A system and method for synthesizing 2,2-di(2-furyl)propane

Abstract

The application belongs to the technical field of compound synthesis, and particularly relates to a system and a method for synthesizing 2,2-di(2-furyl)propane. The system comprises a fixed bed tubular reactor unit, a raw material unit and a reactant treatment unit. The fixed bed tubular reactor unit comprises a fixed bed tubular reactor and an ultrasonic generator, the ultrasonic generator is arranged outside the fixed bed tubular reactor, a catalyst bed is arranged in the fixed bed tubular reactor, and the fixed bed tubular reactor is connected with a feeding pipe and a discharging pipe. The raw material unit comprises a furan tank, an acetone tank, a by-product tank and a nitrogen source. The furan tank, the acetone tank, the by-product tank and the nitrogen source are respectively communicated with the feeding pipe through pipelines. The system and the method are used for synthesizing 2,2-di(2-furyl)propane, and the reaction selectivity, the conversion rate and the product yield of the raw material are all high. Meanwhile, the system and the method can realize continuous and large-scale industrial production, and have strong technical advantages.

Description

Technical Field

[0001] This invention belongs to the field of compound synthesis technology, specifically relating to a system and method for synthesizing 2,2-bis(2-furanyl)propane. Background Technology

[0002] 2,2-Di(2-furanyl)propane, abbreviated as DFP, is an upstream product used in the synthesis of 2,2-di(tetrahydrofuranyl)propane.

[0003] Currently, the main methods used to synthesize 2,2-bis(2-furanyl)propane are:

[0004] (1) US Patent US6194597B1 discloses a method for preparing 2,2-bis(2-furanyl)propane, which includes using furan and acetone as raw materials, adding 37% hydrochloric acid dropwise at 0°C, reacting at room temperature, diluting with one equivalent of n-hexane after the reaction is completed, neutralizing with 10% sodium carbonate to neutral, drying with excess anhydrous sodium sulfate, and then distilling to obtain 2,2-bis(2-furanyl)propane with a product yield of 74%.

[0005] (2) Researchers at the Ontario Agricultural College of Chemistry and the University of Toronto added acetone slowly dropwise to a mixture of furan, ethanol and hydrochloric acid. After the addition was complete, the mixture was reacted at 25°C for 18 hours. After the reaction was completed, the mixture was neutralized to neutral with 5% sodium bicarbonate, dried with anhydrous sodium sulfate, and then distilled to obtain 2,2-bis(2-furanyl)propane.

[0006] (3) CN105367523A discloses a method for synthesizing 2,2-bis(2-furanyl)propane, which includes reacting furan and acetone in the presence of the catalyst trifluoromethanesulfonate to obtain 2,2-bis(2-furanyl)propane, with a product yield of over 89%.

[0007] (4) CN116237066A discloses a solid strong acid catalyst and a method for synthesizing 2,2-bis(2-furanyl)propane using the catalyst, which can achieve a yield of 2,2-bis(2-furanyl)propane of more than 80%.

[0008] The yields of the product 2,2-bis(2-furanyl)propane in the above synthetic methods were not ideal. Summary of the Invention

[0009] The purpose of this invention is to propose a system and method for synthesizing 2,2-bis(2-furanyl)propane, which has high reaction selectivity, conversion rate and product yield of raw materials, and can realize continuous and large-scale industrial production, thus having strong technical advantages.

[0010] Specifically, the present invention provides the following technical solutions:

[0011] A system for synthesizing 2,2-bis(2-furanyl)propane includes a fixed-bed tubular reaction unit, a feed unit, and a reactant processing unit;

[0012] The fixed-bed tubular reaction unit includes a fixed-bed tubular reactor and an ultrasonic generator, wherein the ultrasonic generator is disposed outside the fixed-bed tubular reactor;

[0013] The fixed-bed tubular reactor is equipped with a catalyst bed and is connected to a feed pipe and a discharge pipe.

[0014] The raw material unit includes a furan tank, an acetone tank, a by-product tank, and a nitrogen source; the furan tank, acetone tank, by-product tank, and nitrogen source are respectively connected to the feed pipe through pipelines.

[0015] In this invention, the byproducts refer to dimers and trimers produced by side reactions in the synthesis of 2,2-bis(2-furanyl)propane from furan and acetone.

