CN111621320A - Pyrolysis product grading separation method and multi-inner-tower rectifying device - Google Patents

Abstract

A method for fractional separation of pyrolysis products and a multi-inner column rectification device. The multi-inner rectification column rectification device is composed of an outer rectification column and at least two inner rectification columns arranged inside the outer rectification column. The tower is a dividing wall rectification tower or a tube bundle composed of multiple tubes, which can solve the problems of high energy consumption and low separation purity of heat-sensitive mixtures in the existing multi-component mixture separation technology, and is used for the fractionation of biomass and other pyrolysis products. .

Description

Pyrolysis product fractional separation method and multi-inner column rectification device

technical field

The solution relates to the field of chemical industry, and specifically relates to a method for fractional separation of pyrolysis products and a multi-inner tower rectification device, which are used for mass transfer and separation processes in the fields of chemical industry, oil refining, petrochemical, environmental protection and the like.

Background technique

With the increase of global energy consumption and the aggravation of environmental pollution, more and more attention has been paid to renewable energy. Biomass energy has the characteristics of being friendly to the environment, having a wide range of raw material sources and being renewable, and has become an important force in the international energy transformation. Pyrolysis technology can convert biomass with low energy density (straw, husk, wood chips, etc.) into bio-oil with high energy density. Based on the importance of liquid fuel in the entire energy structure, the preparation and application of bio-oil Much attention. The composition of bio-oil is very complex, with high oxygen content. Hundreds of components have been identified, including almost all oxygen-containing organic compounds, such as ethers, esters, aldehydes, ketones, phenols, acids and alcohols, etc., and have viscosity. The characteristics of high water content, high water content, poor stability and high corrosiveness seriously hinder its application and promotion. If the large-scale and fine separation of bio-oil can be realized, a large number of products with various uses can be obtained, which is expected to bring about a revolution in the raw material and energy industry.

Conventional bio-oil refining and separation methods include distillation, solvent separation, centrifugal separation, chromatographic separation, membrane separation, supercritical extraction and molecular distillation, etc., all of which are to obtain liquid bio-oil products before refining and separation, which will undoubtedly increase technology and technology. For example, in the traditional distillation process, the separation effect of heat-sensitive bio-oil is not ideal and there is a problem of coking and aging. Although vacuum distillation can reduce the boiling point of bio-oil, heat-sensitive bio-oil will still be in the whole distillation column. A variety of reactions occur to generate high-boiling substances, resulting in unsatisfactory product yields and complex composition of fractions; high-boiling substances generated by heat-sensitive bio-oil will appear in each fraction obtained by the multi-side fractionation process; molecular distillation is used It can be operated at a lower temperature, but the molecular distillation production capacity is small, the equipment investment is high, and the obtained fraction composition is also very complicated. If the biomass pyrolysis gas is directly separated into several types of products with different uses and relatively stable properties, and then refined and separated according to their properties, the separation cost and utilization difficulty of bio-oil will be greatly reduced.

The fractional condensation technology is a method of condensing the biomass pyrolysis gas step by step according to the different boiling points of each component, which can realize the preliminary fractionation and separation of the bio-oil from the source, and the quality of the obtained bio-oil has been significantly improved. Simple grading condensation, the obtained bio-oil composition is still very complex, and the utilization is still difficult, and it is urgent to develop a more refined bio-oil refining and separation technology.

Rectification is a widely used chemical separation unit operation, but the rectification process consumes a lot of energy. Improving the energy utilization rate of the rectification process has always been a research hotspot. The existing energy saving methods in the rectification process include Integration, rectification heat exchange network synthesis, and energy integration within a single column, among which thermocouple rectification has attracted widespread attention because of its energy saving and equipment investment.

The internal thermal coupling technology of the distillation column is an ideal energy-saving method, and new devices are constantly being developed. The internal energy-integrated distillation column can make the distillation The section operates at a higher pressure than the stripping section, thereby creating a heat exchange temperature difference large enough to transfer heat from the rectifying column section to the corresponding stripping column section. Japan has successively developed concentric cylindrical and multi-concentric cylindrical bundled thermally coupled rectification towers; however, the concentric cylindrical thermally coupled rectification tower has a relatively simple structure, but the original problem of small internal thermally coupled heat transfer area has not been solved. Although the multi-concentric cylindrical bundled internal thermally coupled distillation column has a larger heat transfer area, the structure is complex and the cost is high, so it is difficult to popularize and apply in practice. Patent 200910087709.9 designs an internal thermally coupled distillation column, which realizes the thermal coupling between the rectification section and the stripping section through three external heat exchangers, and one external heat exchanger for the top of the rectification section and the top of the stripping section. The heat exchange of the internal thermally coupled distillation column is realized without external heat recovery; however, the internal thermally coupled distillation column includes four external heat exchangers and two tower bodies, and the equipment is bulky and expensive. Patent 201010195101.0 discloses a liquid co-current composite tower, including a tower body, the tower body is divided into an inner rectification tower and an outer rectification tower, the inner rectification tower is sheathed in the outer rectification tower, the inner rectification tower and the outer rectification tower There are column plates corresponding to their cross-sections, and the column plate is provided with a descending liquid system that can make the liquid on each layer of the column plate flow in the same direction. This patent eliminates the liquid retention area on the traditional column plate and increases the The effective mass transfer area increases the processing capacity and improves the mass transfer efficiency of the tray, but the heat of the liquid co-flow composite tower is provided by the reboiler at the bottom of the tower, which has high energy consumption and low heat utilization rate. To achieve a better rectification effect, the tower height is usually high, the installation and construction are difficult, and maintenance is not easy. Later, 201420863590.6 and 201420871708.X, a thermally coupled jet co-current tower was disclosed, including a tower body and a multi-layer continuous mass transfer. The column plate, the column body includes an inner rectification column and an outer rectification column, each layer of continuous mass transfer column plate includes a column plate provided with a gas lift hole, a cap and a descending liquid system, the inner rectification column and the outer rectification column. The rectification section and the stripping section are separated by the outer wall of the inner rectification column, and the temperature difference between the stripping section and the rectification section is effectively used for heat exchange and recovery at the wall of the inner rectification column, which increases the exchange rate. The thermal area effectively reduces the heat dissipation and strengthens the heat transfer from the stripping section to the rectifying section, so as to achieve the purpose of energy saving. However, these technologies are all energy-saving distillation methods developed for simple mixtures, and it is difficult to finely fractionate bio-oils with complex components.

In addition, the dividing wall rectifying column is a kind of thermocouple rectifying column. For example, patents 201210172039.2, 201110074332.0 and 201510647969.2 all adopt a dividing wall rectifying column with a dividing wall, which shortens the process flow, reduces equipment investment, and improves the The separation efficiency is improved and the separation energy consumption is reduced. At present, the technology of this dividing wall rectification column using a dividing wall is nearly mature, but it can only be used for the separation of simple 3 components. Separation of four-component and more systems requires more partitions, literature (D Dwivedi, IJ Halvorsen, S Skogestad. Control structureselection for four-product Petlyuk column[J]. Chemical Engineering and Processing & Process Intensification, 2013, 67( 5): 49-59.) Adopt the dividing wall rectification column that is provided with 3 dividing walls for separating methanol, ethanol, propylene glycol, butanol four-component material system; Patent 201310279930.0 adopts the dividing plate with more dividing walls The tower is used to separate and prepare methyl naphthalene and industrial acenaphthene. The washed oil fraction enters the baffle tower for rectification, and multiple product streams are drawn from the baffle tower: naphthalene oil, methyl naphthalene, medium washing oil, acenaphthene fraction, heavy Quality washing oil, product purity and yield increase. However, the structure and control of the dividing wall rectification column with two or more dividing walls tend to be complicated. Adjusting a certain dividing wall will have a great influence on other operating parameters, which makes the operation flexibility, dynamic characteristics and flexibility of the dividing wall rectifying column. The controllability is poor, so the number of partition walls used is limited, generally controlled at 1 to 6 pieces, limited to the separation of 3 to 5 components, and it is difficult to separate the bio-oil with hundreds of components with high purity.

Not only bio-oil, but other pyrolysis products such as petroleum, waste plastics, waste rubber, garbage, coal and other raw materials are also complex multi-component mixtures, which need to be separated to improve the added value of pyrolysis products; in petroleum, chemical, environmental protection There are also a large number of multi-component mixtures in such fields, and high-efficiency and low-consumption separation technology is also required.

SUMMARY OF THE INVENTION

The purpose of this scheme is to provide a pyrolysis product fractional separation method and a multi-inner column rectification device.

