阅读说明：本技术 以异辛烯醛为原料制取异辛酸的生产工艺 (Production process for preparing isooctanoic acid by using isooctenal as raw material ) 是由 楚庆岩 崔课贤 杨彬 刁统贺 周立亮 郭振兴 杨震 孙圆 商芳芳 于 2020-07-01 设计创作，主要内容包括：本发明属于精细化工技术领域,具体涉及一种以异辛烯醛为原料制取异辛酸的生产工艺。在微气泡反应器中,以异辛烯醛为原料,纳米粒子加氢催化剂作用下,进行选择性加氢反应,制得异辛醛；得到的异辛醛加入氧化反应器中,通过空气发生器鼓入微气泡,异辛醛与微气泡中的氧气反应,制得异辛酸。本发明的生产工艺成本低、不使用碱、硫酸、高锰酸钾等高腐蚀性物料,且整个生产过程不产生环境污染物,环境友好性强、原子经济性好。(The invention belongs to the technical field of fine chemical engineering, and particularly relates to a production process for preparing isooctanoic acid by taking isooctenal as a raw material. In a micro-bubble reactor, carrying out selective hydrogenation reaction by taking isooctenal as a raw material under the action of a nano particle hydrogenation catalyst to prepare isooctanal; adding the obtained isooctaldehyde into an oxidation reactor, blowing micro bubbles through an air generator, and reacting the isooctaldehyde with oxygen in the micro bubbles to obtain the isooctanoic acid. The production process has low cost, does not use high-corrosivity materials such as alkali, sulfuric acid, potassium permanganate and the like, does not generate environmental pollutants in the whole production process, and has strong environmental friendliness and good atom economy.)

1. A production process for preparing isooctanoic acid by using isooctenal as a raw material is characterized by comprising the following steps:

(1) in a micro-bubble reactor, carrying out selective hydrogenation reaction by taking isooctenal as a raw material under the action of a nano particle hydrogenation catalyst to prepare isooctanal;

(2) and (2) feeding the isooctaldehyde obtained in the step (1) into an oxidation reactor, blowing micro bubbles through an air generator, and reacting the isooctaldehyde with oxygen in the micro bubbles to obtain the isooctanoic acid.

2. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 1, characterized in that: in the step (1), the nanoparticle hydrogenation catalyst is nanoparticles of gold, palladium, platinum, nickel, vanadium, molybdenum, manganese or oxides thereof; the molar ratio of the nanoparticle hydrogenation catalyst to the isooctenal feed per hour is 0.00008-0.01: 1.

3. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 1, characterized in that: in the step (1), the temperature of the selective hydrogenation reaction is 30-170 ℃, and the pressure is 0.1-10 MPa.

4. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 1, characterized in that: in the step (1), the space velocity of the isooctene aldehyde in the selective hydrogenation reaction process is 0.005-1h^-1The feeding molar ratio of the isooctenal to the hydrogen is 1: 1-40.

5. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 1, characterized in that: in the step (2), the isooctyl aldehyde enters an oxidation reactor for reaction, and the space velocity of the isooctyl aldehyde is 0.005-1h^-1The feeding molar ratio of the isooctyl aldehyde to the oxygen is 1: 1-40; the reaction temperature of the isooctyl aldehyde in the oxidation reactor is 20-150 ℃.

6. The process for preparing isooctanoic acid from isooctenal according to any one of claims 1 to 5, wherein: the method comprises the following steps:

(1) in a micro-bubble reactor, carrying out selective hydrogenation reaction by taking isooctenal as a raw material under the action of a nano particle hydrogenation catalyst to prepare isooctanal;

(2) mixing the isooctaldehyde obtained in the step (1) with an oxidation catalyst, then feeding the mixture into an oxidation reactor, blowing micro bubbles through an air generator, and reacting the isooctaldehyde with oxygen in the micro bubbles to obtain the isooctanoic acid.

7. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 6, wherein: in the step (2), the oxidation catalyst is cobalt acetate, molybdenum acetate, silver acetate, manganese isooctanoate, cobalt isooctanoate, molybdenum isooctanoate, silver isooctanoate, manganese dioxide, silver oxide, vanadium acetylacetonate, molybdenum trioxide, vanadium pentoxide, aluminum oxide, ferric chloride or palladium oxide; the molar ratio of the oxidation catalyst to the amount of isooctylaldehyde fed per hour is 0-0.1: 1.

8. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 6, wherein: the method comprises the following steps:

(1) the microbubble reactor comprises a gas phase inlet (1), a liquid phase inlet (2), a microbubble tube (3) and a reaction zone (6), the microbubble tube (3), the gas phase inlet (1) and the liquid phase inlet (2) are positioned at the upper part of the reaction zone (6), an annular space channel is formed between the microbubble tube (3) and the tube wall of the microbubble reactor, the liquid phase inlet (2) is connected with the annular space channel, and the gas phase inlet (1) is connected with the microbubble tube (3); a nano particle hydrogenation catalyst (4) is arranged in the reaction zone (6), and a heating medium channel (5) is arranged outside the reaction zone (6);

hydrogen enters a micro bubble tube (3) from a gas phase inlet (1), isooctene aldehyde enters an annular space channel formed between the micro bubble tube (3) and the tube wall of the micro bubble reactor from a liquid phase inlet (2), the hydrogen and the isooctene aldehyde undergo selective hydrogenation reaction under the action of a nano particle hydrogenation catalyst (4) in a reaction zone (6) through the micro bubble tube (3) to prepare isooctene aldehyde, and the isooctene aldehyde flows out from the bottom of the micro bubble reactor;

(2) an air generator (9) is arranged at the bottom of the oxidation reactor, an air outlet (7) is arranged at the top of the oxidation reactor, an isooctyl aldehyde inlet (8) is arranged on one side surface of the oxidation reactor, an isooctanoic acid outlet (11) is arranged on the other side surface of the oxidation reactor, the isooctanoic acid outlet (11) is higher than the isooctyl aldehyde inlet (8), and a filter (12) is arranged at the isooctanoic acid outlet (11); an insulating layer (10) is also arranged around the oxidation reactor;

and (2) enabling the isooctaldehyde obtained in the step (1) to enter an oxidation reactor from an isooctaldehyde inlet (8), blowing micro-bubbles through an air generator (9), enabling the isooctaldehyde to react with oxygen in the micro-bubbles to prepare isooctanoic acid, and enabling the isooctanoic acid to flow out of the oxidation reactor from an isooctanoic acid outlet (11).

9. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 8, wherein: in the step (1), the microbubble reactor is an annular space flow fixed bed reactor; the width of the annular gap channel is 1-5 mm; the micro bubble tube (3) is made of a ceramic membrane, the pore size of the ceramic membrane is 5-100nm, and the length of the ceramic membrane is 5-100 cm.

10. The production process for preparing isooctanoic acid from isooctenal as claimed in claim 8, wherein: in the step (2), the air blowing pipes of the air generator are 1-10 groups, the height of the air blowing pipes is 5-100cm, and the width between the air blowing pipes is 5-100 cm.

Technical Field

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a production process for preparing isooctanoic acid by taking isooctenal as a raw material.

Background

Isooctanoic acid, also known as 2-ethylhexanoic acid, is a colorless, slightly odorous liquid, slightly soluble in cold water, soluble in hot water and diethyl ether, slightly soluble in ethanol, is an important fine chemical, and is widely used in the fields of coatings, inks, plastics, medicines, pesticides, national defense and the like. Isooctanoic acid is an alternative chemical to naphthenic acid, mostly used for the production of metal salts of isooctanoic acid. In general, isooctanoate has better performance than naphthenate and is more widely used.

