CN111187239B - Continuous production method of furandicarboxylic acid using furan as raw material - Google Patents

Abstract

The invention discloses a continuous production method of furandicarboxylic acid using furan as raw material: the furan used as raw material is heated to form gaseous furan, and the mixed raw material gas formed after gaseous furan is mixed with carbon dioxide enters a fixed-bed reactor for reaction , a transition metal-supported catalyst is fixed in the fixed-bed reactor; unreacted gaseous furan and carbon dioxide are discharged from the gas outlet at the bottom of the fixed-bed reactor, mixed with the mixed raw material gas, and enter the fixed-bed reaction from the top of the fixed-bed reactor The reaction is carried out in the reactor; the furandicarboxylic acid generated by the reaction is discharged from the outlet at the bottom of the reactor. The preparation of furandicarboxylic acid by the method of the invention has the characteristics of simple process, environmental friendliness, high yield and the like.

Description

Continuous production method of furandicarboxylic acid using furan as raw material

technical field

The invention belongs to the field of chemical industry, and in particular relates to a continuous production method of furandicarboxylic acid using furan as raw material.

Background technique

2,5-Furandicarboxylic acid (FDCA), also known as anhydromucic acid, is a stable compound that was initially detected in human urine. There are two carboxyl groups in the FDCA molecule, which can be used as a monomer for polycondensation reaction with diol or diamine to replace the traditional petroleum-based monomer terephthalic acid to produce new polymer materials such as polyester and polyamide. At present, the FDCA material market contains businesses worth tens of billions of RMB, including plastics, plasticizers, thermosetting materials and coatings, etc.; FDCA is also listed as one of the high value-added bio-based chemical substances by the US Department of Energy. The research on new preparation technology has important economic and social significance.

At present, there are mainly the following routes for the synthesis of FDCA: 5-hydroxymethylfurfural (HMF) route, furoic acid route, hexaric acid cyclization route, furanoylation route, etc.

The HMF route is widely recognized at present, and almost all industrialization researches are carried out along this route. However, although the conversion rates of the two steps are both high, the catalysts and reaction conditions required by the two parts are different. In addition, process problems such as product/catalyst separation difficulties make process integration difficult and affect production efficiency. Although some researchers have developed a one-pot synthesis process from fructose to FDCA, using a Co-SiO ₂ catalyst (Cooperative effect ofcobalt acetylacetonate and silica in the catalytic cyclization and oxidation of fructose to2,5-furandicarboxylic acid.), but not only the reaction Conditions are harsh (165°C, 2MPa air), and the yield of FDCA is also low.

There are few reports on the route of furoic acid. Furoic acid is produced by catalytic oxidation of furfural in alkaline solution, and furoic acid can be prepared from FDCA through disproportionation or carbonylation.

There are relatively few reports on the cyclization route of hexaric acid. G. Bratulescu reported the cyclization of hexaric acid catalyzed by benzenesulfonic acid (Cyclization of the D-saccharic acid to 2,5-furandicarboxylic acid under the effects of microwaves. ), yet the yield is only 58%. The raw materials of this route will undergo isomerization and carbonization reactions under acidic conditions, resulting in lower yields.

There are also few reports on furoyl acylation routes. X.Li et al reported the process of obtaining FDCA by acylation and hydrolysis of furan and oxalyl iodide (Preparation method of 2,5-furandicarboxylic acid.), but this route has poor atom economy and high raw material cost. J.G.Wang et al. reported the process of FDCA (From Furan to High Quality Bio-based Poly(ethylenefurandicarboxylate).) from furan and acetic anhydride through acetylation, demethylation and other steps. There are many steps and poor atom economy. The yield is lower.

In summary, there are problems such as long reaction routes and harsh conditions in the many reported FDCA production routes. To realize the efficient and green production of FDCA involves route selection and the development of efficient catalytic systems.

Contents of the invention

The technical problem to be solved by the present invention is to provide a mild, efficient and clean continuous production method of furandicarboxylic acid using furan as raw material.

