阅读说明：本技术 一种双相逆流连续循环催化生物质定向液化方法及其专用装置 (Two-phase countercurrent continuous circulating catalytic biomass directional liquefaction method and special device thereof ) 是由 王奎 蒋剑春 刘超 叶俊 尹小燕 潘雪媛 蔡婷婷 于 2021-07-26 设计创作，主要内容包括：本发明公开了一种双相逆流连续循环催化生物质定向液化方法及其专用装置,属于生物质资源利用技术领域。该方法为1)将原料与双相溶剂液化体系加入釜中预混合,输送至双相逆流反应釜加热反应；2)反应后停止搅拌,水相进入水相沉降罐,有机相进入有机相分馏塔；3)水相沉降罐中水相经水相回流进口至双相逆流反应釜,沉降木质素至副产品储罐；4)有机相分馏塔将不同沸点产品转移至产品储罐；釜液经有机相回流进口回流至双相逆流反应釜；5)顶部回流水相与中部回流有机相进行逆流混合,残余产物和副产物的进一步萃取分离后进入下一循环。使液化溶剂高效循环使用,有利于产物与液化溶剂高效分离,实现生物质组分定向解聚和产物高效分离。(The invention discloses a two-phase countercurrent continuous circulating catalysis biomass directional liquefaction method and a special device thereof, belonging to the technical field of biomass resource utilization. The method comprises the steps of 1) adding a raw material and a two-phase solvent liquefaction system into a kettle for premixing, and conveying the mixture to a two-phase countercurrent reaction kettle for heating reaction; 2) after the reaction, stopping stirring, allowing the water phase to enter a water phase settling tank and the organic phase to enter an organic phase fractionating tower; 3) water phase in the water phase settling tank flows through a water phase reflux inlet to the two-phase countercurrent reaction kettle, and lignin is settled to a byproduct storage tank; 4) transferring products with different boiling points to a product storage tank by the organic phase fractionating tower; the kettle liquid flows back to the biphase countercurrent reaction kettle through the organic phase reflux inlet; 5) and the top reflux aqueous phase and the middle reflux organic phase are subjected to counter-current mixing, and the residual product and the by-product enter the next cycle after further extraction and separation. The liquefied solvent is efficiently recycled, the product and the liquefied solvent are efficiently separated, and the directional depolymerization of biomass components and the efficient separation of the product are realized.)

1. A two-phase countercurrent continuous circulating catalysis biomass directional liquefaction method is characterized by comprising the following steps:

1) adding a biomass raw material and a two-phase solvent liquefaction system into a slurry premixing kettle (1) for premixing, conveying the mixture into a two-phase countercurrent reaction kettle (2) through a circulating pump, stirring to uniformly mix the reaction raw materials, heating to the reaction temperature, and carrying out liquefaction reaction; the two-phase solvent liquefaction system consists of an aprotic solvent and a metal salt solution;

2) after the reaction is finished, stopping stirring, starting a circulating pump on a liquid outlet pipeline, opening a first valve (9), closing a second valve (10) to control a lower-layer water phase to enter a water phase settling tank (3), then closing the first valve (9), opening the second valve (10) to control an upper-layer organic phase to enter an organic phase fractionating tower (4);

3) the water phase in the water phase settling tank (3) flows back to the two-phase countercurrent reaction kettle (2) through a water phase reflux inlet, and the settled lignin is transferred to a byproduct collecting tank (11);

4) the organic phase fractionating tower (4) transfers products of 5-hydroxymethylfurfural, furfural and acetic acid with different boiling points to a product storage tank (6) after being condensed by a condenser (5) by controlling the number of tower plates; the kettle liquid flows back to the biphase countercurrent reaction kettle (2) through the organic phase reflux inlet;

5) and the water phase refluxed from the top and the organic phase refluxed from the middle are subjected to counter-current mixing, so that the residual product and the by-product are further extracted and separated, and then enter the next cycle.

2. The method for directionally liquefying biomass by continuous circulation of two-phase countercurrent flow as claimed in claim 1, wherein the temperature rise rate of the two-phase countercurrent reaction kettle (2) is 5-20 ℃/min, and the mechanical stirring rate is 1000-2000 rpm; the liquefaction reaction temperature is 150-250 ℃, and the reaction time is 1-5 h.

3. The biphasic counter-current continuous cyclic catalytic biomass directional liquefaction process of claim 1, wherein the aprotic solvent is any one of gamma valerolactone, sulfolane, dimethyl sulfoxide, 1, 3-dimethyl-2-imidazolidinone, or dihydrolevoglucosenone; the metal salt solution is any one of sodium chloride, aluminum chloride, magnesium chloride, aluminum sulfate or sodium sulfate, and the concentration of the metal salt solution is 10-30 wt%.

4. The method for directionally liquefying biomass by continuous circulation of two-phase countercurrent according to claim 1, wherein the mass ratio of the biomass raw material to the two-phase solvent liquefaction system is 1: 10-1: 30; the mass ratio of the aprotic solvent to the metal salt solution is 1: 1-1: 10.