At present, raw materials for synthesizing isooctanoic acid mainly comprise isooctenal, isooctylaldehyde and isooctyl alcohol. Isooctanoic acid is mainly used for preparing various metal salts as drier for coatings and paints, and its esters can be used as raw materials of plasticizer or carbenicillin. 2-ethyl caproic acid is mostly converted into salts of zirconium, cobalt, molybdenum, zinc and the like, and is used as a paint drier and a heat stabilizer of polyvinyl chloride plastics; tin salt is used as an additive of the plastic pipe; barium salt and cadmium salt are used for plastic rolling products and stabilizers, 2-ethylhexanoic acid and esters thereof are also used in the fields of medicines, bactericides, metal lubricants, cosmetics and the like, and glyceride thereof is an excellent plasticizer. 2-ethylhexanoic acid is a starting material for the pharmaceutical carbenicillin, used in the synthesis of many dyes, fragrances, and it is also an intermediate for paint and coating driers, used as an alkyd modifier, and the peroxide produced as a catalyst for polymerization reactions (e.g., PE), lubricating oil esters, and PVC stabilizers.

There are three main methods for the synthesis of 2-ethylhexanoic acid: a 2-ethylhexanol oxidation method; (xii) 2-ethylhexenal oxidation; ③ 2-ethyl hexanol dehydrogenation esterification method. The 2-ethylhexanol oxidation method is mainly characterized in that 2-ethylhexanol reacts with potassium permanganate in an alkaline or acidic medium to generate 2-potassium ethylhexanoate, and the potassium ethylhexanoate is acidified by concentrated sulfuric acid after being cooled to room temperature; the 2-ethylhexanol dehydrogenation esterification method is to use 2-ethylhexanol and sodium hydroxide to carry out oxidative dehydrogenation reaction to prepare 2-ethylhexanoic acid sodium, and then to neutralize with sulfuric acid to obtain isooctanoic acid. The two methods are both traditional processes, the scale of the device is small, and the three wastes are serious.

Chinese patent CN1817845A discloses a new process for preparing isooctanoic acid by a composite catalytic method, which comprises the steps of filling isooctanol and sodium hydroxide aqueous solution into a reaction kettle to ensure that the molar ratio of alcohol to alkali is 1.2-1.5; then adding a composite catalyst which is formed by combining 0.8-1.2 unit mass of calcium oxide, 0.6-0.9 unit mass of vanadium pentoxide and 0.1-0.4 unit mass of rare earth oxide under stirring; stirring and gradually heating to 240-280 ℃ to finish the alcohol-base oxidation reaction for 1.8-2.2 hours; hydrogen gas is discharged; then cooling the reaction materials, adding 5-10% of water for dilution, and filtering out the solid composite catalyst; then adding H with the content of 30-40 percent₂SO₄The pH value of the materials is adjusted to 3 by the water solution, the materials are stirred for acidification reaction for 30 to 40 minutes, and the materials are kept stand for layering and are drained of a water layer; then washing the material with water; and (5) carrying out reduced pressure dehydration to prepare an isooctanoic acid product. The patent belongs to a process for preparing isooctanoic acid by a 2-ethylhexanol oxidation method, the scale of a device is small, sodium hydroxide and sulfuric acid are required in the process, the corrosion to equipment is serious, a large amount of environmental pollutants are generated, and the problem of three wastes is serious.

Chinese patent CN107930647A discloses a catalyst, a preparation method thereof and a preparation method of 2-ethylhexanal. The preparation method of the 2-ethylhexanal comprises the following steps: heating the isooctene aldehyde feed to 180-220 ℃ to gasify the isooctene aldehyde, and introducing hydrogen into the isooctene aldehyde to obtain a mixed gas of the gasified isooctene aldehyde and the hydrogen; and the mixed gas is contacted with a catalyst in the hydrogenation reactor to carry out selective hydrogenation reaction, so as to obtain the mixed gas flow rich in 2-ethylhexanal. The patent has high hydrogenation temperature and large energy consumption, only obtains 2-ethylhexanal, and does not disclose the production process of the isooctanoic acid.

