阅读说明：本技术 一种负压冷凝法精馏切割中链烃的工艺 (Process for rectifying and cutting medium-chain hydrocarbon by negative pressure condensation method ) 是由 洪国忠 于 2019-11-08 设计创作，主要内容包括：本发明属于化工加工技术领域,涉及一种负压冷凝法精馏切割中链烃的工艺。该工艺,包括：1.将中链烃混合物加热到目标单体烃在负压冷凝条件下气化所需要的温度,再从精馏塔的中上部进料；2.通过塔底的再沸器,将目标单体烃及以下轻组分进行过热气化,使高纯度重组分烃从塔底馏出；3.将塔顶馏出的目标单体烃及以下轻组分气体进行低温冷却,使系统产生负压；4.将精馏塔塔顶压力、冷后温度、冷凝冷却介质流量/油气空冷器电机转速进行串级调节,完成负压操作。该工艺,有效降低目标中链单体烃精馏切割时所需的气化温度,减少工艺过程所需要的热量,保证生产装置平稳运行。(The invention belongs to the technical field of chemical processing, and relates to a process for rectifying and cutting medium-chain hydrocarbon by a negative pressure condensation method. The process comprises the following steps: 1. heating the medium-chain hydrocarbon mixture to the temperature required by the gasification of the target monomer hydrocarbon under the negative pressure condensation condition, and feeding the medium-chain hydrocarbon mixture from the middle upper part of the rectifying tower; 2. the target monomer hydrocarbon and the following light components are superheated and gasified by a reboiler at the bottom of the tower, so that high-purity heavy component hydrocarbon is distilled out from the bottom of the tower; 3. performing low-temperature cooling on the target monomer hydrocarbon distilled from the tower top and the following light component gas to enable the system to generate negative pressure; 4. and (4) performing cascade regulation on the top pressure of the rectifying tower, the temperature after cooling, the flow of the condensed cooling medium/the rotating speed of the motor of the oil-gas air cooler to finish negative pressure operation. The process effectively reduces the gasification temperature required by the target medium-chain monomer hydrocarbon during rectification and cutting, reduces the heat required by the process, and ensures the stable operation of a production device.)

1. A process for rectifying and cutting medium-chain hydrocarbon by a negative pressure condensation method is characterized by comprising the following steps:

(1) heating the medium-chain hydrocarbon mixture to the temperature required by the gasification of the target monomer hydrocarbon under the negative pressure condensation condition, and feeding the medium-chain hydrocarbon mixture from the middle upper part of the rectifying tower;

(2) the target monomer hydrocarbon and the following light components are superheated and gasified by a reboiler at the bottom of the tower, so that high-purity heavy component hydrocarbon is distilled out from the bottom of the tower;

(3) performing low-temperature cooling on the target monomer hydrocarbon distilled from the tower top and the following light component gas to enable the system to generate negative pressure;

(4) the top pressure and the cooled temperature of the rectifying tower and the flow rate of a condensing cooling medium/the rotating speed of a motor of an oil-gas air cooler are adjusted in a cascade mode, the outlet temperature of a condensing cooler at the top of the rectifying tower is adjusted by changing the flow rate of the condensing cooling medium/the rotating speed of the motor of the oil-gas air cooler, and then the top pressure of the rectifying tower is adjusted and controlled by utilizing the outlet temperature to complete negative pressure operation.

2. The process of claim 1, wherein in step (1), the medium chain hydrocarbon mixture is a mixture of medium chain hydrocarbon organics having an atmospheric boiling point between 80 ℃ and 360 ℃.

3. The process of claim 1, wherein in the step (1), the overhead reflux ratio of the rectifying tower is 3-9: 1.

4. The process according to claim 1, wherein in the step (1), the number of plates of the rectifying tower is 70 to 80.

5. The process according to claim 1, wherein in the step (1), the operating pressure of the rectifying tower is-0.05 to 0.01 MPa.G.

6. The process according to claim 1, wherein in the step (2), the temperature of the superheated gasification is more than +40 ℃ of the temperature required for the gasification of the target monomeric hydrocarbon under the negative pressure condensation condition.

7. The process of claim 1, wherein in step (3), the temperature of the subcooling is < the atmospheric condensation point of the lightest components of the medium chain hydrocarbon mixture.

Technical Field

The invention belongs to the technical field of chemical processing, and relates to a process for rectifying and cutting medium-chain hydrocarbon by a negative pressure condensation method; in particular to a process for realizing negative pressure rectification cutting of medium-chain hydrocarbon by utilizing the negative condensation point pressure of medium-chain hydrocarbon organic matters with the boiling point within the range of 80-360 ℃.