This solution is realized by the following technical solutions: a multi-inner column rectification device, which is composed of an outer rectification column and at least two inner rectification columns arranged inside the outer rectification column, and the inner rectification columns are arranged At different heights inside the outer rectification tower; the side wall of the outer rectification tower is provided with a feed port, the top of the outer rectification tower is provided with a tower top gas outlet, and the bottom of the outer rectification tower is provided with a column bottom outlet, The upper part of the outer rectification tower is provided with a reflux liquid inlet, and the lower part is provided with a reboiler return column; the top of the outer rectification tower is provided with a condenser and a reflux tank after the condenser, and the reflux tank is provided with a non-condensable gas port and product discharge The pipeline, the product discharge pipeline is divided into two channels, one is equipped with a product valve at the top of the tower, and the other is equipped with a reflux pump at the top of the tower and is connected with the reflux liquid inlet; the bottom of the outer rectification tower is equipped with a reboiler, and the outer rectification tower is equipped with a reboiler. The pipeline after the discharge port at the bottom of the tower is divided into two paths, one path is provided with a tower bottom discharge pump, and the other path is connected to the return tower port of the reboiler after passing through the reboiler; the top of the inner rectification tower is closed and equipped with an internal The air outlet of the rectification tower and the air outlet of the inner rectification tower are of an inverted U-shaped tube structure, which acts as a liquid seal to prevent the liquid phase from entering the inner rectification tower; the bottom of the inner rectification tower is closed and is provided with an inner rectification tower liquid outlet, The liquid discharge port of the inner rectification tower is a U-shaped pipe structure to prevent the gas phase from entering the inner rectification tower; the inner rectification tower is provided with an inner rectification tower liquid inlet on the side wall, and the inner rectification tower enters each inner rectification tower. A liquid distributor is arranged above the liquid port; the liquid inlet of the inner rectification tower is connected with the liquid outlet pipe of the upper liquid distributor through a pipeline.

The liquid distributor adopts a disc-type hole flow distributor, including a cylinder with a bottom plate, and the bottom plate is provided with an air riser, a spray hole and a guide hole, wherein the guide hole is connected with the liquid outlet pipe of the liquid distributor.

The number of the internal rectification towers is at least 2, preferably 3 to 9.

The inner rectifying column is a dividing wall rectifying column, that is, a dividing wall is set inside the inner rectifying column, and the inner rectifying column is divided into 6 parts by the dividing wall, the common rectifying zone I, the common stripping zone VI, and the parts by the dividing wall. The feed section and the side extraction section are separated by the partition wall. The feed section and the side extraction section can be further divided into the feed rectification section II, the side extraction rectification section III, the feed stripping section IV, and the side extraction section. Stripping section V; the feed section of the inner rectification tower is provided with a feed distributor, the side line extraction section of the inner rectification tower is provided with a side line extraction port in the middle of the side wall, and the side line extraction port is connected with the side line extraction pipe; One end of the extraction pipe is connected with the side-drawing distributor in the inner rectification tower, and the other end extends to the outside of the outer rectification tower through the tower wall of the outer rectification tower.

The feed distributor adopts a disc-type orifice flow distributor, including a cylinder with a bottom plate, and the bottom plate is provided with air risers and spray holes.

The side extraction distributor adopts a disc-type orifice flow distributor, including a cylinder with a bottom plate, and the bottom plate is arranged with an air riser, a spray hole and a diversion hole, wherein the diversion hole is connected with the side line extraction pipe.

The inner rectification tower is composed of a tube bundle composed of multiple tubes, the feed section of the inner rectification tower is provided with a box feeder, and the top of the inner rectification tower is provided with an outlet distributor, the top of the outlet distributor is closed and is provided with an inner rectifier. The gas outlet of the rectification tower; the bottom of the inner rectification tower is provided with a liquid collector, and the bottom of the liquid collector is closed and is provided with a liquid outlet of the inner rectification tower; The other end of the side line extraction pipe extends to the outside of the outer rectification tower through the outer rectification tower; the bottom of the common rectification zone I is provided with a common rectification gas-liquid distributor, and the common stripping zone VI The top is provided with a common stripping gas-liquid distributor; the upper end of the tube bundle of the common rectification zone I is communicated with the gas outlet distributor of the inner rectification tower, and the lower end of the tube bundle is communicated with the public rectification gas-liquid distributor of the inner rectification tower; The upper end of the tube bundle of the rectification section II is connected with the common rectification gas-liquid distributor of the inner rectification tower, and the lower end of the tube bundle is communicated with the cassette feeder of the inner rectification tower; the upper end of the tube bundle of the rectification section III is drawn from the side line It is communicated with the public rectification gas-liquid distributor of the inner rectification column, and the lower end of the tube bundle is communicated with the cassette side drawer of the inner rectification column; the upper end of the tube bundle of the feed stripping section IV is communicated with the cassette feeder of the inner rectification column. The lower end of the tube bundle is communicated with the common stripping gas-liquid distributor of the inner rectification tower; the upper end of the tube bundle of the stripping section V of the side line extraction is communicated with the box-type side collector of the inner rectification tower, and the lower end of the tube bundle is communicated with the side collector of the inner rectification tower. The common stripping gas-liquid distributor of the inner rectification tower is connected; the upper end of the tube bundle of the common stripping zone VI is connected with the common stripping gas-liquid distributor of the inner rectification tower, and the lower end of the tube bundle is connected with the liquid collector of the inner rectification tower Connected; the bottom of the liquid collector is closed and is provided with a drain port.

The structure of the cassette feeder, gas outlet distributor, public rectification gas-liquid distributor, cassette-type side drawer, public stripping gas-liquid distributor, and liquid collector is a cylinder with a closed top and a closed bottom, but not limited to With this structure, other devices capable of collecting and distributing liquid and redistributing gas can also be used.

This scheme provides a method for fractional separation of pyrolysis products using the above-mentioned multi-inner rectification tower rectification device, comprising the following steps: adding the pyrolysis products from the feed port of the outer rectification tower into the outer rectification tower for rectification , the liquid phase that reaches the bottom of the outer rectification tower is discharged through the discharge port at the bottom of the tower, and a part of it enters the reboiler for vaporization and returns to the external rectification tower through the reboiler return to the tower port, and the rest of the liquid phase passes through the bottom discharge pump of the tower. It is discharged to the outside of the outer rectification tower; the light components that reach the top of the outer rectification tower are discharged through the top gas outlet, condensed by the condenser and then enter the reflux tank, the non-condensable gas is discharged through the non-condensable gas outlet, and the liquid phase is discharged from the reflux tank After discharge, one way is discharged as product through the product valve at the top of the tower, and the other way is returned to the outer rectification tower through the reflux pump at the top of the tower and the reflux liquid inlet in turn; the liquid phase at a certain height is discharged from the liquid distributor of the outer rectification tower. After the liquid pipe is discharged, it enters the inner rectification tower through the pipeline from the liquid inlet of the inner rectification tower for rectification. The light components and a part of the intermediate components move to the top of the tower, and the heavy components and a part of the intermediate components move to the bottom of the tower. The separation of light components and intermediate components is completed in the rectification zone, and the light components are discharged from the gas outlet of the inner rectification tower and returned to the outer rectification tower to continue rectification; the common stripping zone completes the separation of the intermediate components and heavy components The heavy components are discharged in liquid state from the liquid outlet of the inner rectification tower and enter the outer rectification tower to continue rectification. The intermediate components are extracted from the side line extraction port in liquid state, and then discharged to the outer rectification tower through the side line extraction pipe. In addition, the fractions drawn from the side draw of each inner rectification column are collected.

Methanol or ethanol is passed into the outward rectification column through the reboiler return column port.

The beneficial effects of this scheme are: (1) Several or even dozens of inner rectification towers are arranged inside the outer rectification tower, correspondingly, the pyrolysis products are separated to obtain several or even dozens of fractions, and one device is used to realize the pyrolysis products. The fine fractionation and separation of the system breaks through the limitation that the dividing wall rectification column is only used to separate 3-5 components.

(2) One rectifying tower is used to complete the separation tasks that can be accomplished by a plurality of ordinary rectifying towers, and each inner rectifying tower forms a thermocouple with the outer rectifying tower, and each inner rectifying tower does not need to be further Boiler and condenser, the heat required for the vaporization of the low-boiling fraction in the inner rectifying tower is the heat released by the condensation of the high-boiling fraction in the outer rectifying tower, realizing the coupled utilization of energy.