Chinese patent CN111054437A discloses a catalyst for preparing isooctylaldehyde by selective hydrogenation of isooctylaldehyde, a preparation method and application thereof. The catalyst is a metal-polymer composite catalyst and comprises a polyacid crosslinked polymer matrix and a metal active component, wherein the polyacid crosslinked polymer matrix is obtained by the coordination crosslinking action of the polymer matrix with a polyacid crosslinking agent. The method for preparing isooctylaldehyde comprises the following steps: in the presence of hydrogen, under the conditions of reaction temperature of 50-130 ℃ and reaction pressure of 1.0-5.0MPa, in a high-pressure kettle reactor, isooctyl aldehyde is obtained under the catalytic action of the metal-polymer composite catalyst. The catalyst of the patent requires sulfuric acid, phosphoric acid, peroxymolybdic acid and chloroplatinic acid during preparation, and three wastes are generated.

At present, the market of isooctanoic acid is in short supply, most of isooctanoic acid is produced by an alcohol method in China, and the device scale is small. The isooctanoic acid produced by hydrogenation and oxidation of isooctenal has the advantages of low consumption, little pollution, stable product quality, etc. Therefore, a production process for preparing isooctanoic acid by using isooctenal as a raw material by utilizing the advantages of the isooctenal is needed to meet the increasing demand of isooctanoic acid.

Disclosure of Invention

The invention aims to provide a production process for preparing isooctanoic acid by using isooctenal as a raw material, which has low production cost, does not use high-corrosive materials such as alkali, sulfuric acid, potassium permanganate and the like, and does not generate environmental pollutants in the whole production process.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the production process for preparing isooctanoic acid by using isooctenal as a raw material comprises the following steps:

(1) in a micro-bubble reactor, carrying out selective hydrogenation reaction by taking isooctenal as a raw material under the action of a nano particle hydrogenation catalyst to prepare isooctanal;

(2) adding the isooctyl aldehyde obtained in the step (1) into an oxidation reactor, blowing micro bubbles through an air generator, and reacting the isooctyl aldehyde with oxygen in the micro bubbles to obtain the isooctanoic acid.

Wherein:

in the step (1), the nanoparticle hydrogenation catalyst is nanoparticles of gold, palladium, platinum, nickel, vanadium, molybdenum, manganese or oxides thereof; the molar ratio of the nanoparticle hydrogenation catalyst to the amount of isooctenal fed per hour is 0.00008 to 0.01:1, preferably 0.0001 to 0.009: 1.

In the step (1), the temperature of the selective hydrogenation reaction is 30-170 ℃, preferably 80-160 ℃; the pressure is 0.1-10MPa, preferably 0.2-8 MPa.

In the step (1), the space velocity of the isooctene aldehyde in the selective hydrogenation reaction process is 0.005-1h^-1Preferably 0.01 to 0.9h^-1(ii) a The feed molar ratio of isooctenal to hydrogen is 1:1 to 40, preferably 1:2 to 30.

In the step (2), the isooctyl aldehyde enters an oxidation reactor for reaction, and the space velocity of the isooctyl aldehyde is 0.005-1h^-1Preferably 0.01 to 0.9h^-1(ii) a The reaction temperature of the isooctyl aldehyde in the oxidation reactor is 20-150 ℃, and the preferred temperature is 30-120 ℃; the feed molar ratio of isooctylaldehyde to oxygen is from 1:1 to 40, preferably from 1:2 to 30.

The production process for preparing isooctanoic acid by using isooctenal as a raw material comprises the following steps:

(1) in a micro-bubble reactor, carrying out selective hydrogenation reaction by taking isooctenal as a raw material under the action of a nano particle hydrogenation catalyst to prepare isooctanal;

(2) mixing the isooctyl aldehyde obtained in the step (1) with an oxidation catalyst, adding the mixture into an oxidation reactor, blowing micro bubbles through an air generator, and reacting the isooctyl aldehyde with oxygen in the micro bubbles to obtain isooctanoic acid; the oxidation catalyst is recovered with the mother liquor after being filtered by a filter at an isooctanoic acid outlet for recycling.