5. The method for directionally liquefying biomass by continuous circulation of two-phase countercurrent flow as claimed in claim 1, wherein the biomass raw material is any one of bamboo, straw, poplar, willow or birch.

6. The special device for the two-phase countercurrent continuous circulating catalytic biomass directional liquefaction method of any one of claims 1 to 5, which is characterized by comprising a slurry premixing kettle (1), a two-phase countercurrent reaction kettle (2), a water phase settling tank (3), an organic phase fractionating tower (4), a product storage tank (6) and a byproduct storage tank (11);

a feed inlet and a mixed liquid outlet are arranged on the slurry premixing kettle (1), a mixed liquid inlet, a water phase reflux inlet, an organic phase reflux inlet and a reaction liquid outlet are arranged on the two-phase countercurrent reaction kettle (2), a water phase inlet, a water phase reflux outlet and a byproduct outlet are arranged on the water phase settling tank (3), and an organic phase inlet, a product outlet and a kettle liquid outlet are arranged on the organic phase fractionating tower (4); the water phase backflow inlet is arranged at the top of the kettle body of the double-phase countercurrent reaction kettle (2), and the organic phase backflow inlet is arranged in the middle of the kettle body of the double-phase countercurrent reaction kettle (2);

the mixed liquid outlet is connected with the mixed liquid inlet; the reaction liquid outlet is connected with a liquid outlet pipeline, the liquid outlet pipeline is connected with a water phase shunt pipeline and an organic phase shunt pipeline, the water phase shunt pipeline is connected with the water phase inlet, and the organic phase shunt pipeline is connected with the organic phase inlet; the water phase reflux outlet is connected with the water phase reflux inlet through a first reflux pipeline (7), and the byproduct outlet is connected with a byproduct storage tank (11); the product outlet is connected with the product storage tank (6), and the kettle liquid outlet is connected with the organic phase reflux inlet through a second reflux pipeline (8).

7. The special device for the directional liquefaction method of biomass by continuous circulation of two-phase countercurrent according to claim 6, wherein a first valve (9) is arranged on the aqueous phase shunt pipeline, and a second valve (10) is arranged on the organic phase shunt pipeline.

8. The special device for the directional liquefaction method of biomass by continuous circulation of two-phase countercurrent according to claim 6, wherein the pipeline connecting the product outlet and the product storage tank (6) is provided with a condenser (5), and the number of the product storage tanks (6) is three.

9. The special device for the directional liquefaction method of biomass by continuous circulation of two-phase countercurrent according to claim 6, wherein an infrared thermometer is arranged in the two-phase countercurrent reaction kettle (2), and the infrared thermometer is in a non-contact type; and mechanical stirring devices are arranged in the slurry premixing kettle (1) and the two-phase countercurrent reaction kettle (2).

10. The special device for the directional liquefaction method of biomass by continuous circulation of two-phase countercurrent according to claim 6, wherein circulating pumps are arranged on the liquid outlet pipeline, the connecting pipeline between the mixed liquid outlet and the mixed liquid inlet, the first return pipeline (7) and the second return pipeline (8).

Technical Field

The invention belongs to the technical field of biomass resource utilization, and particularly relates to a method for directionally liquefying biomass by continuous circulation catalysis in a two-phase countercurrent mode and a special device thereof.

Background

The increasing worldwide consumption of petrochemical products has led to the continuous depletion of non-renewable petroleum and fossil resources, thus prompting us to seek renewable resources for the production of chemicals. The wood fiber biomass is a renewable resource which is widely distributed, cheap and easy to obtain, and is an ideal substitute of fossil energy. The wood fiber biomass can be used for producing energy products through high-efficiency conversion to realize zero carbon emission, or preparing chemicals and bio-based materials to realize negative carbon emission, thereby realizing good carbon atom economy. Therefore, the method has very important significance for optimizing the Chinese energy structure by fully utilizing agricultural and forestry wood fiber biomass resources, realizing the strategic goal of 'double carbon', improving the ecological environment and promoting energy conservation and emission reduction.

The method for preparing high value-added chemicals and liquid fuels by adopting the thermochemical conversion technology of the wood fiber biomass is one of important technologies for high-efficiency conversion and reasonable utilization of wood fibers, and is highly concerned by scholars at home and abroad. The thermochemical conversion technology of the wood fiber biomass mainly comprises 3 methods of biomass pyrolysis, biomass gasification and biomass liquefaction. The biomass liquefaction method is widely applied to the preparation of high value-added fuels and chemicals by the efficient conversion of wood fibers due to the advantages of low energy consumption, high conversion efficiency, good product selectivity and the like. However, it should be noted that, the biomass liquefaction method mainly uses a liquefaction reaction kettle to prepare chemicals by a one-pot method at present, and the problems of difficult product separation, difficult solvent recycling and the like are faced. Therefore, the problem that how to realize the efficient separation of the liquefied product and the recycling of the liquefied solvent so as to achieve the aim of catalyzing the directional depolymerization of all the components of the biomass into high value-added chemicals by a green recyclable liquefied system is urgently needed to be solved.

