A catalyst for bdo purification and a preparation method and application thereof

Abstract

The application discloses a catalyst for BDO purification, which is composed of a carrier and Pt, Mo and metal M supported on the carrier, wherein the metal M is Nd, Ce or La, and the carrier is an activated carbon carrier; the content of Pt is 0.03-0.3% by weight percentage, the content of Mo is 0.05-1% by weight percentage, the content of metal M is 0.05-1% by weight percentage, and the rest is the carrier. Meanwhile, the application also discloses a preparation method of the catalyst and application of the catalyst in BDO purification, and specifically, the residual impurity 4-hydroxybutyraldehyde in BDO is continuously hydrogenated to product BDO by using a fixed bed. The catalyst provided by the application has high catalytic activity, selectivity and stability, when used for purifying BDO, the molar conversion rate of the impurity or raw material 4-hydroxybutyraldehyde is greater than 99%, the molar yield of the product BDO is greater than 98%, the purification requirement is met, and the cumulative running time of the catalyst is long.

Description

Invention Field

[0001] This invention belongs to the field of aldehyde-based catalytic hydrogenation technology, specifically relating to a catalyst for BDO purification, its preparation method, and its application. Background Technology

[0002] 1,4-Butanediol (BDO) is an important basic organic chemical and fine chemical raw material. It has a wide range of applications, especially its derivatives, which are high-value-added fine chemical products widely used as solvents, in pharmaceuticals, cosmetics, plasticizers, curing agents, pesticides, rust removers, artificial leather, fibers, and engineering pigments. BDO is also used to manufacture tetrahydrofuran (THF), γ-butyrolactone (GBL), and N-methylpyrrolidone (NMP). Since the 1970s, the rapid development of the polyurethane industry and polybutylene terephthalate (PBT) engineering plastics has promoted the development of BDO. In recent years, PBT engineering plastics and PBT fibers have been widely used in the automotive, machinery, electronics, and electrical industries due to their ease of processing and excellent electrical, mechanical, and heat resistance properties. Polytetrahydrofuran (PTMEG) is a significant factor driving the growth of 1,4-butanediol. It is further processed into spandex elastic fibers, which are characterized by wear resistance, hydrolysis resistance, corrosion resistance, and high elongation, making them a new material widely used in the textile industry in recent years. BDO can also be used in the production of thermoplastic polyurethane elastomer rubber (TPU).

[0003] Residual 4-hydroxybutyraldehyde in BDO affects its purity and color. Color impacts the quality of downstream products. While product quality standards only require BDO color to be <10 APHA, color requirements vary across applications. For example, BDO used in γ-butyrolactone production only needs to meet product standards. PBT manufacturers generally prefer raw material BDO with a color of 5-8 APHA, with a color below 5 APHA being most desirable. High-end applications of BDO include TPU production; however, TPU raw material entry barriers are high. BDO used in TPU production requires not only low conventional color but also control over color after adding hydrochloric acid and after heating and cooling with added hydrochloric acid. During 1,4-butanediol production, color can reduce the yield of premium-grade products; especially during prolonged operation of the equipment and when the reaction catalyst is nearing the end of its lifespan, the appearance and color indicators of 1,4-butanediol may fail to meet the qualified product standards, resulting in a decline in product quality. Therefore, reducing product color and improving product quality are urgent issues. This invention prepares a catalyst for purifying BDO and improves product quality by hydrogenating 4-hydroxybutyraldehyde, which affects color. Summary of the Invention

[0004] Currently, there are no existing technologies for BDO purification. This invention provides a highly efficient BDO purification catalyst, which exhibits good activity, high selectivity, long lifespan, and a simple, environmentally friendly, and safe process. Furthermore, this invention also provides a method for preparing the catalyst and its application in converting 4-hydroxybutyraldehyde, an impurity affecting the color of BDO, into product BDO through hydrogenation in a fixed-bed reactor.

[0005] One object of the present invention is to provide a catalyst for the purification of BDO, which comprises a support and Pt, Mo and metal M supported on the support, wherein the metal M is Nd, Ce or La, and the support is an activated carbon support; based on a weight percentage of 100%, the content of Pt is 0.03-0.3%, the content of Mo is 0.05-1%, the content of metal M is 0.05-1%, and the remainder is the support.

[0006] Preferably, the content of Pt is 0.05-0.2%, the content of Mo is 0.1-0.3%, the content of metallic M is 0.1-0.5%, and the remainder is a carrier.

