A process for the continuous production of nitrile compounds and catalysts used therein

Abstract

The application discloses a method for continuously preparing a nitrile compound by using an acid / ester / amide as a raw material and a biomass catalyst used in the method, and the method comprises the following steps: 1) adding a catalyst in a continuous reactor, heating to a catalyst activation temperature of 300-600 DEG C in an inert atmosphere, and then adjusting to a reaction temperature of 160-450 DEG C after keeping for 1-6 hours; and 2) keeping the reaction pressure in the continuous reactor as 0.1-3 MPa, and feeding the raw material into the reactor to carry out a reaction. The method for continuously preparing the nitrile compound has the advantages of continuous production and high efficiency, and the catalyst used in the method has the advantages of high activity, good stability and long service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical synthesis, in particular to a method for continuously preparing nitrile compounds from acid / ester / amide as raw materials and a biomass catalyst used in the method. BACKGROUND

[0002] Nitrile compounds are widely used intermediates. They have wide applications in material industry, perfume industry and pharmaceutical industry. For example, salicylonitrile can be used as a pharmaceutical intermediate to synthesize bunolol hydrochloride for treating hypertension and angina pectoris, as a pesticide intermediate to synthesize fungicide azoxystrobin, and also to synthesize various perfumes and liquid crystal materials, etc. 1,10-decanedinitrile is an intermediate for synthesizing 1,10-decanediamine, which is widely used in long carbon chain polyamides. The most conventional long carbon chain polyamides, such as polyamide 1010, polyamide 10T, polyamide 10I and polyamide 1012, all use decanediamine as the most important monomer raw material in the synthesis and preparation process.

[0003] The conventional nitrile synthesis method is mainly by amide dehydration. There are various methods for the dehydration reaction, such as using a quantitative dehydration reagent to synthesize nitrile by amide dehydration. The quantitative dehydration reagents include phosgene, solid phosgene, thionyl chloride, phosphorus oxychloride, phosphorus pentoxide and the like. The use of these dehydration reagents has safety risks (such as phosgene is a severe suffocating toxic gas, and is highly toxic), and generates a large amount of three wastes (such as phosphorus reagents, phosphorus is a key nutrient causing water eutrophication. Water eutrophication not only causes algae to grow wildly in water, but also causes the oxygen content in water to drop sharply, affecting the survival of aquatic organisms such as fish). Another method for synthesizing nitrile product by dehydration reaction is catalytic dehydration method, which uses a catalyst (generally solid acid) to make amide dehydrate to synthesize nitrile under heating. Since there is a reaction equilibrium in the dehydration reaction, the water generated in the reaction needs to be removed from the reaction system in time. Therefore, when using a batch kettle reaction, a water carrying agent is usually used to carry away the water from the reaction system in time, so as to promote the reaction to move in the positive direction. However, this method has low efficiency, and the solvent reaction is not complete. In addition, there is also a method of continuous dehydration reaction, which generally uses metal oxides such as alumina, silica, molecular sieve and the like as catalysts. The surface acidity and basicity of the above-mentioned catalysts are generally controlled by controlling the content of each oxide composition, and the conditions such as crystallization temperature, crystallization time and aging temperature during synthesis. It is difficult to accurately control the surface acidity and basicity of the catalysts, and the synthesis process of the catalysts generally needs to use a template agent with high toxicity. In addition, the accumulated carbon generated during the reaction process is easy to block the surface of the active sites of the catalyst, causing the deactivation of the catalyst. At present, there is no successful example of industrialized continuous production. Biomass carbon materials often exhibit different catalytic activity and product selectivity from traditional metal oxides due to their rich surface pore structure and easily controllable surface groups. In addition, the surface properties of carbon materials can be adjusted by doping with heteroelements. Through this means, the catalysts can be rationally designed and controlled according to the active sites required by different reactions, and high-efficiency catalysts with high selectivity for specific reactions can be synthesized. Such catalysts have the advantages of wide raw material sources, renewability, easy adjustment of catalyst surface properties, and no use of metal components, and are gradually attracting attention. How to realize the continuous and efficient catalytic dehydration reaction for synthesizing nitrile compounds is a difficult problem in the synthesis process of nitrile compounds. SUMMARY

[0004] In view of the problems existing in the prior art, the purpose of the present application is to provide a method for continuously preparing nitrile compounds and a catalyst used in the method, which can use acid / ester / amide as raw materials to continuously prepare nitrile compounds by ammination / dehydration reaction.

[0005] According to one aspect of the present application, one object of the present application is to provide a method for continuously preparing a nitrile compound from an acid / ester / amide as a raw material, the method comprising the following steps:

[0006] Step 1. A catalyst is added into a continuous reactor, and the catalyst is activated by heating to a temperature of 300-600°C in an inert atmosphere for 1-6 hours, and then the temperature is adjusted to a reaction temperature of 160-450°C;

[0007] Step 2. The reaction pressure in the continuous reactor is maintained at 0.1-3 MPa, and the raw material is introduced into the reactor for reaction.

[0008] Optionally, the method according to the present application can further comprise: Step 3. The reaction product of Step 2 is subjected to condensation and gas-liquid separation to obtain a product. The obtained product can be recrystallized or distilled to obtain a nitrile product. For example, a salicylonitrile product can be obtained by recrystallization in an organic solvent. Decanedinitrile can be obtained by distillation under reduced pressure.

