Technological process and device for separating isopropanol water solution

Abstract

The invention relates to a novel azeotropic distillation technical method and a device, particularly to a technical method and a device using a bulkhead azeotropic distillation column to produce anhydrous isopropanol. The invention enables the separation between isopropanol and water, as well as the recovery of entrainer to be integrated into the same distillation column. The bulkhead azeotropic distillation column refers to a piece of bulkhead (6) which is arranged in the vertical direction inside the conventional distillation column and extended from the upper part of the distillation column to the bottom part of the distillation column; the total height of the bulkhead (6) is less than that of the distillation column; the bottom of the bulkhead is closed; the bulkhead (6) divides the distillation column into three parts: a public distillation segment (1), a dehydration segment (2) and a lateral line distillation segment (3). The isopropanol aqueous solution which needs to be separated enters into the distillation column from the lower part of the public distillation segment (1) and get the high-purity isopropanol from the bottom of the dehydration segment (2); the , ternary azeotrope is steamed out from the top of the distillation column; the steam at the top of the distillation column is condensed through a condenser (5) and then enters into a phase splitter (4) to be divided into light and heavy two-phase liquid; the light phase (entrainer) flows back, while the heavy phase enters into the lower part of the lateral line distillation segment (3) to get the water containing a small amount of isopropanol at the bottom of the lateral line distillation segment (3).

Description

technical field [0001] The invention relates to an azeotropic rectification process and device, in particular to a novel process and device for producing anhydrous isopropanol by using a next-wall azeotropic rectification tower, which can separate isopropanol and water, entrainer Recycling is combined in one column. Background technique [0002] Isopropanol (IPA) is one of the earliest petrochemical products produced in the world. It is mainly used in the production of acetone and as a solvent. It can also be used to synthesize glycerin, ethyl propyl acetate, ethyl propylamine salt, diethyl nitrite The raw material of propylamine, isopropyl nitrate, hydrogen peroxide, ethyl propyl halide and other products, IPA is also widely used as antifreeze additive of petroleum fuel, used in the manufacture of fungicides, insecticides, disinfectants and preservatives, etc. In recent years, with the strengthening of environmental protection, IPA has been used to replace chlorine solvent...

AI Technical Summary

Problems solved by technology

After separation, isopropanol can be recycled, and ethylene glycol monomethyl ether can be returned to the raw material without causing environmental pollution. However, this operation equipment investment and energy consumption are high, and the purity of isopropanol cannot meet the requirements of some industries.

[0006] Patent CN1249294A invents a method for refining isopropanol in a combined process of adding salt, extraction, azeotropic rectification, first the dilute aqueous solution of isopropanol in industrial production is roughly extracted to the top of the tower through rectification to obtain initially concentrated isopropanol, and then C6 aliphatic hydrocarbon is used as the extraction agent, and the aqueous solution of inorganic sodium salt or potassium salt is used as the salting-out separation agent for salt extraction, and the extracted organic phase is sent to the azeotropic distillation dehydration tower for refining, and the separation agent is recovered by the concentrator Recycling, the product with isopropanol content of more than 99.5% can be obtained in the tower kettle, but the process operation is relatively complicated, and the equipment investment is relatively high

[0007] Patent GB816796 proposes a process for preparing high-purity isopropanol by azeotropic distillation. This process uses ether as an entrainer, and inert gas ethylene is introduced into the tower to make the pressure reach 160-170 psig. A deaerator is installed on the top of the tower. The risk of explosion of the mixture of ether and air is avoided, and the volume concentration of the final isopropanol product is greater than 99.9%. This kind of operation process is complicated and the equipment investment is relatively high

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