Method for resource utilization of isobutene amination waste liquid

Abstract

The application discloses a method for recycling and utilizing isobutylene amination waste liquid, and steps of the method comprise the following: the isobutylene amination waste liquid and heated ammonia gas are introduced into a reaction rectifying tower, the tower is filled with an ammonolysis catalyst bed layer, the isobutylene amination waste liquid and the ammonia gas are reversely contacted in the catalyst bed layer, an ammonolysis reaction is carried out, and a tert-butylamine product is obtained. The method is extremely simple in process, low in equipment investment and operation cost, can recycle and utilize the isobutylene amination waste liquid, reduces product unit consumption and device operation cost, greatly reduces three-waste emissions, and is more green and environment-friendly.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals, specifically relating to a method for the resource utilization of isobutylene amination waste liquid using reactive distillation. Background Technology

[0002] Tert-butylamine, as an important chemical intermediate, plays a crucial role in the field of rubber accelerators. Accelerators are the most basic and important class of rubber additives, and constitute the largest category of rubber additives in my country. The sulfenamide accelerators NS (N-tert-butyl-2-benzothiazole sulfenamide) and TBSI (N-tert-butylbis-2-benzothiazole sulfenamide), synthesized from tert-butylamine, are characterized by not producing carcinogenic nitrosamines during vulcanization. They also possess the advantages of general sulfenamide accelerators, being very safe at operating temperatures, exhibiting good scorch resistance, and allowing for increased use in synthetic rubber and the addition of carbon black as filler. Their performance is very close to that of NOBS (2-morpholinobenzothiazole sulfenamide), the main accelerator currently used in China. With minimal discoloration and pollution, and excellent performance, they are known as "standard accelerators" and are the most ideal substitute for the carcinogenic NOBS accelerator.

[0003] There are various methods for preparing tert-butylamine, such as the tert-butylurea hydrolysis method, the tert-butylamide hydrolysis method, the isobutylene-HCN method, and the haloalkanes amination method. These processes involve the use and treatment of strong acids / bases, resulting in serious equipment corrosion and pollution problems, which do not meet the requirements of green chemistry.

[0004] The direct amination of isobutylene to prepare tert-butylamine is a clean process with 100% atom utilization, meeting the requirements of green chemistry and sustainable development, and is the future direction for the research and industrial production of tert-butylamine.

[0005] In the 1970s, research began abroad on the direct catalytic amination of isobutylene to tert-butylamine, but it failed to be applied due to poor reaction selectivity and short catalyst lifetime.

[0006] US4375002 uses amorphous aluminum silicate or aluminum silicate molecular sieve as catalysts for the direct amination of isobutylene. However, due to the excessively strong acid centers in aluminum silicate materials and aluminum silicate molecular sieves, they easily promote the polymerization of olefins at high temperatures, leading to carbon accumulation on the catalyst surface and rapid deactivation of the catalyst, thus failing to achieve industrial scale-up application.

[0007] US4929759 studied the amination activity of synthesized borosilicate molecular sieves and found that after reacting for 30 min at 350℃, 30 MPa, and a molecular ratio of isobutylene to ammonia of 1:1.5, the isobutylene conversion rate was 14.1% and the selectivity was 95.7%. However, there were a lot of byproducts, which can only be treated as hazardous waste in industry.

[0008] CN104418754A discloses the preparation of tert-butylamine using a tubular fixed bed reactor. The product is obtained through multi-step stripping, with tert-butylamine being extracted from the side stream of the refining tower. The results show that the yield of tert-butylamine for isobutylene in the entire process is 96.1%, of which 3.9% is lost as a heavy component.

[0009] According to existing technologies, the preparation of tert-butylamine by isobutylene amination currently in industrial applications mostly uses a bed reactor. The mother liquor is purified after removing light components to obtain the product. During the product purification process, the heavy components in the bottom of the tower are mainly high-boiling substances generated by the polymerization of raw material isobutylene, or MTBE, tert-butanol, etc., generated by side reactions caused by impurities in the raw material (such as methanol and water), as well as di-tert-butylamine generated by the deamination side reaction of tert-butylamine on the surface of acidic catalyst. These products have complex compositions, many of which have azeotropic properties and are difficult to separate. They generally cannot be used directly in industry and can only be incinerated, resulting in resource waste.

