3-Nitro-o-xylene (3-Nitro-o-xylene) is an important raw material for the production of chemicals, which is widely used in dyestuffs, pharmaceuticals, pesticides and other fields. In this paper, we will introduce a common manufacturing method of 3-Nitro-o-xylene.
I. Raw materials and equipment
1. Raw materials: o-xylene, mixed acid (mixture of nitric acid and sulfuric acid)
2. Equipment: reaction kettle, cooler, separator, scrubber, dryer, etc.
II. Manufacturing steps
1. Dosing: add o-xylene and mixed acid into the reaction kettle according to a certain ratio. Generally speaking, the molar ratio of o-xylene and mixed acid is 1:1.2-1.5.
2. Reaction: Heating up to a certain temperature in the reaction kettle, so that o-xylene and mixed acid undergo nitrification reaction. The reaction temperature is generally 120-140℃ and the reaction time is about 4-6 hours. During the reaction process, constant stirring is required to ensure a uniform reaction.
3. Cooling and separation: After the reaction is completed, the reaction solution is cooled to room temperature, and then the crude 3-nitro-o xylene and the spent acid are separated by a separator.
4. Washing: The crude 3-nitrophthalene is washed with alkaline absorbent to remove the residual acid.
5. Drying: After washing, dry the crude 3-nitro-o xylene with desiccant to get the dried 3-nitro-o xylene product.
3. Precautions
1. During the operation, attention needs to be paid to control the reaction temperature and time to ensure the smooth progress of the reaction.
2. Waste acid needs to be treated to meet the environmental standards before discharge to avoid pollution to the environment.
3. In the production process, it is necessary to strictly abide by the safety operation regulations to ensure the personal safety of employees.
4. Yield and purity
The yield of this manufacturing method is generally 80-90%, and the purity can reach over 98%. The yield and purity are affected by the quality of raw materials, reaction conditions, equipment performance and other factors.
V. Optimization and improvement
In order to improve the yield and purity of 3-nitro-o-xylene, the manufacturing method can be optimized and improved. For example, the efficiency and selectivity of the reaction can be improved by optimizing the parameters such as the proportion of ingredients, reaction temperature and time; more advanced separation and purification techniques can be used to improve the purity of the product; and the maintenance and upkeep of the equipment can be strengthened to reduce the faults and losses in the production process.
VI. Environmental protection and safety
In the process of manufacturing 3-nitro-o xylene, environmental protection and safety regulations need to be strictly followed to ensure that the production process will not cause harm to the environment and employees. For example, waste acid needs to be treated to meet environmental standards before discharge; employees need to wear protective gear to avoid direct contact with hazardous substances.
In conclusion, 3-nitro-o xylene is an important raw material for the production of chemicals, and its manufacturing method involves a number of aspects and considerations. By optimizing the manufacturing method and strengthening environmental protection and safety management, the yield and purity of the product can be improved while reducing the impact on the environment and employees.
