Distillation extraction process. Seeking sharing and guidance

The distillation extraction process, also known as extractive distillation, is a technique that utilizes the differing effects of a selective solvent on the relative volatilities of aromatic and non-aromatic hydrocarbons in a hydrocarbon mixture; separation between these two types of hydrocarbons is achieved through a distillation process in the presence of the solvent. The following is a detailed introduction to the distillation extraction process: I. Process principle The distillation extraction process is based on the following principle: a selective solvent can alter the relative volatility of various components in a hydrocarbon mixture, enabling components that otherwise have similar volatility to be separated more easily with the help of this solvent. Through the distillation process, aromatic and non-aromatic hydrocarbons can be effectively separated. II. Main process types
Arosolvan process: Development background: This process was successfully developed by the German company LURGI in 1960; initially, N-methylpyrrolidone (NMP) was used as the solvent. Solvent selection: After improvements, a mixed solvent of NMP and diethylene glycol is generally used to enhance the selectivity of the solvent. Equipment features: The extraction tower employs a mixed sedimentation tank; the residual oil layer is utilized for olefin removal. This eliminates the need for a clay purification stage, resulting in a simple process with good economic efficiency. Product characteristics: This process has certain advantages in the extraction of benzene products; the resulting products exhibit high purity and good quality. However, for other aromatics, the purity of the obtained products is relatively lower. Formex process: R&D background: In 1971, the Italian company Snam and the petroleum processing division of LRSR developed the Formex process using N-formylmorpholine (NFM) or morpholine as solvents. Solvent characteristics: Using NFM or morpholine as a solvent results in high selectivity for aromatics. Other processes: In addition to the Arosolvan and Formex processes, there are various distillation-extraction processes such as the Morphylane process, GT-BTX process, and SED process, each with its own distinct solvent choices, equipment characteristics, and product advantages. III. Process Characteristics and Applicability: The distillation-extraction process is well-suited for processing materials with narrow boiling ranges, enabling efficient separation of aromatic and non-aromatic compounds. Flexibility: By selecting different solvents and process conditions, it is possible to meet the requirements of various raw materials and products. Economic efficiency: Some processes, such as the Arosolvan process, have improved their economic efficiency by streamlining the process flow and eliminating the clay purification stage.

The distillation-extraction process mainly separates the components in a mixture through two processes: distillation and extraction. In industry, this technology is commonly used for purifying and concentrating chemicals. 1. Distillation: Separates mixtures based on the different boiling points of various substances. When the substance is heated to boiling point, the components with a lower boiling point evaporate first, and then are condensed back into a liquid state and collected through a condenser. 2. Extraction: It involves separation by taking advantage of the different solubilities of a target substance in two immiscible liquids. The mixture and the extractant are combined; the target components preferentially dissolve in the extractant. The extractant layer rich in the target component can be separated using separation equipment such as a separatory funnel. When these two methods are used together, they can effectively improve separation efficiency and purity. For example, this technique is commonly used in the pharmaceutical industry to extract active ingredients from plants. I hope this information is helpful to you! If more detailed technical specifications or operational procedures are required, please provide further details on the specific application scenarios and requirements. .