CN111233945A - Continuous depolymerization process of biomass - Google Patents

Abstract

The invention discloses a continuous depolymerization method of biomass. The method comprises: transporting materials to the double-valve feeder through a feeding port, and transporting the materials to the double-valve feeder through the double-valve feeder Horizontal reactor; use the horizontal reactor to depolymerize the material for the first time, and continue to transport it to the vertical reactor for the second depolymerization to obtain separated liquid depolymerization products and solid residues , The use of double-valve feeder realizes continuous feeding of biomass, improves the automation degree of hydrolysis process, realizes true continuous operation, and improves the depolymerization effect of materials through horizontal reactor and vertical reactor.

Description

Continuous depolymerization method of biomass

technical field

The present invention relates to the field of chemical industrial technology equipment and energy technology of biomass, in particular to a continuous depolymerization method of biomass.

Background technique

The large-scale use of petroleum and fossil fuels has caused serious environmental pollution problems, so the development of renewable energy has attracted more and more attention. Biomass is currently considered to be the only renewable resource that can be converted into liquid fuels and new bio-based materials, and crop straw lignocellulose is one of the most important biomass resources.

In recent years, research and development of efficient conversion and utilization technology and equipment of biomass straw has become a hot research direction at home and abroad. The water-phase depolymerization of straw has the advantages of high efficiency, strong adaptability, high added value of products, and easy connection with existing chemical technology. Therefore, the development and preparation of a new type of straw hydrolysis device system to realize the depolymerization, separation or conversion of the three components of hemicellulose, lignin and cellulose is of great significance for promoting the utilization of crop straw.

However, some of the current depolymerization methods are batch reactions, and the materials stay in the reactor for a long time, which is easy to produce more inhibitory compounds. And this method can only remove the hemicellulose component, the obtained cellulose contains most of the lignin, the cellulose purity is low, the effective separation of cellulose, hemicellulose and lignin cannot be achieved, and the scope of application is narrow. It is not conducive to the comprehensive utilization of lignocellulose, and some current hydrolysis device systems that can feed continuously, because the inside of the feed valve is in a normal pressure environment during operation, when the material rotates to the position of the feed port, it will be removed by the reactor. The high pressure ejection is easy to cause stringing and blocking, which is not conducive to the continuous and uniform feeding of materials, affects the hydrolysis effect, and makes it difficult to repeat the process.

SUMMARY OF THE INVENTION

The present invention provides a method for continuous depolymerization of biomass, aiming at solving the technical problem of discontinuous feeding of the current material, which affects the depolymerization effect and causes difficulty in repeating the process.

In order to achieve the above object, the present invention provides a continuous depolymerization method of biomass, which is applied to a continuous depolymerization device of biomass, and the continuous depolymerization device includes a double valve feeder, The horizontal reactor and the vertical reactor, the upper interface of the horizontal reactor is connected with the double valve feeder, the bottom side interface of the horizontal reactor is connected with the vertical reactor, and the continuous decomposition of the biomass is connected to the vertical reactor. The polymerization method includes the following steps:

The material is conveyed to the double-valve feeder through the feed port, and the material is conveyed to the transverse reactor through the double-valve feeder;

The materials are depolymerized for the first time by using the horizontal reactor, and continue to be transported to the vertical reactor for the second depolymerization, so as to obtain separated liquid depolymerization products and solid residues.

Preferably, the first propelling screw is used to propel the material from the beginning of the transverse reactor to the end of the transverse reactor with stirring, and the material feed is depolymerized for the first time during the propelling process.

Preferably, the second propelling screw is used to stir and propel the material from the bottom end of the vertical reactor to the top end of the vertical reactor;

During the advancing process, the material feed is depolymerized for the second time to obtain the separated liquid depolymerization product and solid residue.

Preferably, the material feed is depolymerized for the second time during the advancing process to obtain a depolymerized product, wherein the depolymerized product includes a liquid depolymerized product and a solid residue;

The second propelling screw is used to continuously propel the solid residue upwards to be transported to the solid storage tank, and the second propelling screw is used to reverse the liquid depolymerization product to the bottom of the vertical reactor for transporting to the liquid storage tank.