In order to solve the above technical problems, the present invention provides a continuous production method of furandicarboxylic acid using furan as raw material: furan as raw material is heated to form gaseous furan, and gaseous furan and carbon dioxide are mixed according to the molar ratio of 1:3-5 Finally, the mixed raw material gas is formed. The mixed raw material gas enters the fixed bed reactor from the top of the fixed bed reactor to react. The mass ratio is 5%-10%; the reaction temperature set in the fixed-bed reactor is 100-120°C; the reaction pressure is normal pressure; the residence time of gaseous furan in the fixed-bed reactor is 100-150 minutes;

Unreacted gaseous furan and carbon dioxide are discharged from the gas outlet at the bottom of the fixed-bed reactor, mixed with the mixed raw material gas (fresh mixed raw material gas), and enter the fixed-bed reactor from the top of the fixed-bed reactor to react together (that is, unreacted furan gas and carbon dioxide carry out secondary reaction); the furandicarboxylic acid generated by the reaction is discharged from the outlet at the bottom of the reactor.

As the improvement of the continuous production method of furandicarboxylic acid with furan as raw material of the present invention: the preparation method of transition metal supported catalyst is to carry out the following steps successively:

①Dipping method:

Dissolving the soluble salt of the transition metal (as the active center) in water to obtain a transition metal salt solution;

Molecular sieve (as a carrier) is dispersed in water to obtain a dispersion;

Mix the transition metal salt solution and the dispersion under stirring conditions for 3-6 hours, and then let stand for 1-2 hours;

The weight ratio of the transition metal in the soluble salt to the molecular sieve is 1.0-1.6:100;

②. Calcining the precipitate obtained in step ① at 400-600° C. for 3-5 hours to obtain a transition metal-supported catalyst.

Note: The precipitate can be conventionally dried and then roasted.

As the further improvement of the continuous production method of furandicarboxylic acid with furan as raw material of the present invention, in the preparation method of transition metal supported catalyst:

The transition metals are: nickel (Ni), copper (Cu), rhodium (Rh), palladium (Pd); the corresponding soluble salts of transition metals are: nickel chloride, copper chloride, rhodium trichloride, palladium potassium chlorate.

Molecular sieves are: 4A type, X type, Y type, ZSM-5 type, Al ₂ O ₃ , SiO ₂ , ZrO ₂ . Al ₂ O ₃ , SiO ₂ , and ZrO ₂ refer to pure Al ₂ O ₃ , pure SiO ₂ , and pure ZrO ₂ .

During the process of invention, the inventor established a technical route for continuous production by comparing the reaction characteristics of different routes and comprehensively considering the difficulty of industrialization of the reaction process. The present invention firstly develops a novel high-efficiency catalyst with transition metal as the active center, and fixes the transition metal supported catalyst (ω%=5%-10%) in a fixed-bed reactor; the raw material furan is placed in a furan gas generator , heated to produce furan gas, which enters the fixed bed reactor from the top of the fixed bed reactor together with carbon dioxide; the catalyst catalyzes the 2,5-dicarbonylation reaction of furan and carbon dioxide to directly generate FDCA, and the unreacted furan gas and carbon dioxide are recycled back to the The top of the fixed-bed reactor, together with fresh furan gas and carbon dioxide, enters the reactor for a second reaction until the reaction is complete. The temperature of the fixed-bed reactor is between 100°C and 120°C, and the reaction is carried out under normal pressure, and the total yield of furandicarboxylic acid reaches over 95%.

Reaction equation of the present invention is as follows:

In the present invention, according to the weight ratio of the transition metal and the molecular sieve set in the present invention, it can ensure that the soluble salts of all transition metals are adsorbed by the molecular sieve; Soluble salts of metals can all be converted to the corresponding transition metals.

