阅读说明：本技术 一种微反应技术合成硝酸异辛酯的方法 (Method for synthesizing isooctyl nitrate by micro-reaction technology ) 是由 廖维林 王宝荣 张文锋 范乃立 于 2019-12-03 设计创作，主要内容包括：本发明公开了一种微反应技术合成硝酸异辛酯的方法,包含如下步骤：(1)配置合成辅助剂,将所述合成辅助剂用滤网固定在微反应器的反应模块内；(2)将异辛醇通过计量泵进入微反应器的第一预冷模块中进行预冷,将硫酸和硝酸按照混合摩尔比硫酸/硝酸=0.2～0.6:1的比例分别通过微反应器的第二预冷模块的两个入口引入,进行混合和预冷；(3)将预冷后的异辛醇和硫酸硝酸混合液引入所述反应模块内,反应温度为10～30℃,流经反应模块的时间为0.5～1h,反应产物静置分层,取上层有机相,经水洗、碱洗再水洗至中性,无水硫酸镁干燥,获得硝酸异辛酯产物。本发明在显著减少硫酸含量的基础上,提高了硝酸异辛酯产品的纯度和收率,节省了后处理成本。(The invention discloses a method for synthesizing isooctyl nitrate by a micro-reaction technology, which comprises the following steps: (1) preparing a synthesis auxiliary agent, and fixing the synthesis auxiliary agent in a reaction module of a microreactor by using a filter screen; (2) the method comprises the following steps of (1) enabling isooctanol to enter a first precooling module of a microreactor through a metering pump for precooling, introducing sulfuric acid and nitric acid through two inlets of a second precooling module of the microreactor according to a mixing molar ratio of sulfuric acid/nitric acid = 0.2-0.6: 1, and mixing and precooling; (3) introducing the precooled isooctyl alcohol and sulfuric acid nitric acid mixed solution into the reaction module, wherein the reaction temperature is 10-30 ℃, the time of flowing through the reaction module is 0.5-1 h, standing and layering the reaction product, taking the upper organic phase, washing with water and alkali, then washing with water to be neutral, and drying with anhydrous magnesium sulfate to obtain the isooctyl nitrate product. The method improves the purity and yield of the isooctyl nitrate product and saves the post-treatment cost on the basis of obviously reducing the content of sulfuric acid.)

1. A method for synthesizing isooctyl nitrate by a micro-reaction technology is characterized by comprising the following steps:

(1) preparing a synthesis auxiliary agent, and fixing the synthesis auxiliary agent in a reaction module of a microreactor by using a filter screen;

(2) the method comprises the following steps of (1) enabling isooctanol to enter a first precooling module of a microreactor through a metering pump for precooling, introducing sulfuric acid and nitric acid through two inlets of a second precooling module of the microreactor according to a mixing molar ratio of sulfuric acid/nitric acid = 0.2-0.6: 1, and mixing and precooling;

(3) introducing the precooled isooctyl alcohol and sulfuric acid-nitric acid mixed solution into the reaction module, wherein the reaction temperature is 10-20 ℃, the time of flowing through the reaction module is 0.5-1 h, standing and layering reaction products, taking an upper organic phase, washing with water and alkali, then washing with water to be neutral, and drying with anhydrous magnesium sulfate to obtain an isooctyl nitrate product;

the preparation method of the adjuvant comprises the following steps:

1) removing seeds of mature pomegranate fruits, cutting the remainder into pieces, soaking the cut pieces in a cerium nitrate solution to form a mixture, vacuumizing the mixture until no bubbles emerge, filtering the mixture, keeping the temperature of a solid phase at 120 +/-10 ℃ for 10-20 hours, cooling the solid phase after the constant temperature is finished, grinding, heating to 600 +/-10 ℃ in a nitrogen atmosphere, keeping the temperature for 5-6 hours, cooling in air to normal temperature, washing with deionized water, and drying to obtain a solid phase A;

2) preparing a hydrogen peroxide solution, soaking the solid phase A in the hydrogen peroxide solution for 20-30 min, filtering, heating the solid phase to 90-100 ℃, keeping the temperature for 6-10 min, and air-cooling to normal temperature to obtain a solid phase B;

3) preparing an aminosulfonic acid solution, soaking the solid phase B in the aminosulfonic acid solution, then placing the solution in a sealed kettle, sealing the kettle body, heating to 120 +/-5 ℃, preserving heat for 8-10 hours, taking out and air-cooling to normal temperature, opening the sealed kettle, carrying out solid-liquid separation, washing the solid phase with deionized water for 2-3 times, and drying to obtain the auxiliary.

2. The method for synthesizing isooctyl nitrate by using the micro-reaction technology as claimed in claim 1, wherein the sulfuric acid is concentrated sulfuric acid with a solute content of 85-98% by mass, and the nitric acid is concentrated nitric acid with a solute content of 80% by mass.

3. The method for synthesizing isooctyl nitrate by using the micro-reaction technology as claimed in claim 1, wherein the molar ratio of isooctyl alcohol to nitric acid in the reaction module is controlled to be that of isooctyl alcohol: nitric acid = 2-4: 2.