Disclosure of Invention

Aiming at the problems in the prior art, the technical problem to be solved by the invention is to provide a two-phase countercurrent continuous circulating catalysis biomass directional liquefaction method, the method can realize high-efficiency separation of products and recycling of solvent catalyst through simple operation, and the product separation cost and the solvent catalyst recovery cost are greatly reduced. The invention aims to solve another technical problem of providing a two-phase countercurrent continuous circulating catalytic biomass directional liquefaction device which is simple in structure and convenient to operate and can realize directional depolymerization of biomass and high-efficiency separation of products.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a two-phase countercurrent continuous circulating catalytic biomass directional liquefaction method comprises the following steps:

1) adding a biomass raw material and a two-phase solvent liquefaction system into a slurry premixing kettle for premixing, conveying the mixture into a two-phase countercurrent reaction kettle through a circulating pump, stirring to uniformly mix the reaction raw materials, heating to the reaction temperature, and carrying out liquefaction reaction; the two-phase solvent liquefaction system consists of an aprotic solvent and a metal salt solution;

2) after the reaction is finished, stopping stirring, starting a circulating pump on a liquid outlet pipeline, opening a first valve, closing a second valve 10 to control a lower-layer aqueous phase (a metal salt solution and lignin) to enter an aqueous phase settling tank, then closing the first valve, opening the second valve to control an upper-layer organic phase (a high-boiling-point polar aprotic solvent, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower;

3) refluxing the water phase (mainly metal salt solution and a small amount of product) in the water phase settling tank to the two-phase countercurrent reaction kettle through a water phase reflux inlet, and transferring the settled lignin to a byproduct collecting tank;

4) the organic phase fractionating tower condenses products with different boiling points, namely 5-hydroxymethylfurfural, furfural and acetic acid by a condenser 5 and transfers the condensed products to a product storage tank by controlling the number of tower plates; refluxing kettle liquid (mainly comprising a high-boiling-point polar aprotic solvent and a small part of dissolved lignin) to the two-phase countercurrent reaction kettle through an organic phase reflux inlet;

5) and the water phase refluxed from the top and the organic phase refluxed from the middle are subjected to counter-current mixing, so that the residual product and the by-product are further extracted and separated, and then enter the next cycle.

According to the method for directionally liquefying the biomass by the continuous circulation catalysis of the two-phase countercurrent, the temperature rising rate of the two-phase countercurrent reaction kettle is 5-20 ℃/min, and the mechanical stirring rate is 1000-2000 rpm; the liquefaction reaction temperature is 150-250 ℃, and the reaction time is 1-5 h.

The two-phase countercurrent continuous circulating catalysis biomass directional liquefaction method is characterized in that the aprotic solvent is any one of gamma-valerolactone, sulfolane, dimethyl sulfoxide, 1, 3-dimethyl-2-imidazolidinone or dihydro levoglucosenone; the metal salt solution is any one of sodium chloride, aluminum chloride, magnesium chloride, aluminum sulfate or sodium sulfate, and the concentration of the metal salt solution is 10-30 wt%.

According to the directional liquefaction method for the biomass by the two-phase countercurrent continuous circulating catalysis, the mass ratio of the biomass raw material to a two-phase solvent liquefaction system is 1: 10-1: 30; the mass ratio of the aprotic solvent to the metal salt solution is 1: 1-1: 10.

The two-phase countercurrent continuous circulating catalysis biomass directional liquefaction method is characterized in that the biomass raw material is any one of bamboo, straw, poplar, willow or birch.

The special device for the two-phase countercurrent continuous circulating catalytic biomass directional liquefaction method comprises a slurry premixing kettle, a two-phase countercurrent reaction kettle, a water phase settling tank, an organic phase fractionating tower, a product storage tank and a byproduct storage tank;

the slurry premixing kettle is provided with a feed inlet and a mixed liquid outlet, the two-phase countercurrent reaction kettle is provided with a mixed liquid inlet, a water phase reflux inlet, an organic phase reflux inlet and a reaction liquid outlet, the water phase settling tank is provided with a water phase inlet, a water phase reflux outlet and a byproduct outlet, and the organic phase fractionating tower is provided with an organic phase inlet, a product outlet and a kettle liquid outlet; the water phase backflow inlet is arranged at the top of the double-phase countercurrent reaction kettle body, and the organic phase backflow inlet is arranged in the middle of the double-phase countercurrent reaction kettle body;

the mixed liquid outlet is connected with the mixed liquid inlet; the reaction liquid outlet is connected with a liquid outlet pipeline, the liquid outlet pipeline is connected with a water phase shunt pipeline and an organic phase shunt pipeline, the water phase shunt pipeline is connected with the water phase inlet, and the organic phase shunt pipeline is connected with the organic phase inlet; the water phase reflux outlet is connected with the water phase reflux inlet through a first reflux pipeline, and the byproduct outlet is connected with a byproduct storage tank; the product outlet is connected with the product storage tank, and the kettle liquid outlet is connected with the organic phase reflux inlet through a second reflux pipeline.

