CN104058961B

CN104058961B - Process and equipment for continuously producing di (trichloromethyl) carbonate by two-step chlorination method

Info

Publication number: CN104058961B
Application number: CN201410271075.3A
Authority: CN
Inventors: 李安民; 张晓生
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-06-07
Filing date: 2014-06-07
Publication date: 2020-03-27
Anticipated expiration: 2034-06-07
Also published as: CN104058961A

Abstract

The invention relates to a process and equipment for continuously producing bis (trichloromethyl) carbonate by a two-step chlorination method, which is characterized in that raw material dimethyl carbonate is continuously added from the lower part of a No. 1 chlorination reactor, and chlorine is continuously introduced under the irradiation of ultraviolet rays for chlorination reaction; along with the reaction, the volume of the reaction materials is obviously increased, the liquid level gradually rises, and when the liquid level rises to the position of the overflow pipe, the reaction materials continuously overflow from the No. 1 chlorination reactor to the intermediate tank; the method comprises the following steps of (1) intermittently adding reaction materials into a 2# chlorination reactor from a middle tank, wherein the 2# chlorination reactor consists of a plurality of chlorination reactors a, b, c, d.. once, and the like, the 2# chlorination reactor is used for intermittent production, a chlorine gas feeding valve of the 2# chlorination reactor is opened, and the 1# chlorination reactor and the 2# chlorination reactor are used for chlorination reaction simultaneously; when the materials in one chlorination reactor in the 2# chlorination reactor are completely chlorinated, opening a discharge valve at the bottom of the 2# chlorination reactor to discharge the materials in the 2# chlorination reactor; and then repeating the steps to realize the continuous production of the bis (trichloromethyl) carbonate.

Description

Process and equipment for continuously producing di (trichloromethyl) carbonate by two-step chlorination method

The invention relates to a process and equipment for continuously producing bis (trichloromethyl) carbonate by a two-step chlorination method, belonging to the field of chemical engineering.

Technical background: bis (trichloromethyl) carbonate is a substance with extremely high reaction activity, can replace phosgene to carry out chemical reactions such as chloromethylation, carbonation, isocyanation, chlorination, chloroformylation and the like, and has a great tendency to replace phosgene with bis (trichloromethyl) carbonate due to the high toxicity of phosgene and the great risk and harm of leakage in the transportation process. At present, the domestic method for producing bis (trichloromethyl) carbonate is intermittent dimethyl carbonate chlorine chlorination, dimethyl carbonate steam and chlorine coexist in a reactor at the early stage of chlorination, and simultaneously, an energy source is provided for explosion due to the existence of an ultraviolet lamp, so that explosion atmosphere is easily formed to cause explosion, and explosion accidents frequently occur in production practice. Meanwhile, the reaction speed is low due to low temperature in the early stage of the reaction, the early activation time is long, and the production efficiency is low. If the materials are heated in the early stage of the reaction, the vapor pressure of the dimethyl carbonate is increased, and the explosion risk is increased.

The invention aims to provide a process and equipment for continuously producing bis (trichloromethyl) carbonate by a two-step continuous chlorination method, so as to solve the defects of the prior art.

The invention content is as follows: the process for continuously producing the bis (trichloromethyl) carbonate by the two-step chlorination method comprises the following steps:

(1) continuously adding raw material dimethyl carbonate from the lower part of a No. 1 chlorination reactor (1), and continuously introducing chlorine under ultraviolet irradiation for chlorination reaction;

(2) along with the reaction, the volume of the reaction materials is obviously increased, the liquid level gradually rises, and when the liquid level rises to the position of the overflow pipe, the reaction materials continuously overflow from the No. 1 chlorination reactor to the intermediate tank (2);

(3) the reaction materials are intermittently added into a 2# chlorination reactor (3) from a middle tank (2), the 2# chlorination reactor (3) is composed of a plurality of chlorination reactors a, b, c, d.. once and the like, the 2# chlorination reactor (3) is intermittently produced, a chlorine gas feeding valve of the 2# chlorination reactor is opened, and the 1# chlorination reactor and the 2# chlorination reactor simultaneously carry out chlorination reaction;

(4) when the materials in one chlorination reactor in the 2# chlorination reactor (3) are completely chlorinated, opening a discharge valve at the bottom of the 2# chlorination reactor (3) to discharge the materials in the 2# chlorination reactor (3);

(5) and then repeating the steps (3) and (4) to realize the continuous production of the bis (trichloromethyl) carbonate.