The production method of furandicarboxylic acid of the present invention has the following technical advantages:

1. Using gaseous carbon dioxide as a raw material, the utilization rate of atoms is high, and no other wastes are produced, ensuring that the production process is environmentally friendly;

2. In the continuous production process, no other solvents are needed, which can further reduce production costs;

3. The continuous cycle operation is adopted, the furan reaction is complete, and the total yield of the product is high; the total yield is over 95%.

In summary, the preparation of furandicarboxylic acid by the method of the present invention has the characteristics of simple process, environmental friendliness and high yield.

Description of drawings

The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is the process diagram of the continuous production method of furandicarboxylic acid taking furan as raw material of the present invention.

Detailed ways

The present invention is further described below in conjunction with specific embodiment, but protection scope of the present invention is not limited thereto:

A kind of furan is the continuous production device of the furandicarboxylic acid of raw material, as shown in Figure 1, comprises furan gas generator 1, fixed-bed reactor 2, the outer surface of fixed-bed reactor 2 is provided with heating mantle 21, and heating mantle 21 is used to control the reaction temperature in the fixed bed reactor 2; the sidewall near the bottom of the fixed bed reactor 2 is provided with a gas outlet 22, and the bottom of the fixed bed reactor 2 is provided with a material outlet 23.

Furan as a raw material is placed in the furan gas generator 1 and heated to a gaseous state. The mixed raw material gas formed after the gaseous furan is mixed with carbon dioxide enters the fixed bed reactor 2 from the top of the fixed bed reactor 2 for reaction, and the fixed bed reaction A transition metal-loaded catalyst is fixed in the reactor, and the fixed-bed reactor 2 is set to a corresponding reaction temperature (100-120° C.), and the reaction pressure is normal pressure. Unreacted furan gas and carbon dioxide are discharged from the bottom of the fixed-bed reactor 2. The gas port 22 is discharged and circulated to the top of the fixed bed reactor 2 to enter the fixed bed reactor 2 together with the fresh mixed raw material gas for secondary reaction. The outlet 23 at the bottom of the fixed bed reactor 2 continuously discharges the furandicarboxylic acid product.

The following examples all adopt this continuous production device.

The purity of the furandicarboxylic acid obtained in the following examples is all ≥99.0%.

Embodiment 1, a kind of continuous production method of furandicarboxylic acid, take furan and carbon dioxide as raw material, carry out following steps successively:

1), preparation of Pd/4A type molecular sieve catalyst by impregnation method: dissolve 3.732g palladium potassium chlorate (containing palladium 1.01g) in 100mL water, fully disperse and dissolve; at the same time fully disperse 100g 4A type molecular sieve in 1000mL water, mix the two Thoroughly stir (about 600r/min) and mix for 3 hours, let it stand for 2 hours, conventionally dry (dry at 40°C for 12 hours), and then calcinate at 400°C for 5 hours to obtain about 101g of Pd/4A molecular sieve catalyst.

2) Fix 100 g of the Pd/4A molecular sieve catalyst obtained in step 1) in the fixed bed reactor 2, add 1.0 kg of furan into the furan gas generator 1, control the gaseous furan and carbon dioxide to mix according to the molar ratio of 1:3 (as fresh mixed raw material gas) enters the fixed-bed reactor 2, and the reaction temperature in the fixed-bed reactor 2 is set at 100°C. The unreacted furan gas and carbon dioxide are discharged from the gas outlet 22 at the bottom of the fixed-bed reactor 2, circulated to the top of the fixed-bed reactor 2 and enter the fixed-bed reactor 2 together with fresh mixed raw material gas for secondary reaction. The residence time of gaseous furan in the fixed-bed reactor 2 was 100 minutes; a total of 2.28 kg of furandicarboxylic acid was obtained, and the total yield was about 98.6%.