[0010] Therefore, if a method can be developed to utilize tert-butylamine waste liquid in a resource-efficient manner, decomposing it into products or light components for reuse, it can significantly reduce product consumption per unit and equipment operating costs, thereby greatly reducing the discharge of waste gas, wastewater, and solid waste, making the process more environmentally friendly. Summary of the Invention

[0011] To address the aforementioned shortcomings in existing technologies, this invention aims to provide a method for the resource-based utilization of isobutylene amination waste liquid. This method involves loading an ammonolysis catalyst bed into a reactive distillation column, and then counter-currently contacting the isobutylene amination waste liquid with heated ammonia gas in the catalyst bed. The waste liquid is then ammonolyzed to produce tert-butylamine. This invention significantly reduces the amount of waste liquid generated in tert-butylamine plants, utilizes reactive heavy components, lowers product consumption and plant operating costs, and substantially reduces emissions of waste gas, wastewater, and solid waste, making it more environmentally friendly.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A method for resource utilization of isobutylene amination waste liquid, comprising the following steps:

[0014] The isobutylene amination waste liquid and heated ammonia gas are passed into a reactive distillation column. The column is filled with an ammonolysis catalyst bed. The isobutylene amination waste liquid and ammonia gas are in countercurrent contact within the catalyst bed to carry out an ammonolysis reaction, yielding tert-butylamine product.

[0015] The isobutylene amination waste liquid originates from the isobutylene amination process to prepare tert-butylamine. It has a complex composition, including heavy components in the bottom of the refining tower during the product purification process (mainly high-boiling substances generated by the polymerization of raw material isobutylene), MTBE, tert-butanol, etc., generated by side reactions caused by impurities in the raw materials (such as methanol and water), and di-tert-butylamine, etc., generated by the deamination side reaction of tert-butylamine on the surface of acidic catalyst.

[0016] In some specific examples, the isobutylene amination waste liquid comprises, by weight percentage: tert-butylamine 1-50 wt%, for example 1 wt%, 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, preferably 5-30 wt%; di-tert-butylamine 5-50 wt%, for example 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, preferably 15-40 wt%; methyl tert-butyl ether (MTBE) 5-50 wt%, for example 5 wt%... 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, preferably 25-40wt%; tert-butanol 10-70wt%, for example 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt%, preferably 35-60wt%; isobutylene polymer 10-80wt%, for example 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, preferably 20-60wt%;

[0017] Preferably, the isobutylene amination waste liquid is preheated before feeding, and the temperature is 100-150℃, for example, 100℃, 110℃, 120℃, 130℃, 140℃, or 150℃.

[0018] In some specific examples, the ammonia gas is high-purity, superior-grade ammonia gas with a purity > 99.9%;

[0019] The ammonia heating temperature is 150-300℃, for example, 150℃, 180℃, 200℃, 230℃, 260℃, 300℃, preferably 160-200℃.

[0020] In some specific examples, preferably, the mass ratio of the isobutylene amination waste liquid to ammonia is 0.1-1:1, for example 0.1:1, 0.3:1, 0.6:1, 0.8:1, 1:1, and more preferably 0.4-0.8:1.

[0021] In some specific examples, the ammonolysis catalyst is a dual transition metal supported catalyst;

[0022] Preferably, the supported dual transition metals include a primary active metal selected from Ni, Co, Pd, and Pt, with a loading of 2-20 wt%, for example, 2 wt%, 5 wt%, 8 wt%, 10 wt%, 13 wt%, 16 wt%, 18 wt%, and 20 wt%, preferably 5-10 wt%; and a secondary active metal selected from Fe, Cu, and Zn, with a loading of 1-15 wt%, for example, 1 wt%, 3 wt%, 6 wt%, 8 wt%, 10 wt%, 13 wt%, and 15 wt%, preferably 5-8 wt%, all of which are based on the total mass of the dual transition metal supported catalyst.