4. The method for synthesizing isooctyl nitrate by using the micro-reaction technology as claimed in claim 1, wherein the mass percentage of solute in the cerium nitrate solution is 5% -8%, and the rest is water; h in the hydrogen peroxide₂O₂The mass percentage of the water-soluble polymer is 20-30 percent, and the rest is water.

5. The method for synthesizing isooctyl nitrate by using the micro-reaction technology as claimed in claim 1, wherein the concentration of sulfamic acid in the sulfamic acid solution is 50-60 g/L, and the rest is water; the mass of the sulfamic acid solution is more than 6 times of that of the solid phase B soaked in the sulfamic acid solution.

Technical Field

The invention belongs to the technical field of production of petrochemical nitrate, and particularly relates to a method for synthesizing isooctyl nitrate by using a micro-reaction technology.

Background

Isooctyl nitrate is mainly used as diesel oil additive for raising its cetane number. The cetane number is an index of spontaneous combustibility of diesel oil during combustion, and the higher the cetane number is, the better the combustion performance of the diesel oil is, and the better the anti-explosion and anti-shock effects are. Isooctyl nitrate can be heated and decomposed to generate active free radicals under the condition of low temperature, and the active free radicals participate in the oxidative decomposition reaction of diesel oil combustion, and the free radicals are used as the center to initiate an oxidation chain reaction, so that the free radicals are subjected to the oxidation reaction at a lower temperature, and the cetane number of the diesel oil is improved, thereby greatly reducing the activation energy of the diesel oil combustion, improving the ignition performance of the diesel oil, protecting the diesel oil vehicle engine, and reducing the engine faults.

Disclosure of Invention

The invention provides a method for synthesizing isooctyl nitrate by a micro-reaction technology, which comprises the following steps:

(1) preparing a synthesis auxiliary agent, and fixing the synthesis auxiliary agent in a reaction module of a microreactor by using a filter screen;

(2) the method comprises the steps that isooctyl alcohol enters a first precooling module of a microreactor through a metering pump for precooling, sulfuric acid and nitric acid are respectively introduced through two inlets of a second precooling module of the microreactor according to the mixing molar ratio of sulfuric acid/nitric acid = 0.2-0.6: 1 for mixing and precooling, and the precooling temperature of the first precooling module and the precooling temperature of the second precooling module are the same as the reaction temperature;

(3) introducing the precooled isooctyl alcohol and sulfuric acid-nitric acid mixed solution into the reaction module, wherein the reaction temperature is 10-20 ℃, the time of flowing through the reaction module is 0.5-1 h, standing and layering reaction products, taking an upper organic phase, washing with water and alkali, then washing with water to be neutral, and drying with anhydrous magnesium sulfate to obtain an isooctyl nitrate product;

the preparation method of the adjuvant comprises the following steps:

1) removing seeds of mature pomegranate fruits, cutting the remainder into pieces, soaking the cut pieces in a cerium nitrate solution to form a mixture, vacuumizing the mixture until no bubbles emerge, filtering the mixture, keeping the temperature of a solid phase at 120 +/-10 ℃ for 10-20 hours, cooling the solid phase after the constant temperature is finished, grinding, heating to 600 +/-10 ℃ in a nitrogen atmosphere, keeping the temperature for 5-6 hours, cooling in air to normal temperature, washing with deionized water, and drying to obtain a solid phase A;

2) preparing a hydrogen peroxide solution, soaking the solid phase A in the hydrogen peroxide solution for 20-30 min, filtering, heating the solid phase to 90-100 ℃, keeping the temperature for 6-10 min, and air-cooling to normal temperature to obtain a solid phase B;

3) preparing an aminosulfonic acid solution, soaking the solid phase B in the aminosulfonic acid solution, then placing the solution in a sealed kettle, sealing the kettle body, heating to 120 +/-5 ℃, preserving heat for 8-10 hours, taking out and air-cooling to normal temperature, opening the sealed kettle, carrying out solid-liquid separation, washing the solid phase with deionized water for 2-3 times, and drying to obtain the auxiliary.

Further, the sulfuric acid is concentrated sulfuric acid with solute content of 85-98% by mass, and the nitric acid is concentrated nitric acid with solute content of 80% by mass.

Further, the molar ratio of isooctyl alcohol to nitric acid in the reaction module is controlled to be between isooctyl alcohol: nitric acid = 2-4: 2.

Further, the mass percentage of solute in the cerium nitrate solution is 5% -8%, and the balance is water; h in the hydrogen peroxide₂O₂The mass percentage of the water-soluble polymer is 20-30 percent, and the rest is water.

Further, in the sulfamic acid solution, the concentration of sulfamic acid is 50-60 g/L, and the balance of water; the mass of the sulfamic acid solution is more than 6 times of that of the solid phase B soaked in the sulfamic acid solution.

Therefore, the beneficial effects of the invention are as follows: according to the invention, by improving the preparation method of isooctyl nitrate and introducing a reaction auxiliary agent into the microreactor, the purity and yield of isooctyl nitrate products are improved on the basis of obviously reducing the content of sulfuric acid, so that the subsequent purification process of isooctyl nitrate products is simpler, and the post-treatment cost is saved.

Drawings

FIG. 1 is a schematic structural diagram of a microreactor according to the present invention.

Detailed Description

The following is a detailed description with reference to examples: