Acetonitrile (CH3CN) is a widely used organic chemical raw material, and is widely used as an organic solvent in the petrochemical industry as an extractant for extracting butadiene and isoprene from olefins and paraffins. Synthetic raw materials for synthesis of chemicals, pharmaceuticals, pesticides, surfactants, dyes, and other fine chemicals, and thin-layer chromatography, paper chromatography, spectroscopy, polarography, and mobile phase solvents for high-performance liquid chromatography (HPLC) have recently been used as DNA. Synthetic/purification solvents, solvents for the synthesis of organic EL materials, cleaning solvents for electronic components, etc. These applications have high requirements for the purity of acetonitrile.
At present, the production of acrylonitrile by the ammoxidation of propylene and the by-product acetonitrile are the main sources of industrial production of acetonitrile, accounting for 2% to 3% of the acrylonitrile production. An annual production capacity of 80,000 tons of acrylonitrile plants can recover 5,400 tons of acetonitrile annually. This is a medium-sized plant with an annual output of 50,000 tons of acrylonitrile. It can also recover 1000 to 1200 tons of acetonitrile annually. Due to the low recovery rate of acetonitrile in the 1960s and the 1970s, high cost, and inefficient use, many acrylonitrile manufacturers burned crude acetonitrile as a fuel or disposed of it through deep well injection, and some even directly discharged into the environment. It can make good use of resources and cause serious pollution to the environment. With the development of science and technology, the use of acetonitrile has become increasingly widespread, and acetonitrile recycling has also received increasing attention.
Over the past two decades, people have continuously improved the acetonitrile purification and refining process. The quality of acetonitrile has been greatly improved, and the demand has been increasing. The annual demand for acetonitrile in China has increased from 4,000 tons at the end of the 1990s to about 18 kt, and the average price of acetonitrile has also risen from 7,000 yuan/ton in the late 1990s to 17500 yuan/ton in early 2008, and rose again in January 2009. To the 120,000 yuan / ton price. Recovery of acetonitrile and effective use of acetonitrile is an important way to increase economic and social benefits. Therefore, for a long time, preparation of high-purity acetonitrile suitable for different purposes, even a high-purity acetonitrile can be applied to a variety of uses, has been a hot topic at home and abroad.