阅读说明：本技术 一种天然脂肪醇的制备方法 (Preparation method of natural fatty alcohol ) 是由 徐跃邦 舒利贞 周尚庆 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种天然脂肪醇的制备方法,其特征在于,包括如下步骤：步骤1、在铜基催化剂的作用下将天然油脂与甲醇进行酯交换反应生成脂肪甲酯；步骤2、将步骤1中所得的脂肪酸甲酯通入反应器组件内与氢气反应得天然脂肪醇粗品；步骤3、将步骤2所得的天然脂肪醇粗品通入蒸发器内进行脱醇处理,最后通过减压精馏得到天然脂肪醇；其中,所述步骤2中先将脂肪酸甲酯雾化后再与氢气反应以提高反应时汽液接触面积。本发明生产工艺简单,能耗低,转化率高,有利于工业化的生产应用。(The invention discloses a preparation method of natural fatty alcohol, which is characterized by comprising the following steps: step 1, carrying out ester exchange reaction on natural grease and methanol under the action of a copper-based catalyst to generate fatty methyl ester; step 2, introducing the fatty acid methyl ester obtained in the step 1 into a reactor component to react with hydrogen to obtain a crude product of natural fatty alcohol; 3, introducing the crude product of the natural fatty alcohol obtained in the step 2 into an evaporator for dealcoholization, and finally carrying out vacuum rectification to obtain the natural fatty alcohol; wherein, in the step 2, the fatty acid methyl ester is atomized and then reacts with the hydrogen to improve the vapor-liquid contact area during the reaction. The invention has simple production process, low energy consumption and high conversion rate, and is beneficial to industrial production and application.)

1. A preparation method of natural fatty alcohol is characterized by comprising the following steps:

step 1, carrying out ester exchange reaction on natural grease and methanol under the action of a copper-based catalyst to generate fatty methyl ester;

step 2, introducing the fatty acid methyl ester obtained in the step 1 into a reactor component to react with hydrogen to obtain a crude product of natural fatty alcohol;

3, introducing the crude product of the natural fatty alcohol obtained in the step 2 into an evaporator for dealcoholization, and finally carrying out vacuum rectification to obtain the natural fatty alcohol;

wherein, in the step 2, the fatty acid methyl ester is atomized and then reacts with the hydrogen to improve the vapor-liquid contact area during the reaction.

2. The method for preparing natural fatty alcohol according to claim 1, wherein: the reactor component comprises a first fixed bed reactor and a second fixed bed reactor which are connected in series, a feeding pipe is fixed at the top end of the first fixed bed reactor, a plurality of grease atomizing nozzles are uniformly distributed on the feeding pipe, and the structure of the second fixed bed reactor is the same as that of the first reactor.

3. The method for preparing natural fatty alcohol according to claim 2, wherein: the process for preparing the crude product of the natural fatty alcohol by introducing the fatty acid methyl ester into the reactor component and reacting with the hydrogen in the step 2 comprises the following steps:

a, conveying fatty acid methyl ester into a feeding pipe at the top end of a first reactor through a conveying pump, atomizing the fatty acid methyl ester by an oil atomizing nozzle, and then spraying the atomized fatty acid methyl ester into the first fixed bed reactor, and simultaneously introducing hydrogen into the first fixed bed reactor from the bottom end of the first fixed bed reactor to react with the fatty acid methyl ester;

b, introducing a part of the primary reaction liquid obtained at the bottom end of the first fixed bed reactor into a feeding pipe at the top end of the first fixed bed reactor through a circulating pump for circulating reaction, and introducing the other part of the primary reaction liquid into a second fixed bed reactor through a conveying pump for secondary reaction with hydrogen;

and step C, conveying one part of the secondary reaction liquid obtained at the bottom end of the second fixed bed reactor through a circulating pump to perform circulating reaction like a feeding pipe at the top end of the second fixed bed reactor, and conveying the other part of the secondary reaction liquid to the next procedure through a conveying pump.

4. The method for preparing natural fatty alcohol according to claim 3, wherein: in the step A, the reaction pressure in the first fixed bed reactor is 18-23 MPa, and the reaction temperature is 170-210 ℃.

5. The method for preparing natural fatty alcohol according to claim 3, wherein: and in the step B, the reaction pressure in the second fixed bed reactor is 15-20 MPa, and the reaction temperature is 150-180 ℃.

Technical Field

The invention relates to a preparation method of natural fatty alcohol.

