supported heteropolyacids or superacid catalysts have been studied one after another. They usually use high-temperature resistant porous materials as carriers to load heteropolyacids or superacids, thereby solving the heat resistance problem of the catalyst and also solving the problem of calcination regeneration and recovery of the catalyst. However, this type of catalyst has more serious problems than resin catalysts, such as: 1) when the reaction temperature is increased, although it is not effective in improving the conversion of cis-butene and trans-butene, it is not effective in improving the conversion of n-butene, cis-butene and trans-butene. The conversion rate of cis-butene and trans-butene is favorable, but it is also favorable for the polymerization reaction of n-butene, resulting in a large amount of n-butene polymerization products. Moreover, since a small amount of isobutylene is also present in the C4 fraction used, it is more likely to undergo polymerization reaction than n-butene. The products of these polymerization reactions will coke and carbonize above 120 degrees Celsius, which not only blocks the catalyst but also causes carbon accumulation and deactivation on the catalyst surface. Therefore, when this type of catalyst is used for the synthesis of isobutyl acetate, although a higher reaction temperature can be used to increase the conversion rate of cis-butene and trans-butene, the problems of catalyst clogging and carbon deposition and deactivation lead to a significantly shortened continuous operation cycle of the system compared to resin catalysts, requiring frequent shutdowns to replace the catalyst and recycle the catalyst, which seriously affects the normal production. In addition, this type of catalyst also has the problem that the active components, heteropolyacids and superacids, are not firmly loaded and easily lost. Summary of the Invention

[0005] The present invention aims to overcome the defects in the prior art and provides a method for preparing sec-butyl acetate by using a magnetic ceramsite catalyst loaded with a heteropolyacid. The catalyst has a high total conversion rate of n-butene, cis-butene and trans-butene, good catalyst selectivity, is not prone to clogging, and is recyclable, thereby greatly extending the life of the catalyst and the continuous operation cycle of the system.

[0006] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0007] A heteropolyacid-loaded magnetic ceramsite catalyst comprises the following raw materials in parts by weight:

[0008] 20-30 parts perlite; 20-30 parts silicon carbide; 10-15 parts zeolite powder; 10-15 parts magnetic material; 6-15 parts N,N'-dimethyl-N,N'-dinitrosoterephthalamide (foaming agent); 80-120 parts PVA solution; 5-10 parts expanded graphite; 3-5 parts calcium carbonate (pore-forming agent); 5-10 parts marble glue.

[0009] The magnetic material is strontium ferrite;

[0010] A magnetic ceramsite catalyst loaded with a heteropoly acid, wherein the heteropoly acid is phosphotungstic acid; and a preparation method thereof, comprising the following steps:

[0011] Step 1, preparing porous magnetic ceramsite: After weighing various raw materials according to weight, first, the raw materials are configured into a magnetic ceramic slurry, and then foaming treatment is performed to obtain a foamed magnetic ceramic body, and then the foamed magnetic ceramic body is crushed, ball-milled, and sieved to obtain a magnetic ceramsite body, and then high-temperature calcination and acid leaching are performed to obtain porous magnetic ceramsite;

[0012] Step 2, loading heteropoly acid: dissolve sodium tungstate and disodium hydrogen phosphate in boiling water to prepare sodium tungstate solution, then add porous magnetic ceramsite to the sodium tungstate solution, stir for 8-12 minutes, add concentrated hydrochloric acid dropwise under stirring, and continue stirring for 0.5-1.5 hours. Take out, dry, wash with water 3-5 times, dry again, and calcine at 300 degrees Celsius for 50-70 minutes to obtain a magnetic ceramsite catalyst loaded with heteropoly acid.

[0013] As a further technical solution, the raw materials are configured into a magnetic ceramic slurry, including: first, the PVA solution and the foaming agent are evenly mixed to prepare a mixed solution of PVA and the foaming agent; then, perlite, silicon carbide, zeolite powder, magnetic material, expanded graphite, pore-forming agent and marble glue are mixed, and after grinding for 30-60 minutes, a freshly prepared mixed solution of PVA and the foaming agent is added, and then grinding and dispersion are continued for 5-15 minutes to obtain the magnetic ceramic slurry.

[0014] As a further technical solution, the foaming treatment includes: pouring the magnetic ceramic slurry into a mold, letting it stand for 45-55 minutes, heating the mold at 145-155°C for 75-85 minutes to perform foaming treatment, and taking out and demolding the material after it is completely dried to obtain a foamed magnetic ceramic body;

[0015] As a further technical solution, the space of the sieve used for screening is 2-3 mm.

[0016] As a further technical solution, the high temperature sintering and acid leaching include: heating the magnetic ceramsite body to 900-1100 ° C in a muffle furnace, calcining for 1.5-2.5 hours, cooling to room temperature, soaking in 3 mol / L sulfuric acid for 25-35 minutes, and using water to remove H + Rinse clean and dry to obtain porous magnetic ceramsite.

