Heat pump rectification process used for C4 separation

Abstract

The invention discloses a heat pump rectification process used for C4 separation. Separation of iso-butane, n-butane and C5 can be completed through two rectifying towers, an iso-butane and n-butane mixture is fed from a front rectifying tower, iso-butane is extracted from the top of the front rectifying tower, part of n-butane is extracted from the inside of the front rectifying tower, n-butane and C5 heavy component are extracted from the bottom of the front rectifying tower, and then enter a rear rectifying tower, residual n-butane is extracted from top of the rear rectifying tower, C5 heavy component is extracted from the bottom of the rear rectifying tower, steam at the top of the front rectifying tower is compressed, heated and pressurized through a steam compressor, the pressurizedenters a front rectifying tower reboiler to be used as a heat source to heat tower kettle material, the material is condensed into a liquid phase, after the liquid phase is cooled through the front rectifying tower, one part of the liquid phase is taken as tower top back flow, and the other part is taken as iso-butane to be discharged. According to the process, the temperature of the tower kettleof the rectifying tower can be reduced greatly, so that the energy consumption of heat pump rectification is lower; and as the content of C5 is about 2-3%, the volume of the rear rectifying tower is greatly different from that of the front rectifying tower, and the investment is far lower than the cost of saved energy consumption.

Description

technical field [0001] The invention relates to the technical field of heat pump rectification, in particular to a heat pump rectification process for C4 separation. Background technique [0002] C4 raw materials are important petrochemical resources. In the previous period of time, C4 in refineries was mainly used to make fuel. With the advancement of economy and technology, the comprehensive utilization of carbon 4 has become more and more important in the industry, and the production process of high value-added products using carbon 4 as raw material emerges in an endless stream. The demand for alkylate oil and MTBE continues to grow, and more and more manufacturers have begun to carry out deep processing of carbon 4. In industrial production, since the demand for isobutane and isobutene is much greater than that of n-butane and n-butene, carbon 4 isomerization, that is, converting normal paraffins into isoparaffins, plays an important role in the entire carbon 4 deep pr...

AI Technical Summary

Problems solved by technology

During the separation of carbon 4, because the raw material contains a small amount of carbon 5 components, the temperature difference between the top and the bottom of the tower is about 60°C, which will greatly increase the energy consumption of the compressor in the heat pump rectification system, resulting in poor energy saving effect

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