[0007] Preferably, the carrier is a columnar or sheet-like activated carbon carrier, and the average outer diameter of the carrier is 0.3-3 mm, and the specific surface area is 800-1700 m². 2 / g, axial compressive strength 20-45N.

[0008] Another object of the present invention is to provide a method for preparing the aforementioned catalyst, comprising the following steps:

[0009] (1) Dissolve the precursor of metal M in dilute hydrochloric acid to obtain solution M1, then add half the volume of pure water to solution M1, mix well, immerse the support in it, stir for 2-5 h, let stand for 12-24 h, filter to obtain solid material M2, vacuum dry solid material M2, then calcine, and naturally cool to room temperature to obtain catalyst precursor supported on M; the precursor of metal M is nitrate of Nd, nitrate of Ce, or nitrate of La;

[0010] (2) Dissolve the Pt precursor in a mixed dilute acid solution of dilute hydrochloric acid and dilute nitric acid at a volume ratio of 1:2 to obtain solution A; then dissolve the Mo precursor in dilute hydrochloric acid to obtain solution B; mix solutions A and B to obtain solution C, add 5% (by mass) phosphoric acid of solution C to it, and mix thoroughly; place the catalyst precursor loaded with M in a sugar coating machine at a speed of 20 r / min, and add the uniformly mixed impregnation solution dropwise to the catalyst rotating at a speed of 50-80 r / min using a peristaltic pump. After the dropwise addition is completed, let it stand for 12-24 h to obtain solid material D. Vacuum dry solid material D, then calcine it, and naturally cool it to room temperature to obtain the catalyst precursor loaded with Pt, Mo and M; the precursors of Pt and Mo are their hydrochloride salts or nitrates; wherein the mass concentration of the dilute hydrochloric acid and dilute nitric acid is 1.5-3.0%;

[0011] (3) The catalyst precursor obtained in step (2) is reduced by a reducing agent to obtain a catalyst for BDO purification.

[0012] Preferably, the reducing agent is hydrazine hydrate, sodium borohydride, potassium borohydride, sodium formate, or hydrogen gas diluted with nitrogen.

[0013] Preferably, the reducing agent is hydrogen diluted with nitrogen, wherein the volume ratio of nitrogen to hydrogen is (1-3):1, the reduction treatment temperature is 150-300℃, and the time is 2-4h.

[0014] Preferably, in steps (1) and (2), the vacuum drying is performed by first vacuum drying at 50-60℃ for 8-12 hours, and then vacuum drying at 110℃ for 8-12 hours.

[0015] Preferably, in steps (1) and (2), the calcination is carried out by first heating to 240°C at a rate of 1°C / min for 2 hours, and then heating to 300-450°C at a rate of 1°C / min for 8-12 hours.

[0016] Another objective of this invention is to provide a purification method, comprising the following steps:

[0017] (1) The catalyst described above and inert ceramic balls with a particle size of 1.0 mm-1.5 mm are alternately packed layer by layer into a fixed bed reactor.

[0018] Then nitrogen gas is introduced until the air in the fixed-bed reactor is completely purged; wherein the volume ratio of the catalyst to the inert ceramic balls is 2:1;

[0019] (2) Introduce hydrogen gas into the fixed-bed reactor, ensuring the hydrogen flow rate is 20 mL / min ≤ V. 氢气Under the condition of ≤50mL / min, the gas pressure in the fixed bed reactor is made to reach 0.05-0.1MPa. The catalyst is heated to 50-80℃ at a heating rate of 1-2℃ / min and then kept at the temperature. Hydrogen and BDO feed liquid containing impurities of 4-hydroxybutyraldehyde are preheated to the reaction temperature and then introduced into the fixed bed reactor for reaction at the reaction temperature and pressure.

[0020] (3) The reaction liquid obtained in step (2) is sent to a gas-liquid separator to separate BDO, and the resulting tail gas hydrogen is recycled by a hydrogen compressor.

[0021] Preferably, in step (2), the molar ratio of hydrogen to 4-hydroxybutyraldehyde, an impurity contained in the BDO feedstock liquid, is (5-12):1; and the mass hourly space velocity of 4-hydroxybutyraldehyde is 1.5-5.0 g / gcat / hr.