[0017] As a further technical solution, during the preparation of the sodium tungstate solution, the ratio of sodium tungstate, sodium dihydrogen phosphate and boiling water is 6.0-6.5g:1g:1500mL;

[0018] Add porous magnetic ceramsite to the sodium tungstate solution at a material-liquid ratio of 1g:7-9mL;

[0019] The amount of concentrated hydrochloric acid added is 0.5-0.6 times the original volume.

[0020] As a further technical solution, a preparation method of a magnetic ceramsite catalyst loaded with heteropolyacid comprises the following steps:

[0021] Step 1: preparing porous magnetic ceramsite, specifically comprising:

[0022] Step 1-1, preparing a magnetic ceramic slurry: After weighing each raw material by weight, first mix the PVA solution and the foaming agent evenly to prepare a mixed solution of PVA and the foaming agent; then mix the perlite, silicon carbide, zeolite powder, magnetic material, expanded graphite, pore-forming agent and marble glue, grind them for 30-60 minutes, add the freshly prepared mixed solution of PVA and the foaming agent, and continue grinding and dispersing for 5-15 minutes to prepare the magnetic ceramic slurry;

[0023] Step 1-2, preparing a foamed magnetic ceramic body: pouring the magnetic ceramic slurry prepared in step 1-1 into a mold, letting it stand for 45-55 minutes, then heating the mold at 145-155° C. for 75-85 minutes to foam the material, and removing the material from the mold after it is completely dry to obtain a foamed magnetic ceramic body;

[0024] Step 1-3, crushing and ball milling: crush the foamed magnetic ceramic body into particles with a particle size of 3-4 mm using a crusher, then dry-grind it using a ball mill, and pass it through a 2-3 mm mesh sieve to obtain a magnetic ceramsite body;

[0025] Step 1-4, sintering and acid leaching: heat the magnetic ceramsite body to 900-1100℃ in a muffle furnace and calcine for 1.5-2.5h. After cooling to room temperature, soak it in 3mol / L sulfuric acid for 25-35min. + Rinse clean and dry to obtain porous magnetic ceramsite.

[0026] Step 2, loading heteropoly acid: Sodium tungstate, sodium dihydrogen phosphate and boiling water = 6.0-6.5g: 1g: 1500mL, sodium tungstate and disodium hydrogen phosphate are dissolved in boiling water to prepare a sodium tungstate solution, and then porous magnetic ceramsite is added to the sodium tungstate solution at a material-liquid ratio of 1g: 7-9mL. After stirring for 8-12 minutes, concentrated hydrochloric acid 0.5-0.6 times the original volume is added under stirring conditions, and then continued to stir for 0.5-1.5 hours. The catalyst is taken out, dried, washed with water 3-5 times, dried again, and calcined at 300 degrees Celsius for 50-70 minutes to obtain a magnetic ceramsite catalyst loaded with heteropoly acid.

[0027] A method for preparing sec-butyl acetate comprises the following steps:

[0028] Step 1, reaction:

[0029] After preheating the C4 fraction after etherification and glacial acetic acid to 90-100 degrees Celsius, control the space velocity of the C4 fraction after etherification to 1.0-2.0h -1 , acid-olefin ratio = 1.1-3.5:1 (the acid-olefin ratio refers to the molar ratio of glacial acetic acid to the total amount of n-butene, maleic butene and trans-butene, and the acid-olefin ratio is preferably 1.5-2.5:1), the etherified C4 fraction and glacial acetic acid are respectively fed into an esterification reaction kettle, the feed temperature is controlled at 90-100 degrees Celsius, the discharge temperature is controlled at 125-130 degrees Celsius, the reaction pressure is controlled at 1.5-3.0 MPa (preferably 2.2-2.4) MPa, and a magnetic field with an intensity of 540-620oe (preferably 550-610oe) is applied for treatment, the n-butene, maleic butene and trans-butene in the etherified C4 olefins flow through the esterification reaction kettle, and an addition reaction occurs with the glacial acetic acid under the action of a fixed catalyst bed to generate sec-butyl acetate, thereby obtaining a reaction product containing sec-butyl acetate; the catalyst used in the fixed catalyst bed is the magnetic ceramsite catalyst loaded with heteropolyacid.

[0030] As a further technical solution, the method further includes step 2, separation and purification; the separation and purification includes:

[0031] Using water as an azeotropic agent, acetic acid and C8 olefins in the reaction product containing sec-butyl acetate generated in step 1 are removed by azeotropic distillation to obtain a sec-butyl acetate product.

[0032] As a further technical solution, in step 1, the acid-olefin ratio is 1.5-2.5:1; and the reaction pressure is 2.2-2.4 MPa.

