Butanol and octanol production device and triple-effect distillation method

Abstract

The present invention includes a butanol and octanol production device and a triple-effect distillation method, comprising two processes: butanol separation and octanol separation. Both processes use the same raw materials, and obtain n-butanol, isobutanol and octanol products by means of different steps. Butanol separation is divided into three parts, in order: hydrogenation, light and heavy component removal, and n / iso separation; octanol separation can be divided into three parts in order: n / iso separation, hydrogenation, and light and heavy component removal; the light and heavy component removal part for butanol is completed by a butanol pre-distillation tower and a butanol distillation tower, and the n / iso separation part for butanol is completed by a butanol isomer tower I and a butanol isomer tower II; the n / iso separation part for octanol is completed by a butyraldehyde isomer tower I and a butyraldehyde isomer tower II, and the light and heavy component removal part for octanol is completed by an octanol pre-distillation tower and an octanol distillation tower; a mixture of n-butyraldehyde and isobutyraldehyde enters the butanol separation process and / or the octanol separation process as a raw material. The present invention has lower energy consumption and achieves heat exchange between towers, greatly reducing production costs.

Description

A butanol and octanol production equipment and triple-effect distillation method Technical Field

[0001] The present invention relates to butanol and octanol production equipment and a triple-effect distillation method. Background Art

[0002] Butanol and octanol can be produced using similar synthesis methods in the same facility, hence the common name of butyl and octanol. Butanol and octanol are important raw materials for the synthesis of fine chemicals, primarily used in the production of plasticizers, solvents, dehydrating agents, defoamers, dispersants, flotation agents, petroleum additives, and synthetic fragrances. Butanol's downstream consumption primarily includes butyl acrylate, butyl acetate, and DBP. Octanol's downstream consumption primarily includes DOP, DOTP, and octyl acrylate.

[0003] Butyl octanol has rapidly grown alongside the development of petrochemicals, the polyvinyl chloride materials industry, and oxo synthesis technology. The main industrial production methods for butyl octanol include acetaldehyde condensation, fermentation, the Ziegler process, and oxo synthesis, with oxo synthesis being the most predominant technology for producing butyl octanol today.

[0004] The separation process of propylene carbonylation to produce butanol and octanol is as follows: (1) Propylene hydroformylation reaction, crude aldehyde is refined to obtain n-butyraldehyde and isobutyraldehyde; (2) n-butyraldehyde and isobutyraldehyde are hydrogenated to obtain n-butanol and isobutanol; (3) n-butyraldehyde is condensed and hydrogenated to obtain octanol. The propylene carbonylation process is divided into high-pressure process, medium-pressure process and low-pressure process. The low-pressure carbonylation Davy technology for producing butanol and octanol was a new process that was not industrialized until the mid-1970s. It was a new technology jointly developed by Union Carbide Corporation of the United States, Davy Company of the United Kingdom and Johnson Mather Company of the United Kingdom. Subsequently, Union Carbide and Davy Company developed the fourth generation low-pressure liquid phase carbonylation process "UCC / Davy MK-IV process".

[0005] Low-pressure butanol (BPA) technology is a low-pressure carbonylation process for producing n- and isobutyraldehyde using propylene and synthesis gas (a mixture of hydrogen and carbon monoxide). For over 30 years, Davy Process Technologies and The Dow Chemical Company have jointly marketed and provided technology transfer and services for low-pressure butanol. To date, this technology has been transferred to 29 projects in 15 countries and regions across four continents. Low-pressure butanol (BPA) technology is considered the world's leading transferable butanol technology, accounting for over 85% of global butanol production produced through transfer using propylene as a feedstock.

[0006] Low-pressure butanol and octanol technology has obvious advantages in each reaction section. However, in the subsequent separation processes such as butyraldehyde separation, butanol separation, and octanol separation, the operating temperature of each tower is high, the temperature difference between single towers is large, there is no heat exchange between towers, and the energy consumption is high. Therefore, it is necessary to make technical improvements to the subsequent separation processes to save energy.

[0007] Butanol and octanol are obtained by distilling the reaction liquid from the butanol-octanol plant. Most existing production facilities use separate processes for light and heavy desorption and normal isomer separation. Both the heat source and refrigerant are externally sourced, and there is no heat exchange between the towers. This results in high energy consumption and high production costs. Reducing energy consumption has become a key issue in process improvement.

[0008] Summary of the Invention

[0009] In view of the shortcomings of the prior art, the present invention aims to provide a butyl octanol production device and a triple-effect distillation method. The method has lower energy consumption, realizes heat exchange between towers, and greatly reduces production costs.

[0010] The technical solution adopted by the present invention to solve the technical problem is:

[0011] In a first aspect, the present invention provides a butanol and octanol production device, comprising a butanol pre-distillation tower 2, a butanol distillation tower 8, a butanol isomerization tower 14, a butanol isomerization tower 20, a butyraldehyde isomerization tower 15, a butyraldehyde isomerization tower 21, an octanol pre-distillation tower 38, and an octanol distillation tower 44, a total of 8 towers, each equipped with a corresponding condenser, a reflux phase separation tank, and a reboiler;

[0012] The feed port of the butanol pre-distillation tower 2 is connected to the discharge of the butanol reaction system 1;

[0013] The bottom discharge of the butanol pre-distillation tower 2 is connected to the feed of the butanol distillation tower 8, and the top of the butanol pre-distillation tower 2 is refluxed and extracted as a light component;

[0014] The heavy components are extracted from the bottom of the butanol distillation tower 8, and the top gas phase is connected to the heat exchange inlet of the bottom reboiler of the butanol isomerization tower 20. The heat exchange outlet of the bottom reboiler of the butanol isomerization tower 20 is connected to the reflux phase separation tank provided at the top of the butanol distillation tower 8 for reflux; at the same time, the reflux material at the top of the butanol distillation tower 8 is connected to the feed inlet of the butanol pre-distillation tower 2 through a pipeline;

[0015] The side outlets of the butanol distillation tower 8 are connected to the butanol isomer tower 14 and the butanol isomer tower 20 respectively;

[0016] The reboiler of the bottom of the butanol isomerization tower 14 is connected to the top of the butanol isomerization tower 20 for heat exchange, and both the bottom of the butanol isomerization tower 14 and the bottom of the butanol isomerization tower 20 produce n-butanol;

[0017] A portion of the condensed reflux material at the top of the butanol isomerization tower 14 is connected to the top inlet of the butanol isomerization tower 14 via a pipeline, and the other portion is used to produce isobutanol.

[0018] Part of the condensed reflux material at the top of the butanol isomerization tower 20 is connected to the top inlet of the butanol isomerization tower 2 through a pipeline, and the other part is used to produce isobutanol;

[0019] The feed of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are both mixed butyraldehydes from the propylene carbonylation reaction. The top reflux outflow of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 is isobutyraldehyde or mixed butyraldehydes, which can also be connected to the feed port of the butanol reaction system 1;

[0020] The bottom reboiler of the butyraldehyde isomerization tower 1 25 exchanges heat with the top of the butyraldehyde isomerization tower 2 31 , and the bottom discharges of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are connected to the feed port of the octanol pre-distillation tower 38 after passing through the octanol reaction system 37 ;

[0021] The bottom reboiler of the second butyraldehyde isomerization tower 31 exchanges heat with the top of the octanol distillation tower;

[0022] A portion of the condensed reflux material at the top of the octanol pre-distillation tower 38 is connected to the top inlet of the octanol pre-distillation tower 38 via a pipeline, and the other portion is used to extract light components;

[0023] The bottom discharge of the octanol pre-distillation tower 38 is connected to the feed port of the octanol distillation tower 44; the heavy components are extracted from the bottom of the octanol distillation tower, and octanol is extracted after condensation and reflux at the top of the tower.

[0024] Furthermore, the butyraldehyde isomer tower 2 31 is provided with two reboilers arranged in parallel, one is the butyraldehyde isomer tower 2 reboiler 32 No. 1, which uses steam as the reboiler heat source; the other is the butyraldehyde isomer tower 2 reboiler 33 No. 2, which uses the top gas phase of the octanol distillation tower as the heat source; the feed of the butanol reaction system is the mixed butyraldehyde from the propylene carbonylation reaction.

[0025] In a second aspect, the present invention provides a butanol separation device, comprising a butanol pre-distillation tower 2, a butanol distillation tower 8, a first butanol isomerization tower 14, and a second butanol isomerization tower 20, each tower being equipped with a corresponding condenser, a reflux phase separation tank, and a reboiler;

[0026] The feed port of the butanol pre-distillation tower 2 is connected to the discharge of the butanol reaction system 1, and the main component of the discharge is mixed butanol;

[0027] The bottom discharge of the butanol pre-distillation tower 2 is connected to the feed of the butanol distillation tower 8, and the top of the butanol pre-distillation tower 2 is refluxed and extracted as a light component;

[0028] The heavy components are extracted from the bottom of the butanol distillation tower 8, and the top gas phase is connected to the heat exchange inlet of the bottom reboiler of the butanol isomerization tower 20. The heat exchange outlet of the bottom reboiler of the butanol isomerization tower 20 is connected to the reflux phase separation tank provided at the top of the butanol distillation tower 8 for reflux; at the same time, the reflux material at the top of the butanol distillation tower 8 is connected to the feed inlet of the butanol pre-distillation tower 2 through a pipeline;

[0029] The side outlets of the butanol distillation tower 8 are connected to the butanol isomer tower 14 and the butanol isomer tower 20 respectively;

[0030] The reboiler of the bottom of the butanol isomerization tower 14 is connected to the top of the butanol isomerization tower 20 for heat exchange, and both the bottom of the butanol isomerization tower 14 and the bottom of the butanol isomerization tower 20 produce n-butanol;

[0031] A portion of the condensed reflux material at the top of the butanol isomerization tower 14 is connected to the top inlet of the butanol isomerization tower 14 via a pipeline, and the other portion is used to produce isobutanol.

[0032] A portion of the condensed reflux material at the top of the second butanol isomerization tower 20 is connected to the top inlet of the second butanol isomerization tower via a pipeline, and the other portion is used to produce isobutanol.

[0033] In a third aspect, the present invention provides an octanol separation device, comprising a first butyraldehyde isomerization tower 25, a second butyraldehyde isomerization tower 31, an octanol pre-distillation tower 38, and an octanol distillation tower 44;

[0034] The feeds of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are both mixed butyraldehydes from the propylene carbonylation reaction, and the top reflux output of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 is isobutyraldehyde or mixed butyraldehydes;

[0035] The bottom reboiler of the butyraldehyde isomerization tower 1 25 exchanges heat with the top of the butyraldehyde isomerization tower 2 31 , and the bottom discharges of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are connected to the feed port of the octanol pre-distillation tower 38 after passing through the octanol reaction system 37 ;

[0036] The bottom reboiler of the second butyraldehyde isomerization tower 31 exchanges heat with the top of the octanol distillation tower;

[0037] A portion of the condensed reflux material at the top of the octanol pre-distillation tower 38 is connected to the top inlet of the octanol pre-distillation tower 38 via a pipeline, and the other portion is used to extract light components;

[0038] The bottom discharge of the octanol pre-distillation tower 38 is connected to the feed port of the octanol distillation tower 44; the heavy components are extracted from the bottom of the octanol distillation tower, and octanol is extracted after condensation and reflux at the top of the tower.

[0039] In a fourth aspect, the present invention provides a triple-effect distillation method for producing butanol and octanol, comprising two processes: butanol separation and octanol separation. The two processes use the same raw materials and are subjected to different steps to obtain normal-butanol, isobutanol, and octanol products, respectively. The butanol separation is sequentially divided into three parts: hydrogenation, light and heavy removal, and normal isomer separation; and the octanol separation is sequentially divided into three parts: normal isomer separation, hydrogenation, and light and heavy removal.

[0040] The light and heavy removal of butanol is carried out by butanol pre-distillation tower 2 and butanol distillation tower 8, and the normal isomerization of butanol is separated by butanol isomerization tower 14 and butanol isomerization tower 20; the normal isomerization of octanol is separated by butyraldehyde isomerization tower 1 25 and butyraldehyde isomerization tower 2 31, and the light and heavy removal of octanol is carried out by octanol pre-distillation tower 38 and octanol distillation tower 44;

[0041] The mixture of n-isobutyraldehyde is fed as a raw material into a butanol separation process and / or an octanol separation process;

[0042] In the butanol separation process, a mixture of n-isobutyraldehyde is hydrogenated as a whole to obtain a mixture of n-isobutanol, i.e., crude butanol. The crude butanol is first passed through a butanol pre-distillation tower 2 to remove light components, and a butanol distillation tower 8 to remove light components, heavy components, and impurities. The crude butanol is then passed through two isomerization towers at different pressures to separate n-butanol and isobutanol, yielding n-butanol and isobutanol products. The pressure settings of the butanol isomerization tower 1 and the butanol isomerization tower 2 meet the requirements for balancing energy consumption and separation efficiency.

[0043] In the octanol separation process, a mixture of n-butyraldehyde and isobutyraldehyde is separated into n-butyraldehyde and isobutyraldehyde by passing through two isomerization towers at different pressures. The n-butyraldehyde is then hydrogenated to obtain a crude octanol product. The crude octanol product is then passed through an octanol pre-distillation tower 38 and an octanol distillation tower 44 to remove light components, heavy components, and impurities, thereby obtaining an octanol product. The butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 each have a high pressure and a low pressure, respectively. The high-pressure tower has a higher temperature, and the top temperature of the high-pressure tower is higher than the bottom temperature of the low-pressure tower, thereby providing a temperature difference.

[0044] The top gas phase of the butanol distillation tower is used as a heat source for the second butanol isomer tower, and the top gas phase of the second butanol isomer tower is used as a heat source for the first butanol isomer tower; the top gas phase of the octanol distillation tower is used as a part of the heat source for the reboiler of the second butyraldehyde isomer tower, and the top gas phase of the second butyraldehyde isomer tower is used as a heat source for the reboiler of the first butyraldehyde isomer tower;

[0045] The top temperature of the butanol distillation tower is greater than the bottom temperature of the second butanol isomer tower, and the top temperature of the second butanol isomer tower is greater than the bottom temperature of the first butanol isomer tower;

[0046] The top temperature of the octanol distillation tower is greater than the bottom temperature of the second butyraldehyde isomer tower, and the top temperature of the second butyraldehyde isomer tower is greater than the bottom temperature of the first butyraldehyde isomer tower;

[0047] And the temperature difference between the two should be no less than 5℃.

[0048] The temperature difference between the two is 5°C to 50°C, preferably 10°C to 30°C.

[0049] The top pressure of the butanol pre-distillation tower 2 is normal pressure to 100 kPa (G), the top temperature is 70 to 140° C., and the bottom temperature is 100 to 170° C.;

[0050] The top pressure of the butanol distillation tower 8 is normal pressure to 100 kPa (G), the top temperature is 90 to 170° C., and the bottom temperature is 110 to 190° C.;

[0051] The top pressure of the butanol isomerization tower 14 is -100 kPa (G) to normal pressure, the top temperature is 20 to 100° C., and the bottom temperature is 40 to 120° C.;

[0052] The top pressure of the second butanol isomerization tower 20 is -60 kPa(G) to 40 kPa(G), the top temperature is 60 to 140°C, and the bottom temperature is 80 to 160°C;

[0053] The top pressure of the butyraldehyde isomerization tower 25 is -100 kPa (G) to normal pressure, the top temperature is 20 to 100° C., and the bottom temperature is 40 to 120° C.;

[0054] The top pressure of the second butyraldehyde isomerization tower 31 is between normal pressure and 200 kPa(G), the top temperature is between 40 and 140°C, and the bottom temperature is between 60 and 160°C.

[0055] The top pressure of the octanol pre-distillation tower 38 is -100 kPa (G) to normal pressure, the top temperature is 60 to 140° C., and the bottom temperature is 100 to 180° C.;

[0056] The top pressure of the octanol distillation tower 44 is -100 kPa (G) to normal pressure, the top temperature is 90 to 160°C, and the bottom temperature is 110 to 190°C.

[0057] Each tower is a plate tower or a packed tower, and the flow parameter FP value of each tower is between 0.02 and 0.2; in the case of a packed tower, the tower internals include packing, packing support rings and liquid distributors.

[0058] The raw material can be a mixture of butyraldehyde and the product of propylene carbonylation reaction, or a mixture of n-butyraldehyde and isobutyraldehyde as the main components; the mass percentage composition range of the raw material is: the mixture of n-butyraldehyde and isobutyraldehyde accounts for 90% to 100%, the light component accounts for 0% to 4%, and the heavy component accounts for 0% to 6%; the ratio of n-butanol to isobutanol is between 1:1 and 15:1.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] 1. The method of the present invention separates the butanol separation process from the octanol separation process, allowing for free adjustment of the butanol-octanol reaction ratio to a certain extent, enabling more flexible adaptation to market demand. The butanol and octanol separation processes each employ a triple-effect energy-saving heat exchange design, significantly reducing energy consumption. This overcomes the problem in conventional butanol-octanol separation processes where the heat source and refrigerant required for distillation tower production are directly heated or cooled using conventional heat sources and refrigerants, resulting in ineffective utilization of waste heat from the overhead gas phase.

[0061] 2. In the present invention, the overhead gas phase of the butanol distillation tower is used as a heat source for the reboiler of the butanol isomerization tower 2, and the overhead gas phase of the octanol distillation tower is used as a heat source for the reboiler of the butyraldehyde isomerization tower 2. The heat of these two high-temperature streams is fully utilized, so that the butanol isomerization tower 2 no longer requires an additional heat source, thereby reducing the energy consumption of the entire process.

[0062] 3. The butanol isomerization tower and the butyraldehyde isomerization tower in the present invention are converted from a single-tower Davy process to a dual-tower thermally coupled process. Different thermally coupled heat exchange processes are designed, splitting the single tower into two. The two towers have the same function but different operating conditions. The towers have different pressures: the higher-pressure tower has a higher tower temperature, while the lower-pressure tower has a lower tower temperature. The top temperature of the high-pressure tower is higher than the bottom temperature of the low-pressure tower, with a certain temperature difference. This allows for dual-effect heat exchange between the two towers. The tower pressures of both the butanol isomerization tower (1) and the butyraldehyde isomerization tower (1) are converted from the slightly positive pressure of the Davy process to reduced pressure, lowering the operating temperature of the entire tower. The overhead gas phase of the butanol isomerization tower (2) serves as a heat source for the reboiler of the butanol isomerization tower (1), while the overhead gas phase of the butyraldehyde isomerization tower (2) serves as a heat source for the reboiler of the butyraldehyde isomerization tower (1). This eliminates the need for additional heat sources for the butanol isomerization tower (1) and the butyraldehyde isomerization tower (1), reducing energy consumption throughout the entire process. This avoids the problems in the existing Davy process where the butanol isomerization tower and the butyraldehyde isomerization tower use slightly positive pressure (the top pressure of the butanol isomerization tower in the Davy process is around 20-40 kPa (G), and the top pressure of the butyraldehyde isomerization tower in the Davy process is around 40-60 kPa (G)), which causes the temperature of the entire tower to be relatively high. At the same time, in order to separate the normal isomers, the entire tower is not only very tall but also consumes huge energy.

[0063] 4. The working conditions of each tower in the Davy process are not deliberately controlled to form a temperature difference, and the bottom temperature of the tower is high and the top temperature is low. The present invention redesigns each tower for different processes according to the different design purposes and working conditions, and explores a more energy-saving working condition on the basis of meeting the separation effect. By controlling the tower pressure, an orderly temperature difference is formed between the towers (the top temperature of the butanol distillation tower> the bottom temperature of the butanol isomer tower 2, the top temperature of the butanol isomer tower 2> the bottom temperature of the butanol isomer tower 1;

[0064] The top temperature of the octanol distillation tower is greater than the bottom temperature of the second butyraldehyde isomer tower, and the top temperature of the second butyraldehyde isomer tower is greater than the bottom temperature of the first butyraldehyde isomer tower;

[0065] And the temperature difference between each other is required to be no less than 5°C), so that a heat exchange network can be constructed according to different temperature differences, laying the foundation for the energy-saving optimization design of the entire system.

[0066] 5. In the embodiments of the present invention, the working conditions of the tower components and each tower have been rearranged. In the Davy process, due to the limitations of time and technology, the towers all used plate tower structures, and the tower plates used in the tower internals resulted in a large pressure drop across the tower and a high bottom temperature. The tower internals of the present invention use fillers to replace the tower plates of the Davy process, which greatly reduces the pressure drop across the tower and further reduces the bottom temperature, providing the basic conditions for the subsequent design of three-effect heat exchange. The present invention can achieve three-effect heat exchange, with low energy consumption, reasonable design, and simple operation. Compared with other industrial energy-saving designs, this method requires less investment, is practical and reliable, and has significant effects. Compared with the Davy process, the process of the present invention can save about 40-60% of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] FIG1 is a process flow diagram of a triple-effect distillation method for producing butyl octanol according to the present invention.