[0022] Preferably, the fixed bed reactor is a tubular fixed bed reactor, wherein the inner diameter of the reaction tubes in the tubular fixed bed reactor is 31-45 mm, and the filling height of the reaction tubes is 3.05-5.25 m.

[0023] The superior effects of this invention:

[0024] (1) The catalyst provided by the present invention has excellent catalytic activity, selectivity and stability, and can efficiently and continuously convert 4-hydroxybutyraldehyde into product BDO. The raw material molar conversion rate is greater than 99%, the product 1,4-butanediol selectivity is greater than 98%, and the catalyst cumulative running time can reach 12060h.

[0025] (2) When purifying BDO, a fixed-bed reactor is used, which provides mild reaction conditions that are easy to control. Continuous production can eliminate more variable operations (temperature, pressure, time) during the production process, avoid the quality differences between batches in batch production, and result in higher product quality stability.

[0026] (3) In the large-scale purification of BDO in industrial production, the degree of automation is high, the production efficiency is high, and the labor cost is low; there is no gas replacement, hydrogen is recycled, the reaction process is continuous, the energy consumption is lower, the precious metal content is low, and the catalytic cost is reduced after the production is stable. Specific implementation plan:

[0027] Unless otherwise specified, the raw materials involved in the embodiments of the present invention can be obtained from commercial sources or synthesized using commercially available starting materials and reagents through conventional methods in the art.

[0028] Example 1

[0029] The catalyst in this embodiment consists of a support and Pt, Mo, and Nd loaded on the support. The support is a columnar activated carbon support; based on a 100% weight percentage, the content of Pt is 0.1%, the content of Mo is 0.25%, the content of Nd is 0.3%, and the remainder is the support; the average outer diameter of the support is 1.8 mm, and the specific surface area is 1460 m². 2 / g, axial compressive strength 27N.

[0030] Its preparation method is as follows:

[0031] (1) Dissolve 0.24 g Nd in 1.5 wt% dilute hydrochloric acid to obtain solution M1. Add 45 mL of pure water, half the volume of solution M1, and mix well. Immerse columnar activated carbon in the solution, stir for 2 h, let stand for 12 h, filter, and obtain solid material M2. First, vacuum dry solid material M2 at 50 °C for 8 h, then vacuum dry at 110 °C for 8 h. Then, calcine at 240 °C for 2 h at a rate of 1 °C / min, then calcine at 300 °C for 10 h at a rate of 1 °C / min. After naturally cooling to room temperature, obtain Nd-supported catalyst precursor.

[0032] (2) Dissolve platinum chloride containing 0.12 g Pt in a mixed dilute acid solution of 1.5 wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.15 g Pt in a mixed dilute acid solution of 1.5 wt% Pt in a mixed dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve pla Molybdenum nitrate pentahydrate was dissolved in 1.5 wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5 g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The Nd-supported catalyst precursor was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was dripped onto the catalyst rotating at a constant speed using a peristaltic pump at a speed of 50 r / min. After the dripping was completed, the mixture was allowed to stand for 12 h to obtain solid material D. Solid material D was first vacuum dried at 50 °C for 8 h, then vacuum dried at 110 °C for 8 h. Then, it was first heated to 240 °C at a rate of 1 °C / min and calcined for 2 h, then heated to 300 °C at a rate of 1 °C / min and calcined for 10 h. After naturally cooling to room temperature, a catalyst precursor supported on Pt, Mo and Nd was obtained.

[0033] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 2:1, the reduction temperature is 200℃, and the time is 3h to obtain a catalyst for BDO purification.

[0034] Example 2

[0035] The catalyst in this embodiment consists of a support and Pt, Mo, and Nd supported on the support. The support is a columnar activated carbon support; based on a 100% weight percentage, the content of Pt is 0.2%, the content of Mo is 0.05%, the content of Nd is 0.2%, and the remainder is the support; the average outer diameter of the support is 1.8 mm, and the specific surface area is 1460 m². 2 / g, axial compressive strength 27N.

[0036] Its preparation method is as follows:

[0037] (1) Dissolve 0.16 g Nd in 1.5 wt% dilute hydrochloric acid to obtain solution M1. Add 45 mL of pure water, half the volume of solution M1, to the solution. Mix well and immerse the support in the solution. Stir for 2 h and let stand for 24 h. Filter to obtain solid material M2. First, vacuum dry solid material M2 at 50 °C for 8 h, then vacuum dry at 110 °C for 12 h. Then, calcine at 240 °C for 2 h at a rate of 1 °C / min, then calcine at 300 °C for 12 h at a rate of 1 °C / min. After naturally cooling to room temperature, obtain Nd-supported catalyst precursor.