[0033] As a further technical solution, in step 1, the magnetic field strength is 550-610oe.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The present invention adopts a magnetic ceramsite catalyst as a carrier of heteropolyacid. Compared with traditional macroporous resin catalysts, the present invention can be recycled and reused almost unlimited times, thereby reducing the cost of solid waste treatment. In addition, the present invention introduces strontium ferrite magnetic material into the magnetic ceramsite catalyst and applies a magnetic field in conjunction with the operating conditions of the reaction process of synthesizing isopropyl acetate, which greatly improves the selectivity of the catalyst. Even at higher temperatures, it can well inhibit the polymerization reaction of butenes (n-butene, cis-butene, trans-butene and iso-butene) and avoid the production of butene polymers. It not only extends the service life of the catalyst and the continuous operation time of the system, but also makes it possible to increase the reaction temperature and improve the conversion rate of cis-butene and trans-butene.

[0036] 2. The present invention greatly improves the loading firmness of phosphotungstic acid by adding expanded graphite to porous magnetic ceramsite and coordinating the loading process of phosphotungstic acid, reduces the loss probability of heteropolyacid, further extends the service life of heteropolyacid, extends the service life of catalyst and the continuous operation time of the system.

[0037] 3. In the preparation process of magnetic ceramsite, the present invention adopts PVC foaming technology to prepare the green body into a foam green body, first forming a closed pore structure, and then during the calcination process, with the carbonization of PVC and the gasification overflow of a small amount of pore-forming agent, a through-porous structure is formed. Compared with the holes formed by foaming or gasification overflow of pore-forming agent during the calcination process in the traditional technology, the porosity and pore uniformity are improved, and the proportion of small pores is increased and the proportion of large pores is reduced; compared with the pore formation by the simple foaming technology, the present invention is more conducive to the formation of through-pores, increases the proportion of through-pores, and greatly reduces the proportion of closed pores. The present invention combines the foaming technology with the pore-forming agent pore-forming technology, and by strictly controlling the amount of PVC and foaming agent, the type of pore-forming agent, and the calcination temperature, the porosity of the magnetic ceramsite is greatly improved. Compared with the pore formation by the simple pore-forming agent or foaming agent foaming technology, the porosity is increased by more than 50-80%, so that the catalytic effect can be achieved after the heteropoly acid is loaded.

[0038] In addition, the present invention rationally configures the ceramic material and selects the pore-forming agent so that the vaporization temperature of the pore-forming agent is close to or slightly lower than the vitrification temperature of the ceramic material, thereby avoiding the problem that the pores caused by the premature vaporization of the pore-forming agent and the late vitrification of the ceramic material close to form closed pores during the vitrification process of the ceramic material. It also avoids the phenomenon that the pore-forming agent fails to form pores due to the ceramic vitrification but the pore-forming agent has not been vaporized.

[0039] 5. In the preparation process of magnetic ceramsite, mica glue is added to improve the hardness of the foam body, facilitate its crushing and ball milling operations, and reduce material loss.

[0040] In summary, the present invention adjusts the formula and process of the magnetic ceramsite catalyst so that the prepared magnetic ceramsite catalyst has an excellent pore structure, so that it can be used as a carrier to prepare a magnetic ceramsite catalyst loaded with heteropolyacid. The present invention screens the magnetic material and determines: strontium ferrite magnetic material, combined with the control of the magnetic field during the reaction process, so that the synthesis reaction of isopropyl acetate can well suppress the polymerization reaction of butene and avoid the formation of butene polymers even at a feed temperature of 90-100 degrees Celsius and a discharge temperature of 125-130 degrees Celsius. It not only extends the life of the catalyst and the continuous operation time of the system, but also greatly improves the conversion rate of n-butene and trans-butene, thereby improving the total conversion rate of n-butene, cis-butene and trans-butene. In addition, the catalyst prepared by the present invention can be calcined at high temperature, which is convenient for recycling and reuse of the catalyst, and can achieve almost unlimited recycling and reuse. DETAILED DESCRIPTION

[0041] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] 1) Strontium ferrite powder (1.3 microns): Shenzhen Xingkaiyue Biotechnology Co., Ltd.

[0043] 2) Barium ferrite powder (600 mesh): Lingshou County Jiale Mineral Products Processing Plant;

[0044] 3) Nickel-zinc ferrite powder: Hebei Teren Alloy Materials Co., Ltd.

[0045] 4) Manganese zinc ferrite powder: Hebei Teren Alloy Material Co., Ltd.;

[0046] 5) Ferroferric oxide powder: Nangong Kejin Welding Materials Co., Ltd.

[0047] 6) Expanded graphite: Qingdao Yanhai Carbon Materials Co., Ltd.

[0048] 7) The etherified C4 fraction used refers to the unreacted C4 fraction remaining after the C4 fraction is subjected to the etherification reaction of isobutylene and methanol; the contents of the raw materials in the etherified C4 fraction are as follows: 30.99wt% of isobutane; 18.75wt% of normal butane; 17.60wt% of trans-butene; 16.20wt% of normal butene; 0.52wt% of isobutylene; 15.79wt% of cis-butene; 0.09wt% of 1,3-butadiene; 0.07-3wt% of C5; and the total olefin content is 49.59%.