[0068] In the figure, there is a 1-butanol reaction system; a 2-butanol pre-distillation tower; a 3-butanol pre-distillation tower reboiler; a 4-butanol pre-distillation tower condenser; a 5-butanol pre-distillation tower reflux phase separation tank; a 6-butanol pre-distillation tower reflux pump; a 7-butanol pre-distillation tower bottom pump; an 8-butanol distillation tower; a 9-butanol distillation tower reboiler; a 10-butanol distillation tower reflux phase separation tank; a 11-butanol distillation tower reflux pump; a 12-butanol distillation tower bottom pump; a 13-butanol distillation tower side line extraction pump; a 14-butanol isomerization tower; a 15-butanol isomerization tower reboiler; a 16-butanol isomerization tower condenser; a 17-butanol isomerization tower reflux tank; a 18-butanol isomerization tower reflux pump; a 19-butanol isomerization tower bottom pump; a 20-butanol isomerization tower; 21-Butanol isomerization tower reboiler; 22-Butanol isomerization tower reflux tank; 23-Butanol isomerization tower reflux pump; 24-Butanol isomerization tower bottom pump; 25-Butyraldehyde isomerization tower one; 26-Butyraldehyde isomerization tower reboiler; 27-Butyraldehyde isomerization tower condenser; 28-Butyraldehyde isomerization tower reflux phase separation tank; 29-Butyraldehyde isomerization tower reflux pump; 30-Butyraldehyde isomerization tower bottom pump; 31-Butyraldehyde isomerization tower two; 32-Butyraldehyde isomerization tower two reboiler No. 1; 33-Butyraldehyde isomerization tower two reboiler No. 2; 34-Butyraldehyde isomerization tower two reflux phase separation tank; 35-Butyraldehyde isomerization tower two reflux pump; 36-Butyraldehyde isomerization tower two bottom pump; 37-Octanol reaction system; 38-Octanol pre-distillation tower; 39-octanol pre-distillation tower reboiler; 40-octanol pre-distillation tower condenser; 41-octanol pre-distillation tower reflux phase separation tank; 42-octanol pre-distillation tower reflux pump; 43-octanol pre-distillation tower bottom pump; 44-octanol distillation tower; 45-octanol distillation tower reboiler; 46-octanol distillation tower reflux tank; 47-octanol distillation tower reflux pump; 48-octanol distillation tower bottom pump. DETAILED DESCRIPTION

[0069] The present invention is further explained below with reference to the embodiments and drawings, but they are not intended to limit the scope of protection of the present application.

[0070] The present invention provides a butanol and octanol production equipment, comprising a butanol pre-distillation tower 2, a butanol distillation tower 8, a butanol isomerization tower 14, a butanol isomerization tower 20, a butyraldehyde isomerization tower 15, a butyraldehyde isomerization tower 21, an octanol pre-distillation tower 38, and an octanol distillation tower 44, a total of 8 towers, each equipped with a corresponding condenser, a reflux phase separation tank, and a reboiler;

[0071] The feed port of the butanol pre-distillation tower 2 is connected to the discharge of the butanol reaction system 1, and the feed of the butanol reaction system is mixed butyraldehyde from the propylene carbonylation reaction;

[0072] The bottom discharge of the butanol pre-distillation tower 2 is connected to the feed of the butanol distillation tower 8, and the top of the butanol pre-distillation tower 2 is refluxed and extracted as a light component;

[0073] The heavy components are extracted from the bottom of the butanol distillation tower 8, and the top gas phase is connected to the heat exchange inlet of the bottom reboiler of the butanol isomerization tower 20. The heat exchange outlet of the bottom reboiler of the butanol isomerization tower 20 is connected to the reflux phase separation tank provided at the top of the butanol distillation tower 8 for reflux; at the same time, the reflux material at the top of the butanol distillation tower 8 is connected to the feed inlet of the butanol pre-distillation tower 2 through a pipeline;

[0074] The side outlet of the butanol distillation tower 8 is connected to the butanol isomer tower 14 and the butanol isomer tower 20 respectively.

[0075] The reboiler of the bottom of the butanol isomerization tower 14 is connected to the top of the butanol isomerization tower 20 for heat exchange, and both the bottom of the butanol isomerization tower 14 and the bottom of the butanol isomerization tower 20 produce n-butanol;

[0076] A portion of the condensed reflux material at the top of the butanol isomerization tower 14 is connected to the top inlet of the butanol isomerization tower 14 via a pipeline, and the other portion is used to produce isobutanol.

[0077] Part of the condensed reflux material at the top of the butanol isomerization tower 20 is connected to the top inlet of the butanol isomerization tower 2 through a pipeline, and the other part is used to produce isobutanol;

[0078] The feeds of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are both mixed butyraldehydes from the propylene carbonylation reaction. The top reflux discharge of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 is mainly isobutyraldehyde or mixed butyraldehydes. The top reflux discharge of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 can be connected to the feed port of the butanol reaction system 1;

[0079] The bottom reboiler of the butyraldehyde isomerization tower 1 25 exchanges heat with the top of the butyraldehyde isomerization tower 2 31 , and the bottom discharges of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are connected to the feed port of the octanol pre-distillation tower 38 after passing through the octanol reaction system 37 ;

[0080] The bottom reboiler of the second butyraldehyde isomerization tower 31 exchanges heat with the top of the octanol distillation tower;

[0081] A portion of the condensed reflux material at the top of the octanol pre-distillation tower 38 is connected to the top inlet of the octanol pre-distillation tower 38 via a pipeline, and the other portion is used to extract light components;

[0082] The bottom discharge of the octanol pre-distillation tower 38 is connected to the feed port of the octanol distillation tower 44; the heavy components are extracted from the bottom of the octanol distillation tower, and octanol is extracted after condensation and reflux at the top of the tower.

[0083] Furthermore, the butyraldehyde isomer tower 2 31 is provided with two reboilers arranged in parallel, one is the butyraldehyde isomer tower 2 reboiler 32 No. 1, which uses steam as the reboiler heat source; the other is the butyraldehyde isomer tower 2 reboiler 33 No. 2, which uses the top gas phase of the octanol distillation tower as the heat source.

[0084] The present invention also protects a butanol separation device, comprising a butanol pre-distillation tower 2, a butanol distillation tower 8, a first butanol isomerization tower 14, and a second butanol isomerization tower 20, each tower being equipped with a corresponding condenser, a reflux phase separation tank, and a reboiler;

[0085] The feed port of the butanol pre-distillation tower 2 is connected to the discharge of the butanol reaction system 1, the main component of which is mixed butanol (n-butanol and isobutanol). The feed of the butanol reaction system is mixed butyraldehyde from the propylene carbonylation reaction;

[0086] The bottom discharge of the butanol pre-distillation tower 2 is connected to the feed of the butanol distillation tower 8, and the top of the butanol pre-distillation tower 2 is refluxed and extracted as a light component;

[0087] The heavy components are extracted from the bottom of the butanol distillation tower 8, and the top gas phase is connected to the heat exchange inlet of the bottom reboiler of the butanol isomerization tower 20. The heat exchange outlet of the bottom reboiler of the butanol isomerization tower 20 is connected to the reflux phase separation tank provided at the top of the butanol distillation tower 8 for reflux; at the same time, the reflux material at the top of the butanol distillation tower 8 is connected to the feed inlet of the butanol pre-distillation tower 2 through a pipeline;

[0088] The side outlets of the butanol distillation tower 8 are connected to the butanol isomer tower 14 and the butanol isomer tower 20 respectively;

[0089] The reboiler of the bottom of the butanol isomerization tower 14 is connected to the top of the butanol isomerization tower 20 for heat exchange, and both the bottom of the butanol isomerization tower 14 and the bottom of the butanol isomerization tower 20 produce n-butanol;

[0090] A portion of the condensed reflux material at the top of the butanol isomerization tower 14 is connected to the top inlet of the butanol isomerization tower 14 via a pipeline, and the other portion is used to produce isobutanol.

[0091] A portion of the condensed reflux material at the top of the second butanol isomerization tower 20 is connected to the top inlet of the second butanol isomerization tower via a pipeline, and the other portion is used to produce isobutanol.

[0092] The present invention also protects an octanol separation device, comprising a first butyraldehyde isomerization tower 25, a second butyraldehyde isomerization tower 31, an octanol pre-distillation tower 38, and an octanol distillation tower 44, each tower being equipped with a corresponding condenser, a reflux phase separation tank, and a reboiler;

[0093] The feeds of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are both mixed butyraldehydes from the propylene carbonylation reaction, and the top reflux output of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 is isobutyraldehyde or mixed butyraldehydes;

[0094] The bottom reboiler of the butyraldehyde isomerization tower 1 25 exchanges heat with the top of the butyraldehyde isomerization tower 2 31 , and the bottom discharges of the butyraldehyde isomerization tower 1 25 and the butyraldehyde isomerization tower 2 31 are connected to the feed port of the octanol pre-distillation tower 38 after passing through the octanol reaction system 37 ;

[0095] The bottom reboiler of the second butyraldehyde isomerization tower 31 exchanges heat with the top of the octanol distillation tower;

[0096] A portion of the condensed reflux material at the top of the octanol pre-distillation tower 38 is connected to the top inlet of the octanol pre-distillation tower 38 via a pipeline, and the other portion is used to extract light components;

[0097] The bottom discharge of the octanol pre-distillation tower 38 is connected to the feed port of the octanol distillation tower 44; the heavy components are extracted from the bottom of the octanol distillation tower, and octanol is extracted after condensation and reflux at the top of the tower.

[0098] The triple-effect distillation method for producing butanol and octanol of the present invention includes two processes, butanol separation and octanol separation. The two processes use the same raw materials and obtain normal-butanol, isobutanol and octanol products respectively through different processes. The butanol separation is divided into three parts in sequence: hydrogenation, light and heavy removal, and normal isomer separation; and the octanol separation is divided into three parts in sequence: normal isomer separation, hydrogenation, and light and heavy removal.

[0099] The light and heavy removal of butanol is carried out by butanol pre-distillation tower 2 and butanol distillation tower 8, and the normal isomerization of butanol is separated by butanol isomerization tower 14 and butanol isomerization tower 20; the normal isomerization of octanol is separated by butyraldehyde isomerization tower 1 25 and butyraldehyde isomerization tower 2 31, and the light and heavy removal of octanol is carried out by octanol pre-distillation tower 38 and octanol distillation tower 44;

[0100] The propylene raw material undergoes carbonylation reaction to obtain a mixture of n-isobutyraldehyde, which then enters the subsequent butanol separation process or octanol separation process;

[0101] In the butanol separation process, a mixture of n-isobutyraldehyde is hydrogenated as a whole to produce a mixture of n-isobutanol, i.e., crude butanol. The crude butanol is first passed through a butanol pre-fractionation tower 2 to remove light components, and a butanol fractionation tower 8 to remove light components, heavy components, water, and other impurities. The crude butanol is then separated into n-butanol and isobutanol products by two isomerization towers operating at different pressures (the pressures of the butanol isomerization tower 1 and the butanol isomerization tower 2 are set to balance energy consumption and separation effectiveness).

