Intermediate is a very important type of fine chemical products. Its essence is a kind of "semi-finished product", which is an intermediate product in the production of certain products. For example, if a product is to be produced, it can be produced from intermediates, saving costs and reducing It is widely used in the synthesis of medicines, pesticides, coatings, dyes and spices. In the field of medicine, intermediates are an important link in the industrial chain of the pharmaceutical industry. They are used for some chemical raw materials or chemical products in the process of drug synthesis. In a word, they are used to produce APIs.

The pesticide intermediate is also an intermediate medium that combines two or more agricultural raw materials. Today, we mainly talk about pesticide intermediates.

Pesticide refers to a substance or several substances that are chemically synthesized or derived from biological or other natural substances used to prevent, eliminate or control diseases, insects, grasses and other harmful organisms that endanger agriculture and forestry, as well as purposefully regulate the growth of plants and insects. mixtures of substances and their preparations. Broadly speaking, pesticides are divided into crop protection pesticides and non-crop protection pesticides. Crop protection pesticides are mainly divided into herbicides, insecticides, fungicides and plant growth regulators according to their uses, which are mainly used in agricultural protection; Crop protection pesticides mainly include rodenticides, insect repellents, health mosquito control products, etc., which are mainly used in residential medicine, public health, forestry management, industrial mildew control, pest control, seasonal medicine, wood preservation, lawn protection and other fields.

The pesticide industry is at the end of the chemical industry chain and belongs to the fine chemical industry. The upstream of the pesticide industry chain is the petroleum/chemical industry, which provides raw materials for the pesticide industry; the midstream industry mainly includes intermediates, technical drugs, and preparations; the downstream is agricultural and non-agricultural applications. The pesticide industry relies heavily on technology, with large R&D investment, long cycle, high risk and low success rate. Under the contradiction between the global population growth and the reduction of arable land, the widespread use of pesticides to increase the yield per unit area is an important way to solve the food problem.

Pesticides are important means of production in agricultural production, and play an extremely important role in controlling pests and weeds, stabilizing and improving crop yields. Although affected by various factors such as the price of agricultural products, planting area, climate, inventory, etc., the sales of pesticides will show certain periodic fluctuations from year to year, but the demand is still relatively rigid. According to the National Bureau of Statistics, since 2017, the national chemical pesticide production has shown a downward trend. In 2017, the output of chemical pesticides was 2.941 million tons, which fell to 2.083 million tons in 2018. In 2019, the output of chemical pesticides stopped falling and rose, and the output was 2.2539 million tons, a year-on-year increase of 1.4%. In recent years, the sales revenue of my country's pesticide industry has maintained an overall upward trend. In 2018, thanks to the development of biological pesticides and the rise in product prices, as well as the expansion of demand for pesticides in cotton and other cash crops and infrastructure fields, the industry sales revenue was about 329 billion yuan; uptrend.

Different pesticides require different intermediates in the production process. The product produced by the processing of agricultural raw materials is also an intermediate medium that combines two or more substances. In pesticides, it can be understood as a synergist, also known as an organic intermediate. It originally refers to the intermediate products produced in the process of synthesizing chemical products such as spices, dyes, resins, drugs, plasticizers, rubber accelerators, etc. using coal tar or petroleum products as raw materials.

The synthesis of intermediates is generally carried out in a reaction kettle, and the generated intermediates are to be separated and purified, usually by extraction technology. Chloroform extraction of pesticide intermediates is a common operation unit in chemical enterprises. The traditional operation process generally adopts rectification tower operation. This operation process is complicated, with low extraction efficiency and high power consumption. Therefore, with the deepening of social division of labor and the development of production technology With progress, most enterprises have begun to carry out technical transformation and choose more efficient processes for operation. Among them, the solvent extraction method has become the main operation unit of the extraction section in the chemical industry. The solvent extraction method is to select a suitable extractant, mix the raw material liquid with the extractant, transfer the organic phase in the raw material liquid to the extractant, and extract the organic phase after the two phases are separated. This method has the advantages of simple operation, high extraction efficiency, cheap and easy-to-obtain extractant, and at the same time, the extractant can be recycled, which effectively saves the comprehensive input cost.