[0049] Unless otherwise specified, the raw materials used in the present invention are all commercially available raw materials.

[0050] Example 1

[0051] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is strontium ferrite and the heteropoly acid is H3O 40 PW 12 ;

[0052] The preparation method is as follows:

[0053] Step 1: Preparation of porous magnetic ceramsite:

[0054] The porous magnetic ceramsite is prepared from the following raw materials in parts by weight:

[0055] 15 parts of perlite; 25 parts of silicon carbide; 13 parts of zeolite powder; 13 parts of magnetic material; 10 parts of N,N'-dimethyl-N,N'-dinitrosoterephthalamide, a foaming agent; 100 parts of PVA solution; 8 parts of expanded graphite; 4 parts of calcium carbonate, a pore-forming agent; 8 parts of marble glue;

[0056] Step 1-1, prepare magnetic ceramic slurry:

[0057] After weighing each raw material by weight, the PVA solution and the foaming agent are first mixed evenly to prepare a mixed solution of PVA and the foaming agent; then, perlite, silicon carbide, zeolite powder, magnetic material, expanded graphite, pore-forming agent and marble glue are mixed, and after grinding for 45 minutes, the freshly prepared mixed solution of PVA and the foaming agent is added, and then grinding and dispersion are continued for 10 minutes to prepare a magnetic ceramic slurry;

[0058] Step 1-2, preparing a foamed magnetic ceramic body: pouring the magnetic ceramic slurry prepared in step 1-1 into a mold, letting it stand for 50 minutes, and then heating the mold at 150° C. for 80 minutes to foam the material. After the material is completely dry, taking it out and demolding it to obtain a foamed magnetic ceramic body;

[0059] Step 1-3, crushing and ball milling: crush the foamed magnetic ceramic body into particles with a particle size of 3-4 mm using a crusher, then dry-grind it using a ball mill, and pass it through a 2-3 mm mesh sieve to obtain a magnetic ceramsite body;

[0060] Step 1-4, sintering and acid leaching: the magnetic ceramsite body is heated to 900-1100°C in a muffle furnace and calcined for 2 hours. After cooling to room temperature, it is soaked in 3 mol / L sulfuric acid for 30 minutes, the H+ is rinsed with water, and the body is dried to obtain porous magnetic ceramsite.

[0061] Step 2, loading heteropoly acid: Sodium tungstate, sodium dihydrogen phosphate and boiling water = 6.25g: 1g: 1500mL, dissolve sodium tungstate and disodium hydrogen phosphate in boiling water to prepare a sodium tungstate solution (containing about 3.1mol / L of sodium tungstate), then add porous magnetic ceramsite to the sodium tungstate solution at a material-liquid ratio of 1g: 8mL, stir for 10min, add 800mL of concentrated hydrochloric acid dropwise under stirring, and continue stirring for 1h, take out, dry, wash with water 3-5 times, dry again, and calcine at 300 degrees Celsius for 1h to obtain a magnetic ceramsite catalyst loaded with heteropoly acid;

[0062] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12 Strontium ferrite magnetic ceramsite catalyst.

[0063] Example 2

[0064] A ceramsite catalyst loaded with heteropoly acid and magnetic material, wherein the magnetic material is strontium ferrite and the heteropoly acid is H3O 40 PW 12 ;

[0065] The preparation method is as follows:

[0066] Step 1, preparing porous ceramsite: the same as step 1 in Example 1, except that no magnetic material is added, and the final product obtained in this example is porous ceramsite.

[0067] Step 2: Loading magnetic materials: Weigh SrCO3 and FeC according to the molar ratio of strontium to iron of 1:10.88. 13 6H2O; then hydrochloric acid is added to SrCO3 to make SrC 12 solution; to FeC 13 ·6H2O and add water to dissolve, and then add SrC 12 The solution was mixed, and then porous ceramsite was added thereto. After stirring for 10 minutes, the pH of the solution was adjusted to 10 with NaOH solution, and stirring was continued for 30 minutes. The solution was removed, and the porous ceramsite was dried and calcined at a high temperature of 700°C for 2 hours to obtain strontium ferrite magnetic ceramsite.

[0068] Step 3, loading heteropoly acid: Sodium tungstate, sodium dihydrogen phosphate and boiling water = 6.25g: 1g: 1500mL, dissolve sodium tungstate and disodium hydrogen phosphate in boiling water to prepare a sodium tungstate solution (containing about 3.1mol / L of sodium tungstate), then add porous magnetic ceramsite to the sodium tungstate solution at a material-liquid ratio of 1g: 8mL, stir for 10min, add 800mL of concentrated hydrochloric acid dropwise under stirring, and continue stirring for 1h, take out, dry, wash with water 3-5 times, dry again, and calcine at 300 degrees Celsius for 1h to obtain a ceramsite catalyst loaded with heteropoly acid and magnetic material;

[0069] The ceramsite catalyst loaded with heteropoly acid and magnetic material prepared in this embodiment is loaded with H3O 40 PW 12 and strontium ferrite ceramsite catalyst.