Background

Fatty alcohol is an important basic raw material for producing surfactants and lubricants, and can react with various compounds by utilizing hydroxyl functional groups in the molecular structure of the fatty alcohol to obtain the fatty alcohol derivative with wide application. The natural fatty alcohol has excellent washing performance and biodegradability, and is widely applied to daily chemical industry, for example, in the cosmetic industry, and the natural fatty alcohol is an ideal raw material in the production of products such as liquid, ointment soap, toothpaste, cosmetic cream and the like. The consumption of natural fatty alcohol in China is high, but the yield is low, most of the reasons are that the natural fatty alcohol is not used for producing a large amount of natural vegetable oil in China, so that a large amount of raw materials mainly come from Malaysia and Indonesia, the production cost of the natural fatty alcohol is too high, and the price of the produced natural fatty alcohol is always high.

The main process routes used in the prior art for the production of natural fatty alcohols include three: 1. directly hydrogenating the grease; 2. hydrolyzing the grease and then hydrogenating; 3. and (4) hydrogenation is carried out after the oil is alcoholyzed. Wherein the hydrogenation process after the oil alcoholysis is to perform ester exchange on the natural oil and methanol to obtain fatty acid ester and then perform hydrogenation. The process has the advantages of relatively mild hydrogenation conditions during the reaction, no acid corrosion problem, capability of recovering glycerol and high yield of fatty alcohol, so the process is widely applied. However, the process still has the problem of high production energy consumption caused by the fact that the vapor-liquid contact area is small in the hydrogenation process and hydrogen needs to be circulated continuously, so that the requirements of people cannot be met.

Disclosure of Invention

In order to solve the problems, the invention provides a preparation method of natural fatty alcohol, which has simple production process and low energy consumption.

The invention adopts the following technical scheme:

a preparation method of natural fatty alcohol comprises the following steps:

step 1, carrying out ester exchange reaction on natural grease and methanol under the action of a copper-based catalyst to generate fatty methyl ester;

step 2, introducing the fatty acid methyl ester obtained in the step 1 into a reactor component to react with hydrogen to obtain a crude product of natural fatty alcohol;

3, introducing the crude product of the natural fatty alcohol obtained in the step 2 into an evaporator for dealcoholization, and finally carrying out vacuum rectification to obtain the natural fatty alcohol;

wherein, in the step 2, the fatty acid methyl ester is atomized and then reacts with the hydrogen to improve the vapor-liquid contact area during the reaction.

As a preferable technical scheme, the reactor assembly comprises a first fixed bed reactor and a second fixed bed reactor which are connected in series, a feeding pipe is fixed at the top end of the first fixed bed reactor, a plurality of grease atomizing nozzles are uniformly distributed on the feeding pipe, and the structure of the second fixed bed reactor is the same as that of the first fixed bed reactor.

As a preferred technical scheme of the invention, the process for preparing the crude natural fatty alcohol by introducing the fatty acid methyl ester into the reactor component and reacting with the hydrogen in the step 2 comprises the following steps:

a, conveying fatty acid methyl ester into a feeding pipe at the top end of a first reactor through a conveying pump, atomizing the fatty acid methyl ester by an oil atomizing nozzle, and then spraying the atomized fatty acid methyl ester into the first fixed bed reactor, and simultaneously introducing hydrogen into the first fixed bed reactor from the bottom end of the first fixed bed reactor to react with the fatty acid methyl ester;

b, introducing a part of the primary reaction liquid obtained at the bottom end of the first fixed bed reactor into a feeding pipe at the top end of the first fixed bed reactor through a circulating pump for circulating reaction, and introducing the other part of the primary reaction liquid into a second fixed bed reactor through a conveying pump for secondary reaction with hydrogen;

and step C, conveying one part of the secondary reaction liquid obtained at the bottom end of the second fixed bed reactor through a circulating pump to perform circulating reaction like a feeding pipe at the top end of the second fixed bed reactor, and conveying the other part of the secondary reaction liquid to the next procedure through a conveying pump.

As a preferable technical scheme of the invention, in the step A, the reaction pressure in the first fixed bed reactor is 18-23 MPa, and the reaction temperature is 170-210 ℃.

As a preferable technical scheme of the invention, in the step B, the reaction pressure in the second fixed bed reactor is 15-20 MPa, and the reaction temperature is 150-180 ℃.

The invention has the beneficial effects that:

the production process is simple, the reactor component adopts the first fixed bed reactor and the second fixed bed reactor which are connected in series to effectively improve the conversion rate of the reaction between the fatty acid methyl ester and the hydrogen, and the grease atomizing nozzle arranged on the feeding pipe can atomize the fatty acid methyl ester, so that the area of vapor-liquid contact during the reaction is increased, the conversion rate is further high, the hydrogen circulation time is reduced, the energy consumption is low, and the popularization and the application of marketization are facilitated.