[0102] In the octanol separation process, a mixture of n-butyraldehyde and isobutyraldehyde is passed through two isomerization towers with different pressures (a butyraldehyde isomerization tower 1 and a butyraldehyde isomerization tower 2, one with high pressure and the other with low pressure; the higher pressure tower has a higher temperature, and the top temperature is higher than the bottom temperature of the lower pressure tower, with a certain temperature difference required for heat exchange). The n-butyraldehyde is then hydrogenated to obtain crude octanol. The crude octanol is then passed through an octanol pre-distillation tower 38 and an octanol distillation tower 44 to remove light components, heavy components, and impurities, thereby obtaining the octanol product.

[0103] The overhead gas phase of the butanol distillation tower serves as a heat source for the second butanol isomerization tower, which in turn serves as a heat source for the first butanol isomerization tower. The overhead gas phase of the octanol distillation tower serves as a partial heat source for the reboiler of the second butyraldehyde isomerization tower, which in turn serves as a heat source for the reboiler of the first butyraldehyde isomerization tower. In the butanol and octanol separation processes, each constitutes a triple-effect heat exchange network, significantly reducing energy consumption. This triple-effect heat exchange network refers to the three towers involved in heat exchange in each process.

[0104] The specific process of the triple-effect distillation method for producing butyl octanol is:

[0105] In the butanol separation process:

[0106] The mixed butyraldehydes from the propylene carbonylation reaction are passed through the butanol reaction system 1 and hydrogenated as a whole to obtain mixed butanol containing a small amount of impurities.

[0107] The mixed butanol is sent to a butanol pre-distillation tower 2, which is provided with a reboiler 3 with steam as a reboiler heat source; the top pressure of the butanol pre-distillation tower 2 is normal pressure to 100 kPa (G), where G represents gauge pressure, the top temperature is 70 to 140° C., and the bottom temperature is 100 to 170° C.; the top gas phase of the butanol pre-distillation tower 2 enters a butanol pre-distillation tower condenser 4 for condensation, with circulating water used as a condenser refrigerant; the condensed liquid enters a butanol pre-distillation tower reflux phase-separation tank 5, the water phase in the reflux phase-separation tank 5 is discharged from the boundary zone, and the organic phase in the reflux phase-separation tank 5 is transported by a butanol pre-distillation tower reflux pump 6, a portion of which is returned to the top of the butanol pre-distillation tower 2 as reflux, and the other portion is extracted as a light component.

[0108] The material at the bottom of butanol pre-distillation tower 2 is transported via a butanol pre-distillation tower bottom pump 7 to a butanol distillation tower 8. Butanol distillation tower 8 is equipped with a reboiler 9 using steam as the reboiler heat source. The top pressure of butanol distillation tower 8 is between atmospheric pressure and 100 kPa(G), the top temperature is between 90°C and 170°C, and the bottom temperature is between 110°C and 190°C. The gaseous phase at the top of butanol distillation tower 8 enters a reboiler 21 for condensation in a second butanol isomerization tower. The condensed liquid enters a butanol distillation tower reflux phase-separation tank 10. The aqueous phase in the reflux phase-separation tank 10 is discharged from the boundary region. The organic phase in the reflux phase-separation tank 10 is transported via a butanol distillation tower reflux pump 11. A portion of the organic phase is returned to the top of butanol distillation tower 8 as reflux, while the remaining portion is withdrawn as light components and returned to butanol pre-distillation tower 2. The heavy components at the bottom of butanol distillation tower 8 are withdrawn via a butanol distillation tower bottom pump 12. The material extracted from the side line of the butanol distillation tower 8 is extracted by the butanol distillation tower side line extraction pump 13 and then divided into two streams, one stream entering the butanol isomer tower 14 and the other stream entering the butanol isomer tower 2 20.

[0109] Butanol Isomerization Tower 14 is equipped with a reboiler 15, using the overhead vapor from Butanol Isomerization Tower 2 as the reboiler heat source. The overhead pressure of Butanol Isomerization Tower 14 ranges from -100 kPa(G) to atmospheric pressure, the top temperature is 20-100°C, and the bottom temperature is 40-120°C. The overhead vapor from Butanol Isomerization Tower 14 enters Butanol Isomerization Tower 1 condenser 16 for condensation, using recycled water as the condenser refrigerant. The condensed liquid enters Butanol Isomerization Tower 1 reflux tank 17. The material in reflux tank 17 is transported by Butanol Isomerization Tower 1 reflux pump 18, with a portion returning to the top of Butanol Isomerization Tower 14 as reflux and a portion withdrawn as isobutanol product. The n-butanol product at the bottom of Butanol Isomerization Tower 14 is transported by Butanol Isomerization Tower 1 bottom pump 19 to the n-butanol product tank.

[0110] Butanol isomerization tower 20 is equipped with a reboiler 21, using the overhead vapor phase of the butanol distillation tower as the reboiler heat source. The overhead pressure of butanol isomerization tower 20 is -60 kPa(G) to 40 kPa(G), the tower top temperature is 60-140°C, and the tower bottom temperature is 80-160°C. The overhead vapor phase of butanol isomerization tower 20 enters the reboiler 15 of butanol isomerization tower 1 for condensation, and the condensed liquid enters the reflux tank 22 of butanol isomerization tower 2. The material in the reflux tank 22 is transported by the reflux pump 23 of butanol isomerization tower 2, with part of it returning to the top of butanol isomerization tower 20 as reflux, and part of it being withdrawn as isobutanol product. The n-butanol product at the bottom of butanol isomerization tower 20 is transported by the bottom pump 24 of butanol isomerization tower 20 to the n-butanol product tank.

[0111] Octanol separation process:

[0112] The mixed butyraldehyde from the propylene carbonylation reaction is divided into two streams, one of which enters the butyraldehyde isomerization column 1 25 and the other enters the butyraldehyde isomerization column 2 31 .

[0113] A reboiler 26 is provided in the butyraldehyde isomer tower 25, and the gas phase at the top of the butyraldehyde isomer tower 2 serves as the reboiler heat source. The top pressure of the butyraldehyde isomer tower 25 is between -100 kPa(G) and atmospheric pressure, the top temperature is between 20°C and 100°C, and the bottom temperature is between 40°C and 120°C. The gas phase at the top of the butyraldehyde isomer tower 25 enters the butyraldehyde isomer tower 1 condenser 27 for condensation, with circulating water serving as the condenser refrigerant. The condensed liquid enters the butyraldehyde isomer tower 1 reflux phase separation tank 28. The material in the reflux phase separation tank 28 is transported by a butyraldehyde isomer tower 1 reflux pump 29, with a portion of the material returning to the top of the butyraldehyde isomer tower 1 as reflux and a portion of the material being withdrawn as isobutyraldehyde or mixed butyraldehyde products. The withdrawn isobutyraldehyde or mixed butyraldehyde products can enter the butanol separation process to participate in subsequent reactions. The material at the bottom of the butyraldehyde isomerization tower 25 is transported by the butyraldehyde isomerization tower bottom pump 30 to produce normal butyraldehyde.

[0114] Butyraldehyde isomerization tower 2 31 is equipped with two reboilers: one is butyraldehyde isomerization tower 2 reboiler 32, which uses steam as the reboiler heat source; the other is butyraldehyde isomerization tower 2 reboiler 33, which uses the overhead vapor phase of octanol distillation tower 44 as the heat source. The overhead pressure of butyraldehyde isomerization tower 2 31 is between atmospheric pressure and 200 kPa(G), the tower top temperature is 40-140°C, and the tower bottom temperature is 60-160°C. The overhead vapor phase of butyraldehyde isomerization tower 2 31 enters butyraldehyde isomerization tower 1 reboiler 26 for condensation, and the condensed liquid enters butyraldehyde isomerization tower 2 reflux phase separation tank 34. The aqueous phase in reflux phase separation tank 34 is discharged from the boundary zone, and the organic phase in reflux phase separation tank 34 is transported by butyraldehyde isomerization tower 2 reflux pump 35. A portion of the organic phase is returned to the top of butyraldehyde isomerization tower 2 31 as reflux, and the remaining portion is withdrawn to an isobutyraldehyde or mixed butyraldehyde storage tank. The material at the bottom of the second butyraldehyde isomerization tower 31 is transported through the bottom pump 36 of the second butyraldehyde isomerization tower to produce normal butyraldehyde.

[0115] The n-butyraldehyde is passed through the octanol reaction system 37 and subjected to overall condensation and hydrogenation to obtain a crude octanol product containing a small amount of impurities.

[0116] The material from the octanol reaction system is delivered to an octanol pre-distillation tower 38, which is provided with a reboiler 39 with steam as the reboiler heat source. The top pressure of the octanol pre-distillation tower 38 is -100 kPa(G) to normal pressure, the top temperature is 60-140°C, and the bottom temperature is 100-180°C. The gas phase at the top of the octanol pre-distillation tower 38 enters the octanol pre-distillation tower condenser 40 for condensation, and the condensed liquid enters the octanol pre-distillation tower reflux phase-separation tank 41. The aqueous phase in the reflux phase-separation tank 41 is discharged from the boundary area, and the organic phase in the reflux phase-separation tank 41 is transported by the octanol pre-distillation tower reflux pump 42, with a portion returned to the top of the octanol pre-distillation tower 38 as reflux and a portion withdrawn as light components.

[0117] The bottoms of octanol pre-distillation tower 38 are transported to octanol distillation tower 44 via octanol pre-distillation tower bottom pump 43. Octanol distillation tower 44 is equipped with a reboiler 45 using steam as the reboiler heat source. The top pressure of octanol distillation tower 44 ranges from -100 kPa(G) to atmospheric pressure, the top temperature is 90-160°C, and the bottom temperature is 110-190°C. The gaseous phase at the top of octanol distillation tower 44 enters the reboiler 33 of the second butyraldehyde isomerization tower for condensation. The condensed liquid enters the octanol distillation tower reflux tank 46. The material in reflux tank 46 is transported by octanol distillation tower reflux pump 47, with some returning to the top of octanol distillation tower 44 as reflux and some withdrawn as octanol product. The bottoms of octanol distillation tower 44 are transported as heavy components via octanol distillation tower bottom pump 48 for withdrawal.