[0070] Example 3

[0071] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is compounded with strontium carbonate and ferric oxide in a molar ratio of strontium to iron of 1:12, and the heteropoly acid is H3O 40 PW 12 ;

[0072] The preparation method thereof is the same as that of Example 1, except that the magnetic material is different;

[0073] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12 Strontium ferrite magnetic ceramsite catalyst.

[0074] Example 4

[0075] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is barium ferrite and the heteropoly acid is H3O40PW12;

[0076] The preparation method is the same as that of Example 1; the only difference is the magnetic material.

[0077] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12 Barium ferrite magnetic ceramsite catalyst.

[0078] Example 5

[0079] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is nickel-zinc ferrite and the heteropoly acid is H3O40PW12;

[0080] The preparation method is the same as that of Example 1, the only difference being the magnetic material;

[0081] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12 Nickel-zinc ferrite magnetic ceramsite catalyst.

[0082] Example 6

[0083] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is manganese zinc ferrite and the heteropoly acid is H3O40PW12;

[0084] The preparation method is the same as that of Example 1, the only difference being the magnetic material;

[0085] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12 Manganese zinc ferrite magnetic ceramsite catalyst.

[0086] Example 7

[0087] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is ferrosoferric oxide and the heteropoly acid is H3O40PW12;

[0088] The preparation method is the same as that of Example 1, the only difference being the magnetic material;

[0089] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12 Fe3O4 magnetic ceramsite catalyst.

[0090] Example 8

[0091] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is strontium ferrite and the heteropoly acid is H3O40PW12;

[0092] The preparation method is as follows: the same as Example 1, except that no expanded graphite is added during the preparation of the porous magnetic ceramsite;

[0093] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12 Strontium ferrite magnetic ceramsite catalyst.

[0094] Example 9

[0095] A magnetic ceramsite catalyst loaded with heteropoly acid, wherein the magnetic material is strontium ferrite and the heteropoly acid is H3O40PW12;

[0096] The preparation method is as follows:

[0097] Step 1, preparing porous magnetic ceramsite: the same as in Example 1;

[0098] Step 2, loading heteropoly acid: adding porous magnetic ceramsite to 0.17 mol / mL phosphotungstic acid solution at a material-liquid ratio of 1 g: 8 mL, stirring and adsorbing for 10 min, drying, and calcining at 300 degrees Celsius for 1 h to obtain a magnetic ceramsite catalyst loaded with heteropoly acid;

[0099] The heteropolyacid-loaded magnetic ceramsite catalyst prepared in this embodiment is loaded with H3O 40 PW 12Strontium ferrite magnetic ceramsite catalyst.

[0100] Example 10

[0101] The regenerated catalyst was obtained by regenerating the catalyst prepared in Example 1 10 times;

[0102] The preparation method of the regenerated catalyst after 5 regenerations comprises the following steps:

[0103] Step 1: Application of catalyst:

[0104] Isobutyl carbonate was synthesized using the etherified C4 fraction and glacial acetic acid as raw materials in the presence of a catalyst. The specific operation included preheating the etherified C4 fraction and glacial acetic acid to 95 degrees Celsius, controlling the space velocity of the etherified C4 fraction to be 1.2h -1 , acid-olefin ratio = 2.5:1, the etherified C4 fraction and glacial acetic acid are respectively fed into a tubular fixed-bed reactor, the feed temperature is controlled at 95 degrees Celsius, the discharge temperature is 128 degrees Celsius, and the reaction pressure is 2.2-2.3 MPa. The n-butene, cis-butene and trans-butene in the C4 olefins flow through the tubular fixed-bed reactor with the glacial acetic acid, and an addition reaction occurs under the action of the fixed catalyst bed to produce sec-butyl acetate. After the catalytic effect of the catalyst is seriously reduced, the spent catalyst is collected and set aside;

[0105] In this step, in order to accelerate the plugging of the catalyst, no magnetic field is applied during the reaction;

[0106] Step 2: Regeneration of spent catalyst:

[0107] The regeneration of spent catalyst includes the following steps:

[0108] Step a, calcination: The collected spent catalyst is placed in a muffle furnace and calcined at 800-900 degrees Celsius for 2 hours in an oxygen atmosphere, cooled to room temperature, and then soaked in 3 mol / L sulfuric acid for 30 minutes. After rinsing with water to remove H+, the catalyst is dried to obtain porous magnetic ceramsite.

[0109] Step b, loading heteropolyacid: Sodium tungstate, sodium dihydrogen phosphate and boiling water = 6.25g: 1g: 1500mL, sodium tungstate and disodium hydrogen phosphate are dissolved in boiling water to prepare a sodium tungstate solution (containing approximately 3.1mol / L of sodium tungstate), and then porous magnetic ceramsite is added to the sodium tungstate solution at a material-liquid ratio of 1g: 8mL. After stirring for 10 minutes, 800mL of concentrated hydrochloric acid is added dropwise under stirring conditions, and then stirring is continued for 1 hour. The catalyst is taken out, dried, washed with water 3-5 times, dried again, and calcined at 300 degrees Celsius for 1 hour to complete the regeneration of the catalyst.