Preferably, the rotational speed of the first propelling screw and the second propelling screw is 0-100 rpm.

Preferably, the reaction temperature of the horizontal reactor and the vertical reactor are both 25-300° C., and the reaction pressure is both 100KPa-15MPa.

Preferably, a catalyst is added to the transverse reactor and/or the vertical reactor, wherein the catalyst includes inorganic acids and solid acids.

Preferably, the gas generator is used to pressurize the filling gas of the horizontal reactor and/or the vertical reactor to accelerate the depolymerization speed of the material, wherein the gas includes nitrogen, oxygen, air, argon, Carbon dioxide, water vapour, acid-carrying water vapour and/or alkali-carrying water vapour.

Preferably, the liquid sampling port of the horizontal reactor and/or the vertical reactor is used for sampling and testing, so as to obtain the degree of depolymerization of the material.

Preferably, the materials include: wheat straw, rice straw, corn cobs, corn stover, bagasse, sunflower seed husks, cotton firewood, cotton seed husks, wheat straw, rice husks, forest trees and/or forages.

Compared with the prior art, the present invention provides and discloses a method for continuous depolymerization of biomass. The material is transported to a double-valve feeder through a feeding port, and the material is transported to a horizontal reaction through the double-valve feeder. Then use the horizontal reactor to depolymerize the material for the first time, and continue to transport it to the vertical reactor for the second depolymerization to obtain the separated liquid depolymerization product and solid residue. It realizes the continuous feeding of biomass, improves the automation degree of the hydrolysis process, realizes the real continuous operation, and improves the depolymerization effect of the material through the horizontal reactor and the vertical reactor.

Description of drawings

Fig. 1 is the schematic flow chart of the first embodiment of the continuous depolymerization method of biomass of the present invention;

2 is a continuous depolymerization device for biomass according to an embodiment of the present invention;

3 is a diagram showing the hydrolysis effect of different types of inorganic acids (sulfuric acid, hydrochloric acid, phosphoric acid) with a mass fraction of 4% on wheat straw according to an embodiment of the present invention;

FIG. 4 is a table of product sugar content of wheat straw hydrolyzed by different types of inorganic acids (sulfuric acid, hydrochloric acid, phosphoric acid) with a mass fraction of 4% according to an embodiment of the present invention.

Description of reference numbers:

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

An embodiment of the present invention provides a method for continuous depolymerization of biomass. Referring to FIG. 1 , FIG. 1 is a schematic flowchart of the first embodiment of the method for continuous depolymerization of biomass according to the present invention.

The continuous depolymerization method of the biomass includes:

In step S10, the material is transported to the double-valve feeder through the feeding port, and the material is transported to the transverse reactor through the double-valve feeder;

In this step, referring to Fig. 2, Fig. 2 is a continuous depolymerization device of biomass. As shown in the figure, the continuous depolymerization device includes a double-valve feeder, a horizontal reactor and a vertical reactor. The horizontal reaction The upper end interface of the reactor is connected with the double valve feeder, and the bottom side end interface of the horizontal reactor is connected with the vertical reactor. Materials suitable for the method of the present invention include: wheat straw, rice straw, corn cobs, corn straw, bagasse, sunflower seed husks, cotton firewood, cotton seed husks, wheat straw, rice husks, forest trees and/or forages

Specifically, when the material is fed into the double-valve feeder through the feeding port, the double-valve feeder includes two feeding bins, and a butterfly valve is arranged at the interface of the two feeding bins, and the butterfly valve is connected to and The two feed bins are cut off, and the bottom of the feed bin is connected to the reactor, and a butterfly valve is provided at the interface between the feed bin and the horizontal reactor to connect and isolate the feed bin and the horizontal reactor through the butterfly valve. Ground, after the material enters the first feeding bin, open the butterfly valve between the two feeding bins, the material enters the second feeding bin under the action of gravity, and then open the space between the feeding bin and the horizontal reactor. At this time, the material enters the horizontal reactor from the feeding bin under the action of gravity, and finally closes the butterfly valve. At this time, a round of feeding operation is completed. After that, if you need to continue feeding, you can continue to repeat the above. step to realize continuous feeding operation.