[0016]

[0017] Preferably, the reactant processing unit includes a separator, the inlet of which is connected to the outlet pipe, and the top vent is connected to the inlet pipe.

[0018] Preferably, the catalyst bed is provided with a catalyst with alumina as support and AgNO3 and Ag as active components; the height-to-diameter ratio of the catalyst bed is 10-18:1-1.2.

[0019] More preferably, the catalyst has a silver content (total silver element content) of 5-15 wt%.

[0020] More preferably, the mass ratio of AgNO3 to Ag is 27-33:67-73.

[0021] The present invention also provides a method for synthesizing 2,2-bis(2-furanyl)propane using the above system, comprising the following steps:

[0022] S1 continuously introduces furan, acetone, byproducts and nitrogen into the fixed-bed tubular reactor through the feed pipe, and the reaction takes place under the action of ultrasound and catalyst.

[0023] S2 continuously discharges unreacted furan and acetone, the main product 2,2-bis(2-furanyl)propane, byproducts, and nitrogen from the discharge pipe of the fixed-bed tubular reactor.

[0024] Preferably, the frequency of the ultrasound is 43-47 Hz and the power is 650-750 W / Kmol of raw material (the raw material refers to the total molar amount of furan and acetone).

[0025] Preferably, the reaction temperature is 33–50°C, the pressure is 550–600 kPa·G, and the reaction space velocity is 2.5–3 h⁻¹. -1 (Reaction space velocity is the total volume of furan and acetone processed per unit volume of catalyst per unit time, in m³ / s) 3 / (m 3 Catalyst (h) can be simplified to h -1 ).

[0026] Preferably, the feed molar ratio of furan to acetone is 2.1-2.5:1-1.2; and the feed molar ratio of acetone to by-product is 1-1.2:0.05-0.1.

[0027] Preferably, the nitrogen is a stabilizer, and the concentration of nitrogen in the feed pipe and the discharge pipe is 80% (vol) or higher.

[0028] Preferably, the process further includes the following steps: furan, acetone, the main product 2,2-bis(2-furanyl)propane, the byproducts, and nitrogen gas discharged from the fixed-bed tubular reactor are introduced into a separatory tank; the temperature of the separatory tank is above 55°C and the pressure is below 80 kPa·A (the above temperature and pressure ensure that the furan and acetone in the separatory tank exist in gaseous form).

[0029] The upper gas in the separator is furan, acetone and nitrogen. After being condensed into liquid by the condenser, it is sent into the feed pipe for recycling.

[0030] The liquid at the bottom of the separator is the main product 2,2-bis(2-furanyl)propane and byproducts. It is sent to the distillation unit to separate the main product 2,2-bis(2-furanyl)propane.

[0031] This invention provides a system and method for synthesizing 2,2-bis(2-furanyl)propane, with the following advantages:

[0032] The reaction selectivity of the raw materials can reach over 96%, the single-pass conversion rate can reach over 98%, and the product yield can reach over 95%. At the same time, it can realize continuous and large-scale industrial production, which has strong technical advantages. Detailed Implementation

[0033] The present invention will now be described by way of preferred embodiments. It should be understood by those skilled in the art that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art, or according to the product instructions. Reagents or instruments used where the manufacturer is not specified are all conventional products that can be purchased through legitimate channels.

[0035] Example 1

[0036] Example 1 provides a system for synthesizing 2,2-bis(2-furanyl)propane, comprising a fixed-bed tubular reaction unit and a feedstock unit;

[0037] The fixed-bed tubular reaction unit includes a fixed-bed tubular reactor and an ultrasonic generator, wherein the ultrasonic generator is mounted (externally attached) outside the fixed-bed tubular reactor;

[0038] The fixed-bed tubular reactor is equipped with a catalyst bed and is connected to a feed pipe and a discharge pipe.

[0039] The raw material unit includes a furan tank, an acetone tank, a by-product tank, and a nitrogen source; the furan tank, acetone tank, by-product tank, and nitrogen source are respectively connected to the feed pipe through pipelines.

[0040] Specifically, the fixed-bed tubular reactor has a specification of Φ40×5mm and a tube length of 4000mm; the outer side of the tube carries the coolant; the reactor is made entirely of SS30403. The reactor is equipped with a level gauge for observing the liquid level in the tube side. The tube is fixed by springs at both the top and bottom, with the maximum end of the spring 50mm from the tube opening. At both the top and bottom, there are 100mm high alumina ceramic balls with a diameter of Φ5mm.