The special device for the two-phase countercurrent continuous circulating catalysis biomass directional liquefaction method is characterized in that a first valve is arranged on the water phase diversion pipeline, and a second valve is arranged on the organic phase diversion pipeline.

According to the special device for the two-phase countercurrent continuous circulating catalytic biomass directional liquefaction method, the product outlet and a product storage tank (6) connecting pipeline are provided with condensers, and the number of the product storage tanks is three.

According to the special device for the directional liquefaction method of the biomass by the two-phase countercurrent continuous circulating catalysis, an infrared thermometer is arranged in the two-phase countercurrent reaction kettle, and the infrared thermometer is in a non-contact type; and mechanical stirring devices are arranged in the slurry premixing kettle and the two-phase countercurrent reaction kettle.

The special device for the two-phase countercurrent continuous circulating catalytic biomass directional liquefaction method is characterized in that circulating pumps are arranged on the liquid outlet pipeline, the connecting pipeline between the mixed liquid outlet and the mixed liquid inlet, the first return pipeline and the second return pipeline.

Has the advantages that: compared with the prior art, the invention has the advantages that:

(1) compared with the traditional one-pot liquefaction method, the biomass directional liquefaction method can realize the efficient recycling of the liquefaction solvent, is beneficial to the efficient separation of the product and the liquefaction solvent, has the recovery rate of the liquefaction solvent being more than 98.0 percent, and has no obvious reduction in the yield of the target product after the liquefaction solvent is recycled for 5 times; greatly reduces the product separation cost and the solvent catalyst recovery cost, realizes the directional depolymerization of biomass components and the high-efficiency separation of products, and conforms to the concept of green chemistry.

(2) The water phase reflux inlet on the biphase countercurrent reaction kettle is arranged at the top of the kettle body, and the organic phase reflux inlet is arranged at the middle part of the kettle body, so that the recovered water phase (metal salt solution) enters from the top and is subjected to countercurrent mixing with the organic phase (high-boiling-point polar aprotic solvent) entering from the middle part, and the product and the by-product are continuously extracted and separated in a biphase system.

(3) The water phase flow dividing pipeline is provided with a first valve, and the organic phase flow dividing pipeline is provided with a second valve; the first valve and the second valve are used for opening and closing the water phase shunt pipeline and the organic phase shunt pipeline, controlling the lower water phase to enter the water phase settling tank, and controlling the upper organic phase to enter the organic phase fractionating tower; the separation of the water phase and the organic phase is realized by controlling the valve, and the operation is convenient.

Drawings

FIG. 1 is a schematic structural diagram of a two-phase countercurrent continuous circulation catalytic biomass directional liquefaction device;

FIG. 2 is a gas mass spectrum of the target product.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below. The yield of the desired product is calculated by the following formula:

Y％＝(n₁/n₀)×100％

y% represents the molar yield of the target product, n₁Amount of substances representing 5-hydroxymethylfurfural, furfural and acetic acid in the target product, n₀Representing the amount of cellulose and hemicellulose substances in the biomass raw material, the cellulose molar mass is 162g/mol, the hemicellulose molar mass is 132g/mol, the molar yield of 5-hydroxymethylfurfural and acetic acid is calculated based on cellulose, and the molar yield of furfural is calculated based on hemicellulose.

Example 1

A two-phase countercurrent continuous circulation catalytic biomass directional liquefaction device is shown in figure 1 in a schematic structural diagram. As can be seen from FIG. 1, the apparatus comprises a slurry premixing kettle 1, a two-phase countercurrent reaction kettle 2, a water phase settling tank 3, an organic phase fractionating tower 4, a product storage tank 6 and a byproduct storage tank 11; a non-contact infrared thermometer is arranged in the two-phase countercurrent reaction kettle 2; mechanical stirring devices are arranged in the slurry premixing kettle 1 and the two-phase countercurrent reaction kettle 2.

The top of the slurry premixing kettle 1 is provided with a feed inlet, and the bottom is provided with a mixed liquid outlet; the organic solvent, the metal salt solution and the biomass raw material enter the slurry premixing kettle 1 through the feeding hole, are fully stirred and mixed by the mechanical stirring device, and then flow out through the mixed liquid outlet to enter the next procedure.

The double-phase countercurrent reaction kettle 2 is provided with a mixed liquid inlet, a water phase reflux inlet, an organic phase reflux inlet and a reaction liquid outlet, wherein the mixed liquid inlet is arranged at the upper part of the kettle body and is used for receiving the mixed liquid flowing out of the slurry premixing kettle 1; the water phase reflux inlet is arranged at the top of the kettle body, the organic phase reflux inlet is arranged in the middle of the kettle body, and the reaction liquid outlet is arranged at the lower part of the kettle body; the mixed liquid outlet is connected with the mixed liquid inlet pipeline, and the connecting pipeline is provided with a circulating pump.