[0023] The dual transition metal supported catalyst, wherein the support is selected from at least one of α-Al2O3, θ-Al2O3, ZrO2, and diatomaceous earth;

[0024] Preferably, the carrier has a bulk density of 0.2-1 g / ml and a specific surface area of ​​20-400 m². 2 / g e.g. 20m 2 / g, 50m 2 / g, 100m 2 / g, 150m 2 / g、200m 2 / g、250m 2 / g、300m 2 / g, 350m 2 / g、400m 2 / g, with pore volumes of 0.1-0.5ml / g, for example, 0.1ml / g, 0.2ml / g, 0.3ml / g, 0.4ml / g, 0.5ml / g;

[0025] Preferably, the dual transition metal supported catalyst is spherical, strip-shaped, or clover-shaped; with a diameter of 2-8 mm, for example, 2 mm, 4 mm, 6 mm, or 8 mm, preferably 2-4 mm; and a bed bulk density of 0.5-10 g / ml, for example, 0.5 g / ml, 1 g / ml, 3 g / ml, 5 g / ml, 7 g / ml, 9 g / ml, or 10 g / ml, preferably 0.8-4 g / ml.

[0026] The dual transition metal supported catalyst of this invention can be prepared using conventional methods for supported catalysts already disclosed in the prior art, such as impregnation. For example, a method for preparing the dual transition metal supported catalyst of this invention includes the following steps:

[0027] 1) Prepare an aqueous solution of the dual transition metal salt, mix it with the carrier, heat it to 30-60℃ (e.g., 30℃, 40℃, 50℃, 60℃) and reflux and stir for 2-6 hours (e.g., 2 hours, 3 hours, 4 hours, 5 hours, 6 hours);

[0028] 2) Add a precipitant dropwise to the system in step 1), preferably at a dropping rate of 1-3 g / min, to perform wet precipitation impregnation. After impregnation, age the system under certain conditions, then filter and wash with deionized water until neutral, dry (preferably at 80-120℃ for 10-24 h), and calcine (preferably at 450-650℃ for 6-18 h) to obtain catalyst powder.

[0029] 3) Mix the catalyst powder with a certain amount of binder evenly, and then add a nitric acid aqueous solution with a concentration of 10-40wt% (preferably 2-10% of the mass of the catalyst powder, such as 1%, 4%, 6%, 8%, or 10%). After kneading, shape the mixture, dry it (preferably at 80-120℃ for 10-24h), and calcine it (preferably at 450-650℃ for 6-18h) to obtain a dual transition metal supported catalyst.

[0030] Preferably, the dual transition metal salt is selected from at least one of the transition metal nitrates, acetates, and carbonates.

[0031] Preferably, the dual transition metal is selected from one of Ni, Co, Pd, and Pt, and one of Fe, Cu, and Zn. More preferably, the mass ratio of the two metal salts is 1:0.2-1.2, for example, 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1, or 1:1.2.

[0032] Preferably, the dual transition metal salt is prepared as an aqueous solution, and its total concentration in the solution is 1-20 wt%, for example, 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, preferably 1-10 wt%.

[0033] Preferably, the mass ratio of the aqueous solution prepared from the dual transition metal salt to the carrier used is 5-100:1, for example, 5:1, 20:1, 40:1, 60:1, 80:1, 100:1, and more preferably 5-50:1.

[0034] Preferably, the precipitant is selected from alkaline solutions, and more preferably from at least one aqueous solution of sodium hydroxide, sodium carbonate, lithium hydroxide, or potassium hydroxide.

[0035] Preferably, the alkaline solution has a concentration of 20-50 wt%, for example, 20 wt%, 30 wt%, 40 wt%, 50 wt%, and more preferably 20-30 wt%.

[0036] Preferably, the molar ratio of the precipitant to the transition metal in the dual transition metal salt is 1.5-5:1, for example, 1.5:1, 2:1, 3:1, 4:1, or 5:1.

[0037] Preferably, the aging process involves an aging temperature of 20-80℃, such as 20℃, 40℃, 60℃, or 80℃, with a preference for 40-60℃, and an aging time of 2-12h, such as 2h, 4h, 6h, 8h, 10h, or 12h, with a preference for 4-8h.