[0110] Step 3: Repeat the above steps 1-2 for 5 times to obtain a regenerated catalyst that has been regenerated 5 times.

[0111] Comparative Example 1

[0112] A ceramsite catalyst loaded with a heteropoly acid, wherein the heteropoly acid is H3O40PW12;

[0113] The preparation method is as follows:

[0114] The same as Example 1, except that no magnetic material was added during the preparation of the porous ceramsite;

[0115] The ceramsite catalyst loaded with heteropoly acid prepared in this embodiment is loaded with H3O 40 PW 12 of ceramsite catalyst.

[0116] Comparative Example 2

[0117] Add SBA-15 carrier to 25 mg / mL phosphotungstic acid solution, stir and adsorb for 10 min, dry, and calcine at 300 degrees Celsius to obtain the loaded heteropoly acid H3O 40 PW 12 SBA-15 catalyst.

[0118] Comparative Example 3

[0119] D72 strong acid cation exchange resin is used.

[0120] Application Example 1: Catalytic Effect Test of Catalyst

[0121] 1. Test method:

[0122] Sec-butyl acetate was synthesized using the following three processes using the C4 fraction after etherification and glacial acetic acid as raw materials in the presence of the catalysts prepared in the Examples and Comparative Examples:

[0123] 1. Process 1:

[0124] The method for synthesizing sec-butyl acetate from a post-ether C4 fraction and glacial acetic acid under the action of a catalyst comprises the following steps:

[0125] Step 1: Loading the catalyst immobilized bed: 20 g of catalyst was loaded into a tubular fixed bed reactor to form a catalyst immobilized bed;

[0126] Step 2, addition reaction:

[0127] After preheating the etherified C4 fraction and glacial acetic acid to 95 degrees Celsius, the space velocity of the etherified C4 fraction was controlled to be 1.2h -1, acid-olefin ratio = 2.5:1, the etherified C4 fraction and glacial acetic acid are respectively fed into a tubular fixed-bed reactor, the feed temperature is controlled at 95 degrees Celsius, the discharge temperature is 128 degrees Celsius, the reaction pressure is 2.2-2.3 MPa, and a magnetic field with an intensity of 580oe is applied. The n-butene, cis-butene and trans-butene in the C4 olefins flow through the tubular fixed-bed reactor with the glacial acetic acid, and an addition reaction occurs under the action of the fixed catalyst bed to produce sec-butyl acetate;

[0128] 2. Process 2: Same as process 1, except that, during the addition reaction in step 2, the post-ether C4 fraction and glacial acetic acid are preheated to 90 degrees Celsius, and the feed temperature is controlled at 90 degrees Celsius and the discharge temperature is controlled at 120 degrees Celsius.

[0129] 3. Process 3: Same as process 1, except that, during the addition reaction in step 2, the post-ether C4 fraction and glacial acetic acid are preheated to 75 degrees Celsius, and the feed temperature is controlled at 75 degrees Celsius and the discharge temperature is controlled at 88 degrees Celsius.

[0130] 2. Index detection:

[0131] 1. After the system is running stably, samples are taken every day for the first three days to detect the contents of n-butene, trans-butene, and cis-butene before and after the addition reaction in step 2, as well as the content of sec-butyl acetate in the reaction solution after the addition reaction in step 2. The average conversion rate of n-butene, trans-butene, and cis-butene and the average total conversion rate of the three, as well as the yield and selectivity of sec-butyl acetate are calculated. The results are shown in Table 1.

[0132] Conversion rate = (the content of a certain reactant before the reaction - the content of a certain reactant after the reaction) / the content of a certain reactant before the reaction * 100%;

[0133] Yield of sec-butyl acetate = actual molar yield of sec-butyl acetate / theoretical molar yield of sec-butyl acetate * 100%;

[0134] Theoretical molar yield of sec-butyl acetate = the total molar amount of n-butene, trans-butene and cis-butene before the reaction (or the molar amount of the three);

[0135] Selectivity of sec-butyl acetate = yield of sec-butyl acetate / (total conversion of n-butene, trans-butene and cis-butene) * 100%;

[0136] 2. The system operates continuously, and samples are taken daily to test the total conversion rate of n-butene, trans-butene, and cis-butene. If the total conversion rate of the three decreases by more than 2% compared with the previous day, or if the total conversion rate decreases by more than 5% compared with the average value of the first three days after the system has been in stable operation, the catalyst needs to be replaced, and the continuous use time of the system, i.e., the life of the catalyst, is recorded;

[0137] 3. Results and Analysis

[0138] Table 1

[0139]

[0140]

[0141] Note: The period of more than 33 days is because the system did not meet the criteria for catalyst replacement when it ran for 33 days, and was automatically shut down.