The water phase settling tank 3 is provided with a water phase inlet, a water phase reflux outlet and a byproduct outlet, wherein the water phase inlet is arranged at the upper part of the tank body, and the water phase reflux outlet and the byproduct outlet are arranged at the lower part of the tank body. The organic phase fractionating tower 4 is provided with an organic phase inlet, a product outlet and a kettle liquid outlet, wherein the organic phase inlet is arranged in the middle of the tower body, the product outlet is arranged at the top of the tower body, and the kettle liquid outlet is arranged at the bottom of the tower body. The recovered water phase (metal salt solution) flows out from a water phase reflux outlet and enters the double-phase countercurrent reaction kettle 2 through a water phase reflux inlet at the top of the double-phase countercurrent reaction kettle, the organic phase (high-boiling-point polar aprotic solvent) is recovered from the organic phase fractionating tower 4 and enters the double-phase countercurrent reaction kettle 2 through an organic phase reflux inlet at the middle part of the double-phase countercurrent reaction kettle 2, the refluxed water phase and the refluxed organic phase form countercurrent mixing, and the continuous extraction and separation of the product and the byproduct in a double-phase system are realized.

The reaction liquid outlet is connected with a liquid outlet pipeline, a circulating pump is arranged on the liquid outlet pipeline, the liquid outlet pipeline is connected with a water phase shunt pipeline and an organic phase shunt pipeline, the water phase shunt pipeline is connected with the water phase inlet, and the organic phase shunt pipeline is connected with the organic phase inlet; a first valve 9 is arranged on the water phase flow dividing pipeline, and a second valve 10 is arranged on the organic phase flow dividing pipeline; the first valve 9 and the second valve 10 are used for opening and closing the water phase shunt pipeline and the organic phase shunt pipeline, controlling the lower water phase to enter the water phase settling tank 3, and controlling the upper organic phase to enter the organic phase fractionating tower 4.

The water phase reflux outlet is connected with the water phase reflux inlet through a first reflux pipeline 7, a circulating pump is arranged on the first reflux pipeline 7, and the byproduct outlet is connected with a byproduct storage tank 11; the product outlet is connected with the product storage tank 6, the kettle liquid outlet is connected with the organic phase backflow inlet through a second backflow pipeline 8, and a circulating pump is arranged on the second backflow pipeline 8. The pipeline connecting the product outlet and the product storage tank 6 is provided with three condensers 5, and the number of the product storage tanks 6 is three; the organic phase fractionating tower transfers three products of 5-HMF, furfural and levulinic acid with different boiling points into different product storage tanks respectively after being condensed by a condenser by controlling the number of tower plates.

Example 2

The two-phase countercurrent continuous circulating catalytic biomass directional liquefaction is carried out by adopting the liquefaction device in the embodiment 1, and the method comprises the following steps:

1) adding bamboo powder (the particle size is less than or equal to 0.125nm, the mass fraction of fibers in the bamboo powder is 40.51%, the mass fraction of hemicellulose is 29.79%, the mass fraction of lignin is 28.83%, and the mass fraction of ash and extract is 0.87%) and a two-phase solvent gamma-valerolactone/15 wt% sodium chloride solution (wherein the mass ratio of the gamma-valerolactone to the sodium chloride solution is 1:1) into a slurry premixing kettle 1 in a mass ratio of 1:10, uniformly mixing, and conveying to a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to stir at 1000 rpm; heating the two-phase countercurrent reaction kettle 2, gradually heating the mixed solution of the bamboo powder and the two-phase solvent liquefaction system to 180 ℃, and timing;

3) after reacting for 2 hours, stopping stirring, starting a circulating pump on a liquid outlet pipeline, opening a first valve 9, closing a second valve 10 to control a lower-layer aqueous phase (15 wt% of sodium chloride solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (gamma-valerolactone, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results (fig. 2) show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 58.1%, the molar yield of furfural is 61.4%, and the molar yield of acetic acid is 10.0%;

4) the water phase in the water phase settling tank 3 mainly comprises 15 wt% of sodium chloride solution and a small amount of products (the mass of the small amount of products is 5% of the mass of the total products in the organic phase), the sodium chloride solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 25% of the mass of the biomass raw material after weighing;

5) the organic phase fractionating tower 4 transfers products with different boiling points, namely 5-hydroxymethylfurfural (molar yield is 56.2%), furfural (molar yield is 57.7%) and acetic acid molar yield (8.3%), to a product storage tank 6 after condensing by a condenser 5 by controlling the number of tower plates; the kettle liquid is mainly gamma-valerolactone and a small part of dissolved lignin (the mass is 3 percent of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 3

The two-phase countercurrent continuous circulating catalytic biomass directional liquefaction is carried out by adopting the liquefaction device in the embodiment 1, and the method comprises the following steps:

1) adding 1:15 poplar powder (the particle size is less than or equal to 0.125nm, the mass fraction of cellulose in the poplar powder is 41.32%, the mass fraction of hemicellulose is 27.88%, the mass fraction of lignin is 30.12%, and the mass fraction of ash and extract is 0.68%) and a two-phase solvent sulfolane/20 wt% aluminum chloride solution (wherein the mass ratio of the sulfolane to the aluminum chloride solution is 1:2) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix at a stirring speed of 1500rpm, heating the two-phase countercurrent reaction kettle 2, gradually heating the poplar powder and the two-phase liquefied solvent system mixed solution to 200 ℃, and starting timing;