Embodiment 2, a kind of continuous production method of furandicarboxylic acid, take furan and carbon dioxide as raw materials, carry out the following steps successively:

1) Preparation of Ni/Y-type molecular sieve catalyst by impregnation method: Dissolve 2.665g of nickel chloride (containing 1.21g of nickel) in 100mL of water, fully disperse and dissolve; Mix them thoroughly for 6 hours, let them stand for 1 hour, dry them and bake them at 600°C for 3 hours to obtain about 101.2 g of Ni/Y molecular sieve catalysts;

2), fix 75g of the Ni/Y type molecular sieve catalyst obtained in step 1) in the fixed bed reactor 2, add 1.0kg of furan into the furan gas generator 1, control the gaseous furan and carbon dioxide to mix according to the molar ratio of 1:5 Enter the fixed bed reactor 2, and the reaction temperature in the fixed bed reactor 2 is set to 120°C. The unreacted furan gas and carbon dioxide are discharged from the gas outlet 22 at the bottom of the fixed-bed reactor 2, circulated to the top of the fixed-bed reactor 2 and enter the fixed-bed reactor 2 together with fresh mixed raw material gas for secondary reaction. The residence time of gaseous furan in the fixed-bed reactor 2 was 150 minutes; a total of 2.22 kg of furandicarboxylic acid was obtained, and the total yield was about 95.5%.

Embodiment 3, a kind of continuous production method of furandicarboxylic acid, take furan and carbon dioxide as raw material, carry out the following steps successively:

1), preparation of Rh/X type molecular sieve catalyst by impregnation method: 3.059g rhodium trichloride (containing rhodium 1.51g) is dissolved in the water of 100mL, fully disperses and dissolves; The X type molecular sieve of 100g is fully dispersed in 1000mL water at the same time, will The two are fully mixed for 4 hours, left to stand for 1.5 hours, dried and calcined at 500°C for 4.5 hours to obtain about 101.5g of Rh/X molecular sieve catalyst;

2) Fix 50 g of the Rh/X molecular sieve catalyst obtained in step 1) in the fixed bed reactor 2, add 1.0 kg of furan into the furan gas generator 1, and control the gaseous furan and carbon dioxide to mix according to the molar ratio of 1:4 Enter the fixed-bed reactor 2, and the reaction temperature in the fixed-bed reactor 2 is set to 110°C. The unreacted furan gas and carbon dioxide are discharged from the gas outlet 22 at the bottom of the fixed-bed reactor 2, circulated to the top of the fixed-bed reactor 2 and enter the fixed-bed reactor 2 together with fresh mixed raw material gas for secondary reaction. The residence time of gaseous furan in the fixed-bed reactor 2 was 120 minutes; a total of 2.23 kg of furandicarboxylic acid was obtained, and the total yield was about 96.5%.

Embodiment 4, a kind of continuous production method of furandicarboxylic acid, take furan and carbon dioxide as raw material, carry out following steps successively:

1), preparation of Pd/Al ₂ O ₃ catalyst by impregnation method: Dissolve 3.732g of potassium palladium chlorate (containing 1.01g of palladium) in 100mL of water, fully disperse and dissolve; at the same time fully disperse 100g of Al ₂ O ₃ in 1000mL of water, and The two are fully mixed for 4 hours, left to stand for 2 hours, dried and calcined at 500°C for 4 hours to obtain about 101.0 g of Pd/Al ₂ O ₃ catalyst;

2) Fix 100 g of the Pd/Al ₂ O ₃ catalyst obtained in step 1) in the fixed bed reactor 2, add 1.0 kg of furan into the furan gas generator 1, and control the gaseous furan and carbon dioxide to mix according to the molar ratio of 1:4 Then enter the fixed-bed reactor 2, and the reaction temperature in the fixed-bed reactor 2 is set to 110°C. The unreacted furan gas and carbon dioxide are discharged from the gas outlet 22 at the bottom of the fixed-bed reactor 2, circulated to the top of the fixed-bed reactor 2 and enter the fixed-bed reactor 2 together with fresh mixed raw material gas for secondary reaction. The residence time of gaseous furan in the fixed-bed reactor 2 was 130 minutes; a total of 2.26 kg of furandicarboxylic acid was obtained, and the total yield was about 97.7%.