Wherein:

in the step (2), the oxidation catalyst is cobalt acetate, molybdenum acetate, silver acetate, manganese isooctanoate, cobalt isooctanoate, molybdenum isooctanoate, silver isooctanoate, manganese dioxide, silver oxide, vanadium acetylacetonate, molybdenum trioxide, vanadium pentoxide, aluminum oxide, ferric chloride or palladium oxide;

the molar ratio of oxidation catalyst to isooctylaldehyde feed per hour is from 0 to 0.1:1, preferably from 0 to 0.09: 1.

Preferably, the production process for preparing isooctanoic acid by using isooctenal as a raw material comprises the following steps:

(1) the microbubble reactor comprises a gas phase inlet, a liquid phase inlet, a microbubble tube and a reaction zone, wherein the microbubble tube, the gas phase inlet and the liquid phase inlet are positioned at the upper part of the reaction zone, an annular space channel is formed between the microbubble tube and the tube wall of the microbubble reactor, the liquid phase inlet is connected with the annular space channel, and the gas phase inlet is connected with the microbubble tube; a nano particle hydrogenation catalyst is arranged inside the reaction zone, and a heating medium channel is arranged outside the reaction zone;

hydrogen enters the micro bubble tube from the gas phase inlet, isooctene aldehyde enters an annular channel formed between the micro bubble tube and the tube wall of the micro bubble reactor from the liquid phase inlet, the hydrogen penetrates through the micro bubble tube and carries out selective hydrogenation reaction with isooctene aldehyde under the action of a nano particle hydrogenation catalyst in a reaction zone to prepare isooctene aldehyde, and the isooctene aldehyde flows out from the bottom of the micro bubble reactor;

(2) an air generator is arranged at the bottom of the oxidation reactor, an air outlet is arranged at the top of the oxidation reactor, an isooctyl aldehyde inlet is arranged on one side surface of the oxidation reactor, an isooctanoic acid outlet is arranged on the other side surface of the oxidation reactor, the isooctanoic acid outlet is higher than the isooctyl aldehyde inlet, and a filter is arranged at the isooctanoic acid outlet; an insulating layer is arranged around the oxidation reactor;

and (2) enabling the isooctaldehyde obtained in the step (1) to enter an oxidation reactor from an isooctaldehyde inlet, blowing micro-bubbles through an air generator, enabling the isooctaldehyde to react with oxygen in the micro-bubbles to obtain isooctanoic acid, and enabling the isooctanoic acid to flow out of the oxidation reactor from an isooctanoic acid outlet.

Wherein: in the step (1), the microbubble reactor is an annular space flow fixed bed reactor; the width of the annular gap channel is 1-5mm, preferably 2-3 mm; the micro bubble tube is made of a ceramic membrane, and the pore size of the ceramic membrane is 5-100nm, preferably 5-10 nm; the length of the ceramic membrane is 5-100cm, preferably 20-30 cm. The material of the micro bubble tube body can also be a metal film.

In the step (2), the air blowing pipes of the air generator are 1-10 groups, preferably 5-8 groups; the height of the air blast pipe is 5-100cm, preferably 50-60 cm; the width between the air blowing tubes is 5-100cm, preferably 30-50 cm.

And (2) introducing a heating medium into the heat-insulating layer for heat insulation, wherein the filter is a membrane filter.

The invention has the following beneficial effects:

the invention provides a production process for preparing isooctanoic acid by using isooctenal as a raw material, which is characterized in that the isooctenal is used as the raw material and is catalyzed by a nano particle hydrogenation catalyst in a microbubble reactor to carry out selective hydrogenation at a certain pressure, temperature and airspeed to prepare the isooctanal, and the obtained isooctanal can directly enter an oxidation system for oxidation reaction without purification.

In the microbubble reactor, hydrogen enters a microbubble tube and is dispersed into a large number of microbubbles to enter a liquid phase, the raw materials of isooctene aldehyde and hydrogen can carry out mass transfer and heat transfer under the micro-nano condition, and then catalytic hydrogenation is carried out on a nano particle hydrogenation catalyst micro interface, the reaction efficiency is high, the reaction selectivity is good, the reaction selectivity is not less than 95%, and the conversion rate is not less than 97%.