[0038] Preferably, the mass ratio of the catalyst powder to the binder is 3-6:1, for example 3:1, 4:1, 5:1, 6:1, and more preferably 4-5:1.

[0039] Preferably, the binder is at least one of diatomaceous earth and guar gum powder.

[0040] Those skilled in the art should understand that the above-described preparation method is merely an exemplary description of the source method of the dual transition metal supported catalyst with the above-described characteristics of the present invention, and does not constitute any limitation.

[0041] In some preferred embodiments, the ammonolysis catalyst bed is first activated by heat treatment in a hydrogen atmosphere before the reaction begins. Since the catalyst used in this invention is a dual transition metal supported catalyst, the supported oxidized catalyst needs to be reduced to the metal active state before use.

[0042] Preferably, during the activation process, the activation temperature is 200-300℃, for example, 200℃, 220℃, 240℃, 260℃, 280℃, 300℃, and more preferably 200-250℃; the activation pressure is 0.1-5MPaG, for example, 0.1MPaG, 1MPaG, 2MPaG, 3MPaG, 4MPaG, 5MPaG, and more preferably 0.1-0.5MPaG; and the activation time is 12-72h, for example, 12h, 20h, 40h, 60h, 72h, and more preferably 12-24h.

[0043] In some specific examples, during the ammonolysis reaction process, the pressure of the reactive distillation column is controlled at 1-5 MPaG, for example, 1 MPaG, 2 MPaG, 3 MPaG, 4 MPaG, or 5 MPaG, preferably 1.5-2.5 MPaG; the reaction feed space velocity is 1-5 h⁻¹. -1 (Based on tert-butylamine waste liquid) For example, 1h -1 2h -1 3h -1 4h -1 5h -1 Preferred 1-3 hours -1 ;

[0044] Preferably, the temperature at the top of the tower is 100-200℃, for example, 100℃, 120℃, 140℃, 160℃, 180℃, or 200℃, and more preferably 120-180℃; the temperature at the bottom of the tower is 150-250℃, for example, 150℃, 170℃, 190℃, 210℃, 230℃, or 250℃, and more preferably 170-220℃.

[0045] In some preferred examples, a gaseous product is obtained from the top of the reactive distillation column, and tert-butylamine and unreacted ammonia are separated. The tert-butylamine is sent to a product storage tank as a product, while the ammonia is recycled.

[0046] In the method of this invention, the isobutylene amination waste liquid undergoes ammonolysis in a catalyst bed. The heavy component di-tert-butylamine is ammonolyzed to generate tert-butylamine, the heavy component MTBE is ammonolyzed to methanol and tert-butylamine, and a portion of the heavy component tert-butanol is amination to tert-butylamine and water. The tert-butylamine produced after ammonolysis of each component is discharged as a product at the top of the column as a recovered product. The gaseous product also contains some unreacted ammonia, which is recycled. The remaining unammonolyzed waste liquid at the bottom of the column, mainly containing a small amount of isobutylene polymer, as well as methanol and water produced by decomposition, is treated as waste liquid and incinerated.

[0047] Compared with the prior art, the positive effects of the technical solution of this invention are as follows:

[0048] This invention employs a reactive distillation column packed with an ammonolysis catalyst to convert the components of isobutylene amination waste liquid into recyclable tert-butylamine product. Simultaneously, unreacted ammonia gas is returned to the unit for recycling. This method significantly reduces the amount of waste liquid generated in tert-butylamine plants, utilizes the reaction components as resources, lowers product consumption and plant operating costs, and substantially reduces emissions of waste gas, wastewater, and solid waste, making it more environmentally friendly. Detailed Implementation

[0049] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0050] The main raw material sources in the various embodiments and comparative examples of this invention are shown in Table 1 below. Unless otherwise specified, all other raw materials were purchased from commercially available finished products.