Embodiment 5, a kind of continuous production method of furandicarboxylic acid, take furan and carbon dioxide as raw materials, carry out the following steps successively:

1), preparation of Rh/ _SiO2 catalyst by impregnation method: 3.059g rhodium trichloride (containing rhodium 1.51g) is dissolved in the water of 100mL, fully disperses and dissolves; Simultaneously fully disperses the _SiO2 of 100g in 1000mL water, mix both Mix well for 4 hours, let stand for 1.5 hours, after drying, bake at 400°C for 4 hours to obtain about 101.5g of Rh/SiO ₂ catalyst;

2), fix 80g of the Rh/ _SiO2 catalyst obtained in step 1) in the fixed bed reactor 2, add 1.0kg of furan into the furan gas generator 1, control the gaseous furan and carbon dioxide to mix according to the molar ratio of 1:4 and enter In the fixed bed reactor 2, the reaction temperature in the fixed bed reactor 2 was set to 100°C. The unreacted furan gas and carbon dioxide are discharged from the gas outlet 22 at the bottom of the fixed-bed reactor 2, circulated to the top of the fixed-bed reactor 2 and enter the fixed-bed reactor 2 together with fresh mixed raw material gas for secondary reaction. The residence time of gaseous furan in the fixed-bed reactor 2 was 140 minutes; a total of 2.20 kg of furandicarboxylic acid was obtained, and the total yield was about 95.1%.

Embodiment 6, a kind of continuous production method of furandicarboxylic acid, take furan and carbon dioxide as raw materials, carry out the following steps successively:

1) Preparation of Cu/ZSM-5 molecular sieve catalyst by impregnation method: Dissolve 3.125g of copper chloride (containing 1.01g of copper) in 100mL of water, fully disperse and dissolve; at the same time, fully disperse 100g of ZSM-5 molecular sieve in 100mL In water, fully mix the two for 6 hours, let stand for 2 hours, dry and roast at 500°C for 5 hours to obtain about 101.0 g of Cu/ZSM-5 molecular sieve catalyst;

2) Fix 100 g of the Cu/ZSM-5 molecular sieve obtained in step 1) in the fixed bed reactor 2, add 1.0 kg of furan into the furan gas generator 1, and control the gaseous furan and carbon dioxide to mix according to the molar ratio of 1:3 Then enter the fixed-bed reactor 2, and the reaction temperature in the fixed-bed reactor 2 is set to 110°C. The unreacted furan gas and carbon dioxide are discharged from the gas outlet 22 at the bottom of the fixed-bed reactor 2, circulated to the top of the fixed-bed reactor 2 and enter the fixed-bed reactor 2 together with fresh mixed raw material gas for secondary reaction. The residence time of gaseous furan in the fixed-bed reactor 2 was 110 minutes; a total of 2.23 kg of furandicarboxylic acid was obtained, and the total yield was about 96.6%.

Embodiment 7, a kind of continuous production method of furandicarboxylic acid, take furan and carbon dioxide as raw material, carry out the following steps successively:

1), preparation of Cu/ _ZrO2 catalyst by impregnation method: dissolve 3.125g of copper chloride (1.01g of copper) in 100mL of water, fully disperse and dissolve; at the same time, fully disperse 100g of _ZrO2 in 100mL of water, fully dissolve the two Mix for 5 hours, let stand for 2 hours, dry and bake at 600°C for 4 hours to obtain about 101.0 g of Cu/ZrO ₂ catalyst;

2) Fix 100 g of Cu/ZrO ₂ obtained in step 1) in fixed bed reactor 2, add 1.0 kg of furan into furan gas generator 1, control gaseous furan and carbon dioxide to enter the fixed bed after mixing according to the molar ratio of 1:5 In the bed reactor 2, the reaction temperature in the fixed bed reactor 2 was set to 120°C. The unreacted furan gas and carbon dioxide are discharged from the gas outlet 22 at the bottom of the fixed-bed reactor 2, circulated to the top of the fixed-bed reactor 2 and enter the fixed-bed reactor 2 together with fresh mixed raw material gas for secondary reaction. The residence time of gaseous furan in the fixed-bed reactor 2 was 140 minutes; a total of 2.20 kg of furandicarboxylic acid was obtained, and the total yield was about 95.4%.