The obtained isooctyl aldehyde is added into an oxidation reactor, the periphery of the oxidation reactor is wrapped by a heating medium to ensure that the reaction is carried out at constant temperature, an air generator can generate a large amount of controllable micro bubbles, the control is carried out in real time according to the reaction condition, an air outlet is arranged at the upper part of the reactor to ensure that redundant gas is discharged, isooctyl aldehyde and an oxidation catalyst are uniformly mixed and then enter the oxidation reactor to be oxidized into isooctyl acid by oxygen in the micro bubbles, the product isooctyl acid is discharged at an outlet, the oxidation catalyst is recovered with mother liquor after the isooctyl acid is filtered by a filter at the outlet of the isooctyl acid and is recycled, the selectivity of the reaction is more than or equal.

The production process has low cost, does not use high-corrosivity materials such as alkali, sulfuric acid, potassium permanganate and the like, does not generate environmental pollutants in the whole production process, and has strong environmental friendliness and good atom economy.

Drawings

FIG. 1 is a schematic diagram of a microbubble reactor;

FIG. 2 is a schematic diagram of the structure of an oxidation reactor;

wherein: 1. a gas phase inlet; 2. a liquid phase inlet; 3. a micro bubble tube; 4. a nanoparticle hydrogenation catalyst; 5. a heating medium passage; 6. a reaction zone; 7. an air outlet; 8. an iso-octanal inlet; 9. an air generator; 10. a heat-insulating layer; 11. an isooctanoic acid outlet; 12. and (3) a filter.

Detailed Description

The present invention is further described below with reference to examples.

As shown in fig. 1 and 2, the microbubble reactor according to the present invention includes a gas phase inlet 1, a liquid phase inlet 2, a microbubble tube 3, and a reaction zone 6, wherein the microbubble tube 3, the gas phase inlet 1, and the liquid phase inlet 2 are located at an upper portion of the reaction zone 6, an annular gap channel is formed between the microbubble tube 3 and a tube wall of the microbubble reactor, the liquid phase inlet 2 is connected to the annular gap channel, and the gas phase inlet 1 is connected to the microbubble tube 3; a nano particle hydrogenation catalyst 4 is arranged inside the reaction zone 6, and a heating medium channel 5 is arranged outside the reaction zone 6;

the bottom of the oxidation reactor is provided with an air generator 9, the top of the oxidation reactor is provided with an air outlet 7, one side surface of the oxidation reactor is provided with an isooctyl aldehyde inlet 8, the other side surface of the oxidation reactor is provided with an isooctyl acid outlet 11, the isooctyl acid outlet 11 is higher than the isooctyl aldehyde inlet 8, and a filter 12 is arranged at the isooctyl acid outlet 11; an insulating layer 10 is also arranged around the oxidation reactor.

The microbubble reactor is an annular space flow fixed bed reactor; the width of the annular gap channel is 1-5 mm; the micro bubble tube 3 is made of a ceramic membrane, the pore of the ceramic membrane is 5-100nm, and the length of the ceramic membrane is 5-100 cm.

The air generator has 1-10 groups of air blowing pipes, the height of the air blowing pipes is 5-100cm, and the width between the air blowing pipes is 5-100 cm.

Hydrogen enters a micro bubble tube 3 from a gas phase inlet 1, isooctene aldehyde enters an annular space channel formed between the micro bubble tube 3 and the tube wall of a micro bubble reactor from a liquid phase inlet 2, the hydrogen penetrates through the micro bubble tube 3 and carries out selective hydrogenation reaction with the isooctene aldehyde under the action of a nano particle hydrogenation catalyst 4 in a reaction zone 6 to prepare the isooctene aldehyde, and the isooctene aldehyde flows out from the bottom of the micro bubble reactor; the obtained isooctaldehyde enters the oxidation reactor from an isooctaldehyde inlet 8, micro-bubbles are blown in through an air generator 9, the isooctaldehyde reacts with oxygen in the micro-bubbles to prepare isooctanoic acid, and the isooctanoic acid flows out of the oxidation reactor from an isooctanoic acid outlet 11.