[0051] α-Al₂O₃: Loose bulk density is 0.6 g / ml, specific surface area is 56 m². 2 / g, pore volume is 0.3ml / g, manufacturer is Zibo Yishengjia Aluminum Co., Ltd.;

[0052] ZrO2: Loose bulk density is 0.5 g / ml, specific surface area is 70 m² / ml. 2 / g, pore volume is 0.2ml / g, manufacturer is Hangzhou Hengna New Materials Co., Ltd.;

[0053] Diatomaceous earth: loose bulk density is 0.3 g / ml, specific surface area is 40 m². 2 / g, pore volume is 0.1ml / g, manufacturer is Shengzhou Huali Diatomite Products Co., Ltd.;

[0054] HY molecular sieve: silicon-to-aluminum ratio of 25, manufactured by Zhuoran Environmental Protection Technology Co., Ltd.

[0055] Isobutylene amination waste liquid: Liquid ammonia and isobutylene react at 250℃ with HY molecular sieve catalyst and 20MPa in the reactor to generate reaction mother liquor. The reaction mother liquor is then distilled and the bottom of the column is used to obtain tert-butylamine waste liquid.

[0056] Preparation of dual transition metal supported catalysts (cat1-3)

[0057] Preparation Example 1 (cat-1)

[0058] 10 g of α-Al₂O₃ support was placed in a three-necked flask with reflux, and then 156 g of 2 wt% nickel nitrate aqueous solution and 216 g of [unclear text - possibly a typo, should be "added"] were added. A 1 wt% ferric nitrate aqueous solution was refluxed and stirred at 50°C for 2 h. Then, 49 g of a 10 wt% sodium hydroxide aqueous solution (the molar ratio of sodium hydroxide to the total amount of transition metals Ni and Fe was 4.6:1) was added at a rate of 3 g / min. After the addition was complete, the solution was aged at 60°C for 6 h and stirred until clear. The solution was then filtered and washed with deionized water until neutral. The solution was dried at 80°C for 10 h and then calcined at 450-650°C for 12 h to obtain catalyst powder. 10 g of the obtained catalyst powder was mixed evenly with 2.5 g of pseudohydrate boehmite in a mortar. Then, 0.4 g of a 30 wt% nitric acid aqueous solution was added. The mixture was kneaded into strips, dried at 80°C for 10 h, and then calcined at 500°C for 10 h to obtain a dual transition metal supported catalyst with a Ni loading of 10 wt% and an Fe loading of 5 wt%, a diameter of 2-3 mm, and a bed density of 0.7 g / ml.

[0059] Preparation Example 2 (cat-2)

[0060] 10g of ZrO2 support was placed in a three-necked flask with reflux, and then 49g of 5wt% cobalt nitrate aqueous solution and 8g of 8wt% zinc nitrate aqueous solution were added. The mixture was refluxed and stirred at 30°C for 3h. Then, 35g of 5wt% lithium hydroxide aqueous solution (the molar ratio of lithium hydroxide to the total amount of transition metals Co and Zn was 4:1) was added at a rate of 2g / min. After the addition was completed, the mixture was aged at 50°C for 6h and stirred until the solution was clear. The solution was then filtered and washed with deionized water until neutral. The sample was dried at 80°C for 10h and then calcined at 450-650°C for 18h to obtain catalyst powder. The powder was then kneaded and molded in the same way as in Preparation Example 1 to obtain a dual transition metal supported catalyst with a Co loading of 10wt% and a Zn loading of 5wt%, a diameter of 2-3mm, and a bed density of 0.6g / ml.

[0061] Preparation Example 3 (cat-3)

[0062] 10g of diatomaceous earth support was placed in a three-necked flask with reflux, and then 19g of 10wt% palladium acetate solution and 41g of 5wt% copper nitrate aqueous solution were added. The mixture was stirred at 60℃ for 4h, and then 83g of 10wt% lithium hydroxide aqueous solution (the molar ratio of lithium hydroxide to the total amount of transition metals Pd and Cu was 4:1) was added at a rate of 2g / min. After the addition was completed, the mixture was aged at 40℃ for 8h and stirred until the solution was clear. The solution was then filtered and washed with deionized water until neutral. The sample was dried at 80℃ for 10h and then calcined at 450-650℃ for 15h to obtain catalyst powder. The powder was then kneaded and molded in the same way as in Preparation Example 1 to obtain a dual transition metal supported catalyst with a Pd loading of 9wt% and a Cu loading of 7wt%, a diameter of 4-5mm, and a bed bulk density of 0.7g / ml.

