A highly efficient composite solubilizer for the hydration of butene to sec-butanol

Abstract

This invention discloses a highly efficient composite solubilizer for the hydration of butene to sec-butanol, belonging to the field of chemical process technology. Its composition includes: 0-60 parts of a polyether-based polymeric surfactant, 15-35 parts of a highly polar aprotic solvent, and 10-20 parts of a co-catalyst. The main solubilizing component of this invention disperses oily butene into extremely small droplets, allowing it to mix uniformly in water, thereby increasing the surface area for the reaction. The co-solvent, as the main component, provides a stable environment, ensuring that this highly mixed state is maintained for a certain period. The added additives, possessing both water and oil solubility, facilitate smoother dissolution of the mixture and help the reactants quickly contact the active sites of the catalyst. This accelerates the reaction rate of butene and water, significantly improving the efficiency of the one-time conversion to sec-butanol and greatly saving the large amount of energy required for material recycling.

Description

Technical Field

[0001] This invention relates to the field of chemical process technology, specifically to a highly efficient composite solubilizer for the hydration of butene to sec-butanol, which can improve the reaction efficiency of direct hydration of butene to sec-butanol and solve the problems of high mass transfer resistance and low conversion rate in traditional two-phase hydration processes. Background Technology

[0002] sec-Butanol is a key chemical intermediate, primarily used in the production of methyl ethyl ketone (MEK) and widely applied in solvents, fragrances, and plasticizers. Industrially, sec-butanol is mainly produced through the direct hydration reaction of butene with water. This reaction is thermodynamically unfavorable, with an extremely low equilibrium constant at room temperature, resulting in a single-pass conversion rate typically less than 5%, becoming a core bottleneck restricting the process's economic viability. The essence of this limitation lies in the extremely poor miscibility of C4 olefins with water, forming a distinct liquid-liquid two-phase system. The reaction occurs only at a limited interface, resulting in significant mass transfer resistance, severely hindering the effective contact and conversion of reactant molecules.

[0003] Traditional butene hydration technologies mainly include indirect hydration with sulfuric acid and direct hydration with solid acid catalysis. The sulfuric acid method uses concentrated sulfuric acid to react with butene to produce esters, which are then hydrolyzed. Although it achieves a high conversion rate, it suffers from severe equipment corrosion, difficult waste acid treatment, and environmental pollution, and has been largely phased out. The current mainstream technology is direct hydration, which uses solid phosphoric acid or supported phosphoric acid (such as phosphoric acid / diatomaceous earth) as a catalyst, operating at high temperature and pressure to slightly improve the equilibrium conversion rate. However, this process is still plagued by poor two-phase contact: C4 and water exhibit significant stratification in the reactor, making it difficult for the catalyst surface to be effectively wetted by both phases simultaneously, resulting in a low reaction rate. To obtain a considerable yield, it is necessary to rely on the recycling and separation of large amounts of unreacted butene, requiring a large distillation system that leads to high energy consumption. Simultaneously, the catalyst is prone to pulverization or loss of active components in high-temperature hydrothermal environments, resulting in a limited lifespan.

[0004] In summary, despite continuous advancements in catalysts and processes, existing butene hydration technologies have yet to overcome the problems of low mass transfer efficiency and high energy consumption caused by poor contact between C4 and water.

[0005] Therefore, developing a solubilizer that can effectively enhance the miscibility of two phases and improve molecular contact to improve phase interface properties is of great industrial value for improving reaction rate, conversion rate and process economy. Summary of the Invention

[0006] In view of this, the present invention provides a highly efficient composite solubilizer for the hydration of butene to sec-butanol. The present invention fundamentally improves the reaction system by introducing a specific solubilizer. This solubilizer aims to significantly enhance the dispersibility of butene in the aqueous phase or greatly expand the contact interface between the two phases, promoting uniform mixing and close contact of the reactants to minimize mass transfer resistance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A highly efficient composite solubilizer for the hydration of butene to produce sec-butanol comprises the following raw materials in parts by weight: 0-60 parts of polyether-based polymeric surfactant, 15-35 parts of highly polar aprotic solvent, and 10-20 parts of co-catalyst.