3) after reacting for 3 hours, stopping stirring, starting a circulating pump on a liquid outlet pipeline, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (20 wt% of aluminum chloride solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (sulfolane, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 47.3 percent, the molar yield of furfural is 55.2 percent, and the molar yield of acetic acid is 8.5 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 20 wt% of aluminum chloride solution and a small amount of products (the mass of the small amount of products is 4% of the mass of the total products in the organic phase), the aluminum chloride solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 26% of the mass of the biomass raw material after weighing;

5) the organic phase fractionating tower 4 transfers products 5-hydroxymethylfurfural with different boiling points, furfural and acetic acid to a product storage tank 6 after condensing by a condenser 5 by controlling the number of tower plates; the kettle liquid is mainly sulfolane and a small part of dissolved lignin (the mass is 2.5 percent of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 4

The two-phase countercurrent continuous circulating catalytic biomass directional liquefaction is carried out by adopting the liquefaction device in the embodiment 1, and the method comprises the following steps:

1) adding straw powder (the particle size is less than or equal to 0.125nm, the cellulose mass fraction in the straw powder is 39.19%, the hemicellulose mass fraction is 30.22%, the lignin mass fraction is 29.82%, and the ash content and extract mass fraction are 0.77%) and a two-phase solvent dimethyl sulfoxide/25 wt% aluminum sulfate solution (the mass ratio of the dimethyl sulfoxide to the aluminum sulfate solution is 1:5) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix the straw powder and the double-phase liquefied solvent at a stirring speed of 1300rpm, heating the double-phase countercurrent reaction kettle 2, gradually heating the mixed solution of the straw powder and the double-phase liquefied solvent system to 220 ℃, and starting timing;

3) after reacting for 4 hours, stopping stirring, starting a circulating pump on a liquid outlet pipeline, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (25 wt% of aluminum sulfate solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (dimethyl sulfoxide, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 45.6 percent, the molar yield of furfural is 65.8 percent, and the molar yield of acetic acid is 6.7 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 25 wt% of aluminum sulfate solution and a small amount of products (the mass is 3% of the total product mass in the organic phase), the aluminum sulfate solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 27% of the mass of the biomass raw material through weighing;

5) the organic phase fractionating tower 4 is used for condensing products of 5-hydroxymethylfurfural with different boiling points (the molar yield is 43.2%), furfural (the molar yield is 62.9%) and acetic acid (the molar yield is 4.6%) through a condenser 5 and then transferring the products to a product storage tank 6 by controlling the number of tower plates; the kettle liquid mainly comprises dimethyl sulfoxide and a small part of dissolved lignin (the mass is 1.9 percent of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 5

The two-phase countercurrent continuous circulating catalytic biomass directional liquefaction is carried out by adopting the liquefaction device in the embodiment 1, and the method comprises the following steps:

1) adding 1:30 willow powder (the particle size is less than or equal to 0.125nm, the mass fraction of cellulose in the willow powder is 35.88%, the mass fraction of hemicellulose is 32.56%, the mass fraction of lignin is 30.73%, and the mass fraction of ash and extract is 0.83%) and a two-phase solvent 1, 3-dimethyl-2-imidazolidinone/30 wt% sodium sulfate solution (wherein the mass ratio of the 1, 3-dimethyl-2-imidazolidinone to the sodium sulfate solution is 1:8) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix at a stirring speed of 2000rpm, heating the two-phase countercurrent reaction kettle 2, gradually heating the mixed solution of the willow powder and the two-phase liquefied solvent system to 160 ℃, and starting timing;

3) after reacting for 1.5h, stopping stirring, starting a circulating pump, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (30 wt% of sodium sulfate solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (1, 3-dimethyl-2-imidazolidinone, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 39.8 percent, the molar yield of furfural is 70.2 percent, and the molar yield of acetic acid is 7.1 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 30 wt% of sodium sulfate solution and a small amount of products (the mass is 2% of the total product mass in the organic phase), the sodium sulfate solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 24% of the mass of the biomass raw material through weighing;

5) the organic phase fractionating tower 4 is used for condensing products of 5-hydroxymethylfurfural with different boiling points (the molar yield is 36.6%), furfural (the molar yield is 68.4%) and acetic acid (the molar yield is 6.0%) through a condenser 5 and then transferring the products to a product storage tank 6 by controlling the number of tower plates; the kettle liquid is mainly 1, 3-dimethyl-2-imidazolidinone and a small part of dissolved lignin (the mass is 4 percent of the settled lignin in the water phase), and the kettle liquid is returned to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 6

The two-phase countercurrent continuous circulating catalytic biomass directional liquefaction is carried out by adopting the liquefaction device in the embodiment 1, and the method comprises the following steps:

1) adding birch wood powder (the particle size is less than or equal to 0.125nm, the mass fraction of cellulose in the birch wood powder is 37.27%, the mass fraction of hemicellulose is 30.16%, the mass fraction of lignin is 31.32%, and the mass fraction of ash and extract is 1.25%) and a two-phase solvent dihydrolevoglucosenone/10 wt% magnesium chloride solution (wherein the mass ratio of the dihydrolevoglucosenone to the magnesium chloride solution is 1:10) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix at a stirring speed of 1000rpm, heating the two-phase countercurrent reaction kettle 2, gradually heating the birch powder and two-phase liquefied solvent system mixed solution to 250 ℃, and starting timing;

3) after reacting for 1 hour, stopping stirring, starting a circulating pump, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (10 wt% of magnesium chloride solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (dihydrolevoglucosenone, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 59.2 percent, the molar yield of furfural is 60.9 percent, and the molar yield of acetic acid is 5.6 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 10 wt% of magnesium chloride solution and a small amount of products (the mass of the products is 3% of the total mass of the products in the organic phase), the magnesium chloride solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 23.5% of the mass of the biomass raw material after weighing;

5) the organic phase fractionating tower 4 is used for condensing products of 5-hydroxymethylfurfural with different boiling points (the molar yield is 57.1%), furfural (the molar yield is 58.3%) and acetic acid (the molar yield is 3.2%) through a condenser 5 and then transferring the products to a product storage tank 6 by controlling the number of tower plates; the kettle liquid is mainly composed of dihydrolevoglucosenone and a small part of dissolved lignin (the mass is 2% of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 7

The method adopts the liquefaction device in the embodiment 1 and the two-phase solvent recovered in the embodiment 6 to carry out two-phase countercurrent continuous circulation catalytic biomass directional liquefaction, and comprises the following steps:

1) adding birch wood powder (the particle size is less than or equal to 0.125nm, the mass fraction of cellulose in the birch wood powder is 37.27%, the mass fraction of hemicellulose is 30.16%, the mass fraction of lignin is 31.32%, and the mass fraction of ash and extract is 1.25%) and a two-phase solvent dihydrolevoglucosenone/10 wt% magnesium chloride solution (fresh dihydrolevoglucosenone and magnesium chloride solution are added to keep the mass ratio of 1:10) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix at a stirring speed of 1000rpm, heating the two-phase countercurrent reaction kettle 2, gradually heating the birch powder and two-phase liquefied solvent system mixed solution to 250 ℃, and starting timing;

3) after reacting for 1 hour, stopping stirring, starting a circulating pump, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (10 wt% of magnesium chloride solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (dihydrolevoglucosenone, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 56.9 percent, the molar yield of furfural is 58.7 percent, and the molar yield of acetic acid is 4.9 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 10 wt% of magnesium chloride solution and a small amount of products (the mass of the products is 3% of the total mass of the products in the organic phase), the magnesium chloride solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 24.6% of the mass of the biomass raw material after weighing;

5) the organic phase fractionating tower 4 is used for condensing products of 5-hydroxymethylfurfural with different boiling points (the molar yield is 55.7%), furfural (the molar yield is 56.8%) and acetic acid (the molar yield is 4.1%) through a condenser 5 and then transferring the products to a product storage tank 6 by controlling the number of tower plates; the kettle liquid is mainly composed of dihydrolevoglucosenone and a small part of dissolved lignin (the mass is 2% of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 8

The method adopts the liquefaction device in the embodiment 1 and the two-phase solvent recovered in the embodiment 7 to carry out two-phase countercurrent continuous circulation catalytic biomass directional liquefaction, and comprises the following steps:

1) adding birch wood powder (the particle size is less than or equal to 0.125nm, the mass fraction of cellulose in the birch wood powder is 37.27%, the mass fraction of hemicellulose is 30.16%, the mass fraction of lignin is 31.32%, and the mass fraction of ash and extract is 1.25%) and a two-phase solvent dihydrolevoglucosenone/10 wt% magnesium chloride solution (fresh dihydrolevoglucosenone and magnesium chloride solution are added to keep the mass ratio of 1:10) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix at a stirring speed of 1000rpm, heating the two-phase countercurrent reaction kettle 2, gradually heating the birch powder and two-phase liquefied solvent system mixed solution to 250 ℃, and starting timing;

3) after reacting for 1 hour, stopping stirring, starting a circulating pump, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (10 wt% of magnesium chloride solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (dihydrolevoglucosenone, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 57.6 percent, the molar yield of furfural is 57.4 percent, and the molar yield of acetic acid is 5.0 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 10 wt% of magnesium chloride solution and a small amount of products (the mass of the products is 3% of the total mass of the products in the organic phase), the magnesium chloride solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 25.7% of the mass of the biomass raw material after weighing;

5) the organic phase fractionating tower 4 is used for condensing products of 5-hydroxymethylfurfural with different boiling points (the molar yield is 54.1%), furfural (the molar yield is 53.8%) and acetic acid (the molar yield is 5.6%) through a condenser 5 and then transferring the products to a product storage tank 6 by controlling the number of tower plates; the kettle liquid is mainly composed of dihydrolevoglucosenone and a small part of dissolved lignin (the mass is 2% of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 9