The invention has the following advantages:

1. because the 2# chlorination reactor (3) consists of a plurality of chlorination reactors a, b, c, d.. the like, although a single 2# chlorination reactor is in batch production, one or more 2# chlorination reactors are in continuous production at any time, the production process is macroscopically continuous, and is relatively stable;

2. because dimethyl carbonate is fed continuously in the reaction process of the No. 1 chlorination reactor (1), the activation period is not provided, and the production efficiency is relatively improved;

3. because dimethyl carbonate enters the reactor from the lower part of the reactor and reacts immediately after entering the reactor, the upper space of the reactor is almost free from dimethyl carbonate steam, the possibility of explosion is avoided, and the improved reactor never has explosion accidents in fact.

The equipment of the process for continuously producing the bis (trichloromethyl) carbonate by the two-step chlorination method comprises the following steps: the device comprises a 1# chlorination reactor (1), an intermediate tank (2), a 2# chlorination reactor (3), a crystallization packaging machine (4), a hydrochloric acid device (5) and the like, wherein the 1# chlorination reactor (1) is connected with the intermediate tank (2) through an overflow pipe, the upper part of the 1# chlorination reactor is connected with the hydrochloric acid device (5) through a pipeline, the upper part of the intermediate tank (2) is connected with the 1# chlorination reactor (1) through a pipeline, the lower part of the intermediate tank is connected with the 2# chlorination reactor (3) through a pipeline, the 2# chlorination reactor (3) is connected with the hydrochloric acid device (5) and the crystallization packaging machine (4) through pipelines, the packaging machine (4) is connected with the 2# chlorination reactor (3) through a pipeline, and the hydrochloric acid device (5) is connected with the 1# chlorination reactor (1) and the 2# chlorination reactor (3) through pipelines.

The drawings illustrate the following:

FIG. 1 is a schematic diagram of the process equipment of the present invention, wherein (1) is a No. 1 chlorination reactor, (2) is an intermediate tank, (3) is a No. 2 chlorination reactor, (4) is a packing machine, and (5) is a hydrochloric acid device.

The following are further commented by examples:

example (b):

1. continuously adding raw material dimethyl carbonate from the lower part of a No. 1 chlorination reactor (1), and continuously introducing chlorine under ultraviolet irradiation for chlorination reaction;

2. along with the reaction, the volume of the reaction materials is obviously increased, the liquid level gradually rises, and when the liquid level rises to the position of the overflow pipe, the reaction materials continuously overflow from the No. 1 chlorination reactor to the intermediate tank (2);

3. the reaction materials are intermittently added into a 2# chlorination reactor (3) from a middle tank (2), the 2# chlorination reactor (3) is composed of a plurality of chlorination reactors a, b, c, d.. once and the like, the 2# chlorination reactor (3) is intermittently produced, a chlorine gas feeding valve of the 2# chlorination reactor is opened, and the 1# chlorination reactor and the 2# chlorination reactor simultaneously carry out chlorination reaction;

4. when the materials in one chlorination reactor in the 2# chlorination reactor (3) are completely chlorinated, opening a discharge valve at the bottom of the 2# chlorination reactor (3) to discharge the materials in the 2# chlorination reactor (3);

5. and then repeating the steps (3) and (4) to realize the continuous production of the bis (trichloromethyl) carbonate.

Claims

1. The process for continuously producing the bis (trichloromethyl) carbonate by the two-step chlorination method is characterized by comprising the following steps of: (1) continuously adding raw material dimethyl carbonate from the lower part of a No. 1 chlorination reactor (1), and continuously introducing chlorine under ultraviolet irradiation for chlorination reaction;

(3) the reaction materials are intermittently added into a 2# chlorination reactor (3) from a middle tank (2), the 2# chlorination reactor (3) is composed of a plurality of chlorination reactors a, b, c and d... the 2# chlorination reactor (3) is in intermittent production, a chlorine gas feeding valve of the 2# chlorination reactor is opened, and the 1# chlorination reactor and the 2# chlorination reactor are subjected to chlorination reaction simultaneously;

2. The apparatus for the continuous production of bis (trichloromethyl) carbonate according to claim 1, comprising: the device is composed of a 1# chlorination reactor (1), an intermediate tank (2), a 2# chlorination reactor (3), a crystallization packing machine (4) and a hydrochloric acid device (5), wherein the 1# chlorination reactor (1) is connected with the intermediate tank (2) through an overflow pipe, the upper part of the 1# chlorination reactor is connected with the hydrochloric acid device (5) through a pipeline, the upper part of the intermediate tank (2) is connected with the 1# chlorination reactor (1) through a pipeline, the lower part of the intermediate tank is connected with the 2# chlorination reactor (3) through a pipeline, the 2# chlorination reactor (3) is connected with the hydrochloric acid device (5) and the crystallization packing machine (4) through pipelines, the packing machine (4) is connected with the 2# chlorination reactor (3) through a pipeline, and the hydrochloric acid device (5) is connected with the 1# chlorination reactor (1) and the 2# chlorination reactor (3) through pipelines.