Heat integration for pressure swing distillation separation of butanone/isopropanol/n-heptane and control method thereof

The invention belongs to the field of multi-element azeotropic mixture separation in chemical separation and purification, and particularly relates to heat integration for pressure swing distillation separation of butanone/isopropanol/n-heptane and a control method thereof. In order to solve the problem that a butanone, isopropanol and n-heptane ternary azeotropic system shows different azeotropic behaviors along with pressure change in a pressure swing rectification process, three rectifying towers with different operation pressures are adopted on the basis of conventional three-tower pressure swing rectification separation of butanone/isopropanol/n-heptane ternary azeotropes; efficient separation of the three components is achieved through a specific three-component azeotrope separation sequence, meanwhile, a heat-free integration link, a partial heat integration link and a total heat integration process are designed respectively, energy conservation and consumption reduction of the separation process are a