Device and process for separating C4 fractions by adopting binary mixed solvent

Abstract

The invention provides a device and process for separating C4 fractions by adopting a binary mixed solvent. The device comprises an extraction and rectifying column, an extraction and rectifying column top condenser, an extraction and rectifying column refluxing tank, an extraction and rectifying column refluxing pump, an extraction and rectifying column bottom re-boiler, an extraction and rectifying column residue pump, a stripping column, a stripping column top condenser, a stripping column refluxing tank, a stripping column refluxing pump, a stripping column bottom re-boiler, a stripping column residue pump and a lean solvent cooler. C4 separation is carried out by adopting the process so that the relative volatility between butene and butane can be greatly improved and the solvent selectivity is improved; a solvent / feeding ratio is reduced and the temperature of a column reactor is reduced; the heat load of the column reactor is reduced and the aims of saving energy and reducing consumption are realized.

Description

technical field [0001] The invention belongs to the field of separation of carbon four fractions in petrochemical industry, and relates to a process for extracting and rectifying separation of butene and butane using a binary mixed solvent of phenol and water. Specifically, on the basis of the existing conventional technology, extractive distillation is used to separate the butene-butane system. Wherein, the extractant is a binary mixed solvent of phenol and water, and the purity of the butene after purification reaches more than 99.0%. Background technique [0002] The relative volatility of butene and butane is close to 1, so it is difficult to separate them by ordinary distillation. At present, extractive distillation is commonly used in industry to separate butene and butane. The principle is to add a polar solvent to the C4 fraction to increase the relative volatility between butene and butane, and realize the separation of butene and butane. Separation of butane. Th...

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Problems solved by technology

However, in the process of using the above solvents for C4 separation, there are phenomena such as large solvent / feed ratio and high temperature in the tower kettle, which lead to problems such as large solvent loss and high energy consumption at high temperature during the separation process.

[0005] Patent CN101417913A provides a method for extracting and rectifying separation of butene and butane with a multi-component mixed solvent. The invention uses a multi-component mixture of ionic liquids, salts, methyl ethyl ketone and N-formylmorpholine as a solvent, and the butene is separated The purity can reach 98.0%, but the temperature of the stripping column is high, the heat source level required is high, and the loss of ionic liquid is large during the operation, resulting in high energy consumption and material consumption in the separation process

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