(3) Adjusting a certain inner distillation column has little effect on other operating parameters, and has good operating flexibility, dynamic characteristics and controllability.

(4) The inner rectification column adopts a dividing wall rectification column. During operation, the liquid phase at a certain height enters an inner rectification column for rectification, and the light components and heavy components are separated from the top and bottom of the inner rectification column. It is discharged and returned to the outer rectification tower to continue rectification, and the intermediate components (target components) are extracted from the side line of the inner rectification tower, which can separate the high-boiling substances generated by the heat-sensitive bio-oil in the outer rectification tower into the corresponding boiling range fractions, At the same time, the stabilization of bio-oil is achieved, and high-quality distillate oil with clear boiling range is obtained.

Description of drawings

Figure 1 is a schematic diagram of a multi-inner column rectification device. Figure 2 is a schematic diagram of the structure and division of an internal rectifying column using a dividing wall rectifying column. Fig. 3 is the structural representation of the dividing wall rectifying column in which the inner rectifying column adopts the tube bundle form. FIG. 4 is a schematic structural diagram of a disc-type hole flow distributor used in the liquid distributor. Figure 5 is a schematic structural diagram of a disc-type hole flow distributor used in the feed distributor. FIG. 6 is a schematic structural diagram of the disc-type hole flow distributor used in the side-collection distributor.

In the figure: 101-top gas outlet; 102-outer rectification tower; 1031-first inner rectification tower; 1032-second inner rectification tower; 1033-third inner rectification tower; 1034-fourth inner rectification tower Distillation column; 1035-Fifth inner rectification column; 1036-Sixth inner rectification column; 1037-Seventh inner rectification column; 104-Feed inlet; 105-Column bottom outlet; 106-Condenser; 107 -Non-condensable gas port; 108- reflux tank; 109- tower top product valve; 110- tower top reflux pump; 111- reflux liquid inlet; 112- inner rectifying tower liquid inlet; 113- inner rectifying tower gas outlet; 114 - side line extraction outlet; 115- side line extraction pipe; 116- dividing wall; 117- liquid outlet of inner rectification tower; 118- liquid distributor; 119- liquid outlet pipe of liquid distributor; 120- reboiler return tower 121-reboiler; 122-bottom discharge pump; 201-feed distributor; 202-side draw distributor; 301-cassette feeder; 302-outlet distributor; 303-public rectified gas Liquid distributor; 304-box side sampler; 305-common stripping gas-liquid distributor; 306-liquid collector; 401-gas riser; 402-bottom plate; 403-cylinder; 404-spray hole; diversion hole.

Detailed ways

The present scheme will be further described in detail below with reference to the accompanying drawings and through specific embodiments.

Embodiment 1: as shown in Figure 1, a kind of multi-inner column rectification device, it is made up of outer rectification column 102 and seven inner rectification columns arranged in the outer rectification column 102, and the inner rectification column is arranged At different height positions inside the outer rectifying tower 102, the top inner rectifying tower is named as the first inner rectifying tower 1031, and is named as the second inner rectifying tower 1032, the third inner rectifying tower 1033, the second inner rectifying tower 1032, Four inner rectification towers 1034, fifth inner rectification towers 1035, sixth inner rectification towers 1036, and seventh inner rectification towers 1037; The top of 102 is provided with a column top gas outlet 101, the bottom of the outer rectification column 102 is provided with a column bottom discharge port 105, the upper part of the outer rectification column 102 is provided with a reflux liquid inlet 111, and the bottom is provided with a reboiler return column port 120.

The top of the outer rectifying tower 102 is provided with a condenser 106 and a reflux tank 108 behind the condenser 106. The reflux tank 108 is provided with a non-condensable gas port 107 and a product discharge pipeline. The product discharge pipeline is divided into two paths, one with a tower The top product valve 109, the other way is provided with a tower top reflux pump 110 and is connected with the reflux liquid inlet 111.

A reboiler 121 is provided at the bottom of the outer rectification tower 102, and the pipeline after the outlet 105 at the bottom of the outer rectification tower 102 is divided into two paths, one path is provided with a tower bottom discharge pump 122, and the other path passes through the reboiler After 121, it is connected with the reboiler return column port 120.

The top of the inner rectification tower is closed and provided with an inner rectification tower gas outlet 113, the bottom of the inner rectification tower is closed and is provided with an inner rectification tower liquid outlet 117, and the inner rectification tower side wall is provided with an inner rectification tower liquid inlet. 112. Inside the outer rectification tower 102, a liquid distributor 118 is provided above the liquid inlet 112 of each inner rectification tower, and the liquid distributor 118 can play the role of liquid distribution and gas redistribution; The liquid port 112 communicates with the liquid outlet pipe 119 of the upper liquid distributor 118 through a pipeline. The gas outlet 113 of the inner rectification tower is an inverted U-shaped pipe structure, which acts as a liquid seal to prevent the liquid phase from entering the inner rectification tower; the liquid discharge port 117 of the inner rectification tower is a U-shaped pipe structure to prevent the gas phase from entering the inner rectification tower.

As shown in Figure 2, the inner rectifying column is a dividing wall rectifying column, that is, a dividing wall 116 is arranged inside the inner rectifying column, and the inner rectifying column is divided into 6 parts by the dividing wall 116, including the common rectifying zone I, Common stripping section VI, and the feed section and side draw section separated by the dividing wall 116, wherein the feed section and side draw section can be further divided into feed rectification section II, side draw rectification section III and Feed stripping section IV and side extraction stripping section V; the feed section of the inner rectification tower is provided with a feed distributor 201, and the side extraction section of the inner rectification tower is provided with a side extraction outlet 114 in the middle of the side wall, The side line extraction port 114 is connected with the side line extraction pipe 115; one end of the side line extraction pipe 115 is connected with the side extraction distributor 202 in the inner rectification tower, and the other end extends to the outer rectification tower through the column wall of the outer rectification tower 102 102 outside.

The outer rectification tower 102 is 6 meters high and has an inner diameter of 0.22 meters. It is filled with stainless steel θ mesh ring packing with a diameter and height of 4 mm. The top of the packing section is 0.4 meters away from the top of the outer rectification tower 102, and the bottom of the packing section is away from the outer rectification column. The bottom of the tower 102 is 1.5 meters; the feed port 104 of the outer rectification tower 102 is 0.6 meters higher than the lower end of the packing section of the outer rectification tower 102; mm stainless steel θ mesh ring packing, the top of the packing section is 0.02 meters away from the top of the outer rectification column 102, and the bottom of the packing section is 0.10 meters away from the bottom of the outer rectification column 102; the top of the seventh inner rectification column 1037 is higher than the outer rectification column 102. The lower end of the packing section of the distillation column 102 is 1.15 meters, the top of the sixth inner rectifying column 1036 is 0.4 meters higher than the top of the seventh inner rectifying column 1037, and the top of the fifth inner rectifying column 1035 is higher than that of the sixth inner rectifying column 1035. The column top of the distillation column 1036 is 0.4 meters, the column top of the fourth inner rectifying column 1034 is 0.3 meters higher than the column top of the fifth inner rectifying column 1035, and the column top of the third inner rectifying column 1033 is higher than the fourth inner rectifying column 1033. The column top of the distillation column 1034 is 0.3 meters, the column top of the second inner rectifying column 1032 is 0.3 meters higher than the column top of the third inner rectifying column 1033, and the column top of the first inner rectifying column 1031 is higher than the second inner rectifying column 1031. The top of the distillation column 1032 is 0.3 meters; the liquid distributor 118 is 0.2 meters higher than the inner rectification column liquid inlet 112 of the adjacent inner rectification column.

The liquid inlet 112 of the inner rectification tower is 0.35 meters higher than the lower end of the packing section of the inner rectification tower, and the side line extraction outlet 114 is higher than the lower end of the inner rectification tower packing section by 0.35 meters; It is 0.2 meters higher than the lower end of the packing section of the inner rectification tower.

The liquid distributor 118 adopts a disc-type orifice flow distributor, as shown in FIG. 4 , including a cylinder 403 with a bottom plate 402, and eight air risers 401 are evenly arranged around the center of the bottom plate 402, and spray holes 404 are also arranged on the bottom plate 402. and a guide hole 405 , wherein the guide hole 405 is connected with the liquid outlet pipe 119 of the liquid distributor 118 . The bottom plate 402 is circular with a diameter of 0.22 meters; the cylinder body 403 has a diameter of 0.22 meters and a height of 0.05 meters; the diameter and height of the air riser 401 are 0.042 meters and 0.03 meters respectively, and the distance between the center of the air riser 401 and the center of the bottom plate 402 is 0.06 meters . The diameter of the spray holes 404 is 0.005 meters, and the distance between the centers of the holes is 0.02 meters; the center of the guide holes 405 is located at the center of the bottom plate 402, and the diameter of the guide holes 405 is 0.04 meters.