Further, before step S10, it also includes,

Step S101, adding a catalyst into the horizontal reactor and/or the vertical reactor, wherein the catalyst includes inorganic acid and solid acid.

In this step, it is understood that, in order to speed up the depolymerization speed of the material, a catalyst, such as inorganic acid and solid acid, can be added to the material. On the ground, the continuous depolymerization process screening of various types of acidic catalysts was carried out on 200g wheat straw, including sulfuric acid, hydrochloric acid and phosphoric acid. , to detect the amount of sugar after hydrolysis of the material under each catalyst condition.

Specifically, under the conditions of a temperature of 180°C, 0.5MPa N2, 4wt% acid content, a horizontal axis speed of 10rpm, a vertical axis speed of 2rpm, and a liquid-solid ratio of 12 (g/L), 200g of wheat straw raw materials were put in, different types of inorganic acids ( The hydrolysis effect of sulfuric acid, hydrochloric acid, phosphoric acid) on wheat straw is shown in Figure 3. Acid hydrolysis mainly yields xylose, glucose and arabinose, of which the content of xylose is the highest, and the acquisition of xylose mainly comes from the hemicellulose in biomass straw. The hydrolysis of arabinose is also derived from the hydrolysis product of hemicellulose, while glucose is mainly derived from the hydrolysis product of cellulose. It can be seen from Figure 4 that when the acid mass fraction is 4%, hydrochloric acid is used to hydrolyze the wheat straw to reach the maximum reducing sugar sugar yield, and the total sugar amount received is 31.4 g. While 4% sulfuric acid and 4% phosphoric acid hydrolyzed wheat straw to obtain total sugar content of 17.7g and 14.8g. For wheat straw, the hydrolysis effect of hydrochloric acid is obviously better than that of other inorganic acids. The main reason is that the hydrochloric acid Cl- has an erosive effect on cellulose, and the hydrochloric acid molecule is smaller than other inorganic acid molecules, which is conducive to penetrating and destroying the cellulose crystal area. The 1,4-β-glycosidic bond between the glucose groups is favorable for hydrolysis.

In step S20, the material is depolymerized for the first time by using the horizontal reactor, and is continuously transported to the vertical reactor for the second depolymerization, so as to obtain the separated liquid depolymerization product and solid residue.

In this step, after the material enters the transverse reactor, a catalyst is added to the transverse reactor, wherein the catalyst includes inorganic acid and solid acid, such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, acetic acid and/or formic acid, specifically , after adding the catalyst, start the propelling screw of the horizontal reactor, use the horizontal reactor to depolymerize the material for the first time, and continue to transport it to the vertical reactor for the second depolymerization, so as to obtain a post-separation The liquid depolymerization products and solid residues are obtained, wherein, as shown in FIG. 2, the top interface of the vertical reactor is connected to the solid storage tank, and the bottom interface of the vertical reactor is connected to the liquid storage tank. After obtaining the separated liquid depolymerization After the polymerized product and the solid residue, the solid residue is transported into the solid storage tank, and the liquid depolymerized product is transported into the liquid storage tank, so as to separate the liquid depolymerized product and the solid residue.

Specifically, step S20 includes,

In step S201, the first propelling screw is used to propel the material from the beginning of the transverse reactor to the end of the transverse reactor with stirring, and the material feed is depolymerized for the first time during the propelling process.

In this step, the horizontal reactor is provided with a first propelling screw. After the material enters the horizontal reactor, the first propelling screw is used to stir and propel the material from the beginning of the horizontal reactor to the end of the horizontal reactor. In the process, the material and the catalyst are fully mixed and decomposed by extrusion, and the catalyst is used to depolymerize the material feed for the first time during the propulsion process, wherein the rotation speed of the first propulsion screw is 0-100 rpm.