[0009] This invention addresses a serious technical deficiency in existing processes for the direct hydration of butene to sec-butanol, caused by the extremely poor miscibility of C4 olefins with water. In current mainstream solid acid-catalyzed direct hydration methods, the reactant system exists in a liquid-liquid two-phase separation state, and the reaction is confined to a limited interfacial region. The significant mass transfer resistance severely hinders the effective transfer of reactant molecules to the active sites of the catalyst, which is the fundamental reason for the slow reaction rate and low single-pass conversion of butene. To overcome this thermodynamic limitation, existing processes are forced to employ harsh operating conditions of high temperature and high pressure, relying on large-scale material circulation and separation systems, resulting in extremely high energy consumption, huge equipment investment, and catalyst deactivation and short lifespan in harsh hydrothermal environments. Compared to existing technologies, this invention significantly improves the single-pass conversion of butene and the selectivity of sec-butanol under the same or milder conditions, thereby greatly reducing the amount of unreacted feedstock recycled and separation energy consumption, simplifying the process flow, and improving the efficiency and stability of the catalyst. Ultimately, it provides a breakthrough solution for the efficient, energy-saving, and economical production of sec-butanol.

[0010] Furthermore, the polyether-based polymeric surfactant is any one or a mixture of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and polyoxyethylene laurate.

[0011] The polyether-based polymeric surfactant used in this invention combines highly hydrophilic polyoxyethylene segments with lipophilic alkyl / aryl segments, which can be efficiently adsorbed at the oil-water interface, significantly reducing interfacial tension and forming micelles or microemulsions, thereby dispersing butene in the aqueous phase and greatly increasing the reaction interface area.

[0012] Furthermore, the highly polar aprotic solvent is any one or a mixture of sulfolane, N-methylpyrrolidone, and dimethyl sulfoxide.

[0013] The present invention uses a highly polar aprotic solvent as the continuous phase host, which has good solubility for C4 olefins, and works synergistically with the main solubilizer to construct a homogeneous and stable enhanced reaction medium.

[0014] Furthermore, the cocatalyst is an ether alcohol compound.

[0015] Furthermore, the ether alcohol compound is any one or a mixture of ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, and propylene glycol phenyl ether.

[0016] The cocatalyst used in this invention contains both ether bonds and hydroxyl groups in its molecule, which can serve as a highly efficient coupling agent and polarity modifier, effectively reducing the viscosity of the mixed system and promoting the diffusion of reactant molecules in the medium.

[0017] The present invention also provides a method for using the above-mentioned solubilizer: dissolving the prepared solubilizer in water to make the solubilizer content in the water 0.1 to 2 wt%.

[0018] The beneficial effects of this invention are as follows: The composite solubilizer provided by this invention solves the core problem of the immiscibility between butene and water. It works through the synergistic effect of several components: the core solubilizing component disperses oily butene into extremely small droplets, allowing them to mix uniformly into water, thereby increasing the surface area for the reaction; the auxiliary solvent, as the main component, provides a stable environment, ensuring that this highly mixed state is maintained for a certain period; and the added additives, due to their simultaneous water and oil solubility, facilitate the dissolution of the mixture and help the reactants quickly contact the active sites of the catalyst. This greatly accelerates the reaction rate of butene and water, significantly improving the efficiency of the one-time conversion to sec-butanol, and substantially saving the large amount of energy required for material recycling, achieving both high efficiency and economy. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In a specific embodiment of the present invention, the composition of the butene raw material is shown in Table 1.

[0021] Table 1

[0022] Example 1: Highly efficient composite solubilizer for the hydration of butene to sec-butanol A highly efficient composite solubilizer for the hydration of butene to produce sec-butanol was obtained by mixing 10 parts of nonylphenol polyoxyethylene ether as the main solubilizer, 15 parts of sulfolane as the auxiliary solubilizer, and 10 parts of ethylene glycol monobutyl ether as the co-catalyst.

[0023] The prepared solubilizer was mixed with water to obtain a 0.1% (w / w) solution. The mixture was then subjected to a water-to-olefin molar ratio of 2:1, a pressure of 6 MPa, and a space velocity of 0.5 h⁻¹. -1 The reaction was carried out under the specified conditions. The results showed that the conversion rate of butene was 15.7%.

[0024] Example 2: Highly efficient composite solubilizer for the hydration of butene to sec-butanol A highly efficient composite solubilizer for the hydration of butene to produce sec-butanol was obtained by mixing 60 parts of octylphenol polyoxyethylene ether as the main solubilizer, 35 parts of N-methylpyrrolidone as the auxiliary solubilizer, and 20 parts of diethylene glycol monomethyl ether as the co-catalyst.

