Manufacturing method of o-Dichlorobenzene
o-Dichlorobenzene (ODCB) is an important organic chemical raw material, which is widely used in pesticides, pharmaceuticals, dyestuffs, spices and other fields. This article will introduce the manufacturing method of o-Dichlorobenzene in detail, including raw material preparation, reaction process, post-treatment and precautions.
I. Raw material preparation
The main raw materials for manufacturing o-dichlorobenzene are benzene and chlorine. In order to ensure the smooth progress of the reaction, it is necessary to choose higher purity of benzene and chlorine. Meanwhile, certain catalysts, such as aluminum trichloride or ferric chloride, need to be prepared to promote the reaction.
II. Reaction process
The manufacturing process of o-dichlorobenzene mainly includes the following steps:
1. Add benzene and catalyst into the reactor and stir well.
2. Admit chlorine gas, and control the reaction temperature within a suitable range, generally 50-60℃.
3. Continuous stirring is required during the reaction process to ensure that the reaction materials are in full contact.
4. The o-dichlorobenzene product is obtained by controlling the rate of chlorine gas intake and reaction time.
3. Post-treatment
After the reaction, the product needs to be post-treated to obtain o-dichlorobenzene with higher purity. The specific steps are as follows:
1. Cool the reaction solution to room temperature and add alkaline absorbent to neutralize the residual acidic catalyst.
2. Separate the upper organic phase from the lower aqueous phase.
3. Distill the organic phase to collect the o-dichlorobenzene fraction.
4. Refining of the collected o-dichlorobenzene, such as recrystallization or adsorption treatment, to improve product purity.
4. Precautions
In the manufacturing process of o-dichlorobenzene, the following matters need to be paid attention to:
1. Strictly control the purity of raw materials to avoid the influence of impurities on the reaction.
2. Ensure that the reaction temperature is within the appropriate range to avoid the influence of too high or too low temperature on the reaction.
3. Chlorine gas is a toxic gas, which needs to be operated in a well-ventilated environment and equipped with corresponding safety protection measures.
4. In the post-treatment process, it is necessary to choose suitable absorbents and refining methods to ensure product purity.
In conclusion, the manufacturing process of o-dichlorobenzene needs to strictly control the conditions of each link to ensure the smooth progress of the reaction and the improvement of product purity. Meanwhile, the operation process needs to pay attention to safety and comply with relevant regulations and norms.
