Energy-efficient process for separation of 1-butene from a hydrocarbon stream with optimized vapour compression

A process for separating 1-butene from a raffinate 2 stream containing at least 1-butene, 2-butene, n-butane, isobutene and isobutane in a separation unit comprising a first distillation column DK1 and a second distillation column DK2, wherein

• the first distillation column DK1 has at least one reboiler SV1 and the second distillation column DK2 has at least one reboiler SV2;
• the at least one reboiler SV1 is fed with a stream which is withdrawn at a lower end of the first distillation column DK1 and, after passing through a respective reboiler, is guided back to the first distillation column DK1;
• the at least one reboiler SV2 is fed with a stream which is withdrawn at a lower end of the second distillation column DK2 and, after passing through a respective reboiler, is guided back to the second distillation column DK2;
• the process comprising:
• (a) directing the raffinate 2 stream to the first distillation column DK1 and separating the raffinate 2 stream in the first distillation column DK1 into at least one vapour stream BS1 which comprises at least 1-butene and isobutane and is withdrawn at a top of the first distillation column DK1, and at least one bottom stream which comprises at least 1-butene, n-butane and 2-butene and is withdrawn at a bottom of the first distillation column DK1;
• (b) compressing at least a portion of the at least one vapour stream BS1, giving rise to a compressed stream VB1 relative to the at least one vapour stream BS1;
• (c) transferring energy from the compressed stream VB1 to a stream in the at least one reboiler SV1;
• (d) directing the compressed stream VB1 at least partly to the second distillation column DK2 and separating the compressed stream VB1 in the second distillation column DK2 into at least one vapour stream BS2 which comprises at least isobutane and is withdrawn at a top of the second distillation column DK2, and at least one bottom stream which comprises at least 1-butene and is withdrawn at a bottom of the second distillation column DK2;
• (e) at least partly compressing the at least one vapour stream BS2, giving rise to a compressed stream VB2 relative to the at least one vapour stream BS2;
• and
• (f) transferring energy from the compressed stream VB2 to the stream in the at least one reboiler SV2.