Further, step S20 also includes,

Step S202, using the second propelling screw to stir and propel the material from the bottom end of the vertical reactor to the top of the vertical reactor;

In step S203, the material feed is depolymerized for the second time during the advancing process, so as to obtain the separated liquid depolymerization product and solid residue.

In this step, start the vertical reactor, use the second propelling screw to push the material from the bottom of the vertical reactor to the top of the vertical reactor, and then depolymerize the material for the second time during the propulsion process, In order to obtain the separated liquid depolymerization product and solid residue.

Specifically, step S203 includes,

Step S204, depolymerizing the material feed for the second time during the advancing process to obtain a depolymerized product, wherein the depolymerized product includes a liquid depolymerized product and a solid residue;

In step S205, the second propelling screw is used to continuously propel the solid residue upwards to be transported to the solid storage tank, and the second propelling screw is used to reverse the liquid depolymerization product to the bottom of the vertical reactor for transporting to the liquid storage tank.

In this step, it can be understood that the vertical reactor is provided with a second propulsion screw, the top interface of the vertical reactor is connected to the solid storage tank, and the bottom interface of the vertical reactor is connected to the liquid storage tank. In the reactor, that is, when the material is at the bottom of the vertical reactor, the vertical reactor is started, and the material feed is depolymerized for the second time during the advancing process to obtain a depolymerized product, wherein the depolymerized product includes liquid depolymerization. The polymerized product and solid residue are further propelled upward by the second propelling screw to be transported to the solid storage tank, and the liquid depolymerization product is backflowed to the bottom of the vertical reactor by the second propelling screw to be transported to the liquid storage tank. tank, wherein the rotational speed of the second propelling screw is 0-100 rpm.

Further, in this embodiment, before the material is depolymerized, the reaction temperature of the horizontal reactor and the vertical reactor are controlled to be both 25-300°C, and the reaction pressure is both 100KPa-15MPa.

Wherein, the reaction pressure can be controlled by the gas generator provided on the horizontal reactor and the vertical reactor, and the horizontal reactor and the vertical reactor are both provided with gas generators. The horizontal reactor depolymerizes the material for the first time, and continues to transport it to the vertical reactor for the second depolymerization process, using a gas generator to fill the horizontal reactor and/or the vertical reactor with gas. Pressurized to accelerate the depolymerization rate of the material, wherein the gas includes nitrogen, oxygen, air, argon, carbon dioxide, water vapor, acid-carrying water vapor and/or alkali-carrying water vapor.

Further, both the horizontal reactor and the vertical reactor are provided with a liquid sampling port, before obtaining the separated liquid depolymerization product and solid residue, the liquid from the horizontal reactor and/or the vertical reactor can also be used. The sampling port is sampled and tested to obtain the degree of depolymerization of the material. After the degree of depolymerization of the material reaches the target degree of depolymerization, the liquid depolymerization product and the solid residue are separated.

The method for continuous depolymerization of biomass proposed by the present invention is to transport the material to a double-valve feeder through a feeding port, and to transport the material to a transverse reactor through the double-valve feeder, and then use the transverse reaction The first depolymerization of the material is carried out by the reactor, and the material is continuously transported to the vertical reactor for the second depolymerization to obtain the separated liquid depolymerization product and solid residue. The double valve feeder is used to realize continuous biomass Feeding, the automation degree of the hydrolysis process is improved, the real continuous operation is realized, and the depolymerization effect of the material is improved by the horizontal reactor and the vertical reactor.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or system comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or system. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article or system that includes the element.

The above-mentioned serial numbers of the embodiments of the present invention are only for description, and do not represent the advantages or disadvantages of the embodiments.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent structure or process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields , are similarly included in the scope of patent protection of the present invention.