[0118] Furthermore, the top temperature of the butanol distillation tower is greater than the bottom temperature of the second butanol isomer tower, and the top temperature of the second butanol isomer tower is greater than the bottom temperature of the first butanol isomer tower;

[0119] The top temperature of the octanol distillation tower is greater than the bottom temperature of the second butyraldehyde isomer tower, and the top temperature of the second butyraldehyde isomer tower is greater than the bottom temperature of the first butyraldehyde isomer tower;

[0120] And the temperature difference between each other is required to be no less than 5°C, and the temperature difference between each other is 5°C to 50°C, preferably the temperature difference is 10°C to 30°C.

[0121] Temperature difference is the driving force of heat transfer in heat exchanger. According to the basic heat transfer equation: Q=KAΔtm

[0122] Where, Q is the heat transfer rate, W is the

[0123] K——Proportional coefficient, W / m2·℃

[0124] A——heat exchange area, m 2

[0125] Δtm——heat transfer driving force, ℃

[0126] The driving force for heat transfer comes from the temperature difference between the hot stream and the cold stream. If the temperature difference is too small, it is easy to cause temperature cross-affecting heat exchange, and the heat exchange area of ​​the heat exchanger will be very large, which is not economically reasonable. In order to construct the temperature difference between different towers, the pressure needs to be controlled. If the pressure difference between the two towers is increased blindly just to expand the temperature difference between the two towers, it is also not economically reasonable. Therefore, the temperature difference between the top and bottom of the two towers that need heat exchange is limited to 5~50℃.

[0127] The raw material in the present invention can be a mixture of butyraldehyde and the product of the propylene carbonylation reaction, or a mixture of n-butyraldehyde and isobutyraldehyde as the main components. The preferred raw material composition range that meets the process requirements is: the mixture of n-butyraldehyde and isobutyraldehyde accounts for 90% to 100%, the light component accounts for 0% to 4%, and the heavy component accounts for 0% to 6%. The ratio of n-butanol to isobutanol can be between 1:1 and 15:1.

[0128] In the present invention, the top refluxed material of the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 is isobutyraldehyde or mixed butyraldehyde, which can be recovered for other uses, preferably fed into the butanol reaction system as a raw material to participate in the reaction again.

[0129] The tower internals are selected based on the different physical properties of the gas phase and liquid phase of each tower. The selection can be made according to the following formula:

[0130] Traffic parameters

[0131] Where, L is the liquid load, kmol / s

[0132] V——gas load, kmol / s

[0133] ρ g ——Gas density, kg / m 3

[0134] ρ l ——Liquid density, kg / m 3

[0135] When FP = 0.02-0.3, packed towers have higher efficiency than plate towers. The FP values ​​of each tower in the present process are all between 0.02 and 0.2, making packed towers more suitable. Furthermore, packed towers offer better separation performance at the same tower height and lower pressure drop across the tower, making them more suitable for the heat exchange system of the present invention. In the following examples, packed towers were selected.

[0136] Example 1:

[0137] In the butanol separation process:

[0138] Mixed butyraldehydes from the carbonylation reaction of propylene (wherein the ratio of normal butyraldehyde to isobutyraldehyde is approximately 10:1) are passed through the butanol reaction system 1 and hydrogenated as a whole to obtain mixed butanol containing a small amount of impurities.

[0139] The mixed butanol is sent to a butanol pre-distillation tower 2, which is provided with a reboiler 3 with steam as a reboiler heat source; the tower top pressure of the butanol pre-distillation tower 2 is 50 kPa (G), the tower top temperature is 99° C., and the tower bottom temperature is 133° C. The top gas phase of the butanol pre-distillation tower 2 enters a butanol pre-distillation tower condenser 4 for condensation, with circulating water as the condenser refrigerant, and the condensed liquid enters a butanol pre-distillation tower reflux phase-separation tank 5, the water phase in the butanol pre-distillation tower reflux phase-separation tank 5 is discharged from the boundary area, and the organic phase in the butanol pre-distillation tower reflux phase-separation tank 5 is transported by a butanol pre-distillation tower reflux pump 6, a part of which is returned to the top of the butanol pre-distillation tower 2 as reflux, and the other part is extracted as a light component.

[0140] The material at the bottom of butanol pre-rectifier 2 is pumped via butanol pre-rectifier bottom pump 7 to butanol rectifying tower 8. Butanol rectifying tower 8 is equipped with a butanol rectifying tower reboiler 9, which uses steam as its heat source. The top pressure of butanol rectifying tower 8 is 50 kPa(G), the top temperature is 137°C, and the bottom temperature is 168°C. The gaseous phase at the top of butanol rectifying tower 8 enters the reboiler 21 of the second butanol isomerization tower for condensation. The condensed liquid enters the butanol rectifying tower reflux phase-separation tank 10. The aqueous phase in the butanol rectifying tower reflux phase-separation tank 10 is discharged from the boundary zone. The organic phase in the butanol rectifying tower reflux phase-separation tank 10 is pumped via butanol rectifying tower reflux pump 11. A portion of the organic phase is returned to the top of butanol rectifying tower 8 as reflux, while the remaining portion is withdrawn as light components and returned to butanol pre-rectifier 2. The heavy components at the bottom of butanol rectifying tower 8 are withdrawn via butanol rectifying tower bottom pump 12. The material extracted from the side line of the butanol distillation tower 8 is extracted by the butanol distillation tower side line extraction pump 13 and then divided into two streams, one stream entering the butanol isomer tower 14 and the other stream entering the butanol isomer tower 2 20.

[0141] Butanol isomerization tower 14 is equipped with a butanol isomerization tower 1 reboiler 15, using the overhead vapor from butanol isomerization tower 2 as the heat source for the butanol isomerization tower 1 reboiler. The top pressure of butanol isomerization tower 14 is -60 kPa(G), the top temperature is 76°C, and the bottom temperature is 90°C. The overhead vapor from butanol isomerization tower 14 enters butanol isomerization tower 1 condenser 16 for condensation, using recycled water as the condenser refrigerant. The condensed liquid enters butanol isomerization tower 1 reflux tank 17. The material in butanol isomerization tower 1 reflux tank 17 is transported by butanol isomerization tower 1 reflux pump 18, with a portion returning to the top of butanol isomerization tower 14 as reflux and a portion withdrawn as isobutanol product. The n-butanol product at the bottom of butanol isomerization tower 14 is transported by butanol isomerization tower 1 bottom pump 19 to the n-butanol product tank.

[0142] Butanol isomerization tower 20 is equipped with a butanol isomerization tower reboiler 21, using the overhead vapor from the butanol distillation tower as the reboiler heat source. The top pressure of butanol isomerization tower 20 is -15 kPa(G), the top temperature is 110°C, and the bottom temperature is 125°C. The overhead vapor from butanol isomerization tower 20 enters the reboiler 15 of butanol isomerization tower 1 for condensation, and the condensed liquid enters the butanol isomerization tower 2 reflux tank 22. The material in the butanol isomerization tower 2 reflux tank 22 is transported by the butanol isomerization tower 2 reflux pump 23, with a portion returning to the top of butanol isomerization tower 20 as reflux, and a portion being withdrawn as isobutanol product. The n-butanol product at the bottom of butanol isomerization tower 20 is transported by the butanol isomerization tower 2 bottom pump 24 to the n-butanol product tank.

[0143] Octanol separation process:

[0144] The mixed butyraldehyde from the propylene carbonylation reaction (wherein the ratio of normal butyraldehyde to isobutyraldehyde is about 10:1) is divided into two streams, one of which enters the butyraldehyde isomerization column 1 25 and the other enters the butyraldehyde isomerization column 2 31 .

[0145] Butyraldehyde isomerization tower 1 25 is equipped with a butyraldehyde isomerization tower 1 reboiler 26, using the overhead vapor from butyraldehyde isomerization tower 2 as the heat source for the butyraldehyde isomerization tower 1 reboiler. The top pressure of butyraldehyde isomerization tower 1 25 is -50 kPa(G), the top temperature is 55°C, and the bottom temperature is 70°C. The overhead vapor from butyraldehyde isomerization tower 1 25 enters butyraldehyde isomerization tower 1 condenser 27 for condensation, using recycled water as the condenser refrigerant. The condensed liquid enters butyraldehyde isomerization tower 1 reflux phase-separation tank 28. The material in butyraldehyde isomerization tower 1 reflux phase-separation tank 28 is transported by butyraldehyde isomerization tower 1 reflux pump 29, with a portion returning to the top of butyraldehyde isomerization tower 1 as reflux, and a portion being withdrawn as isobutanol or mixed butanol products. The material at the bottom of butyraldehyde isomerization tower 1 25 is transported by butyraldehyde isomerization tower 1 bottom pump 30 to produce n-butyraldehyde.

[0146] Butyraldehyde isomerization tower 2 31 is equipped with two reboilers: one is reboiler 32 for butyraldehyde isomerization tower 2, which uses steam as the reboiler heat source; the other is reboiler 33 for butyraldehyde isomerization tower 2, which uses the overhead vapor phase from the octanol distillation tower as the heat source. The overhead pressure of butyraldehyde isomerization tower 2 31 is 100 kPa(G), the tower top temperature is 80°C, and the tower bottom temperature is 98°C. The overhead vapor phase of butyraldehyde isomerization tower 2 31 enters reboiler 26 for butyraldehyde isomerization tower 1 for condensation. The condensed liquid enters reflux phase-separation tank 34 for butyraldehyde isomerization tower 2. The aqueous phase in reflux phase-separation tank 34 is discharged from the boundary zone. The organic phase in reflux phase-separation tank 34 is transported by reflux pump 35 for butyraldehyde isomerization tower 2, with a portion returning to the top of butyraldehyde isomerization tower 2 31 as reflux, and the remaining portion being withdrawn to an isobutyraldehyde or mixed butyraldehyde storage tank. The material at the bottom of the second butyraldehyde isomerization tower 31 is transported through the bottom pump 36 of the second butyraldehyde isomerization tower to produce normal butyraldehyde.

[0147] The n-butyraldehyde is passed through the octanol reaction system 37 and subjected to overall condensation and hydrogenation to obtain a crude octanol product containing a small amount of impurities.

[0148] The material from the octanol reaction system is sent to the octanol pre-distillation tower 38, which is provided with an octanol pre-distillation tower reboiler 39 with steam as the heat source of the octanol pre-distillation tower reboiler; the top pressure of the octanol pre-distillation tower 38 is -50 kPa (G), the top temperature is 80°C, and the bottom temperature is 146°C; the top gas phase of the octanol pre-distillation tower 38 enters the octanol pre-distillation tower condenser 40 for condensation, and the condensed liquid enters the octanol pre-distillation tower reflux phase-separation tank 41, the water phase in the octanol pre-distillation tower reflux phase-separation tank 41 is discharged from the boundary area, and the organic phase in the octanol pre-distillation tower reflux phase-separation tank 41 is transported by the octanol pre-distillation tower reflux pump 42, with part of it returning to the top of the octanol pre-distillation tower 38 as reflux, and part of it being extracted as light components.