[0041] Specifically, the system also includes a separator, the inlet of which is connected to the outlet pipe, and the top vent is connected to the inlet pipe.

[0042] Specifically, the catalyst bed is provided with honeycomb-shaped activated alumina as a carrier (size Φ5×10mm, specific surface area ≥20m²). 2 / m 3 The catalyst has AgNO3 and Ag as active components, and the active components are fixed on the surface of the support by impregnation followed by sintering; the height-to-diameter ratio of the catalyst bed is 14:1.

[0043] Specifically, the catalyst contains 7.22 wt% silver.

[0044] Specifically, the mass ratio of AgNO3 to Ag is 30:70.

[0045] Specifically, the discharge pipe is inverted U-shaped to ensure that the liquid level in the fixed-bed tubular reactor is basically consistent with the height of its discharge port during the reaction process, thus forming a "liquid seal" effect.

[0046] Example 1 also provides a method for synthesizing 2,2-bis(2-furanyl)propane using the above system, comprising the following steps:

[0047] 1) The air in the fixed-bed tubular reactor is replaced with nitrogen;

[0048] 2) After nitrogen purging is completed, inject by-products (dimers, trimers) into the fixed-bed tubular reactor to a level of 50% to 60%;

[0049] 3) Furan, acetone, byproducts and nitrogen are continuously introduced into the fixed-bed tubular reactor through the feed pipe, and the reaction is carried out under the action of ultrasound and catalyst;

[0050] 4) Unreacted furan and acetone, the main product 2,2-bis(2-furanyl)propane, by-products and nitrogen are continuously discharged from the fixed-bed tubular reactor through the discharge pipe and enter the separator; the temperature in the separator is 60°C and the pressure is 80 kPa.A.

[0051] The upper gas in the separator is furan, acetone and nitrogen, which is circulated into the feed pipe by an axial flow compressor;

[0052] The liquid at the bottom of the separator is the main product 2,2-di(2-furanyl)propane and byproducts. It is sent to the distillation unit to separate the main product 2,2-di(2-furanyl)propane and byproduct dimers and trimers.

[0053] Specifically, the ratio of the main raw material furan to acetone is 2.1:1 (mol); the ratio of acetone to by-products (dimers and trimers) is 1:0.05. The N2 concentration in the feed pipe and discharge pipe is maintained above 80% (vol).

[0054] Specifically, the heat of reaction is carried away by the coolant in the shell side, maintaining the reaction temperature at 40–42°C, the reaction pressure at 555 kPa·G, and the reaction space velocity at 3 h⁻¹. -1 By controlling the ultrasonic generator frequency at 47Hz and setting the power at 730W / Kmol of raw material, the single-pass conversion rate of raw material can reach 98%, the reaction selectivity of raw material can reach 96%, and the product yield can reach 95%.

[0055] Comparative Example 1

[0056] The only difference compared to Example 1 is that the reaction space velocity was reduced to 1.8 h⁻¹. -1As a result, the yield of the byproduct dimer increased to 10%; the yield of the trimer increased by 60%, to 0.44%.

[0057] Comparative Example 2

[0058] The only difference compared to Example 1 is that the reaction space velocity is increased to 3.5 h⁻¹. -1 While selectivity could be increased to over 97%, the conversion rate quickly dropped below 50%.

[0059] Comparative Example 3

[0060] Compared to Example 1, the only difference was that the reaction pressure was lower than 450 kPa·G or the reaction temperature was higher than 60°C. As a result, a large amount of the raw materials furan and acetone vaporized, making the reaction more difficult, the conversion rate decreased rapidly, and the amount of by-products increased.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for synthesizing 2,2-bis(2-furanyl)propane, characterized in that, It includes a fixed-bed tubular reaction unit, a raw material unit, and a reactant processing unit; The fixed-bed tubular reaction unit includes a fixed-bed tubular reactor and an ultrasonic generator, wherein the ultrasonic generator is disposed outside the fixed-bed tubular reactor; The fixed-bed tubular reactor is equipped with a catalyst bed and is connected to a feed pipe and a discharge pipe. The raw material unit includes a furan tank, an acetone tank, a by-product tank, and a nitrogen source; the furan tank, acetone tank, by-product tank, and nitrogen source are respectively connected to the feed pipe through pipelines; The catalyst bed is provided with a catalyst with alumina as support and AgNO3 and Ag as active components; the height-to-diameter ratio of the catalyst bed is 10~18:1~1.