[0038] (2) Dissolve platinum chloride containing 0.24 g Pt in a mixed dilute acid solution of 1.5 wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.03 g Pt in a mixed dilute acid solution of 1.5 wt% Pt in a mixed dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; Molybdenum nitrate pentahydrate was dissolved in 1.5 wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5 g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The Nd-supported catalyst precursor was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was dripped onto the catalyst rotating at a constant speed using a peristaltic pump at a speed of 50 r / min. After the dripping was completed, the mixture was allowed to stand for 24 h to obtain solid material D. Solid material D was first vacuum dried at 50 °C for 8 h, then vacuum dried at 110 °C for 12 h. Then, it was first heated to 240 °C at a rate of 1 °C / min and calcined for 2 h, then heated to 300 °C at a rate of 1 °C / min and calcined for 8 h. After naturally cooling to room temperature, a catalyst precursor supported on Pt, Mo and Nd was obtained.

[0039] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 1:1, the reduction temperature is 200℃, and the time is 3h to obtain a catalyst for BDO purification.

[0040] Example 3

[0041] The catalyst in this embodiment consists of a support and Pt, Mo and Nd loaded on the support. The support is a columnar activated carbon support. Based on a weight percentage of 100%, the content of Pt is 0.25%, the content of Mo is 0.2%, the content of Nd is 0.4%, and the remainder is the support. The support has an average outer diameter of 1.8 mm, a specific surface area of ​​1460 m2 / g, and an axial compressive strength of 27 N.

[0042] Its preparation method is as follows:

[0043] (1) Dissolve 0.32 g Nd in 1.5 wt% dilute hydrochloric acid to obtain solution M1. Add 45 mL of pure water, half the volume of solution M1, to the solution. Mix well and then immerse the support in the solution. Stir for 5 h and let stand for 12 h. Filter to obtain solid material M2. First, vacuum dry solid material M2 at 55 °C for 8 h, then vacuum dry at 110 °C for 10 h. Then, calcine at 240 °C for 2 h at a rate of 1 °C / min, then calcine at 450 °C for 8 h at a rate of 1 °C / min. After naturally cooling to room temperature, obtain Nd-supported catalyst precursor.

[0044] (2) Dissolve platinum chloride containing 0.3g Pt in a mixed dilute acid solution of 1.5wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.12g Pt in a mixed dilute acid solution of 1.5wt% Pt and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; Molybdenum nitrate pentahydrate was dissolved in 1.5 wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5 g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The Nd-supported catalyst precursor was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was added dropwise to the catalyst rotating at a constant speed using a peristaltic pump at a speed of 80 r / min. After the addition was completed, the mixture was allowed to stand for 12 h to obtain solid material D. Solid material D was first vacuum dried at 55 °C for 8 h, then vacuum dried at 110 °C for 10 h. Then, it was first heated to 240 °C at a rate of 1 °C / min and calcined for 2 h, then heated to 450 °C at a rate of 1 °C / min and calcined for 8 h. After naturally cooling to room temperature, a catalyst precursor supported on Pt, Mo and Nd was obtained.

[0045] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 3:1, the reduction temperature is 300℃, and the time is 2h to obtain a catalyst for BDO purification.

[0046] Example 4

[0047] The catalyst in this embodiment consists of a support and Pt, Mo, and Nd loaded on the support. The support is a columnar activated carbon support; based on a 100% weight percentage, the content of Pt is 0.04%, the content of Mo is 0.5%, the content of Nd is 0.1%, and the remainder is the support; and the average outer diameter of the support is 1.8 mm, and the specific surface area is 1460 m². 2 / g, axial compressive strength 27N.

[0048] Its preparation method is as follows:

[0049] (1) Dissolve 0.08 g Nd in 1.5 wt% dilute hydrochloric acid to obtain solution M1. Add 45 mL of pure water, half the volume of solution M1, to the solution. Mix well and then immerse the support in the solution. Stir for 2 h and let stand for 12 h. Filter to obtain solid material M2. First, vacuum dry solid material M2 at 60 °C for 4 h, then vacuum dry at 110 °C for 12 h. Then, calcine at 240 °C for 2 h at a rate of 1 °C / min, then calcine at 300 °C for 8 h at a rate of 1 °C / min. After naturally cooling to room temperature, obtain Nd-supported catalyst precursor.