[0149] The bottoms of octanol pre-distillation tower 38 are transported to octanol distillation tower 44 via octanol pre-distillation tower bottom pump 43. Octanol distillation tower 44 is equipped with an octanol distillation tower reboiler 45, which uses steam as the reboiler heat source. The top pressure of octanol distillation tower 44 is -50 kPa(G), the top temperature is 146°C, and the bottom temperature is 170°C. The top gas phase of octanol distillation tower 44 enters the butyraldehyde isomerization tower reboiler 33 for condensation, and the condensed liquid enters the octanol distillation tower reflux tank 46. The material in the octanol distillation tower reflux tank 46 is transported by octanol distillation tower reflux pump 47, with part of it returning to the top of octanol distillation tower 44 as reflux and part of it being withdrawn as octanol product. The bottoms of octanol distillation tower 44 are transported as heavy components via octanol distillation tower bottom pump 48 for withdrawal.

[0150] Example 2:

[0151] In the butanol separation process:

[0152] Mixed butyraldehyde (wherein the ratio of normal butyraldehyde to isobutyraldehyde is about 5:1) passes through the butanol reaction system 1 and is hydrogenated as a whole to obtain mixed butanol containing a small amount of impurities.

[0153] The mixed butanol is sent to a butanol pre-distillation tower 2, which is provided with a reboiler 3 with steam as a reboiler heat source; the top pressure of the butanol pre-distillation tower 2 is 20 kPa (G), the top temperature is 82° C., and the bottom temperature is 113° C.; the top gas phase of the butanol pre-distillation tower 2 enters a butanol pre-distillation tower condenser 4 for condensation, with circulating water used as a condenser refrigerant; the condensed liquid enters a butanol pre-distillation tower reflux phase-separation tank 5, the water phase in the butanol pre-distillation tower reflux phase-separation tank 5 is discharged from the boundary area, and the organic phase in the butanol pre-distillation tower reflux phase-separation tank 5 is transported by a butanol pre-distillation tower reflux pump 6, a part of which is returned to the top of the butanol pre-distillation tower 2 as reflux, and the other part is extracted as a light component.

[0154] The material at the bottom of butanol pre-rectifier 2 is pumped via butanol pre-rectifier bottom pump 7 to butanol rectifying tower 8. Butanol rectifying tower 8 is equipped with a butanol rectifying tower reboiler 9, which uses steam as its heat source. The top pressure of butanol rectifying tower 8 is 20 kPa(G), the top temperature is 114°C, and the bottom temperature is 133°C. The gaseous phase at the top of butanol rectifying tower 8 enters the reboiler 21 of the second butanol isomerization tower for condensation. The condensed liquid enters the butanol rectifying tower reflux phase-separation tank 10. The aqueous phase in the butanol rectifying tower reflux phase-separation tank 10 is discharged from the boundary zone. The organic phase in the butanol rectifying tower reflux phase-separation tank 10 is pumped via butanol rectifying tower reflux pump 11. A portion of the organic phase is returned to the top of butanol rectifying tower 8 as reflux, while the remaining portion is withdrawn as light components and returned to butanol pre-rectifier 2. The heavy components at the bottom of butanol rectifying tower 8 are withdrawn via butanol rectifying tower bottom pump 12. The material extracted from the side line of the butanol distillation tower 8 is extracted by the butanol distillation tower side line extraction pump 13 and then divided into two streams, one stream entering the butanol isomer tower 14 and the other stream entering the butanol isomer tower 2 20.

[0155] Butanol Isomerization Tower 14 is equipped with a Butanol Isomerization Tower 1 reboiler 15, using the overhead vapor from Butanol Isomerization Tower 2 as the heat source for the Butanol Isomerization Tower 1 reboiler. The top pressure of Butanol Isomerization Tower 14 is -78 kPa(G), the top temperature is 45°C, and the bottom temperature is 71°C. The overhead vapor from Butanol Isomerization Tower 14 enters Butanol Isomerization Tower 1 condenser 16 for condensation, using recycled water as the condenser refrigerant. The condensed liquid enters Butanol Isomerization Tower 1 reflux tank 17. The material in Butanol Isomerization Tower 1 reflux tank 17 is transported by Butanol Isomerization Tower 1 reflux pump 18, with a portion returning to the top of Butanol Isomerization Tower 14 as reflux and a portion withdrawn as isobutanol product. The n-butanol product at the bottom of Butanol Isomerization Tower 14 is transported by Butanol Isomerization Tower 1 bottom pump 19 to the n-butanol product tank.

[0156] Butanol isomerization tower 20 is equipped with a butanol isomerization tower reboiler 21, using the overhead vapor phase of the butanol distillation tower as the reboiler heat source. The overhead pressure of butanol isomerization tower 20 is -45 kPa(G), the tower top temperature is 88°C, and the tower bottom temperature is 102°C. The overhead vapor phase of butanol isomerization tower 20 enters the reboiler 15 of butanol isomerization tower 1 for condensation, and the condensed liquid enters the butanol isomerization tower 2 reflux tank 22. The material in the butanol isomerization tower 2 reflux tank 22 is transported by the butanol isomerization tower 2 reflux pump 23, with part of it returning to the top of butanol isomerization tower 20 as reflux, and part of it being withdrawn as isobutanol product. The n-butanol product at the bottom of butanol isomerization tower 20 is transported by the butanol isomerization tower 2 bottom pump 24 to the n-butanol product tank.

[0157] Octanol separation process:

[0158] The mixed butyraldehyde (wherein the ratio of normal butyraldehyde to isobutyraldehyde is about 5:1) is divided into two streams, one stream entering the butyraldehyde isomerization tower 1 25 and the other stream entering the butyraldehyde isomerization tower 2 31 .

[0159] Butyraldehyde isomerization tower 1 25 is equipped with a butyraldehyde isomerization tower 1 reboiler 26, using the overhead vapor from butyraldehyde isomerization tower 2 as the heat source for the butyraldehyde isomerization tower 1 reboiler. The top pressure of butyraldehyde isomerization tower 1 25 is -98 kPa(G), the top temperature is 21°C, and the bottom temperature is 42°C. The overhead vapor from butyraldehyde isomerization tower 1 25 enters butyraldehyde isomerization tower 1 condenser 27 for condensation, using recycled water as the condenser refrigerant. The condensed liquid enters butyraldehyde isomerization tower 1 reflux phase-separation tank 28. The material in butyraldehyde isomerization tower 1 reflux pump 29 is transported to the top of butyraldehyde isomerization tower 1 25 as reflux, and a portion is withdrawn as isobutanol or mixed butanol products. The material at the bottom of butyraldehyde isomerization tower 1 25 is transported by butyraldehyde isomerization tower 1 bottom pump 30 to produce n-butyraldehyde.

[0160] Butyraldehyde isomerization tower 2 31 is equipped with two reboilers: one, reboiler 1 32, uses steam as its reboiler heat source; and the other, reboiler 2 33, uses the overhead vapor phase from the octanol distillation tower as its heat source. The overhead pressure of butyraldehyde isomerization tower 2 31 is 50 kPa(G), the tower top temperature is 61°C, and the tower bottom temperature is 81°C. The overhead vapor phase from butyraldehyde isomerization tower 2 31 enters reboiler 26 of butyraldehyde isomerization tower 1 for condensation. The condensed liquid enters reflux phase-separation tank 34 of butyraldehyde isomerization tower 2. The aqueous phase in reflux phase-separation tank 34 is discharged from the boundary zone. The organic phase in reflux phase-separation tank 34 is transported by reflux pump 35 of butyraldehyde isomerization tower 2. A portion of the organic phase is returned to the top of butyraldehyde isomerization tower 2 31 as reflux, and the remaining portion is withdrawn to an isobutyraldehyde or mixed butyraldehyde storage tank. The material at the bottom of the second butyraldehyde isomerization tower 31 is transported through the bottom pump 36 of the second butyraldehyde isomerization tower to produce normal butyraldehyde.

[0161] The n-butyraldehyde is passed through the octanol reaction system 37 and subjected to overall condensation and hydrogenation to obtain a crude octanol product containing a small amount of impurities.

[0162] The material from the octanol reaction system is sent to the octanol pre-distillation tower 38, which is provided with an octanol pre-distillation tower reboiler 39 with steam as the heat source of the octanol pre-distillation tower reboiler; the top pressure of the octanol pre-distillation tower 38 is -88 kPa (G), the top temperature is 75 ° C, and the bottom temperature is 138 ° C; the top gas phase of the octanol pre-distillation tower 38 enters the octanol pre-distillation tower condenser 40 for condensation, and the condensed liquid enters the octanol pre-distillation tower reflux phase-separation tank 41, the water phase in the octanol pre-distillation tower reflux phase-separation tank 41 is discharged from the boundary area, and the organic phase in the octanol pre-distillation tower reflux phase-separation tank 41 is transported by the octanol pre-distillation tower reflux pump 42, with part of it returning to the top of the octanol pre-distillation tower 38 as reflux, and part of it is extracted as light components.

[0163] The bottoms of octanol pre-distillation tower 38 are transported to octanol distillation tower 44 via octanol pre-distillation tower bottom pump 43. Octanol distillation tower 44 is equipped with an octanol distillation tower reboiler 45, which uses steam as the reboiler heat source. The top pressure of octanol distillation tower 44 is -90 kPa(G), the top temperature is 97°C, and the bottom temperature is 153°C. The top vapor of octanol distillation tower 44 enters the butyraldehyde isomerization tower reboiler 33 for condensation, and the condensed liquid enters the octanol distillation tower reflux tank 46. The material in the octanol distillation tower reflux tank 46 is transported by octanol distillation tower reflux pump 47, with part of it returning to the top of octanol distillation tower 44 as reflux and part of it being withdrawn as octanol product. The bottoms of octanol distillation tower 44 are transported as heavy components via octanol distillation tower bottom pump 48 for withdrawal.

[0164] Example 3:

[0165] In the butanol separation process:

[0166] Mixed butyraldehyde (wherein the ratio of normal butyraldehyde to isobutyraldehyde is approximately 13:1) passes through the butanol reaction system 1 and is hydrogenated as a whole to obtain mixed butanol containing a small amount of impurities.

[0167] The mixed butanol is sent to a butanol pre-distillation tower 2, which is provided with a reboiler 3 with steam as a reboiler heat source; the tower top pressure of the butanol pre-distillation tower 2 is 96 kPa (G), the tower top temperature is 135° C., and the tower bottom temperature is 166° C.; the top gas phase of the butanol pre-distillation tower 2 enters a butanol pre-distillation tower condenser 4 for condensation, with circulating water as the condenser refrigerant, and the condensed liquid enters a butanol pre-distillation tower reflux phase-separation tank 5, the water phase in the butanol pre-distillation tower reflux phase-separation tank 5 is discharged from the boundary area, and the organic phase in the butanol pre-distillation tower reflux phase-separation tank 5 is transported by a butanol pre-distillation tower reflux pump 6, a part of which is returned to the top of the butanol pre-distillation tower 2 as reflux, and the other part is extracted as a light component.

[0168] The material at the bottom of butanol pre-rectifier 2 is pumped via butanol pre-rectifier bottom pump 7 to butanol rectifying tower 8. Butanol rectifying tower 8 is equipped with a butanol rectifying tower reboiler 9, which uses steam as its heat source. The top pressure of butanol rectifying tower 8 is 92 kPa(G), the top temperature is 162°C, and the bottom temperature is 183°C. The gaseous phase at the top of butanol rectifying tower 8 enters the reboiler 21 of the second butanol isomerization tower for condensation. The condensed liquid enters the butanol rectifying tower reflux phase-separation tank 10. The aqueous phase in the butanol rectifying tower reflux phase-separation tank 10 is discharged from the boundary zone. The organic phase in the butanol rectifying tower reflux phase-separation tank 10 is pumped via butanol rectifying tower reflux pump 11. A portion of the organic phase is returned to the top of butanol rectifying tower 8 as reflux, while the remaining portion is withdrawn as light components and returned to butanol pre-rectifier 2. The heavy components at the bottom of butanol rectifying tower 8 are withdrawn via butanol rectifying tower bottom pump 12. The material extracted from the side line of the butanol distillation tower 8 is extracted by the butanol distillation tower side line extraction pump 13 and then divided into two streams, one stream entering the butanol isomer tower 14 and the other stream entering the butanol isomer tower 2 20.

[0169] Butanol isomerization tower 14 is equipped with a butanol isomerization tower 1 reboiler 15, using the overhead vapor from butanol isomerization tower 2 as the heat source for the butanol isomerization tower 1 reboiler. The top pressure of butanol isomerization tower 14 is -20 kPa(G), the top temperature is 85°C, and the bottom temperature is 109°C. The overhead vapor from butanol isomerization tower 14 enters butanol isomerization tower 1 condenser 16 for condensation, using recycled water as the condenser refrigerant. The condensed liquid enters butanol isomerization tower 1 reflux tank 17. The material in butanol isomerization tower 1 reflux tank 17 is transported by butanol isomerization tower 1 reflux pump 18, with a portion returning to the top of butanol isomerization tower 14 as reflux and a portion withdrawn as isobutanol product. The n-butanol product at the bottom of butanol isomerization tower 14 is transported by butanol isomerization tower 1 bottom pump 19 to the n-butanol product tank.

[0170] Butanol isomerization tower 20 is equipped with a butanol isomerization tower reboiler 21, using the overhead vapor phase of the butanol distillation tower as the reboiler heat source. The overhead pressure of butanol isomerization tower 20 is 30 kPa(G), the tower top temperature is 128°C, and the tower bottom temperature is 145°C. The overhead vapor phase of butanol isomerization tower 20 enters the reboiler 15 of butanol isomerization tower 1 for condensation, and the condensed liquid enters the butanol isomerization tower 2 reflux tank 22. The material in the butanol isomerization tower 2 reflux tank 22 is transported by the butanol isomerization tower 2 reflux pump 23, with part of it returning to the top of butanol isomerization tower 20 as reflux, and part of it being withdrawn as isobutanol product. The n-butanol product at the bottom of butanol isomerization tower 20 is transported by the butanol isomerization tower 2 bottom pump 24 to the n-butanol product tank.

[0171] Octanol separation process:

[0172] The mixed butyraldehyde (wherein the ratio of normal butyraldehyde to isobutyraldehyde is about 13:1) is divided into two streams, one stream enters the butyraldehyde isomerization tower 1 25 , and the other stream enters the butyraldehyde isomerization tower 2 31 .

[0173] Butyraldehyde isomerization tower 1 25 is equipped with a butyraldehyde isomerization tower 1 reboiler 26, using the overhead vapor from butyraldehyde isomerization tower 2 as the heat source for the butyraldehyde isomerization tower 1 reboiler. The top pressure of butyraldehyde isomerization tower 1 25 is -15 kPa(G), the top temperature is 67°C, and the bottom temperature is 81°C. The overhead vapor from butyraldehyde isomerization tower 1 25 enters butyraldehyde isomerization tower 1 condenser 27 for condensation, using recycled water as the condenser refrigerant. The condensed liquid enters butyraldehyde isomerization tower 1 reflux phase-separation tank 28. The material in butyraldehyde isomerization tower 1 reflux pump 29 is transported to the top of butyraldehyde isomerization tower 1 25 as reflux, and a portion is withdrawn as isobutanol or mixed butanol products. The material at the bottom of butyraldehyde isomerization tower 1 25 is transported by butyraldehyde isomerization tower 1 bottom pump 30 to produce n-butyraldehyde.

[0174] Butyraldehyde isomerization tower 2 31 is equipped with two reboilers: one is reboiler 32 for butyraldehyde isomerization tower 2, which uses steam as the reboiler heat source; the other is reboiler 33 for butyraldehyde isomerization tower 2, which uses the overhead vapor phase from the octanol distillation tower as the heat source. The overhead pressure of butyraldehyde isomerization tower 2 31 is 180 kPa(G), the tower top temperature is 110°C, and the tower bottom temperature is 129°C. The overhead vapor phase of butyraldehyde isomerization tower 2 31 enters reboiler 26 for butyraldehyde isomerization tower 1 for condensation. The condensed liquid enters reflux phase-separation tank 34 for butyraldehyde isomerization tower 2. The aqueous phase in reflux phase-separation tank 34 is discharged from the boundary zone. The organic phase in reflux phase-separation tank 34 is transported by reflux pump 35 for butyraldehyde isomerization tower 2, with a portion returning to the top of butyraldehyde isomerization tower 2 31 as reflux, and the remaining portion being withdrawn to an isobutyraldehyde or mixed butyraldehyde storage tank. The material at the bottom of the second butyraldehyde isomerization tower 31 is transported through the bottom pump 36 of the second butyraldehyde isomerization tower to produce normal butyraldehyde.

[0175] The n-butyraldehyde is passed through the octanol reaction system 37 and subjected to overall condensation and hydrogenation to obtain a crude octanol product containing a small amount of impurities.

[0176] The material from the octanol reaction system is delivered to the octanol pre-distillation tower 38, which is provided with an octanol pre-distillation tower reboiler 39 with steam as the heat source for the octanol pre-distillation tower reboiler. The top pressure of the octanol pre-distillation tower 38 is -10 kPa(G), the top temperature is 123°C, and the bottom temperature is 171°C. The gas phase at the top of the octanol pre-distillation tower 38 enters the octanol pre-distillation tower condenser 40 for condensation, and the condensed liquid enters the octanol pre-distillation tower reflux phase-separation tank 41. The aqueous phase in the octanol pre-distillation tower reflux phase-separation tank 41 is discharged from the boundary zone. The organic phase in the octanol pre-distillation tower reflux phase-separation tank 41 is transported by the octanol pre-distillation tower reflux pump 42, with a portion returned to the top of the octanol pre-distillation tower 38 as reflux and a portion extracted as light components.

[0177] The bottoms of octanol pre-distillation tower 38 are transported to octanol distillation tower 44 via octanol pre-distillation tower bottom pump 43. Octanol distillation tower 44 is equipped with an octanol distillation tower reboiler 45, which uses steam as the reboiler heat source. The top pressure of octanol distillation tower 44 is -8 kPa(G), the top temperature is 143°C, and the bottom temperature is 182°C. The overhead vapor phase of octanol distillation tower 44 enters the butyraldehyde isomerization tower reboiler 33 for condensation, and the condensed liquid enters octanol distillation tower reflux tank 46. The material in octanol distillation tower reflux tank 46 is transported by octanol distillation tower reflux pump 47, with part of it returning to the top of octanol distillation tower 44 as reflux and part of it being withdrawn as octanol product. The bottoms of octanol distillation tower 44 are transported as heavy components via octanol distillation tower bottom pump 48 for withdrawal.

[0178] The energy consumption ratio under the same feeding conditions is as follows

[0179] In the present invention, the top gas phase of the butanol distillation tower is used as a heat source for the reboiler of the butanol isomerization tower 2; the top gas phase of the butanol isomerization tower 2 is used as a heat source for the reboiler of the butanol isomerization tower 1; the top gas phase of the butyraldehyde isomerization tower 2 is used as a heat source for the reboiler of the butyraldehyde isomerization tower 1; and the top gas phase of the octanol distillation tower is used as a heat source for the reboiler of the butyraldehyde isomerization tower 2. Thus, the butanol separation process and the octanol separation process are thermally coupled by three-effect heat exchange, which can greatly reduce the usage of steam and cooling water and reduce production energy consumption.

[0180] The triple-effect distillation method for producing butanol and octanol in the present invention performs heat exchange settings for a butanol separation process and an octanol separation process respectively. The two processes can work independently for butanol separation and octanol separation respectively, or can be used in combination. When used in combination, the two processes use the same raw materials, and the ratio of the raw materials of the two processes can be arbitrarily allocated according to market conditions to produce required butanol and octanol.