The feed distributor 201 adopts a disc-type orifice flow distributor, as shown in FIG. 5 , and includes a cylinder 403 with a bottom plate 402 on which an air riser 401 and a spray hole 404 are arranged. The bottom plate 402 is semicircular with a diameter of 0.042 meters; the cylinder 403 has a diameter of 0.042 meters and a height of 0.03 meters; four air risers 401 are evenly arranged around the center of the circle on the bottom plate 402, and the diameter and height of the air risers 401 are 0.006 meters and 0.02 meters respectively. m, the distance between the center of the air riser 401 and the center of the bottom plate 402 is 0.016 m. The diameter of the spray holes 404 is 0.004 meters, and the distance between the centers of the holes is 0.012 meters.

The side sampling distributor 202 adopts a disc-type orifice flow distributor, as shown in FIG. 6, including a cylinder 403 with a bottom plate 402, and the bottom plate 402 is arranged with an air riser 401, a spray hole 404 and a guide hole 405, wherein the guide The orifice 405 is connected to the sideline draw pipe 115 . The bottom plate 402 is semicircular with a diameter of 0.042 meters; the cylinder 403 has a diameter of 0.042 meters and a height of 0.03 meters; four air risers 401 are evenly arranged around the center of the circle on the bottom plate 402, and the diameter and height of the air risers 401 are 0.006 meters and 0.02 meters respectively. m, the distance between the center of the air riser 401 and the center of the bottom plate 402 is 0.016 m. The diameter of the spray holes 404 is 0.004 meters, and the distance between the centers of the holes is 0.012 meters. The center of the guide hole 405 is located on the symmetry axis of the semicircular bottom plate 402 , and the distance from the center of the bottom plate 402 is 0.0065 meters.

Bio-oil is prepared by using the above-mentioned multi-inner rectifying tower rectification device to fractionate and separate the pine wood pyrolysis products. The 20-50 mesh pine wood powder (water content 10%) is used as the raw material. The feed is fed into the spiral pyrolysis reactor (length 1500 mm, inner diameter 15 mm), the pyrolysis temperature is 550 °C, and the solid carbon products produced by the pyrolysis directly enter the carbon box for collection; the pyrolysis gas products are dedusted by the cyclone separator and then enter the cooling system The device is cooled to 240 ° C, and is added to the outer rectification tower 102 from the feed port 104 of the outer rectification tower 102 for rectification. After the reboiler 121 is vaporized, it is returned to the outer rectification tower 102 through the reboiler return column port 120, and the rest of the liquid phase is discharged to the outer rectification tower 102 through the column bottom discharge pump 122; the reboiler 121 adopts electric heating Type reboiler, by controlling the heating power of the reboiler 121, the liquid phase temperature at the bottom of the outer rectification column 102 is stabilized at 260°C.

The light components arriving at the top of the outer rectifying tower 102 are discharged through the top gas outlet 101, and after being condensed by the condenser 106, they enter the reflux tank 108, the non-condensable gas is discharged through the non-condensable gas port 107, and the liquid phase is discharged from the reflux tank 108. The product valve 109 at the top of the tower is discharged as a product, and the other way returns to the outer rectifying tower 102 through the tower top reflux pump 110 and the reflux liquid inlet 111 in turn, and the reflux ratio is controlled at 2:1. 80°C; the condenser 106 adopts a water-cooled condenser, and the temperature of the condensate after passing through the condenser 106 is reduced to 45°C by controlling the flow rate of the influent water.

The liquid phase at a certain height is discharged from the liquid outlet pipe 119 of the liquid distributor 118 of the outer rectification tower 102 and then enters the inner rectification tower through the pipeline from the liquid inlet 112 of the inner rectification tower for rectification. The intermediate components move to the top of the tower, the heavy components and a part of the intermediate components move to the bottom of the tower, and the separation of the light components and the intermediate components is completed in the common rectification zone. Discharge and return to the outer rectifying tower 102 to continue rectification; the common stripping zone completes the separation of the intermediate component and the heavy component, and the heavy component is discharged from the inner rectifying tower liquid outlet 117 in a liquid state and enters the outer rectifying tower 102 to continue rectifying, The intermediate components are extracted from the side draw outlet 114 in a liquid state, and then discharged to the outside of the outer rectifying tower 102 through the side draw pipe 115, and the fractions drawn from the side draw of each inner rectifying tower are collected. The distillation range of the sample was determined according to "GB/T 6536-2010 Determination of Atmospheric Distillation Characteristics of Petroleum Products".

The distillate discharged from the top product valve 109 of the external distillation column 102 is a colorless liquid, and the distillate volume at 30~90°C during the determination of the distillation range accounts for 92.8% of the sample volume, and is stored at 30°C for 24 hours. The viscosity rises by 3.5%; the distillate discharged from the first inner rectifying tower 1031 is a colorless liquid, and the distillate volume at 90~110°C during the determination of the distillation range accounts for 91.9% of the sample volume. Heating at 80°C for 24 hours, 40°C The viscosity at lower temperature increased by 6.2%; the distillate discharged from the second inner distillation column 1032 was a colorless liquid, and the distillate volume at 110~130°C during the determination of the distillation range accounted for 90.5% of the sample volume. Heating at 80°C for 24 hours, The viscosity at 40°C increased by 8.4%; the distillate discharged from the third inner rectifying tower 1033 was a pale yellow liquid, and the distillate volume at 130~150°C during the distillation range determination process accounted for 90.0% of the sample volume, and heated at 80°C for 24 hours, the viscosity at 40°C increased by 10.6%; the distillate discharged from the fourth inner distillation column 1034 was a pale yellow liquid, and the distillate volume at 150~170°C during the distillation range determination process accounted for 89.1% of the sample volume, and at 80°C After heating for 24 hours, the viscosity at 40°C increased by 12.9%; the fraction discharged from the fifth inner distillation column 1035 was a light yellow liquid. Heating at 80°C for 24 hours, the viscosity at 40°C increased by 13.1%; the distillate discharged from the sixth inner distillation column 1036 was a light yellow liquid, and the distillate volume at 190~210°C during the distillation range determination process accounted for 88.0% of the sample volume , heated at 80 °C for 24 hours, the viscosity at 40 °C increased by 15.8%; the fraction discharged from the seventh inner distillation column 1037 was a light yellow liquid, and the distillate volume at 210~240 °C during the distillation range determination process accounted for 3% of the sample volume. 86.5%, heated at 80 °C for 24 hours, the viscosity at 40 °C increased by 16.3%; the material discharged from the bottom discharge pump 122 of the external rectification tower 102 was a black viscous liquid, and the distillation range was measured at 30~240 °C. The distillate volume was 10.3% of the sample volume.

Bio-oil prepared by conventional pyrolysis and refining methods has poor stability, such as literature (Zhang Wei, Zhao Zengli, Zheng Anqing, et al. Experimental study on storage stability of bio-oil [J]. Journal of Fuel Chemistry, 2012, 40(2) : 184-189) Bio-oil prepared from pine wood by conventional pyrolysis and refining methods was heated at 80 °C for 24 hours, and the viscosity measured at 40 °C increased by about 113%. Another example is the literature (Oasmaa A., Kuoppala E. Fast Pyrolysis of Forestry Residue. 3. Storage Stability of Liquid Fuel [J]. Energy & Fuels, 2003, 17(4): 1075-1084.) using pine as raw material and using conventional The bio-oil prepared by the pyrolysis and refining method was heated at 80°C for 24 hours, and the viscosity measured at 40°C increased by about 89-143%. The viscosity of the bio-oil obtained in this example is obviously smaller after heating, indicating that the present invention can obtain a relatively stable bio-oil product.

In this embodiment, one rectifying tower is used to complete the separation tasks that can be accomplished by a plurality of common rectifying towers, and a thermocouple is formed between each inner rectifying tower and the outer rectifying tower, and each inner rectifying tower does not need to be further Boiler and condenser, the heat required for the vaporization of the low-boiling fraction in the inner rectifying tower is the heat released by the condensation of the high-boiling fraction in the outer rectifying tower, realizing the coupled utilization of energy.