Comparative Example 1. The reaction temperature in Step 2) of Example 1 was changed from 100° C. to 150° C., and the total reaction time was about 15 hours; the rest were the same as in Example 1.

As a result, the yield of furandicarboxylic acid was 62.3%.

Comparative Example 2, the use of the catalyst in Example 1 was canceled, that is, the fixed-bed reactor was not provided with a Pd/4A type molecular sieve catalyst; the rest were identical to Example 1.

As a result, the yield of furandicarboxylic acid was 5.1%.

Comparative example 3,

Change step 1) of Example 1 to prepare the catalyst according to the deposition-precipitation method: Weigh 3.732 g of potassium palladium chlorate and dissolve it in 100 mL of deionized water, add 0.05 mol L ^-1 NaOH solution dropwise under heating and stirring at 60 ° C, Use a pH meter to accurately adjust the pH of the solution to 7.5±0.1; then add an aqueous solution of 4A molecular sieve (100g of 4A molecular sieve is fully dispersed in 1000mL of water), adjust the pH again to 7.5±0.1, and continue stirring for 2h; filter and use the filter cake Wash with ion water (3×50mL), vacuum dry at 40°C for 12h, and finally roast in a muffle furnace (400°C and air atmosphere) for 4h to obtain the Pd/4A molecular sieve catalyst;

React according to embodiment 1 step 2) with the catalyst obtained.

The result obtained was that the yield of furandicarboxylic acid was 56.6%.

Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (1)

1. take furan as the continuous production method of 2,5-furandicarboxylic acid of raw material, it is characterized in that: The furan used as the raw material is heated to form gaseous furan. The gaseous furan and carbon dioxide are mixed according to the molar ratio of 1:3~5 to form a mixed raw material gas. The mixed raw material gas enters the fixed bed reactor from the top of the fixed bed reactor for reaction. A transition metal-supported catalyst is fixed in the fixed-bed reactor, and the mass ratio of the transition-metal-supported catalyst to the total amount of furan to be reacted is 5% to 10%; the reaction temperature set in the fixed-bed reactor is 100-120°C The reaction pressure is normal pressure; the residence time of gaseous furan in the fixed bed reactor is 100～150 minutes; The unreacted gaseous furan and carbon dioxide are discharged from the gas outlet at the bottom of the fixed-bed reactor, mixed with the mixed raw material gas, and then enter the fixed-bed reactor from the top of the fixed-bed reactor for reaction; the 2,5-furan produced by the reaction Formic acid is discharged from the outlet at the bottom of the reactor; The transition metal supported catalyst is any of the following: Pd/4A molecular sieve catalyst, Ni/Y molecular sieve catalyst, Rh/X molecular sieve catalyst, Pd/Al ₂ O ₃ catalyst, Rh/SiO ₂ catalyst, Cu/ZSM-5 Type molecular sieve catalyst, Cu/ZrO ₂ catalyst; The preparation method of transition metal supported catalyst is to carry out the following steps successively: ①, dipping method: Dissolving soluble salts of transition metals in water to obtain transition metal salt solutions; Disperse the molecular sieve in water to obtain a dispersion; Mix the transition metal salt solution and the dispersion under stirring conditions for 3-6 hours, and then let stand for 1-2 hours; The weight ratio of the transition metal in the soluble salt to the molecular sieve is 1.0-1.6:100; The transition metal is any of the following: nickel, copper, rhodium, palladium; The molecular sieve is any of the following: 4A type, X type, Y type, ZSM-5 type, Al ₂ O ₃ , SiO ₂ , ZrO _{2 ,} ②. Calcining the precipitate obtained in step ① at 400-600° C. for 3-5 hours to obtain a transition metal-supported catalyst.

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