[0050] (2) Dissolve platinum chloride containing 0.48 g Pt in a mixed dilute acid solution of 1.5 wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.30 g Pt in a mixed dilute acid solution of 1.5 wt% Pt in a mixed dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; Molybdenum nitrate pentahydrate was dissolved in 1.5 wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5 g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The Nd-supported catalyst precursor was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was added dropwise to the catalyst rotating at a constant speed using a peristaltic pump at a speed of 70 r / min. After the addition was completed, the mixture was allowed to stand for 12 h to obtain solid material D. Solid material D was first vacuum dried at 60 °C for 4 h, then vacuum dried at 110 °C for 12 h. Then, it was first heated to 240 °C at a rate of 1 °C / min and calcined for 2 h, then heated to 300 °C at a rate of 1 °C / min and calcined for 8 h. After naturally cooling to room temperature, a catalyst precursor supported on Pt, Mo and Nd was obtained.

[0051] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 2:1, the reduction temperature is 150℃, and the time is 4h to obtain a catalyst for BDO purification.

[0052] Example 5

[0053] The catalyst in this embodiment consists of a support and Pt, Mo, and Nd loaded on the support. The support is a columnar activated carbon support; based on a 100% weight percentage, the content of Pt is 0.15%, the content of Mo is 1%, the content of Nd is 0.7%, and the remainder is the support; and the average outer diameter of the support is 1.8 mm, and the specific surface area is 1460 m². 2 / g, axial compressive strength 27N.

[0054] Its preparation method is as follows:

[0055] (1) Dissolve 0.56 g Nd in 1.5 wt% dilute hydrochloric acid to obtain solution M1. Add 45 mL of pure water, half the volume of solution M1, to the solution. Mix well and then immerse the support in the solution. Stir for 2 h and let stand for 12 h. Filter to obtain solid material M2. First, vacuum dry solid material M2 at 60 °C for 4 h, then vacuum dry at 110 °C for 10 h. Then, calcine at 240 °C for 2 h at a rate of 1 °C / min, then calcine at 450 °C for 12 h at a rate of 1 °C / min. After naturally cooling to room temperature, obtain Nd-supported catalyst precursor.

[0056] (2) Dissolve platinum chloride containing 0.18 g Pt in a mixed dilute acid solution of 1.5 wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.6 g Pt in a mixed dilute acid solution of 1.5 wt% Pt in a mixed dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; Molybdenum nitrate pentahydrate was dissolved in 1.5 wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5 g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The Nd-supported catalyst precursor was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was added dropwise to the catalyst rotating at a constant speed using a peristaltic pump at a speed of 50 r / min. After the addition was completed, the mixture was allowed to stand for 12 h to obtain solid material D. Solid material D was first vacuum dried at 60 °C for 4 h, then vacuum dried at 110 °C for 10 h. Then, it was first heated to 240 °C at a rate of 1 °C / min and calcined for 2 h, then heated to 450 °C at a rate of 1 °C / min and calcined for 12 h. After naturally cooling to room temperature, a catalyst precursor supported on Pt, Mo and Nd was obtained.

[0057] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 2:1, the reduction temperature is 150℃, and the time is 6h to obtain a catalyst for BDO purification.

[0058] Example 6

[0059] The catalyst in this embodiment consists of a support and Pt, Mo, and Ce loaded on the support. The support is a columnar activated carbon support; based on a 100% weight percentage, the content of Pt is 0.03%, the content of Mo is 0.1%, the content of Ce is 1%, and the remainder is the support; and the average outer diameter of the support is 0.3 mm, and the specific surface area is 800 m². 2 / g, axial compressive strength 20N.

[0060] Its preparation method is as follows:

[0061] (1) Dissolve cerium nitrate containing 5.4g Ce in 2wt% dilute hydrochloric acid to obtain solution M1. Add 45mL of pure water, half the volume of solution M1, to the solution. After mixing evenly, immerse the support in the solution, stir for 2h, let stand for 12h, filter, and obtain solid material M2. First, vacuum dry solid material M2 at 50℃ for 8h, then vacuum dry at 110℃ for 12h. Then, first heat the solid material M2 to 240℃ at a rate of 1℃ / min and calcine for 2h, then heat the solid material M2 to 300℃ at a rate of 1℃ / min and calcine for 8h. After naturally cooling to room temperature, obtain the catalyst precursor supported on Ce.