Claims (10)

1. A continuous depolymerization method of biomass is applied to a continuous depolymerization device of biomass, the continuous depolymerization device comprises a double-valve feeder, a horizontal reactor and a vertical reactor, an upper end port of the horizontal reactor is connected with the double-valve feeder, a bottom side port of the horizontal reactor is connected with the vertical reactor, and the continuous depolymerization method of biomass comprises the following steps:

conveying the material to the double-valve feeder through a feed port and conveying the material to the transverse reactor through the double-valve feeder;

and carrying out primary depolymerization on the material by using the transverse reactor, and continuously conveying the material to the vertical reactor for secondary depolymerization to obtain a separated liquid depolymerization product and a separated solid residue.

2. The continuous depolymerization process for biomass according to claim 1, wherein said horizontal reactor is provided with a first auger screw, and said first depolymerization step of the material with said horizontal reactor comprises:

and stirring and propelling the material from the initial end of the transverse reactor to the tail end of the transverse reactor by using the first propelling screw, and performing first depolymerization on the material feed in the propelling process.

3. The continuous depolymerization process for biomass according to claim 1, wherein the step of continuing to convey the second depolymerization to the vertical reactor to obtain a separated liquid depolymerization product and a solid residue comprises:

stirring and propelling the materials from the bottom end of the vertical reactor to the top end of the vertical reactor by using the second propelling screw;

the feed material is depolymerized for a second time during the advancement process to obtain separated liquid depolymerized products and solid residues.

4. The continuous depolymerization method for biomass according to claim 3, wherein the vertical reactor is provided with a second propelling screw, the top end interface of the vertical reactor is connected with a solid storage tank, the bottom end interface of the vertical reactor is connected with a liquid storage tank, and the step of performing second depolymerization on the material feed during propelling to obtain a separated liquid depolymerization product and a solid residue comprises:

depolymerizing the material feed for a second time during the propelling to obtain depolymerized products, wherein the depolymerized products comprise liquid depolymerized products and solid residues;

and continuously pushing the solid residues upwards by using a second pushing screw to convey the solid residues to a solid storage tank, and reversely flowing the liquid depolymerization product to the bottom of the vertical reactor by using the second pushing screw to convey the liquid depolymerization product to the liquid storage tank.

5. The continuous depolymerization method for biomass according to claim 2, in which the rotation speed of the first screw and the second screw is 0-100 rpm.

6. The continuous depolymerization method for biomass according to claim 1, wherein the reaction temperature of each of the horizontal reactor and the vertical reactor is 25-300 ℃ and the reaction pressure is 100KPa-15 MPa.

7. The method of continuous depolymerization of biomass as claimed in claim 1, wherein said step of first depolymerization of the material with a horizontal reactor is preceded by the steps of:

and adding a catalyst into the horizontal reactor and/or the vertical reactor, wherein the catalyst comprises an inorganic acid and a solid acid.

8. The method of claim 1, wherein the horizontal reactor and the vertical reactor are provided with gas generators, and the steps of performing the first depolymerization of the material by the horizontal reactor and further delivering the material to the vertical reactor for the second depolymerization further comprise:

and filling gas into the horizontal reactor and/or the vertical reactor by using the gas generator for pressurization so as to accelerate the depolymerization speed of the material, wherein the gas comprises nitrogen, oxygen, air, argon, carbon dioxide, water vapor, acid-carrying water vapor and/or alkali-carrying water vapor.

9. The method of claim 1, wherein the horizontal reactor and the vertical reactor are provided with liquid sampling ports, and the step of obtaining the separated liquid depolymerization product and the solid residue further comprises:

sampling by using a liquid sampling port of the horizontal reactor and/or the vertical reactor, and detecting to obtain the depolymerization degree of the material.

10. The continuous depolymerization process of biomass according to any one of claims 1 to 9, characterised in that said material comprises: wheat straw, rice straw, corn cobs, corn stover, bagasse, sunflower seed hulls, cotton stalks, cotton seed hulls, wheat straw, rice hulls, forest trees, and/or forage.

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