[0063] Preparation of Comparative Example 1 (cat-1')

[0064] 10g of α-Al2O3 carrier was mixed with 2.5g of pseudo-hydrated diatomite in a mortar, and then 0.4g of 30wt% nitric acid aqueous solution was added. After kneading, the mixture was shaped, dried at 80℃ for 10h, and then calcined at 500℃ for 10h to obtain the shaped carrier.

[0065] Preparation of Comparative Example 2 (cat-2')

[0066] The preparation method is the same as in Preparation Example 1, but only 156g of 2wt% nickel nitrate aqueous solution is added during the addition of the dual transition metal solution, and ferric nitrate aqueous solution is not added.

[0067] Preparation of Comparative Example 3 (cat-3')

[0068] The preparation method is the same as in Preparation Example 2, but only 49g of 5wt% cobalt nitrate aqueous solution is added during the addition of the dual transition metal solution, and zinc nitrate aqueous solution is not added.

[0069] Preparation of Comparative Example 4 (cat-4')

[0070] The preparation method is the same as in Preparation Example 3, but only 19g of 10wt% palladium acetate aqueous solution is added during the addition of the dual transition metal solution, and copper nitrate aqueous solution is not added.

[0071] Examples 1-3

[0072] The catalysts obtained in Preparation Examples 1-3 were respectively loaded into the ammonolysis catalyst bed of a reactive distillation column. Before the reaction started, the temperature was adjusted to about 250°C in a hydrogen atmosphere to activate the catalyst for 20 hours, while maintaining a pressure of 0.1 MPaG. Unreacted hydrogen and water generated during the activation process were discharged from the top of the column with the gas phase.

[0073] After activation, the feed temperature of ammonia (purity > 99.9%) is adjusted to approximately 180℃, and the feed temperature of the isobutylene amination waste liquid is adjusted to approximately 120℃. The isobutylene amination waste liquid (composition includes 5wt% tert-butylamine, 15wt% di-tert-butylamine, 25wt% MTBE, 35wt% tert-butylamine, and 20wt% isobutylene polymer) passes through the catalyst bed from the top via a liquid distributor, while ammonia passes through the reactor from the bottom. The waste liquid and ammonia undergo a counter-current ammonolysis reaction through the catalyst bed, with an ammonia to waste liquid mass ratio of approximately 1:1. The tower pressure is controlled at approximately 2MPaG via a top regulating valve, and the reaction feed space velocity is 2.5 h⁻¹. -1 The temperature at the top of the column is 130℃ and the temperature at the bottom of the column is 200℃. The gaseous products generated after the ammoniactomy of the waste liquid are unreacted ammonia and tert-butylamine. The gaseous products, carrying the heat of reaction, leave through a separate gaseous channel and return to the light tower of the unit. The ammonia is recycled, and the tert-butylamine is used as a product and enters the product storage tank. Samples of the tert-butylamine at the top of the column as a product and samples from the bottom of the column were taken and analyzed. The results are shown in Table 1.

[0074] Comparative Examples 1-4

[0075] The method of Example 1 was followed, but the catalyst was replaced with that used in Comparative Examples 1-4. The results are shown in Table 1.

[0076] Table 1

[0077]

[0078] The results above show that after reactive distillation and ammonolysis, over 99% of the organic products at the top of the isobutylene amination waste liquid are tert-butylamine, with only a small amount of methanol being distilled to the top as well. At the bottom, the heavy components, including MTBE, tert-butanol, and di-tert-butylamine, are almost completely ammonolyzed, with tert-butanol decreasing from 35% to below 5%. This demonstrates that this treatment method can utilize the isobutylene amination waste liquid in a resource-efficient manner, reusing a large number of heavy components in the waste liquid by ammonolysis into the product tert-butylamine, reducing product consumption per unit and equipment operating costs, and significantly reducing emissions of waste gas, wastewater, and solid waste, making it more environmentally friendly.