[0025] The prepared solubilizer was mixed with water to obtain a 2% (w / w) solution. The mixture was then subjected to an incubation period of 5:1 water-to-olefin molar ratio, 8 MPa pressure, and 3 h⁻¹ space velocity. -1 The reaction was carried out under the specified conditions. The results showed that the conversion rate of butene was 17.1%.

[0026] Example 3: Highly efficient composite solubilizer for the hydration of butene to sec-butanol A highly efficient composite solubilizer for the hydration of butene to produce sec-butanol was obtained by mixing 50 parts of polyoxyethylene laurate as the main solubilizer, 20 parts of dimethyl sulfoxide as the auxiliary solubilizer, and 15 parts of propylene glycol phenyl ether as the co-catalyst.

[0027] The prepared solubilizer was mixed with water to obtain a 1% (w / w) solution. The mixture was then subjected to an incubation period of 3:1 water-to-olefin molar ratio, 7 MPa pressure, and 2 h⁻¹ space velocity. -1 The reaction was carried out under the specified conditions. The results showed that the conversion rate of butene was 14.9%.

[0028] Comparative Example 1 The solubilizer was prepared by mixing 40 parts of nonylphenol polyoxyethylene ether as the main solubilizer and 15 parts of sulfolane as the auxiliary solubilizer.

[0029] The prepared solubilizer was mixed with water to obtain a 0.1% (w / w) solution. The mixture was then subjected to a water-to-olefin molar ratio of 2:1, a pressure of 6 MPa, and a space velocity of 0.5 h⁻¹. -1 The reaction was carried out under the specified conditions. The results showed that the conversion rate of butene was 6.8%.

[0030] Comparative Example 2 A solubilizer was obtained by mixing 60 parts of octylphenol polyoxyethylene ether as the main solubilizer and 20 parts of diethylene glycol monomethyl ether as the co-catalyst.

[0031] The prepared solubilizer was mixed with water to obtain a 2% (w / w) solution. The mixture was then subjected to an incubation period of 5:1 water-to-olefin molar ratio, 8 MPa pressure, and 3 h⁻¹ space velocity. -1 The reaction was carried out under the specified conditions. The results showed that the conversion rate of butene was 6.3%.

[0032] Comparative Example 3 A solubilizer was obtained by mixing 20 parts of dimethyl sulfoxide as an auxiliary solvent and 15 parts of propylene glycol phenyl ether as a co-catalyst.

[0033] The prepared solubilizer was mixed with water to obtain a 1% (w / w) solution. The mixture was then subjected to an incubation period of 3:1 water-to-olefin molar ratio, 7 MPa pressure, and 2 h⁻¹ space velocity. -1 The reaction was carried out under the specified conditions. The results showed that the conversion rate of butene was 6.6%.

[0034] Comparative Example 4 No solubilizer was used. The water-to-olefin molar ratio was 3:1, the pressure was 7 MPa, and the space velocity was 2 h⁻¹. -1 The reaction was carried out under the specified conditions. The results showed that the conversion rate of butene was 5.2%.

[0035] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A highly efficient composite solubilizer for the hydration of butene to produce sec-butanol, characterized in that, The raw materials include the following parts by weight: 10-60 parts of polyether-based polymeric surfactant, 15-35 parts of highly polar aprotic solvent, and 10-20 parts of co-catalyst.

2. The highly efficient composite solubilizer for the hydration of butene to produce sec-butanol according to claim 1, characterized in that, The polyether-based polymeric surfactant is any one or a mixture of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and polyoxyethylene laurate.

3. The highly efficient composite solubilizer for the hydration of butene to produce sec-butanol according to claim 1, characterized in that, The highly polar aprotic solvent is any one or a mixture of sulfolane, N-methylpyrrolidone, and dimethyl sulfoxide.

4. The highly efficient composite solubilizer for the hydration of butene to sec-butanol according to claim 1, characterized in that, The cocatalyst is an ether alcohol compound.

5. The highly efficient composite solubilizer for the hydration of butene to sec-butanol according to claim 4, characterized in that, The ether alcohol compound is any one or a mixture of ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, and propylene glycol phenyl ether.

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