[0062] (2) Dissolve platinum chloride containing 0.036 g Pt in a mixed dilute acid solution of 1.5 wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.06 g Pt in a mixed dilute acid solution of 1.5 wt% Pt in a mixed dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; Molybdenum nitrate pentahydrate was dissolved in 2wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The Ce-loaded catalyst precursor was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was added dropwise to the catalyst rotating at a constant speed using a peristaltic pump at a speed of 50 r / min. After the addition was completed, the mixture was allowed to stand for 12 h to obtain solid material D. Solid material D was first vacuum dried at 50℃ for 8 h, then vacuum dried at 110℃ for 12 h. Then, it was first heated to 240℃ at a rate of 1℃ / min and calcined for 2 h, then heated to 300℃ at a rate of 1℃ / min and calcined for 8 h. After naturally cooling to room temperature, a catalyst precursor loaded with Pt, Mo and Ce was obtained.

[0063] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 2:1, the reduction temperature is 180℃, and the time is 3.5h to obtain a catalyst for BDO purification.

[0064] Example 7

[0065] The catalyst in this embodiment consists of a support and Pt, Mo, and Ce loaded on the support. The support is a columnar activated carbon support; based on a 100% weight percentage, the content of Pt is 0.3%, the content of Mo is 0.5%, the content of Ce is 0.05%, and the remainder is the support; and the average outer diameter of the support is 3 mm, with a specific surface area of ​​1700 m². 2 / g, axial compressive strength 45N.

[0066] Its preparation method is as follows:

[0067] (1) Dissolve cerium nitrate containing 0.27g Ce in 3wt% dilute hydrochloric acid to obtain solution M1. Add 45mL of pure water, half the volume of solution M1, to the solution. Mix well and then immerse the support in the solution. Stir for 2h and let stand for 12h. Filter to obtain solid material M2. First, vacuum dry solid material M2 at 50℃ for 8h, then vacuum dry at 110℃ for 12h. Then, calcine at 240℃ for 2h at a rate of 1℃ / min, then calcine at 300℃ for 8h at a rate of 1℃ / min. After naturally cooling to room temperature, obtain the catalyst precursor supported on Ce.

[0068] (2) Dissolve platinum chloride containing 0.36g Pt in a mixed dilute acid solution of 1.5wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.3g Pt in a mixed dilute acid solution of 1.5wt% Pt in a mixed dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride Molybdenum nitrate pentahydrate was dissolved in 3wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The Ce-loaded catalyst precursor was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was added dropwise to the catalyst rotating at a constant speed using a peristaltic pump at a speed of 50 r / min. After the addition was completed, the mixture was allowed to stand for 12 h to obtain solid material D. Solid material D was first vacuum dried at 50℃ for 8 h, then vacuum dried at 110℃ for 12 h. Then, it was first heated to 240℃ at a rate of 1℃ / min and calcined for 2 h, then heated to 300℃ at a rate of 1℃ / min and calcined for 8 h. After naturally cooling to room temperature, a catalyst precursor loaded with Pt, Mo and Ce was obtained.

[0069] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 1:1, the reduction temperature is 300℃, and the time is 2h to obtain a catalyst for BDO purification.

[0070] Example 8

[0071] The catalyst in this embodiment consists of a support and Pt, Mo, and La loaded on the support. The support is a columnar activated carbon support; based on a 100% weight percentage, the content of Pt is 0.05%, the content of Mo is 0.3%, the content of La is 0.5%, and the remainder is the support; the average outer diameter of the support is 5 mm, and the specific surface area is 1200 m². 2 / g, axial compressive strength 38N.

[0072] Its preparation method is as follows:

[0073] (1) Dissolve lanthanum nitrate containing 0.64 g La in 3 wt% dilute hydrochloric acid to obtain solution M1. Add 45 mL of pure water, half the volume of solution M1, to the solution. Mix well and then immerse the support in the solution. Stir for 2 h and let stand for 12 h. Filter to obtain solid material M2. First, vacuum dry solid material M2 at 50 °C for 8 h, then vacuum dry at 110 °C for 12 h. Then, calcine at 240 °C for 2 h at a rate of 1 °C / min, then calcine at 300 °C for 8 h at a rate of 1 °C / min. After naturally cooling to room temperature, obtain the catalyst precursor supported on La.