[0079] Examples 4-6

[0080] The tower pressure in Example 1 was controlled at 1 MPaG, 1.5 MPaG, and 2.5 MPaG, while other operations and parameters remained unchanged. The results are shown in Table 2.

[0081] Examples 7-8

[0082] The reactive distillation temperature in Example 1 was controlled at 160℃ and 200℃ respectively, while other operations and parameters remained unchanged. The results are shown in Table 2.

[0083] Table 2

[0084]

[0085] The results above show that by controlling the reactive distillation parameters, the purity of tert-butylamine in the organic product at the top of the column can be controlled to above 99.8%, the di-tert-butylamine and MTBE in the heavy components at the bottom of the column can be aminated to above 95%, and the tert-butanol in the bottom of the column can be amination to above 80%. This proves that this treatment method can convert more than 70% of the heavy components in the isobutylene amination waste liquid into valuable tert-butylamine products for reuse, greatly reducing product consumption and equipment operating costs, significantly reducing the emission of waste gas, wastewater, and solid waste, and making it more green and environmentally friendly.

Claims

1. A method for resource utilization of isobutylene amination waste liquid, characterized in that the steps include: include: The isobutylene amination waste liquid and heated ammonia gas are passed into a reactive distillation column. The column is filled with an ammonolysis catalyst bed. The isobutylene amination waste liquid and ammonia gas are in countercurrent contact within the catalyst bed to carry out an ammonolysis reaction to obtain tert-butylamine product. The isobutylene amination waste liquid comprises, by weight percentage: 1-50 wt% tert-butylamine, 5-50 wt% di-tert-butylamine, 5-50 wt% methyl tert-butyl ether, 10-70 wt% tert-butanol, and 10-70 wt% isobutylene polymer. The ammonolysis catalyst is a dual transition metal supported catalyst. The dual transition metals supported are selected as follows: the main active metal is selected from Ni, Co, Pd, and Pt, and its loading is 2-20 wt%; the auxiliary active metal is selected from Fe, Cu, and Zn, and its loading is 1-15 wt%. The loading amounts are all based on the total mass of the dual transition metal supported catalyst.

2. The method according to claim 1, characterized in that, The isobutylene amination waste liquid is preheated before feeding to a temperature of 100-150℃.

3. The method according to claim 1, characterized in that, The purity of the ammonia gas is >99.9%.

4. The method according to claim 1, characterized in that, The ammonia gas is heated at a temperature of 150-300℃.

5. The method according to claim 4, characterized in that, The heating temperature is 160-200℃.

6. The method according to claim 1, characterized in that, The mass ratio of the isobutylene amination waste liquid to ammonia is 0.1-1:

1.

7. The method according to claim 6, characterized in that, The mass ratio of the isobutylene amination waste liquid to ammonia is 0.4-0.8:

1.

8. The method according to claim 1, characterized in that, The loading of the main active metal is 5-10 wt%.

9. The method according to claim 1, characterized in that, The loading of the auxiliary active metal is 5-8 wt%.

10. The method according to claim 1, characterized in that, The dual transition metal supported catalyst, wherein the support is selected from at least one of α-Al2O3, θ-Al2O3, ZrO2, and diatomaceous earth.

11. The method according to claim 10, characterized in that, The carrier has a bulk density of 0.2-1 g / ml and a specific surface area of ​​20-400 m². 2 / g, with a pore volume of 0.1-0.5ml / g.

12. The method according to claim 1, characterized in that, The dual transition metal supported catalyst is spherical, strip-shaped, or clover-shaped; with a diameter of 2-8 mm and a bed bulk density of 0.5-10 g / ml.

13. The method according to claim 12, characterized in that, The diameter is 2-4 mm, and the bed bulk density is 0.8-4 g / ml.