Background

With the rapid development of the industrialization process, high-purity medium-chain hydrocarbon (medium-chain hydrocarbon organic matter with the normal pressure boiling point within the range of 80-360 ℃) is widely applied to various industries such as chemical industry, military, electronics, medicine, agriculture, daily chemicals and the like. The traditional method for industrially producing high-purity medium-chain hydrocarbon is to use mixed hydrocarbon such as petroleum hydrocarbon, coal gasification synthetic hydrocarbon, vegetable oil and the like as main raw materials and obtain the high-purity medium-chain hydrocarbon by adopting a normal-pressure rectification cutting technology; namely, under normal pressure, the mixed hydrocarbon is heated to the gasification temperature to be gasified, and then each medium-chain monomer hydrocarbon in the mixed hydrocarbon is rectified, cut and separated to obtain the target product, namely the high-purity medium-chain hydrocarbon.

However, the atmospheric distillation cutting technique also has a number of drawbacks; specifically, the gasification temperature is high, the energy consumption is high, the operation process is easily interfered by a plurality of factors, such as the boiling point and the condensation point pressure of the medium-chain monomeric hydrocarbon and the following components, and the smooth operation condition is difficult to establish.

Disclosure of Invention

The invention aims to provide a process for rectifying and cutting medium-chain hydrocarbon by using a negative pressure condensation method, which reduces the gasification temperature required by rectifying and cutting medium-chain monomer hydrocarbon, reduces the heat required by the process and fuel consumption, and has more stable operation.

The technical scheme of the invention for solving the technical problems is as follows.

A process for rectifying and cutting medium-chain hydrocarbon by a negative pressure condensation method comprises the following steps:

(1) heating the medium-chain hydrocarbon mixture to the temperature required by the gasification of the target monomer hydrocarbon under the negative pressure condensation condition, and feeding the medium-chain hydrocarbon mixture from the middle upper part of the rectifying tower;

(2) the target monomer hydrocarbon and the following light components are superheated and gasified by a reboiler at the bottom of the tower, so that high-purity heavy component hydrocarbon is distilled out from the bottom of the tower;

(3) performing low-temperature cooling on the target monomer hydrocarbon distilled from the tower top and the following light component gas to enable the system to generate negative pressure;

(4) the top pressure and the cooled temperature of the rectifying tower and the flow rate of a condensing cooling medium/the rotating speed of a motor of an oil-gas air cooler are adjusted in a cascade mode, the outlet temperature of a condensing cooler at the top of the rectifying tower is adjusted by changing the flow rate of the condensing cooling medium/the rotating speed of the motor of the oil-gas air cooler, and then the top pressure of the rectifying tower is adjusted and controlled by utilizing the outlet temperature to complete negative pressure operation.

Further, in the step (1), the medium-chain hydrocarbon mixture is a mixture of medium-chain hydrocarbon organic matters with the normal-pressure boiling point of between 80 and 360 ℃.

Further, in the step (1), the reflux ratio of the top of the rectifying tower is 3-9: 1, the number of tower plates is 70-80, and the operating pressure is-0.05-0.01 MPa.G.

Further, in the step (2), the temperature of the superheated gasification is > the temperature +40 ℃ required for the gasification of the target monomeric hydrocarbon under the negative pressure condensation condition.

Further, in step (3), the temperature of the sub-cooling is < the atmospheric condensation point of the lightest components in the medium chain hydrocarbon mixture.

The process for rectifying and cutting the medium-chain hydrocarbon by the negative pressure condensation method has the beneficial effects that:

(1) by utilizing the characteristic that the condensation point pressures of the monomer hydrocarbons in the mixed hydrocarbon are different under different temperature conditions, in the rectification cutting process, the target chain monomer hydrocarbon and the components below the chain monomer hydrocarbon after being gasified at the top of the rectification tower are excessively cooled by adjusting and controlling the cooling temperature of the target chain monomer hydrocarbon and the components below the chain monomer hydrocarbon, so that when the cooling temperature is lower than the normal-pressure condensation point temperature of the target chain monomer hydrocarbon and the components below the chain monomer hydrocarbon, a system generates negative pressure, and meanwhile, the lower the cooling temperature is, the higher the negative pressure generated by the system is, and further the negative pressure operation in the rectification process is realized;

(2) the gasification temperature required by the target medium-chain monomer hydrocarbon during rectification cutting is effectively reduced, the heat required by the technological process is reduced, the fuel consumption is reduced by 8-15%, and the energy-saving effect is very obvious;

(3) by adjusting the tower top pressure of the rectifying tower, the temperature after cooling, the flow of a condensed cooling medium/the rotating speed of a motor of an oil-gas air cooler in a cascade manner, the interference of factors such as boiling points and condensing point pressures of chain monomer hydrocarbon and the following components in a target to the operation is effectively avoided, the establishment of operation conditions is optimized, and the stable operation of a production device is ensured;

(4) the method has the advantages of simple process, low cost and easy operation, and meets the requirement of sustainable development.

Drawings

FIG. 1 is a flow chart of the process control for rectifying and cutting chain hydrocarbon by the negative pressure condensation method.

Detailed Description