[0074] (2) Dissolve platinum chloride containing 0.06 g Pt in a mixed dilute acid solution of 1.5 wt% dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; then dissolve platinum chloride containing 0.18 g Pt in a mixed dilute acid solution of 1.5 wt% Pt in a mixed dilute nitric acid and dilute hydrochloric acid in a volume ratio of 1:2 to obtain solution A; Molybdenum nitrate pentahydrate was dissolved in 3wt% dilute hydrochloric acid to obtain solution B. Solution A and solution B were mixed to obtain solution C. 4.5g of phosphoric acid (5% by mass of solution C) was added to solution C and mixed evenly. The catalyst precursor supported on La was placed in a coating machine at a speed of 20 r / min. The evenly mixed impregnation solution was added dropwise to the catalyst rotating at a constant speed using a peristaltic pump at a speed of 50 r / min. After the addition was completed, the mixture was allowed to stand for 12 h to obtain solid material D. Solid material D was first vacuum dried at 50℃ for 8 h, then vacuum dried at 110℃ for 12 h. Then, it was first heated to 240℃ at a rate of 1℃ / min and calcined for 2 h, then heated to 300℃ at a rate of 1℃ / min and calcined for 8 h. After naturally cooling to room temperature, a catalyst precursor supported on Pt, Mo and La was obtained.

[0075] (3) The catalyst precursor obtained in step (2) is reduced by hydrogen diluted with nitrogen. The volume ratio of nitrogen to hydrogen is 2:1, the reduction temperature is 250℃, and the time is 3h to obtain a catalyst for BDO purification.

[0076] Comparative Example 1

[0077] Without the addition of the second component Mo, the other processes and steps are the same as in Example 1.

[0078] Comparative Example 2

[0079] Without the addition of component Nd, the other processes and steps are the same as in Example 1.

[0080] Example 11

[0081] The catalysts described in Examples 1-8 and Comparative Examples 1 and 2 are used for BDO purification, which is a method of purification by continuously hydrogenating and reducing the residual impurity 4-hydroxybutyraldehyde in BDO to product BDO using a fixed bed. The method includes the following steps:

[0082] (1) The catalyst and inert ceramic balls with a particle size of 1.0 mm to 1.5 mm are alternately packed layer by layer in a fixed bed reactor. The fixed bed reactor is a tubular fixed bed reactor with an inner diameter of 35 mm and a packing height of 4.5 m. Nitrogen gas is then introduced until the air in the fixed bed reactor is completely purged. The volume ratio of the catalyst to the inert ceramic balls is 2:1.

[0083] (2) Hydrogen gas is introduced into the fixed bed reactor at a flow rate of 40 mL / min to make the gas pressure in the fixed bed reactor reach 0.06 MPa. The catalyst is heated to 60°C at a heating rate of 1.5°C / min and then kept at that temperature. The hydrogen gas and the feed liquid are preheated to the reaction temperature and then introduced into the fixed bed reactor. The reaction is carried out at the reaction temperature and pressure. The molar ratio of hydrogen gas to the impurity (4-hydroxybutyraldehyde) to be removed from BDO is 8:1. The mass hourly space velocity of the 4-hydroxybutyraldehyde is 3.0 g / gcat / hr.

[0084] (3) The reaction liquid obtained in step (2) is sent to a gas-liquid separator for separation, and the resulting tail gas hydrogen is recycled by a hydrogen compressor.

[0085] The reaction results are shown in Table 1.

[0086] Table 1 shows the results of BDO purification using the catalyst in a fixed-bed process.

[0087]

[0088]

[0089] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A catalyst for BDO purification, characterized in that: It consists of a carrier and Pt, Mo and metal M loaded on the carrier, wherein the metal M is Nd, Ce or La, and the carrier is an activated carbon carrier; based on a weight percentage of 100%, the content of Pt is 0.03-0.3%, the content of Mo is 0.05-1%, the content of metal M is 0.05-1%, and the remainder is the carrier.

2. The catalyst according to claim 1, characterized in that: The content of Pt is 0.05-0.2%, the content of Mo is 0.1-0.3%, the content of metallic M is 0.1-0.5%, and the remainder is a carrier.

3. The catalyst according to claim 1 or 2, characterized in that: The carrier is a columnar or sheet-shaped activated carbon carrier, and the average outer diameter of the carrier is 0.3-3 mm, the specific surface area is 800-1700 m2 / g, and the axial compressive strength is 20-45 N.