2.

2. The system for synthesizing 2,2-bis(2-furanyl)propane according to claim 1, characterized in that, The catalyst contains 5-15 wt% silver.

3. The system for synthesizing 2,2-bis(2-furanyl)propane according to claim 1 or 2, characterized in that, The mass ratio of AgNO3 to Ag is 27~33:67~73.

4. A method for synthesizing 2,2-bis(2-furanyl)propane using the system described in any one of claims 1-3, characterized in that, Includes the following steps: S1 continuously introduces furan, acetone, byproducts and nitrogen into the fixed-bed tubular reactor through the feed pipe, and the reaction takes place under the action of ultrasound and catalyst. S2 continuously discharges unreacted furan and acetone, the main product 2,2-bis(2-furanyl)propane, byproducts, and nitrogen from the discharge pipe of the fixed-bed tubular reactor.

5. The method for synthesizing 2,2-bis(2-furanyl)propane according to claim 4, characterized in that, The frequency of the ultrasound is 43~47Hz, and the power is 650~750W / Kmol of raw material.

6. The method for synthesizing 2,2-bis(2-furanyl)propane according to claim 4 or 5, characterized in that, The reaction was carried out at a temperature of 33–50 °C, a pressure of 550–600 kPa·G, and a reaction space velocity of 2.5–3 h⁻¹. -1 .

7. The method for synthesizing 2,2-bis(2-furanyl)propane according to claim 4 or 5, characterized in that, The feed molar ratio of furan to acetone is 2.1~2.5:1~1.2; the feed molar ratio of acetone to by-product is 1~1.2:0.05~0.

1.

8. The method for synthesizing 2,2-bis(2-furanyl)propane according to claim 6, characterized in that, The feed molar ratio of furan to acetone is 2.1~2.5:1~1.2; the feed molar ratio of acetone to by-product is 1~1.2:0.05~0.

1.

9. The method for synthesizing 2,2-bis(2-furanyl)propane according to claim 4, 5 or 8, characterized in that, It also includes the following steps: Furan, acetone, the main product 2,2-bis(2-furanyl)propane, by-products, and nitrogen gas discharged from the fixed-bed tubular reactor enter a separatory tank; the temperature of the separatory tank is above 55°C and the pressure is below 80 kPa·A. The upper gas in the separator is furan, acetone and nitrogen, which is sent into the feed pipe for recycling. The liquid at the bottom of the separator is the main product 2,2-bis(2-furanyl)propane and byproducts. It is sent to the distillation unit to separate the main product 2,2-bis(2-furanyl)propane.

10. The method for synthesizing 2,2-bis(2-furanyl)propane according to claim 6, characterized in that, It also includes the following steps: Furan, acetone, the main product 2,2-bis(2-furanyl)propane, by-products, and nitrogen gas discharged from the fixed-bed tubular reactor enter a separatory tank; the temperature of the separatory tank is above 55°C and the pressure is below 80 kPa·A. The upper gas in the separator is furan, acetone and nitrogen, which is sent into the feed pipe for recycling. The liquid at the bottom of the separator is the main product 2,2-bis(2-furanyl)propane and byproducts. It is sent to the distillation unit to separate the main product 2,2-bis(2-furanyl)propane.

11. The method for synthesizing 2,2-bis(2-furanyl)propane according to claim 7, characterized in that, It also includes the following steps: Furan, acetone, the main product 2,2-bis(2-furanyl)propane, by-products, and nitrogen gas discharged from the fixed-bed tubular reactor enter a separatory tank; the temperature of the separatory tank is above 55°C and the pressure is below 80 kPa·A. The upper gas in the separator is furan, acetone and nitrogen, which is sent into the feed pipe for recycling. The liquid at the bottom of the separator is the main product 2,2-bis(2-furanyl)propane and byproducts. It is sent to the distillation unit to separate the main product 2,2-bis(2-furanyl)propane.

Images