In this embodiment, the inner rectification column adopts a dividing wall rectification column, and during operation, a liquid phase at a certain height enters an inner rectification column for rectification, and light components and heavy components are respectively removed from the top of the inner rectification column. And the bottom is discharged back to the outer rectification tower to continue rectification, and the intermediate components (target components) are extracted from the side line of the inner rectification tower, which can separate the high-boiling substances generated by the heat-sensitive bio-oil in the outer rectification tower into the corresponding boiling range fractions At the same time, the stabilization of bio-oil is achieved, and high-quality distillate oil with clear boiling range is obtained.

Embodiment 2: the same part of this embodiment and embodiment 1 will not be repeated, the difference is: the top of the second inner rectifying tower 1032 is 0.4 meters higher than the top of the third inner rectifying tower 1033, and the second The inner rectification column 1032 is packed with stainless steel θ mesh ring packing with diameter and height of 5mm.

The distillate discharged from the top product valve 109 of the external distillation column 102 is a colorless liquid, and the distillate volume at 30 to 90°C during the determination of the distillation range accounts for 92.7% of the sample volume, and is stored at 30°C for 24 hours. Viscosity rises by 3.4%; the distillate discharged from the first inner rectifying tower 1031 is a colorless liquid, and the distillate volume at 90~110°C during the determination of the distillation range accounts for 91.7% of the sample volume. Heating at 80°C for 24 hours at 40°C The viscosity at lower temperature increased by 6.1%; the distillate discharged from the second inner distillation column 1032 was a colorless liquid, and the distillate volume at 110~130°C during the determination of the distillation range accounted for 90.7% of the sample volume. Heating at 80°C for 24 hours, The viscosity at 40°C increased by 8.2%; the distillate discharged from the third inner rectifying tower 1033 was a light yellow liquid, and the distillate volume at 130~150°C during the distillation range determination process accounted for 90.0% of the sample volume, and heated at 80°C for 24 hours, the viscosity at 40°C increased by 10.5%; the distillate discharged from the fourth inner distillation column 1034 was a pale yellow liquid, and the distillate volume at 150~170°C during the distillation range determination process accounted for 89.5% of the sample volume, and at 80°C Heating for 24 hours, the viscosity at 40°C increased by 12.6%; the fraction discharged from the fifth inner distillation column 1035 was a light yellow liquid. Heating at 80°C for 24 hours, the viscosity at 40°C increased by 13.6%; the distillate discharged from the sixth inner distillation column 1036 was a light yellow liquid, and the distillate volume at 190~210°C during the distillation range determination process accounted for 87.0% of the sample volume , heated at 80 °C for 24 hours, the viscosity at 40 °C increased by 15.6%; the distillate discharged from the seventh inner rectifying tower 1037 was a light yellow liquid, and the distillation volume at 210~240 °C during the distillation range determination process accounted for the sample volume. 86.7%, heated at 80 °C for 24 hours, the viscosity at 40 °C increased by 16.1%; the material discharged from the bottom discharge pump 122 of the external rectification tower 102 was a black viscous liquid, and the distillation range was measured at 30~240 °C. The distillate volume was 10.1% of the sample volume.

This example shows that adjusting a certain inner rectification column of the multi-inner column rectification device has little influence on other operating parameters, and has good operation flexibility, dynamic characteristics and controllability.

Embodiment 3: the same part of this embodiment and embodiment 1 will not be repeated, the difference is: a kind of multi-inner tower rectification device, it is composed of outer rectification tower 102 and the inner part of outer rectification tower 102. 2 inner rectification towers are formed, and the inner rectification towers are arranged at different height positions inside the outer rectification tower 102, the inner rectification tower above is named as the first inner rectification tower 1031, and the inner rectification tower below is named as the second inner rectification tower. Internal distillation column 1032. The feed port 104 of the outer rectifying tower 102 is 0.8 meters higher than the lower end of the packing section of the outer rectifying tower 102; the top of the second inner rectifying tower 1032 is 1.6 meters higher than the lower end of the packing section of the outer rectifying tower 102, and the The top of the distillation column 1031 is 1.5 meters higher than the top of the second inner distillation column 1032.

Bio-oil is prepared by fractional separation of pine wood pyrolysis products using the above-mentioned multi-inner rectifying tower rectification device. The distillate discharged from the top product valve 109 of the external distillation column 102 is a colorless liquid, and the distillate volume at 30 to 90°C during the determination of the distillation range accounts for 90.2% of the sample volume. The viscosity rises by 10.8%; the distillate discharged from the first inner rectifying tower 1031 is a light yellow liquid, and the distillate volume at 90~150°C during the determination of the distillation range accounts for 85.4% of the sample volume. Heating at 80°C for 24 hours at 40°C The viscosity at lower temperature increased by 18.5%; the distillate discharged from the second inner rectifying tower 1032 was a light yellow liquid, and the distillate volume at 150~220°C during the distillation range determination process accounted for 85.6% of the sample volume, heated at 80°C for 24 hours, The viscosity at 40°C increased by 20.1%; the material discharged from the bottom discharge pump 122 of the external rectification tower 102 was a black viscous liquid, and the distillate volume at 30-240°C during the distillation range determination process accounted for 12.7% of the sample volume.

Embodiment 4: the same part of this embodiment and embodiment 1 will not be repeated, the difference is: a kind of multi-inner tower rectification device, it is composed of outer rectification tower 102 and the inner part of outer rectification tower 102. 3 inner rectification towers are formed, and the inner rectification towers are arranged at different height positions inside the outer rectification tower 102. The uppermost inner rectification tower is named the first inner rectification tower 1031, and it is named as the second inner rectification tower 1031 in turn. Distillation column 1032, third inner rectification column 1033. The feed port 104 of the outer rectification column 102 is 0.7 meters higher than the lower end of the packing section of the outer rectification column 102; the top of the third inner rectification column 1033 at the bottom is 1.3 meters higher than the lower end of the packing section of the outer rectification column 102. The top of the second inner rectifying column 1032 is 0.9 meters higher than the top of the third inner rectifying column 1033, and the top of the first inner rectifying column 1031 is 1.0 meters higher than the top of the second inner rectifying column 1032. The liquid distributor 118 is 0.3 meters higher than the inner rectification column inlet 112 of the lower adjacent inner rectification column.

Bio-oil is prepared by using the above-mentioned multi-inner rectifying tower rectification device to fractionate and separate the pyrolysis product of corn stalk, and use 20-50 mesh corn stalk powder (water content 10%) as the raw material. The pyrolysis gas product is dedusted by the cyclone separator and then enters the cooler to be cooled to 220 ° C, and is added to the outer rectification tower 102 from the feed port 104 of the outer rectification tower 102 for rectification, and is regenerated at a speed of 1.15 kg/h. The boiler returns to the column opening 120 to pass methanol into the outward rectifying column 102 . The reflux ratio is controlled at 1.5:1, the temperature at the top of the outer rectifying tower 102 is 60°C, and the temperature of the condensate drops to 40°C after passing through the condenser 106 .

The distillate discharged from the top product valve 109 of the external rectification tower 102 is a colorless liquid, and the distillate volume at 30~130°C during the determination of the distillation range accounts for 92.8% of the sample volume, and is stored at 30°C for 24 hours. The viscosity rises by 5.4%; the fraction discharged from the first inner distillation column 1031 is a colorless liquid, and the distillate volume at 120~160°C during the determination of the distillation range accounts for 90.5% of the sample volume. Heating at 80°C for 24 hours at 40°C The viscosity at lower temperature increased by 7.0%; the distillate discharged from the second inner rectifying tower 1032 was a pale yellow liquid, and the distillate volume at 160~200°C accounted for 88.9% of the sample volume during the determination of the distillation range. Heating at 80°C for 24 hours, The viscosity at 40°C increased by 8.1%; the fraction discharged from the third inner rectifying tower 1033 was a light yellow liquid, and the distillate volume at 180~240°C during the distillation range determination process accounted for 88.0% of the sample volume, and heated at 80°C for 24 Within hours, the viscosity at 40 °C increased by 10.5%; the material discharged from the bottom discharge pump 122 of the external distillation column 102 was a black viscous liquid, and the distillation volume at 30~240 °C during the distillation range determination process accounted for 8.9% of the sample volume. %.

Embodiment 5 (comparative example): the same parts of this embodiment and embodiment 4 will not be repeated, the difference is: the first inner rectifying tower 1031, the second inner rectifying tower 1032 and the third inner rectifying tower 1033 There is no dividing wall 116 in the interior, and there is no side sampling distributor 202 and side line extraction port 114. After the inner rectification tower liquid outlet 117, a pipeline is set to extend to the outer rectification tower 102 through the outer rectification tower 102 tower wall. external.