4. A method for preparing the catalyst according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Dissolve the precursor of metal M in dilute hydrochloric acid to obtain solution M1, then add half the volume of pure water to solution M1, mix evenly, immerse the support in it, stir for 2-5 h, let stand for 12-24 h, filter to obtain solid material M2, vacuum dry solid material M2, then calcine, and naturally cool to room temperature to obtain catalyst precursor supported on M; the precursor of metal M is nitrate of Nd, nitrate of Ce, or nitrate of La; (2) Dissolve the Pt precursor in a mixed dilute acid solution of dilute hydrochloric acid and dilute nitric acid at a volume ratio of 1:2 to obtain solution A; then dissolve the Mo precursor in dilute hydrochloric acid to obtain solution B; mix solutions A and B to obtain solution C, add 5% (by mass) phosphoric acid of solution C to it, and mix evenly; place the catalyst precursor loaded with M in a sugar coating machine at a speed of 20 r / min, and drip the evenly mixed impregnation solution onto the surface of the catalyst rotating at a constant speed using a peristaltic pump at a speed of 50-80 r / min. After the dripping is completed, let it stand for 12-24 h to obtain solid material D. Vacuum dry solid material D, then calcine it, and naturally cool it to room temperature to obtain the catalyst precursor loaded with Pt, Mo and M; the precursors of Pt and Mo are their hydrochloride salts or nitrate salts; wherein the mass concentration of the dilute hydrochloric acid and dilute nitric acid is 1.5-3.0%; (3) The catalyst precursor obtained in step (2) is reduced by a reducing agent to obtain a catalyst for BDO purification.

5. The method for preparing the catalyst according to claim 4, characterized in that: The reducing agent is hydrazine hydrate, sodium borohydride, potassium borohydride, sodium formate, or hydrogen gas diluted with nitrogen.

6. The method for preparing the catalyst according to claim 5, characterized in that: The reducing agent is hydrogen diluted with nitrogen, wherein the volume ratio of nitrogen to hydrogen is (1-3):1, the reduction treatment temperature is 150-300℃, and the time is 2-4h.

7. The method for preparing the catalyst according to claim 4, characterized in that: In steps (1) and (2), the vacuum drying is performed by first vacuum drying at 50-60℃ for 8-12 hours, and then vacuum drying at 110℃ for 8-12 hours.

8. The method for preparing the catalyst according to claim 4, characterized in that: In steps (1) and (2), the calcination is carried out by first heating to 240℃ at a rate of 1℃ / min for 2 hours, and then heating to 300-450℃ at a rate of 1℃ / min for 8-12 hours.

9. A method for purifying BDO, characterized in that, The method includes the following steps: (1) The catalyst according to any one of claims 1-3 and inert ceramic balls with a particle size of 1.0 mm-1.5 mm are alternately packed layer by layer in a fixed bed reactor, and then nitrogen is introduced until the air in the fixed bed reactor is exhausted; wherein the volume ratio of the catalyst to the inert ceramic balls is 2:

1. (2) Hydrogen is introduced into the fixed bed reactor. Under the condition that the hydrogen flow rate meets 20 mL / min ≤ V hydrogen ≤ 50 mL / min, the gas pressure in the fixed bed reactor reaches 0.05-0.1 MPa. The catalyst is heated to 50-80℃ at a heating rate of 1-2℃ / min and then kept at the temperature. The hydrogen and BDO feed liquid containing impurities 4-hydroxybutyraldehyde are preheated to the reaction temperature and then introduced into the fixed bed reactor. The reaction is carried out at the reaction temperature and pressure. (3) The reaction liquid obtained in step (2) is sent to a gas-liquid separator to separate BDO, and the resulting tail gas hydrogen is recycled by a hydrogen compressor.

10. The method for purifying BDO according to claim 9, characterized in that: The molar ratio of hydrogen gas to 4-hydroxybutyraldehyde impurity in BDO feedstock liquid in step (2) is (5-12):1; the mass hourly space velocity of 4-hydroxybutyraldehyde is 1.5-5.0 g / gcat / hr.

11. The method for purifying BDO according to claim 9, characterized in that, The fixed-bed reactor is a tubular fixed-bed reactor, wherein the inner diameter of the reaction tubes in the tubular fixed-bed reactor is 31-45 mm, and the filling height of the reaction tubes is 3.05-5.25 m.

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