The method adopts the liquefaction device in the embodiment 1 and the two-phase solvent recovered in the embodiment 8 to carry out two-phase countercurrent continuous circulation catalytic biomass directional liquefaction, and comprises the following steps:

1) adding birch wood powder (the particle size is less than or equal to 0.125nm, the mass fraction of cellulose in the birch wood powder is 37.27%, the mass fraction of hemicellulose is 30.16%, the mass fraction of lignin is 31.32%, and the mass fraction of ash and extract is 1.25%) and a two-phase solvent dihydrolevoglucosenone/10 wt% magnesium chloride solution (fresh dihydrolevoglucosenone and magnesium chloride solution are added to keep the mass ratio of 1:10) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix at a stirring speed of 1000rpm, heating the two-phase countercurrent reaction kettle 2, gradually heating the birch powder and two-phase liquefied solvent system mixed solution to 250 ℃, and starting timing;

3) after reacting for 1 hour, stopping stirring, starting a circulating pump, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (10 wt% of magnesium chloride solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (dihydrolevoglucosenone, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 60.6 percent, the molar yield of furfural is 63.5 percent, and the molar yield of acetic acid is 4.7 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 10 wt% of magnesium chloride solution and a small amount of products (the mass of the products is 3% of the total mass of the products in the organic phase), the magnesium chloride solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 26.2% of the mass of the biomass raw material after weighing;

5) the organic phase fractionating tower 4 is used for condensing products of 5-hydroxymethylfurfural with different boiling points (the molar yield is 58.9%), furfural (the molar yield is 60.8%) and acetic acid (the molar yield is 6.1%) through a condenser 5 and then transferring the products to a product storage tank 6 by controlling the number of plates; the kettle liquid is mainly composed of dihydrolevoglucosenone and a small part of dissolved lignin (the mass is 2% of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).

Example 10

The method adopts the liquefaction device in the embodiment 1 and the two-phase solvent recovered in the embodiment 9 to carry out two-phase countercurrent continuous circulation catalytic biomass directional liquefaction, and comprises the following steps:

1) adding birch wood powder (the particle size is less than or equal to 0.125nm, the mass fraction of cellulose in the birch wood powder is 37.27%, the mass fraction of hemicellulose is 30.16%, the mass fraction of lignin is 31.32%, and the mass fraction of ash and extract is 1.25%) and a two-phase solvent dihydrolevoglucosenone/10 wt% magnesium chloride solution (fresh dihydrolevoglucosenone and magnesium chloride solution are added to keep the mass ratio of 1:10) into a slurry premixing kettle 1 for mixing, and then conveying the mixture into a two-phase countercurrent reaction kettle 2 through a circulating pump;

2) starting a mechanical stirring device to uniformly mix at a stirring speed of 1000rpm, heating the two-phase countercurrent reaction kettle 2, gradually heating the birch powder and two-phase liquefied solvent system mixed solution to 250 ℃, and starting timing;

3) after reacting for 1 hour, stopping stirring, starting a circulating pump, opening a first valve 9, opening a second valve 10 to control a lower-layer aqueous phase (10 wt% of magnesium chloride solution and lignin) to enter an aqueous phase settling tank 3, then closing the first valve 9, opening the second valve 10 to control an upper-layer organic phase (dihydrolevoglucosenone, 5-hydroxymethylfurfural, furfural and acetic acid) to enter an organic phase fractionating tower 4; the GC and HPLC analysis results show that the molar yield of 5-hydroxymethylfurfural in the organic phase is 59.4 percent, the molar yield of furfural is 61.6 percent, and the molar yield of acetic acid is 5.7 percent;

4) the water phase in the water phase settling tank 3 mainly comprises 10 wt% of magnesium chloride solution and a small amount of products (the mass of the products is 3% of the total mass of the products in the organic phase), the magnesium chloride solution and the small amount of products flow back to the top of the two-phase countercurrent reaction kettle 2 through a circulating pump, the settled lignin is transferred to a byproduct collecting tank 11, and the mass of the lignin is 25.8% of the mass of the biomass raw material after weighing;

5) the organic phase fractionating tower 4 is used for condensing products of 5-hydroxymethylfurfural with different boiling points (the molar yield is 57.1%), furfural (the molar yield is 59.3%) and acetic acid (the molar yield is 4.8%) through a condenser 5 and then transferring the products to a product storage tank 6 by controlling the number of tower plates; the kettle liquid is mainly composed of dihydrolevoglucosenone and a small part of dissolved lignin (the mass is 2% of the settled lignin in the water phase), and returns to the two-phase countercurrent reaction kettle 2 through a circulating pump;

6) and (3) carrying out countercurrent mixing on the water phase refluxed at the top and the organic phase refluxed at the middle to realize further extraction and separation of residual products and byproducts: a small amount of lignin in the organic phase is settled to the bottom of the water phase, and a small amount of products such as furfural and the like in the water phase are extracted to the organic phase. Then enter the next cycle and start from step (1).