During the rectification process, the liquid phase at a certain height is discharged from the liquid outlet pipe 119 of the liquid distributor 118 of the outer rectification tower 102 and then enters the inner rectification tower through the pipeline from the liquid inlet 112 of the inner rectification tower for rectification, The light components and a part of the intermediate components move to the top of the column and are discharged from the gas outlet 113 of the inner rectification column and return to the outer rectification column 102 to continue rectification, and the heavy components and a part of the intermediate components move to the bottom of the column and are in a liquid state. The liquid is discharged from the liquid outlet 117 of the inner rectification column to the outside of the outer rectification column 102 through a pipeline, and each fraction is collected. The liquid distributor 118 is 0.4 meters higher than the inner rectification column inlet 112 of the lower adjacent inner rectification column.

The distillate discharged from the top product valve 109 of the external distillation column 102 is a colorless liquid, and the distillate volume at 30~130°C during the determination of the distillation range accounts for 83.1% of the sample volume. The viscosity increased by 12.8%; the distillate discharged from the first inner rectifying tower 1031 was a colorless liquid, and the distillate volume at 120~160°C accounted for 81.7% of the sample volume during the distillation range determination. Heating at 80°C for 24 hours, 40°C The viscosity at lower temperature increased by 16.8%; the distillate discharged from the second inner rectifying tower 1032 was a pale yellow liquid, and the distillate volume at 160~200°C during the distillation range determination process accounted for 81.0% of the sample volume, heated at 80°C for 24 hours, The viscosity at 40°C increased by 14.9; the fraction discharged from the third inner rectifying tower 1033 was a light yellow liquid, and the distillate volume at 180~240°C during the distillation range determination accounted for 80.2% of the sample volume, and heated at 80°C for 24 hours , the viscosity at 40°C increased by 14.5%; the material discharged from the bottom discharge pump 122 of the outer rectification tower 102 was a black viscous liquid, and the distillate volume at 30~240°C during the determination of the distillation range accounted for 9.6% of the sample volume .

The inner rectification tower in this example is not provided with a dividing wall, the distillation range distribution of the obtained fraction is wider than that of the fraction obtained in Example 4, the viscosity rises greatly after heating, and the thermal stability is slightly worse.

Embodiment 6: the similarities between the present embodiment and embodiment 1 will not be repeated, the difference is: the multi-inner rectifying tower rectification device consists of the outer rectifying tower 102 and the 5 inner rectification towers arranged in the outer rectifying tower 102. The rectification tower is formed, the inner rectification tower is arranged at different height positions inside the outer rectification tower 102, the uppermost inner rectification tower is named as the first inner rectification tower 1031, and it is named as the second inner rectification tower 1032 in turn. , the third inner rectification tower 1033, the fourth inner rectification tower 1034, and the fifth inner rectification tower 1035. The top of the bottom fifth inner rectifying column 1035 is 1.2 meters higher than the lower end of the packing section of the outer rectifying column 1034, and the column top of the fourth inner rectifying column 1034 is 0.5 meters higher than the top of the fifth inner rectifying column 1035 , the top of the third inner rectifying column 1033 is 0.5 meters higher than the top of the fourth inner rectifying column 1034, and the top of the second inner rectifying column 1032 is 0.5 meters higher than the top of the third inner rectifying column 1033 , the top of the first inner rectification column 1031 is 0.5 meters higher than the top of the second inner rectification column 1032.

As shown in Figure 3, the inner rectification tower is composed of a tube bundle composed of a plurality of circular tubes with an inner diameter of 0.015 meters. The circular tubes are filled with stainless steel θ mesh rings with a diameter and height of 4 mm, and the distance between the two adjacent tubes is 5 mm, a cassette feeder 301 is provided in the feed section of the inner rectification tower, an outlet distributor 302 is arranged at the top of the inner rectification tower, and the top of the outlet distributor 302 is closed and provided with an outlet 113 of the inner rectification tower; The bottom of the distillation column is provided with a liquid collector 306, the bottom of the liquid collector 306 is closed and is provided with a liquid discharge port 117 of the inner rectification column; in the side line extraction section, one end of the side line extraction pipe 115 The side drawer 304 is connected, and the other end of the side draw pipe 115 extends to the outside of the outer rectification tower 102 through the wall of the outer rectification tower 102; the bottom of the public rectification zone I is provided with a public rectification gas-liquid distributor 303, The top of the common stripping zone VI is provided with a common stripping gas-liquid distributor 305; the upper end of the tube bundle of the common rectifying zone I is connected to the gas outlet distributor 302 of the inner rectifying tower, and the lower end of the tube bundle is connected to the common rectifying tower of the inner rectifying tower. The gas-liquid distributor 303 is communicated; the upper end of the tube bundle of the feed rectification section II is communicated with the public rectification gas-liquid distributor 303 of the inner rectification tower, and the lower end of the tube bundle is communicated with the cassette feeder 301 of the inner rectification tower The upper end of the tube bundle of the rectification section III of the side line extraction is communicated with the public rectification gas-liquid distributor 303 of the inner rectification tower, and the lower end of the tube bundle is communicated with the cassette side collector 304 of the inner rectification tower; the feed stripping section The upper end of the tube bundle of IV is communicated with the cassette feeder 301 of the inner rectifying tower, and the lower end of the tube bundle is communicated with the common stripping gas-liquid distributor 305 of the inner rectifying tower; The box-type side extractor 304 of the rectifying tower is communicated, and the lower end of the tube bundle is communicated with the common stripping gas-liquid distributor 305 of the inner rectifying tower; the upper end of the tube bundle of the common stripping zone VI is connected with the common stripping gas of the inner rectifying tower. The liquid distributor 305 is communicated with, and the lower end of the tube bundle is communicated with the liquid collector 306 of the inner rectification column; the bottom of the liquid collector 306 is closed and provided with a liquid discharge port.

The distance between the cassette feeder 301 and the public rectification gas-liquid distributor 303 is 0.2 meters, and 5 pipes are provided; the distance between the cassette feeder 301 and the public stripping gas-liquid distributor 305 is 0.15 meters, and there are 5 pipes; the distance between the box-type side sampler 304 and the public rectification gas-liquid distributor 303 is 0.25 meters, and there are 3 pipes; the distance between the box-type side sampler 304 and the public stripping gas-liquid distributor 305 is 0.1 The distance between the public rectification gas-liquid distributor 303 and the gas outlet distributor 302 is 0.35 meters, and there are 8 pipes; the distance between the public stripping gas-liquid distributor 305 and the liquid collector 306 is 0.2 meters m, set with 8 pipes.

The structure of the cassette feeder 301, the gas outlet distributor 302, the common rectification gas-liquid distributor 303, the cassette side-drawer 304, the common stripping gas-liquid distributor 305, and the liquid collector 306 are closed at the top and closed at the bottom Cylinder, the height of the cylinder is 0.02 meters, but it is not limited to this structure, and other devices that can play the role of liquid collection and distribution and gas redistribution can also be used. In this embodiment, the volume ratio of the liquid phase flowing out from the common rectification gas-liquid distributor 303 and entering the feed section of the inner rectification tower and the side line extraction section is 5:3; 60% of the total volume of liquid phase passing through cassette side extractor 304.

Bio-oil is prepared by adopting the above-mentioned multi-inner rectifying tower rectification device to fractionate and separate the pyrolysis products of poplar sawdust, and using 20-50 mesh poplar sawdust (water content 5%) as the raw material.

After the pyrolysis gas product is dedusted by the cyclone, it enters the cooler to be cooled to 220 ° C, is fed into the outer rectification tower 102 from the feed port 104 of the outer rectification tower 102 for rectification, and is regenerated at a speed of 1.05 kg/h. The boiler returns to the column opening 120 and feeds ethanol into the outward rectifying column 102. The reflux ratio is controlled at 1.5:1, the temperature at the top of the outer rectifying tower 102 is 75°C, and the temperature of the condensate drops to 50°C after passing through the condenser 106 .