14. The method according to claim 1, characterized in that, The preparation method of the dual transition metal supported catalyst includes the following steps: 1) Prepare an aqueous solution of the dual transition metal salt, mix it with the carrier, heat it to 30-60℃ and reflux and stir for 2-6 hours; 2) Add a precipitant dropwise to the system in step 1) and perform wet precipitation impregnation. After impregnation, age the system under certain conditions, then filter and wash with deionized water until neutral, dry, and calcine to obtain catalyst powder. 3) Mix the catalyst powder with a certain amount of binder evenly, then add a nitric acid aqueous solution with a concentration of 10-40wt%, knead and shape, dry and calcine to obtain a dual transition metal supported catalyst.

15. The method according to claim 14, characterized in that, The dual transition metal salt is selected from at least one of the nitrates, acetates, and carbonates of transition metals.

16. The method according to claim 14, characterized in that, The dual transition metal is selected from one of Ni, Co, Pd, and Pt, and one of Fe, Cu, and Zn.

17. The method according to claim 16, characterized in that, The mass ratio of the two metal salts is 1:0.2-1.

2.

18. The method according to claim 14, characterized in that, The dual transition metal salt is prepared as an aqueous solution, and its total concentration in the solution is 1-20 wt%.

19. The method according to claim 18, characterized in that, The total concentration of the dual transition metal salt in the solution is 1-10 wt%.

20. The method according to claim 14, characterized in that, The mass ratio of the aqueous solution prepared from the dual transition metal salt to the carrier used is 5-100:

1.

21. The method according to claim 20, characterized in that, The mass ratio of the aqueous solution prepared from the dual transition metal salt to the carrier used is 5-50:

1.

22. The method according to claim 14, characterized in that, The precipitant is selected from alkaline solutions.

23. The method according to claim 22, characterized in that, The precipitant is selected from at least one aqueous solution of sodium hydroxide, sodium carbonate, lithium hydroxide, and potassium hydroxide.

24. The method according to claim 22, characterized in that, The alkaline solution has a concentration of 20-50 wt%.

25. The method according to claim 24, characterized in that, The alkaline solution has a concentration of 20-30 wt%.

26. The method according to claim 14, characterized in that, The molar ratio of the precipitant to the transition metal in the dual transition metal salt is 1.5-5:

1.

27. The method according to claim 14, characterized in that, The aging process involves an aging temperature of 20-80℃ and an aging time of 2-12 hours.

28. The method according to claim 27, characterized in that, The aging process involves an aging temperature of 40-60℃ and an aging time of 4-8 hours.

29. The method according to claim 14, characterized in that, The mass ratio of the catalyst powder to the binder is 3-6:

1.

30. The method according to claim 29, characterized in that, The mass ratio of the catalyst powder to the binder is 4-5:

1.

31. The method according to claim 14, characterized in that, The binder is at least one of diatomaceous earth and guar gum powder.

32. The method according to claim 1, characterized in that, Before the reaction begins, the ammonolysis catalyst bed is first activated by heat treatment in a hydrogen atmosphere.

33. The method according to claim 32, characterized in that, During the activation process, the activation temperature is 200-300℃, the activation pressure is 0.1-5MPaG, and the activation time is 12-72h.

34. The method according to claim 33, characterized in that, The activation temperature is 200-250℃, the activation pressure is 0.1-0.5MPaG, and the activation time is 12-24h.

35. The method according to claim 1, characterized in that, In the ammonolysis reaction process, the pressure of the reactive distillation column is controlled at 1-5 MPaG; the feed space velocity is 1-5 h⁻¹. -1 Based on tert-butylamine waste liquid; The ammonolysis reaction process yields a gaseous product from the top of the reactive distillation column, which is then separated to obtain tert-butylamine and unreacted ammonia.

36. The method according to claim 35, characterized in that, The pressure of the reactive distillation column is 1.5-2.5 MPaG.

37. The method according to claim 35, characterized in that, The reaction feed space velocity is 1-3 h. -1 .

38. The method according to claim 35, characterized in that, The temperature at the top of the reactive distillation column is 100-200℃, and the temperature at the bottom is 150-250℃.

39. The method according to claim 35, characterized in that, The temperature at the top of the tower is 120-180℃, and the temperature at the bottom of the tower is 170-220℃.

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