阅读说明：本技术 一种碳酸丙烯酯、碳酸乙烯酯、1,2丙二醇，乙二醇减压精馏方法 (Vacuum rectification method for propylene carbonate, ethylene carbonate, 1, 2-propylene glycol and ethylene glycol ) 是由 王新路 于 2020-07-08 设计创作，主要内容包括：本发明提供了一种碳酸丙烯酯、碳酸乙烯酯、1,2丙二醇,乙二醇减压精馏方法,包括以下步骤,物料进入精馏塔中,真空设备启动进行减压,升温到物料沸点后稳定全回流；全回流后系统负压稳定后关闭真空设备切断真空设备连接阀门,封闭泄压阀,同时1：1进行采出轻液一个小时,保持系统负压；然后降低采轻量一直通过外采出稳定系统压力,一直到产品合格,继续往半成品罐采出产品,直至产品全部出完。本专利是减压精馏的基础上,完成了连续减压精馏,并且间歇使用真空泵,达到减少能耗,增加收率的目的。蒸馏效果较好,适于推广应用。(The invention provides a method for rectifying propylene carbonate, ethylene carbonate, 1,2 propylene glycol and ethylene glycol under reduced pressure, which comprises the following steps that materials enter a rectifying tower, vacuum equipment is started to reduce the pressure, and the materials are heated to the boiling point and then are subjected to stable total reflux; after the negative pressure of the system is stable, the vacuum equipment is closed to cut off the vacuum equipment connecting valve after the total reflux, the pressure release valve is closed, and simultaneously 1: 1, extracting light liquid for one hour, and keeping the negative pressure of the system; and then reducing the pressure of the external extraction stabilizing system until the product is qualified, and continuously extracting the product from the semi-finished product tank until the product is completely extracted. On the basis of the vacuum rectification, the continuous vacuum rectification is completed, and the vacuum pump is intermittently used, so that the aims of reducing energy consumption and increasing yield are fulfilled. The distillation effect is better, is suitable for popularization and application.)

1. A method for rectifying propylene carbonate, ethylene carbonate, 1,2 propylene glycol and ethylene glycol under reduced pressure is characterized in that: comprises the following steps of (a) carrying out,

s1, the material enters a rectifying tower, vacuum equipment is started to reduce pressure, and after the temperature is raised to the boiling point of the material, the material is stabilized to be totally refluxed;

s2, after the negative pressure of the system is stable, closing the vacuum equipment and cutting off the vacuum equipment connecting valve, closing the pressure release valve, and simultaneously 1: 1, extracting light liquid for one hour, and keeping the negative pressure of the system;

and S3, reducing the mining weight until the pressure of the external mining stabilizing system is reduced until the product is qualified, and continuously mining the product from the semi-finished product tank until the product is completely mined.

2. The method for rectifying propylene carbonate, ethylene carbonate, 1,2 propylene glycol and ethylene glycol under reduced pressure according to claim 1 is characterized in that: the vacuum equipment starts to depressurize to-100 KP.

3. The method for rectifying propylene carbonate, ethylene carbonate, 1,2 propylene glycol and ethylene glycol under reduced pressure according to claim 1 is characterized in that: the total reflux time was three hours.

4. The method for rectifying propylene carbonate, ethylene carbonate, 1,2 propylene glycol and ethylene glycol under reduced pressure according to claim 1 is characterized in that: the time for extracting light liquid is one hour.

Technical Field

The invention relates to the field of chemical distillation, in particular to a method for rectifying propylene carbonate, ethylene carbonate, 1, 2-propylene glycol and ethylene glycol under reduced pressure.

Background

The existing distillation mode is reduced pressure distillation, the technical defects are high in energy consumption and large in material loss, materials are extracted and lost when vacuum equipment is used for reducing pressure, and power consumption of the vacuum equipment is large after the vacuum equipment is used for a long time.

Disclosure of Invention

The invention aims to overcome the defects of the traditional technology and provide a method for rectifying propylene carbonate, ethylene carbonate, 1,2 propylene glycol and ethylene glycol under reduced pressure, which can effectively solve the technical problems.

The aim of the invention is achieved by the following technical measures: a vacuum rectification method of propylene carbonate, ethylene carbonate, 1,2 propylene glycol and ethylene glycol comprises the following steps,

the material enters the rectifying tower, the vacuum equipment starts to reduce the pressure to-100 KP, the total reflux is stabilized after the temperature is raised to the boiling point of the material, the reflux amount is calculated according to the total amount of the entering equipment, for example, the total feeding amount is 30 tons, the total reflux amount is controlled at 1 ton per hour, the total reflux is three hours, the vacuum equipment is closed after the system negative pressure is stabilized for three hours of the total reflux, the vacuum equipment is cut off a connecting valve of the vacuum equipment, a pressure release valve is closed, and simultaneously 1: 1, extracting light liquid for one hour, keeping the negative pressure of a system, reducing the light extraction weight until the pressure of the external extraction stable system is reduced until the product is qualified, and continuously extracting the product from a semi-finished product tank until the product is completely extracted; the whole process is firstly decompressed to a certain pressure through decompression equipment, the vacuum degree is kept by means of the tightness and continuous extraction of the system, the specific pressure data is about-95 KP, the whole process is completed in a sealed mode, and the energy consumption of vacuum equipment and the material loss of the equipment in a vacuum state are saved.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the advantages that: (ii) a On the basis of the vacuum rectification, the continuous vacuum rectification is completed, and the vacuum pump is intermittently used, so that the aims of reducing energy consumption and increasing yield are fulfilled. The distillation effect is better, is suitable for popularization and application.

The invention is further described with reference to the following figures and detailed description.

Drawings

FIG. 1 is a schematic flow diagram of the present invention.

Detailed Description