The distillate discharged from the top product valve 109 of the external distillation column 102 is a colorless liquid, and the distillate volume at 30~115°C during the determination of the distillation range accounts for 92.9% of the sample volume. The viscosity increased by 4.9%; the fraction discharged from the first inner distillation column 1031 was a colorless liquid, and the distillate volume at 110~135°C accounted for 91.7% of the sample volume during the determination of the distillation range. Heating at 80°C for 24 hours, 40°C The viscosity at lower temperature increased by 11.5%; the distillate discharged from the second inner rectifying tower 1032 was a light yellow liquid, and the distillate volume at 135~160°C during the determination of the distillation range accounted for 89.0% of the sample volume. Heating at 80°C for 24 hours, The viscosity at 40°C increased by 11.7%; the fraction discharged from the third inner rectifying tower 1033 was a light yellow liquid, and the distillate volume at 160~185°C accounted for 86.3% of the sample volume during the determination of the distillation range, and heated at 80°C for 24 The viscosity at 40°C increased by 14.1% within 14 hours; the distillate discharged from the fourth inner distillation column 1034 was a light yellow liquid, and the distillate volume at 185-210°C during the determination of the distillation range accounted for 85.1% of the sample volume, and at 80°C Heating for 24 hours, the viscosity at 40°C increased by 14.5%; the fraction discharged from the fifth inner distillation column 1035 was a pale yellow liquid, and the distillate volume at 210~240°C during the distillation range determination process accounted for 83.9% of the sample volume. Heating at 80°C for 24 hours, the viscosity at 40°C increases by 14.8%; the material discharged from the bottom discharge pump 122 of the external rectification tower 102 is a black viscous liquid. 7.5% of the sample volume, heated at 80°C for 24 hours, the viscosity at 40°C increased by 19.8%.

Embodiment 7: the similarities between the present embodiment and embodiment 1 will not be repeated, the difference is: the multi-inner rectifying tower rectification device is composed of the outer rectifying tower 102 and the 9 inner rectification towers arranged in the outer rectifying tower 102. The composition of the rectification tower, the inner rectification tower is filled with stainless steel θ mesh ring packing with a diameter and height of 6 mm, the inner rectification tower is arranged at different heights inside the outer rectification tower 102, and the uppermost inner rectification tower is named No. An inner rectification tower 1031, named as the second inner rectification tower 1032, the third inner rectification tower 1033, the fourth inner rectification tower 1034, the fifth inner rectification tower 1035, and the sixth inner rectification tower 1036, the seventh inner rectification column 1037, the inner rectification column 1038, and the inner rectification column 1039. The top of the bottom inner rectifying tower 1039 is 1.1 meters higher than the lower end of the packing section of the outer rectifying tower 102, and the top of the inner rectifying tower 1038 is 0.3 meters higher than the top of the inner rectifying tower 1039. The top of the column 1037 is 0.25 meters higher than the top of the inner rectification column 1038, the top of the sixth inner rectification column 1036 is 0.25 meters higher than the top of the seventh inner rectification column 1037, and the fifth inner rectification column 1035 The top of the tower is 0.3 meters higher than the top of the sixth inner rectification tower 1036, the tower top of the fourth inner rectification tower 1034 is higher than the tower top of the fifth inner rectification tower 1035 by 0.3 meters, and the third inner rectification tower 1033 The top of the tower is 0.3 meters higher than the top of the fourth inner rectifying tower 1034, the top of the second inner rectifying tower 1032 is 0.35 meters higher than the tower top of the third inner rectifying tower 1033, and the first inner rectifying tower 1031 The top of the column is 0.35 meters higher than the top of the second inner rectifying column 1032.

Bio-oil is prepared by adopting the above-mentioned multi-inner rectifying tower rectification device to fractionate the pyrolysis product of the mixture of pine wood pyrolysis crude oil and pine wood. As raw material, it was fed into a spiral pyrolysis reactor (length 1500 mm, inner diameter 15 mm) at a rate of 10 kg/h through a screw feeding system. The pyrolysis temperature was 550 °C, and the solid carbon products produced by pyrolysis directly entered The carbon box is collected; the pyrolysis gas product is dedusted by the cyclone separator and then enters the two-stage spray tower to be cooled to 80 °C, and the liquid phase is discharged from the bottom of the tower to collect the corn stalk pyrolysis crude oil. was 1.1 g/ml, and the acid value was 42.28 mg KOH/g. The pine wood pyrolysis crude oil prepared above is mixed with pine wood powder (water content 5%, 20-50 mesh) according to a mass ratio of 1:5, followed by pyrolysis as a raw material, and the pyrolysis gas product enters cooling after being dedusted by a cyclone separator. The reboiler is cooled to 220° C., and is added to the outer rectification tower 102 from the feed port 104 of the outer rectification tower 102 for rectification, and is returned to the outer rectification tower 102 through the reboiler return port 120 at a rate of 1.1 kg/h. Introduced with ethanol. By controlling the heating power of the reboiler 121, the temperature of the liquid phase at the bottom of the outer rectifying tower 102 is stabilized at 240°C, the temperature at the top of the outer rectifying tower 102 is 80°C, and the temperature of the condensate drops to 40°C after passing through the condenser 106 .

The distillate discharged from the top product valve 109 of the external distillation column 102 is a colorless liquid, and the distillate volume at 30~100°C during the determination of the distillation range accounts for 92.8% of the sample volume, and is stored at 30°C for 24 hours. The viscosity rises by 3.5%; the distillate discharged from the first inner distillation column 1031 is a colorless liquid, and the distillate volume at 90~105°C during the distillation range determination process accounts for 85.4% of the sample volume. Heating at 80°C for 24 hours, 40°C The viscosity at lower temperature increased by 13.0%; the distillate discharged from the second inner rectifying tower 1032 was a light yellow liquid, and the distillate volume at 105~120°C accounted for 84.0% of the sample volume during the determination of the distillation range. Heating at 80°C for 24 hours, The viscosity at 40°C increased by 13.5%; the distillate discharged from the third inner distillation column 1033 was a pale yellow liquid, and the distillate volume at 120~135°C during the distillation range determination process accounted for 83.3% of the sample volume, and heated at 80°C for 24 hours, the viscosity at 40°C increased by 13.9%; the distillate discharged from the fourth inner distillation column 1034 was a pale yellow liquid, and the distillate volume at 130~145°C during the distillation range determination process accounted for 83.2% of the sample volume, and at 80°C After heating for 24 hours, the viscosity at 40°C increased by 14.3%; the distillate discharged from the fifth inner distillation column 1035 was a light yellow liquid, and the distillate volume at 140~155°C during the distillation range determination accounted for 82.8% of the sample volume. Heating at 80°C for 24 hours, the viscosity at 40°C increased by 14.8%; the distillate discharged from the sixth inner distillation column 1036 was a light yellow liquid, and the distillate volume at 150~165°C during the distillation range determination process accounted for 82.1% of the sample volume , heated at 80 °C for 24 hours, the viscosity at 40 °C increased by 15.3%; the distillate discharged from the seventh inner distillation column 1037 was a light yellow liquid, and the distillate volume at 160~175 °C during the distillation range determination process accounted for the sample volume. 81.5%, heated at 80°C for 24 hours, the viscosity at 40°C increased by 16.0%; the distillate discharged from the internal distillation column 1038 was a light yellow liquid, and the distillate volume at 170~185°C during the distillation range determination process accounted for the sample volume. 80.4%, heated at 80°C for 24 hours, the viscosity at 40°C increased by 16.7%; the distillate discharged from the inner distillation column 1039 was a light yellow liquid, and the distillate volume at 180~200°C during the distillation range determination process accounted for the sample volume. 80.1%, heated at 80 °C for 24 hours, the viscosity at 40 °C increased by 17.1%; the material discharged from the bottom discharge pump 122 of the external rectification tower 102 was a black viscous liquid, and the distillation range was measured at 30~220 °C. The distillate volume was 6.1% of the sample volume. After heating at 80°C for 24 hours, the viscosity at 40°C increased by 18.7%.

Embodiment 8: the same part of this embodiment and embodiment 6 will not be repeated, the difference is: adopt the multi-inner tower rectifying device to fractionate the gasoline for commercial use, and after the gasoline is heated to 50 ℃, the gasoline is heated to 4.0 kg/h. The speed is added into the outer rectification column 102 from the feed port 104 of the outer rectification column 102 to carry out rectification, the liquid phase temperature at the bottom of the outer rectification column 102 is stabilized at 180 ° C, the reflux ratio is controlled at 2:1, and the outer rectification column is rectified. The temperature at the top of the tower 102 is 60°C, and the temperature of the condensate drops to 40°C after passing through the condenser 106 . Ethanol is not passed into the outer rectifying column 102 through the reboiler return column port 120.

