Equipment for production of butanol and octanol and triple-effect distillation method

A butanol separation device, wherein the butanol separation device comprises a butanol pre-distillation column, a butanol distillation column, a first butanol isomer column and a second butanol isomer column;

• and each column is equipped with a corresponding condenser, a reflux phase separation tank and a reboiler;
• a feed inlet of the butanol pre-distillation column is connected to an outlet of a butanol reaction system, and the main component of the outlet is a mixture of butanol;
• a bottom outlet of the butanol pre-distillation column is connected to a feed of the butanol distillation column, and a top reflux of the butanol pre-distillation column is taken out as light components;
• a bottom of the butanol distillation column takes out heavy components, and a top gas phase of the butanol distillation column is connected to a heat exchange inlet of the reboiler at a bottom of the second butanol isomer column, and a heat exchanger outlet of the reboiler at the bottom of the second butanol isomer column is connected to the reflux phase separation tank set at the top of the butanol distillation column for reflux at the top of the butanol distillation column;
• at the same time, a reflux material from the top of the butanol distillation column is connected to the feed inlet of the butanol pre-distillation column via a pipeline;
• a side outlet of the butanol distillation column is connected to the first butanol isomer column and the second butanol isomer column, respectively;
• the reboiler at a bottom of the first butanol isomer column is connected to a top of the second butanol isomer column for heat exchange, and both the bottom of the first butanol isomer column and the bottom of the second butanol isomer column take out n-butanol;
• a portion of the reflux material condensed at the top of the first butanol isomer column is connected to a top inlet of the first butanol isomer column via the pipeline, and another portion is taken out as iso-butanol;
• and
• a portion of the reflux material condensed at the top of the second butanol isomer column is connected to a top inlet of the second butanol isomer column via the pipeline, and another portion is taken out as iso-butanol.

An octanol separation device, wherein the octanol separation device comprises a first butyraldehyde isomer column, a second butyraldehyde isomer column, an octanol pre-distillation column and an octanol distillation column;

• a feed for both the first butyraldehyde isomer column and the second butyraldehyde isomer column is a mixture of butyraldehyde derived from propylene carbonylation reaction, and reflux outlets at tops of the first butyraldehyde isomer column and the second butyraldehyde isomer column are iso-butyraldehyde or the mixture of butyraldehyde;
• a reboiler at a bottom of the first butyraldehyde isomer column is connected to a top of the second butyraldehyde isomer column for heat exchange, and bottom outlets of both the first butyraldehyde isomer column and the second butyraldehyde isomer column are processed through an octanol reaction system before being connected to a feed inlet of the octanol pre-distillation column;
• a reboiler at a bottom of the second butyraldehyde isomer column exchanges heat with a top of the octanol distillation column;
• a portion of a reflux material condensed at a top of the octanol pre-distillation column is connected to a top inlet of the octanol pre-distillation column via a pipeline, and another portion is taken out as light components;
• and
• a bottom outlet of the octanol pre-distillation column is connected to a feed inlet of the octanol distillation column, a bottom of the octanol distillation column takes out heavy components, and after condensation reflux at the top, octanol is taken out.

A triple-effect distillation method for production of butanol and octanol, comprising two processes:

• butanol separation and octanol separation, both processes use same feedstocks to obtain n-butanol, iso-butanol and octanol products through different procedures, respectively, wherein butanol separation process is sequentially divided into hydrogenation, removal of light and heavy components and separation of isomeric;
• and octanol separation process is sequentially divided into separation of isomeric, hydrogenation and removal of light and heavy components;
• the removal of light and heavy components for butanol is carried out by a butanol pre-distillation column and a butanol distillation column, and the separation of isomeric for butanol is carried out by a first butanol isomer column and a second butanol isomer column;
• and the separation of isomeric for octanol is carried out by a first butyraldehyde isomer column and a second butyraldehyde isomer column, and the removal of light and heavy components for octanol is carried out by an octanol pre-distillation column and an octanol distillation column;
• a mixture of n-butyraldehyde and iso-butyraldehyde serves as the feedstock entering the butanol separation process and/or the octanol separation process;
• in the butanol separation process, the mixture of n-butyraldehyde and iso-butyraldehyde is hydrogenated as a whole to obtain a mixture of n-butanol and iso-butanol, namely crude butanol;
• the crude butanol is first separated in the butanol pre-distillation column to remove light components and then in the butanol distillation column to remove light components, heavy components and impurities, subsequently, the mixture is sent through two isobutanol separation columns at different pressures to separate n-butanol and iso-butanol, resulting in the production of n-butanol and iso-butanol;
• and the pressure settings for the first butanol isomer column and the second butanol isomer column are adjusted to balance energy consumption and separation efficiency;
• in the octanol separation process, the mixture of n-butyraldehyde and iso-butyraldehydes is subjected to separation in two first butyraldehyde isomer columns at different pressures to separate n-butyraldehyde and iso-butyraldehyde, and the n-butyraldehyde is then hydrogenated to obtain crude octanol;
• the crude octanol is finally separated in the octanol pre-distillation column and the octanol distillation column to remove light components, heavy components and impurities, resulting in the production of octanol;
• and the isomerization columns, the first butyraldehyde isomer column and the second butyraldehyde isomer column operate at different pressures, wherein one is a higher-pressure column and another is a lower-pressure column, the higher-pressure column having a higher temperature, and a top temperature of the higher-pressure column is higher than a bottom temperature of the lower-pressure column, thereby creating a temperature difference;
• a top gas phase of the butanol distillation column serves as a heat source for the second butanol isomer column, and a top gas phase of the second butanol isomer column serves as a heat source for the first butanol isomer column;
• and a top gas phase of the octanol distillation column serves as a portion of the heat source for the reboiler of the second butyraldehyde isomer column, and a top gas phase of the second butyraldehyde isomer column serves as the heat source for the reboiler of the first butyraldehyde isomer column;
• a top temperature of the butanol distillation column is higher than a bottom temperature of the second butanol isomer column, and a top temperature of the second butanol isomer column is higher than a bottom temperature of the first butanol isomer column;
• a top temperature of the octanol distillation column is higher than a bottom temperature of the second butyraldehyde isomer column, and a top temperature of the second butyraldehyde isomer column is higher than a bottom temperature of the first butyraldehyde isomer column;
• and
• a temperature difference between each pair is greater than or equal to 5° C.