Detailed Description

The present invention will now be described in further detail with reference to examples.

Example 1

A preparation method of natural fatty alcohol comprises the following steps:

step 1, carrying out ester exchange reaction on natural grease and methanol under the action of a copper-based catalyst to generate fatty methyl ester;

step 2, introducing the fatty acid methyl ester obtained in the step 1 into a reactor component to react with hydrogen to obtain a crude product of natural fatty alcohol;

3, introducing the crude product of the natural fatty alcohol obtained in the step 2 into an evaporator for dealcoholization, and finally carrying out vacuum rectification to obtain the natural fatty alcohol;

wherein, in the step 2, the fatty acid methyl ester is atomized and then reacts with the hydrogen to improve the vapor-liquid contact area during the reaction.

Further, the reactor component comprises a first fixed bed reactor and a second fixed bed reactor which are connected in series, a feeding pipe is fixed at the top end of the first fixed bed reactor, a plurality of grease atomizing nozzles are uniformly distributed on the feeding pipe, and the structure of the second fixed bed reactor is the same as that of the first reactor.

The process for preparing the crude product of the natural fatty alcohol by introducing the fatty acid methyl ester into the reactor component and reacting with the hydrogen in the step 2 comprises the following steps:

a, conveying fatty acid methyl ester into a feeding pipe at the top end of a first reactor through a conveying pump, atomizing the fatty acid methyl ester by an oil atomizing nozzle, and then spraying the atomized fatty acid methyl ester into the first fixed bed reactor, and simultaneously introducing hydrogen into the first fixed bed reactor from the bottom end of the first fixed bed reactor to react with the fatty acid methyl ester;

b, introducing a part of the primary reaction liquid obtained at the bottom end of the first fixed bed reactor into a feeding pipe at the top end of the first fixed bed reactor through a circulating pump for circulating reaction, and introducing the other part of the primary reaction liquid into a second fixed bed reactor through a conveying pump for secondary reaction with hydrogen;

and step C, conveying one part of the secondary reaction liquid obtained at the bottom end of the second fixed bed reactor through a circulating pump to perform circulating reaction like a feeding pipe at the top end of the second fixed bed reactor, and conveying the other part of the secondary reaction liquid to the next procedure through a conveying pump.

Wherein the reaction pressure in the first fixed bed reactor in the step A is 18-23 MPa, and the reaction temperature is 170-210 ℃. In this embodiment, the reaction pressure in the first fixed bed reactor is 20MPa, the reaction temperature is 180 ℃, and in the actual application process, a person skilled in the art can select the required reaction pressure and reaction temperature from the above reaction pressure range and reaction temperature range according to the actual requirement;

wherein the reaction pressure in the second fixed bed reactor in the step B is 15-20 MPa, and the reaction temperature is 150-180 ℃; in this embodiment, the reaction pressure in the first fixed bed reactor is 18MPa, the reaction temperature is 160 ℃, and in the actual application process, a person skilled in the art can select the required reaction pressure and reaction temperature from the above reaction pressure range and reaction temperature range according to the actual requirement;

comparative example 1

The difference in this comparative example from example 1 above is that:

the reactor assembly in step 2 of this comparative example 1 was fabricated using a fixed bed reactor conventionally used in the art in the prior art, and thus the fatty acid methyl ester and hydrogen gas were directly reacted in step 2 by passing them through the fixed bed reactor, respectively.

Comparative example 2

The difference in this comparative example from example 1 above is that:

the reactor component in step 2 of the comparative example 2 is prepared by two fixed bed reactors which are connected in series and are conventionally used in the prior art, and therefore, in step 2, the fatty acid methyl ester and the hydrogen respectively pass through the two fixed bed reactors in turn to react.

TABLE 1 comparison of the properties of the products obtained in the above examples and comparative examples

	Fatty acid conversion/%)	Fatty alcohol molar yield/%
			Example 1	98.6	93.2
Comparative example 1	77.5	69.5
			Comparative example 2	83.6	80.3

As can be seen from the above table, the conversion rate of fatty acid and the yield of fatty alcohol can be effectively improved by the preparation method of the present invention compared to the prior art.

Finally, it should be noted that: these embodiments are merely illustrative of the present invention and do not limit the scope of the present invention. In addition, other variations and modifications will be apparent to persons skilled in the art based on the foregoing description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.