The fraction discharged from the top product valve 109 of the outer rectification tower 102 is a colorless liquid, and the distillate volume at 30-65°C during the distillation range determination process accounts for 94.2% of the sample volume; the fraction discharged from the first inner rectification tower 1031 is Colorless liquid, the distillate volume at 60~80℃ during the distillation range determination accounts for 93.1% of the sample volume; the distillate discharged from the second inner distillation column 1032 is a colorless liquid, and the distillation range determination process is at 80~100℃ The distillate volume of 100-120°C during the determination of the distillation range accounts for 88.6% of the sample volume; The fraction discharged from the rectifying tower 1034 is a colorless liquid, and the distillate volume at 120~150°C during the determination of the distillation range accounts for 87.8% of the sample volume; the fraction discharged from the fifth inner rectifying tower 1035 is a pale yellow liquid, and the distillation range During the measurement process, the distillate volume at 150~180°C accounts for 87.5% of the sample volume; the material discharged from the bottom discharge pump 122 of the external rectification tower 102 is a light yellow liquid, and the distillation range at 30~180°C during the measurement of the distillation range. The output volume was 8.2% of the sample volume.

Claims (10)

1. a multi-inner tower rectifying device is characterized in that it is made up of outer rectification tower and at least 2 inner rectification towers arranged in the outer rectification tower interior, and the inner rectification tower is arranged in the outer rectification tower interior Different height positions; the side wall of the outer rectification tower is provided with a feed port, the top of the outer rectification tower is provided with a tower top gas outlet, the bottom of the outer rectification tower is provided with a column bottom outlet, and the upper part of the outer rectification tower is provided with a column bottom outlet. There is a reflux liquid inlet, and the lower part is provided with a reboiler return column; the top of the outer rectification column is provided with a condenser and a reflux tank after the condenser, and the reflux tank is provided with a non-condensable gas port and a product discharge pipeline The route is divided into two routes, one is provided with a product valve at the top of the tower, and the other is provided with a reflux pump at the top of the column and is connected to the reflux liquid inlet; the bottom of the outer rectification tower is provided with a reboiler, and the outlet at the bottom of the outer rectification tower is provided The subsequent pipeline is divided into two paths, one is provided with a tower bottom discharge pump, and the other is connected with the reboiler return to the tower port after passing through the reboiler; the top of the inner rectifying tower is closed and is provided with an inner rectifying tower gas outlet, The air outlet of the inner rectification tower is an inverted U-shaped pipe structure, which acts as a liquid seal to prevent the liquid phase from entering the inner rectification tower; the bottom of the inner rectification tower is closed and is provided with a liquid discharge port of the inner rectification tower, and the inner rectification tower is discharged. The port is a U-shaped pipe structure to prevent the gas phase from entering the inner rectification tower; the inner rectification tower is provided with an inner rectification tower liquid inlet on the side wall, and the outer rectification tower is provided with a liquid inlet above each inner rectification tower. There is a liquid distributor; the liquid inlet of the inner rectification tower is connected with the liquid outlet pipe of the upper liquid distributor through the pipeline. 2. multi-inner tower rectification device according to claim 1, is characterized in that liquid distributor adopts disc type hole flow distributor, comprises the cylinder body with bottom plate, and is arranged with gas riser, spray hole and guide plate on the bottom plate. Flow hole, wherein the guide hole is connected with the liquid outlet pipe of the liquid distributor. 3. The multiple inner column rectification device according to claim 1, wherein the number of the inner rectification column is at least 2. 4 . The multi-inner column rectification device according to claim 3 , wherein the number of the inner rectification columns is 3 to 9. 5 . 5. multiple inner tower rectifying device according to claim 1 is characterized in that the inner rectifying tower is a dividing wall rectifying tower, i.e. a dividing wall is arranged inside the inner rectifying tower, and the inner rectifying tower is divided into a dividing wall by the dividing wall. 6 parts, common rectification zone I, common stripping zone VI, and feed section and side draw section separated by dividing wall, wherein the feed section and side draw section can be further divided into feed rectification section II , side extraction rectification section III and feed stripping section IV, side extraction stripping section V; the feed section of the inner rectification tower is provided with a feed distributor, and the side extraction section of the inner rectification tower is on the side wall There is a side line extraction port in the middle, which is connected with the side line extraction pipe; one end of the side line extraction pipe is connected with the side extraction distributor in the inner rectification tower, and the other end extends through the outer rectification tower tower wall to the outside Outside the distillation column. 6 . The multi-inner column rectification device according to claim 5 , wherein the feed distributor adopts a disc-type hole flow distributor, comprising a cylinder with a bottom plate, and a gas riser and a spray hole are arranged on the bottom plate. 7 . 7. The multi-inner tower rectifying device according to claim 5, is characterized in that the side-collection distributor adopts the disc type hole flow distributor, comprises the cylinder body with bottom plate, and is arranged with gas riser, spray hole and The guide hole, wherein the guide hole is connected with the side line production pipe. 8. multiple inner tower rectifying device according to claim 1, it is characterized in that inner rectifying tower adopts the tube bundle that is made up of many pipes to form, and inner rectifying tower feed section is provided with box-type feeder, inner rectifying tower is provided with box feeder. The top of the distillation column is provided with a gas outlet distributor, the top of the gas outlet distributor is closed and is provided with the gas outlet of the inner rectification column; the bottom of the inner rectification column is provided with a liquid collector, and the bottom of the liquid collector is closed and is provided with an inner rectification column row Liquid port; one end of the side line draw pipe is connected to the cassette side drawer in the inner rectification tower, and the other end of the side line draw pipe extends through the outer rectification tower wall to the outside of the outer rectification tower; public rectification area The bottom of the I is provided with a public rectification gas-liquid distributor, and the top of the common stripping zone VI is provided with a public stripping gas-liquid distributor; The lower end of the tube bundle is communicated with the common rectification gas-liquid distributor of the inner rectification column; the upper end of the tube bundle of the feed rectification section II is communicated with the common rectification gas-liquid distributor of the inner rectification column, and the lower end of the tube bundle is communicated with the inner rectification column. The upper end of the tube bundle of the rectification section III drawn from the side line is communicated with the common rectification gas-liquid distributor of the inner rectification column, and the lower end of the tube bundle is communicated with the box-type side collector of the inner rectification column. ; The upper end of the tube bundle of the feed stripping section IV is communicated with the cassette feeder of the inner rectifying tower, and the lower end of the tube bundle is communicated with the common stripping gas-liquid distributor of the inner rectifying tower; The upper end of the tube bundle is communicated with the cassette side extractor of the inner rectification tower, and the lower end of the tube bundle is communicated with the common stripping gas-liquid distributor of the inner rectification tower; The distillate-liquid distributor is communicated, and the lower end of the tube bundle is communicated with the liquid collector of the inner rectifying tower; the bottom of the liquid collector is closed and provided with a liquid drain. 9. a method for using above-mentioned multiple inner rectifying tower rectifying device to carry out pyrolysis product fractionation, it is characterized in that it comprises the following steps: pyrolysis product is joined in outer rectifying tower from outer rectifying tower feed port Carry out rectification, the liquid phase that reaches the bottom of the outer rectification tower is discharged through the discharge port at the bottom of the tower, a part of it enters the reboiler for vaporization and returns to the outer rectification tower through the reboiler return to the tower port, and the rest of the liquid phase passes through the bottom of the tower. The discharge pump is discharged to the outside of the outer rectification tower; the light components that reach the top of the outer rectification tower are discharged through the top gas outlet, and after being condensed by the condenser, they enter the reflux tank, and the non-condensable gas is discharged through the non-condensable gas outlet, and the liquid phase is discharged. After being discharged from the reflux tank, one way is discharged as the product through the top product valve, and the other way is returned to the outer rectification column through the column top reflux pump and the reflux liquid inlet in turn; the liquid phase at a certain height is distributed from the liquid of the outer rectification column. After the liquid outlet pipe of the device is discharged, it enters the inner rectification tower through the pipeline from the liquid inlet of the inner rectification tower for rectification. The light components and a part of the intermediate components move to the top of the tower, and the heavy components and a part of the intermediate components move to the bottom of the tower. , the separation of light components and intermediate components is completed in the common rectification area, and the light components are discharged from the gas outlet of the inner rectification tower and returned to the outer rectification tower to continue rectification; the public stripping area completes the intermediate components and recombination. Separation of fractions, heavy fractions are discharged in liquid state from the discharge port of the inner rectifying tower and enter the outer fractionating tower to continue rectification. Outside the distillation column, the fractions drawn from the side line of each inner distillation column are collected. 10. The method according to claim 9 that uses the above-mentioned multi-inner rectifying tower rectifying device to carry out the fractional separation of pyrolysis products, characterized in that methanol or ethanol is passed into the outward rectifying tower through the reboiler return column opening.

Images