[0181] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A butanol and octanol production equipment, characterized in that: The equipment includes a butanol pre-distillation tower, a butanol distillation tower, a butanol isomerization tower, a butanol isomerization tower, a butanol isomerization tower, a butyraldehyde isomerization tower, a butyraldehyde isomerization tower, an octanol pre-distillation tower, and an octanol distillation tower, a total of 8 towers, all of which are equipped with corresponding condensers, reflux phase separation tanks and reboilers; The feed inlet of the butanol pre-distillation tower is connected to the discharge of the butanol reaction system; The bottom discharge of the butanol pre-distillation tower is connected to the feed of the butanol distillation tower, and the top of the butanol pre-distillation tower is refluxed and extracted as a light component; The heavy components are extracted from the bottom of the butanol distillation tower, and the top gas phase is connected to the heat exchange inlet of the bottom reboiler of the butanol isomerization tower II, and the heat exchange outlet of the bottom reboiler of the butanol isomerization tower II is connected to the reflux phase separation tank arranged at the top of the butanol distillation tower to reflux at the top of the butanol distillation tower; at the same time, the reflux material at the top of the butanol distillation tower is simultaneously connected to the feed inlet of the butanol pre-distillation tower through a pipeline; The side line outlet of the butanol distillation tower is connected to the butanol isomerization tower 1 and the butanol isomerization tower 2 respectively; The tower bottom reboiler of the butanol isomerization tower 1 is connected to the tower top of the butanol isomerization tower 2 for heat exchange, and both the tower bottom of the butanol isomerization tower 1 and the tower bottom of the butanol isomerization tower 2 produce n-butanol; A portion of the material condensed and refluxed from the top of the butanol isomerization tower is connected to the top inlet of the butanol isomerization tower through a pipeline, and the other portion is used to produce isobutanol; Part of the material condensed and refluxed from the top of the butanol isomerization tower is connected to the top inlet of the butanol isomerization tower through a pipeline, and the other part is used to produce isobutanol; The feeds of the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 are mixed butyraldehyde from propylene carbonylation reaction, and the top reflux outflow of the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 is isobutyraldehyde or mixed butyraldehyde, and can also be connected to the feed port of the butanol reaction system; The bottom reboiler of the butyraldehyde isomerization tower 1 exchanges heat with the top of the butyraldehyde isomerization tower 2, and the bottom discharges of the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 are connected to the feed port of the octanol pre-distillation tower after passing through the octanol reaction system; The bottom reboiler of the second butyraldehyde isomerization tower exchanges heat with the top of the octanol distillation tower; A portion of the condensed refluxed material at the top of the octanol pre-distillation tower is connected to the top inlet of the octanol pre-distillation tower via a pipeline, and the other portion is used to extract light components; The bottom discharge of the octanol pre-distillation tower is connected to the feed port of the octanol distillation tower; the heavy components are extracted from the bottom of the octanol distillation tower, and octanol is extracted after condensation and reflux at the top of the tower.

2. The butanol and octanol production equipment according to claim 1, characterized in that: The butyraldehyde isomerization tower is provided with two reboilers connected in parallel, one is the first reboiler of the butyraldehyde isomerization tower, which uses steam as the reboiler heat source; the other is the second reboiler of the butyraldehyde isomerization tower, which uses the top gas phase of the octanol distillation tower as the heat source; the feed of the butanol reaction system is mixed butyraldehyde from the propylene carbonylation reaction.

3. A butanol separation device, characterized in that: The butanol separation device comprises a butanol pre-distillation tower, a butanol distillation tower, a butanol isomerization tower 1, and a butanol isomerization tower 2, each tower being equipped with a corresponding condenser, a reflux phase separation tank, and a reboiler; The feed inlet of the butanol pre-distillation tower is connected to the discharge of the butanol reaction system, and the main component of the discharge is mixed butanol; The bottom discharge of the butanol pre-distillation tower is connected to the feed of the butanol distillation tower, and the top of the butanol pre-distillation tower is refluxed and extracted as a light component; The heavy components are extracted from the bottom of the butanol distillation tower, and the top gas phase is connected to the heat exchange inlet of the bottom reboiler of the butanol isomerization tower II, and the heat exchange outlet of the bottom reboiler of the butanol isomerization tower II is connected to the reflux phase separation tank arranged at the top of the butanol distillation tower to reflux at the top of the butanol distillation tower; at the same time, the reflux material at the top of the butanol distillation tower is simultaneously connected to the feed inlet of the butanol pre-distillation tower through a pipeline; The side line outlet of the butanol distillation tower is connected to the butanol isomerization tower 1 and the butanol isomerization tower 2 respectively; The tower bottom reboiler of the butanol isomerization tower 1 is connected to the tower top of the butanol isomerization tower 2 for heat exchange, and both the tower bottom of the butanol isomerization tower 1 and the tower bottom of the butanol isomerization tower 2 produce n-butanol; A portion of the material condensed and refluxed from the top of the butanol isomerization tower is connected to the top inlet of the butanol isomerization tower through a pipeline, and the other portion is used to produce isobutanol; A part of the material condensed and refluxed at the top of the butanol isomerization tower is connected to the top inlet of the butanol isomerization tower through a pipeline, and the other part is used to produce isobutanol.

4. An octanol separation device, characterized in that: The octanol separation device comprises a first butyraldehyde isomerization tower, a second butyraldehyde isomerization tower, an octanol pre-distillation tower and an octanol distillation tower; The feeds of the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 are both mixed butyraldehyde from the propylene carbonylation reaction, and the top reflux output of the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 is isobutyraldehyde or mixed butyraldehyde; The bottom reboiler of the butyraldehyde isomerization tower 1 exchanges heat with the top of the butyraldehyde isomerization tower 2, and the bottom discharges of the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 are connected to the feed port of the octanol pre-distillation tower after passing through the octanol reaction system; The bottom reboiler of the second butyraldehyde isomerization tower exchanges heat with the top of the octanol distillation tower; A portion of the condensed refluxed material at the top of the octanol pre-distillation tower is connected to the top inlet of the octanol pre-distillation tower via a pipeline, and the other portion is used to extract light components; The bottom discharge of the octanol pre-distillation tower is connected to the feed port of the octanol distillation tower; the heavy components are extracted from the bottom of the octanol distillation tower, and octanol is extracted after condensation and reflux at the top of the tower.

5. A triple-effect distillation method for producing butanol and octanol, comprising two processes of butanol separation and octanol separation, wherein the two processes use the same raw materials and obtain n-butanol, isobutanol and octanol products respectively through different processes, characterized in that: Butanol separation can be divided into three parts in sequence: hydrogenation, desorption of light and heavy, and separation of normal isomers; octanol separation can be divided into three parts in sequence: separation of normal isomers, hydrogenation, and desorption of light and heavy. The light and heavy removal of butanol is completed by a butanol pre-distillation tower and a butanol distillation tower, and the normal isomerization of butanol is separated by a butanol isomerization tower 1 and a butanol isomerization tower 2; the normal isomerization of octanol is separated by a butyraldehyde isomerization tower 1 and a butyraldehyde isomerization tower 2, and the light and heavy removal of octanol is completed by an octanol pre-distillation tower and an octanol distillation tower; The mixture of n-isobutyraldehyde is used as a raw material to enter the butanol separation process and / or the octanol separation process; In the butanol separation process, a mixture of normal and isobutyraldehyde is hydrogenated as a whole to obtain a mixture of normal and isobutanol, i.e., crude butanol; the crude butanol first passes through a butanol pre-distillation tower to remove light components and a butanol distillation tower to remove light components, heavy components and impurities, and then passes through two isomerization towers with different pressures to separate normal butanol and isobutanol to obtain normal butanol and isobutanol products; the pressure settings of the first butanol isomerization tower and the second butanol isomerization tower meet the requirements of balancing energy consumption and separation effect; In the octanol separation process, the mixture of n-butyraldehyde and isobutyraldehyde is separated into n-butyraldehyde and isobutyraldehyde through two isomerization towers with different pressures, and the n-butyraldehyde is hydrogenated to obtain crude octanol. The crude octanol is finally passed through an octanol pre-distillation tower and an octanol distillation tower to remove light components. The heavy components and impurities are separated to obtain an octanol product; the butyraldehyde isomerization tower 1 and the butyraldehyde isomerization tower 2 have a high pressure and a low pressure, the tower with high pressure has a high temperature, the top temperature of the tower with high pressure is higher than the bottom temperature of the tower with low pressure, and there is a temperature difference; The top gas phase of the butanol distillation tower uses the second butanol isomer tower as a heat source, and the top gas phase of the second butanol isomer tower uses the first butanol isomer tower as a heat source; the top gas phase of the octanol distillation tower uses the reboiler of the second butyraldehyde isomer tower as a part of the heat source, and the top gas phase of the second butyraldehyde isomer tower uses the reboiler of the first butyraldehyde isomer tower as a heat source; The top temperature of the butanol distillation tower is greater than the bottom temperature of the butanol isomerization tower 2, and the top temperature of the butanol isomerization tower 2 is greater than the bottom temperature of the butanol isomerization tower 1; The top temperature of the octanol distillation tower is greater than the bottom temperature of the butyraldehyde isomer tower 2, and the top temperature of the butyraldehyde isomer tower 2 is greater than the bottom temperature of the butyraldehyde isomer tower 1; And the temperature difference between the two is required to be no less than 5℃.

6. The triple-effect distillation method for producing butyl octanol according to claim 5, characterized in that: The temperature difference between the two is 5°C to 50°C, preferably 10°C to 30°C.

7. The triple-effect distillation method for producing butyl octanol according to claim 5, characterized in that: The top pressure of the butanol pre-distillation tower is normal pressure to 100 kPa (G), the top temperature is 70 to 140° C., and the bottom temperature is 100 to 170° C.; The top pressure of the butanol distillation tower is normal pressure to 100 kPa (G), the top temperature is 90 to 170°C, and the bottom temperature is 110 to 190°C; The top pressure of the butanol isomerization tower is -100 kPa (G) to normal pressure, the top temperature is 20 to 100°C, and the bottom temperature is 40 to 120°C; The top pressure of the second butanol isomerization tower is -60 kPa (G) to 40 kPa (G), the top temperature is 60 to 140°C, and the bottom temperature is 80 to 160°C; The top pressure of the butyraldehyde isomerization tower is -100 kPa (G) to normal pressure, the top temperature is 20 to 100°C, and the bottom temperature is 40 to 120°C; The top pressure of the second butyraldehyde isomerization tower is normal pressure to 200 kPa (G), the top temperature is 40 to 140°C, and the bottom temperature is 60 to 160°C; The top pressure of the octanol pre-distillation tower is -100 kPa (G) to normal pressure, the top temperature is 60 to 140°C, and the bottom temperature is 100 to 180°C; The top pressure of the octanol distillation tower is -100 kPa (G) ~ normal pressure, the top temperature is 90 ~ 160 ° C, and the bottom temperature is 110 ~ 190 ° C.

8. The triple-effect distillation method for producing butyl octanol according to claim 5, characterized in that: Each tower is a plate tower or a packed tower, and the flow parameter FP value of each tower is between 0.02 and 0.2; in the case of a packed tower, the tower internals include packing, packing support rings and liquid distributors.

9. The triple-effect distillation method for producing butyl octanol according to claim 5, characterized in that: The raw material can be a product of propylene carbonylation reaction mixed with butyraldehyde, or a mixture of normal butyraldehyde and isobutyraldehyde as main components; the mass percentage composition range of the raw material is: the mixture of normal butyraldehyde and isobutyraldehyde accounts for 90% to 100%, the light component accounts for 0% to 4%, and the heavy component accounts for 0% to 6%; the ratio of normal butanol to isobutanol is between 1:1 and 15:1.

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