[0142] Application Example 2-7: Optimization of Reaction Conditions for Synthesis of Sec-Butyl Acetate from Post-Ether C4 Fraction and Glacial Acetic Acid

[0143] 1. Test method:

[0144] The method for synthesizing sec-butyl acetate from a post-ether C4 fraction and glacial acetic acid under the action of a catalyst comprises the following steps:

[0145] Step 1, loading the catalyst immobilized bed: 20 g of the catalyst prepared in Example 1 was loaded into a tubular fixed bed reactor to form a catalyst immobilized bed;

[0146] Step 2, addition reaction:

[0147] After preheating the etherified C4 fraction and glacial acetic acid to 90 degrees Celsius, the space velocity of the etherified C4 fraction was controlled to be 1.2h -1 The C4 fraction and glacial acetic acid are fed into a tubular fixed-bed reactor with an acid-olefin ratio of 1.0-2.0:1. The feed temperature is controlled at 90 degrees Celsius, the discharge temperature is 128 degrees Celsius, the reaction pressure is 2.2-2.4 MPa, and a magnetic field of 500-620 oe is applied. The n-butene, cis-butene, and trans-butene in the etherified C4 olefins flow through the tubular fixed-bed reactor with the glacial acetic acid, where an addition reaction occurs under the action of the fixed catalyst bed to produce sec-butyl acetate.

[0148] The reaction parameters of Application Examples 2-7 are shown in Table 2;

[0149] 2. Index detection:

[0150] Same as Application Example 1, the results are shown in Table 2;

[0151] 3. Results and Analysis

[0152] Table 2

[0153]

[0154]

[0155] Note: - means the test was not conducted; the period of more than 33 days is because the system did not meet the catalyst replacement criteria when it ran for 33 days, and the system was automatically stopped.

[0156] Application Example 8: Industrial Application Example

[0157] The method for synthesizing sec-butyl acetate from a post-etherification C4 fraction and glacial acetic acid comprises the following steps:

[0158] Step 1, loading the catalyst immobilized bed: loading the catalyst prepared in Example 1 into the esterification reaction kettle to form a catalyst immobilized bed;

[0159] Step 2, addition reaction:

[0160] After preheating the etherified C4 fraction and glacial acetic acid to 90 degrees Celsius, the space velocity of the etherified C4 fraction was controlled to be 1.2h -1 The acid-olefin ratio is 1.5:1. The C4 fraction and glacial acetic acid are respectively fed into an esterification reactor. The feed temperature is controlled at 90 degrees Celsius, the discharge temperature is 128 degrees Celsius, the reaction pressure is 2.2-2.4 MPa, and a magnetic field with an intensity of 580 oe is applied. The butenes in the C4 olefins flow through the esterification reactor and react with the glacial acetic acid under the action of the fixed catalyst bed to produce sec-butyl acetate, thereby obtaining a reaction product containing sec-butyl acetate.

[0161] Step 3: Using water as an azeotropic solvent, the reaction product containing sec-butyl acetate generated in step 2 is subjected to azeotropic distillation to remove acetic acid and C8 olefins to obtain a sec-butyl acetate product.

[0162] After the system was operated continuously for 300 h, it was shut down, the sec-butyl acetate product obtained was collected and weighed, and its purity (sec-butyl acetate content) was measured, and the total yield of sec-butyl acetate was calculated;

[0163] The content of sec-butyl acetate was determined by gas chromatography;

[0164] Total yield of sec-butyl acetate (%) = (weight of sec-butyl acetate product * purity / molecular weight of sec-butyl acetate) / molar amount of n-butene, trans-butene and cis-butene fed * 100%;

[0165] The total yield of sec-butyl acetate obtained in this application example is 90.27%; the purity (content) of the sec-butyl acetate product is 99.1%.

[0166] The above-described embodiments are only preferred embodiments of the present invention and are not exhaustive of all feasible implementations of the present invention. For those skilled in the art, any obvious modifications made thereto without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A magnetic ceramsite catalyst loaded with heteropoly acid for the reaction of synthesizing sec-butyl acetate from a post-etherification C4 fraction and glacial acetic acid, characterized in that: The composition comprises the following raw materials in parts by weight: 20-30 parts perlite; 20-30 parts silicon carbide; 10-15 parts zeolite powder; 10-15 parts magnetic material; 6-15 parts N,N'-dimethyl-N,N'-dinitrosoterephthalamide (foaming agent); 80-120 parts PVA solution; 5-10 parts expanded graphite; 3-5 parts calcium carbonate (pore-forming agent); 5-10 parts marble glue. The magnetic material is strontium ferrite; A magnetic ceramsite catalyst loaded with a heteropoly acid, wherein the heteropoly acid is phosphotungstic acid; and a preparation method thereof, comprising the following steps: Step 1, preparing porous magnetic ceramsite: After weighing various raw materials according to weight, first, the raw materials are configured into a magnetic ceramic slurry, and then foaming treatment is performed to obtain a foamed magnetic ceramic body, and then the foamed magnetic ceramic body is crushed, ball-milled, and sieved to obtain a magnetic ceramsite body, and then high-temperature calcination and acid leaching are performed to obtain porous magnetic ceramsite; Step 2, loading heteropoly acid: dissolve sodium tungstate and disodium hydrogen phosphate in boiling water to prepare sodium tungstate solution, then add porous magnetic ceramsite to the sodium tungstate solution, stir for 8-12 minutes, add concentrated hydrochloric acid dropwise under stirring, and continue stirring for 0.5-1.5 hours. Take out, dry, wash with water 3-5 times, dry again, and calcine at 300 degrees Celsius for 50-70 minutes to obtain a magnetic ceramsite catalyst loaded with heteropoly acid.

2. The magnetic ceramsite catalyst loaded with heteropoly acid for the reaction of the post-ether C4 fraction with glacial acetic acid to synthesize sec-butyl acetate according to claim 1, characterized in that: The raw materials are configured into a magnetic ceramic slurry, including: first, uniformly mixing a PVA solution and a foaming agent to prepare a mixed solution of PVA and the foaming agent; then, mixing perlite, silicon carbide, zeolite powder, magnetic material, expanded graphite, a pore-forming agent and marble glue, grinding the mixture for 30-60 minutes, adding a freshly prepared mixed solution of PVA and the foaming agent, and continuing to grind and disperse the mixture for 5-15 minutes to obtain the magnetic ceramic slurry.

3. The magnetic ceramsite catalyst loaded with heteropoly acid for the reaction of the post-ether C4 fraction and glacial acetic acid to synthesize sec-butyl acetate according to claim 1, characterized in that: The foaming treatment includes: pouring the magnetic ceramic slurry into the mold, letting it stand for 45-55 minutes, heating the mold at 145-155°C for 75-85 minutes to perform foaming treatment, taking out the material after it is completely dried, demoulding, and obtaining a foamed magnetic ceramic body.

4. The magnetic ceramsite catalyst loaded with heteropoly acid for the reaction of the post-ether C4 fraction with glacial acetic acid to synthesize sec-butyl acetate according to claim 1, characterized in that: The high temperature sintering and acid leaching include: heating the magnetic ceramsite body to 900-1100°C in a muffle furnace, calcining for 1.5-2.5h, cooling to room temperature, soaking in 3mol / L sulfuric acid for 25-35min, and using water to remove H + Rinse clean and dry to obtain porous magnetic ceramsite.

5. The magnetic ceramsite catalyst loaded with heteropoly acid for the reaction of the post-ether C4 fraction and glacial acetic acid to synthesize sec-butyl acetate according to claim 1, characterized in that: During the preparation of sodium tungstate solution, the ratio of sodium tungstate, sodium dihydrogen phosphate and boiling water is 6.0-6.5g:1g:1500mL; Add porous magnetic ceramsite to the sodium tungstate solution at a material-liquid ratio of 1g:7-9mL.

6. A method for preparing sec-butyl acetate, characterized in that: The steps include: Step 1, reaction: After preheating the C4 fraction after etherification and glacial acetic acid to 90-100 degrees Celsius, control the space velocity of the C4 fraction after etherification to 1.0-2.0h -1 , acid-olefin ratio = 1.1-3.5:1, the etherified C4 fraction and glacial acetic acid are respectively fed into an esterification reaction kettle, the feed temperature is controlled at 90-100 degrees Celsius, the discharge temperature is controlled at 125-130 degrees Celsius, the reaction pressure is controlled at 1.5-3.0 MPa, and a magnetic field with an intensity of 540-620 Oe is applied for treatment, the n-butene, maleic butene and trans-butene in the etherified C4 olefins flow through the esterification reaction kettle with the glacial acetic acid, and an addition reaction occurs under the action of a fixed catalyst bed to generate sec-butyl acetate, thereby obtaining a reaction product containing sec-butyl acetate; the catalyst used in the fixed catalyst bed is the heteropolyacid-loaded magnetic ceramsite catalyst for the reaction of synthesizing sec-butyl acetate from the etherified C4 fraction and glacial acetic acid as described in any one of claims 1-5.

7. The method for preparing sec-butyl acetate according to claim 6, wherein: Also includes step 2, separation and purification; The separation and purification comprises: Using water as an azeotropic agent, acetic acid and C8 olefins in the reaction product containing sec-butyl acetate generated in step 1 are removed by azeotropic distillation to obtain a sec-butyl acetate product.

8. The method for preparing sec-butyl acetate according to claim 6, wherein In step 1, the acid-olefin ratio is 1.5-2.5:1; and the reaction pressure is 2.2-2.4 MPa.

9. The method for preparing sec-butyl acetate according to claim 6, wherein In step 1, the magnetic field strength is 550-610 Oe.

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