[0009] In Step 1 described above, the continuous reactor can be a fixed bed reactor or a fluidized bed reactor. For example, the fixed bed reactor has a reaction tube with an inner diameter of 12 mm, an outer diameter of 21 mm, and a length of 400 mm, and is filled with about 10 g of catalyst; the fluidized bed reactor has an upper section with an inner diameter of 100 mm, an outer diameter of 108 mm, and a length of 300 mm, and a lower section with an inner diameter of 40 mm, an outer diameter of 48 mm, and a length of 200 mm, and is filled with 300 g of catalyst. However, the fixed bed reactor or the fluidized bed reactor according to the present application is not limited to the specific sizes described above, and the size of the reactor and the amount of catalyst filled can be adjusted according to actual needs.

[0010] In Step 1 described above, the catalyst activation temperature can be 300-500°C, and the reaction temperature can be 160-400°C.

[0011] In Step 1 described above, the inert atmosphere is one or more of nitrogen, helium, and argon.

[0012] In Step 2 described above, the reaction pressure is preferably 0.1-1 MPa.

[0013] In Step 2 described above, the raw material is selected from the following reaction substances of the following structural formula:

[0014]

[0015]

[0016] wherein R and R1 are each independently selected from hydrogen and C1-C6 alkyl;

[0017] R2and R3are each independently selected from the group consisting of hydrogen, hydroxyl, C1-C6alkyl, C1-C6alkoxy.

[0018] n is an integer between 2 and 15, for example n can be an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15.

[0019] Preferably, R and R1are each independently selected from the group consisting of hydrogen, C1-C4alkyl.

[0020] Preferably, R2and R3are each independently selected from the group consisting of hydrogen, hydroxyl, C1-C4alkyl, C1-C4alkoxy.

[0021] Preferably, n is an integer between 2 and 10, for example n can be an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10.

[0022] Preferably, R and R1are each independently selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, t-butyl.

[0023] Preferably, R2and R3are each independently selected from the group consisting of hydrogen, hydroxyl, methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, t-butyl, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, sec-butoxy, t-butoxy.

[0024] Preferably, n is an integer between 2 and 8, for example n can be an integer of 2, 3, 4, 5, 6, 7, 8.

[0025] Preferably, n is an integer between 2 and 6, for example n can be an integer of 2, 3, 4, 5, 6.

[0026] In the above step 2, if the raw material is an acid and / or an ester, an ammonia source raw material also needs to be added to the reaction system, which can be one or more of ammonia gas, aqueous ammonia, methanolic ammonia, tetrahydrofuran solution of ammonia, ethanolic ammonia, toluene solution of ammonia, urea, ammonium carbonate, ammonium bicarbonate.

[0027] Preferably, in the above step 2, the molar ratio of the raw material acid and / or ester to ammonia is 1:1-1:20, preferably 1:2-1:10, more preferably 1:3-1:8. If the molar ratio of acid and / or ester to ammonia is higher than 1:1, the conversion rate will decrease, and if the molar ratio of acid and / or ester to ammonia is lower than 1:20, it will cause waste of ammonia.

[0028] Preferably, in the above step 2, the reaction space velocity is 0.05-8h -1 , preferably 0.1-4h -1 . If the reaction space velocity is higher than 8h -1When the reaction space velocity is higher than 0.05 h -1 When the reaction space velocity is lower than 0.05 h

[0029] In the above step 2, when the raw material is liquid, it can be fed into the reactor through a feed pump, when the raw material is solid, it can be fed into the reactor through a solid feeder, and when the raw material is gas, it can be fed into the reactor through a gas flow meter.

[0030] In the above step 3, the recrystallization solvent is one or more of toluene, xylene, dichloromethane, dichloroethane, n-hexane, and n-heptane.

[0031] According to another aspect of the present application, another object of the present application is to provide a catalyst for the above-mentioned method for continuously preparing a nitrile compound, which is prepared by a method comprising the following steps:

[0032] 1. The dry biomass raw material is crushed by a pulverizer and added to a ball mill together with a solid acid catalyst to form a fine powder of 200-400 mesh, which is then added to a reaction kettle, distilled water is added, the reaction kettle is sealed and heated to 150-250°C, and a hydrolysis reaction is carried out for 4-10 h. After the reaction is completed, the temperature is lowered, the pressure is released, and then the product is filtered under reduced pressure. The filtrate is distilled and concentrated to 20% of the original volume to obtain a concentrated solution;

[0033] 2. The acid solution is added to the concentrated solution obtained in step 1 under vigorous stirring, mixed uniformly, and then chitosan is added and transferred to an autoclave for hydrothermal treatment at 160-220°C for 4-20 h. After cooling and releasing the pressure, the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110°C for 12 h to obtain a doped carbon material;

[0034] 3. The doped carbon material obtained in step 2 is mixed with an alkali under stirring, and then placed in a tube furnace for carbonization treatment at 300-700°C under an inert gas atmosphere for 4-20 h. After the carbonization is completed,

[0035] the temperature is lowered, and the obtained material is washed with distilled water until the filtrate is neutral, and then dried at 110°C for 12 h;

[0036] 4. The doped carbon material obtained in step 3 is mixed with an acid or an oxidizing agent under stirring, heated to 60-90°C for 4-10 h, and then filtered after the treatment is completed. The material is washed with distilled water until the filtrate is neutral, and then dried at 110°C for 12 h.

[0037] Preferably, the filter cake obtained after the reaction in step 1 is filtered under reduced pressure, the filter cake is calcined at 350-550°C for 3-6 h to remove organic matter, and the solid acid catalyst is obtained, which can be recycled.

[0038] In the above step 1, the biomass material includes one or more of corn cob, corn straw, sawdust, peanut shell, bamboo shoot.

[0039] Preferably, the biomass material in the above step 1 includes one or more of corn cob, corn straw, peanut shell.

[0040] More preferably, the biomass material in the above step 1 includes one or more of corn cob, corn straw.

[0041] In the above step 1, the solid acid catalyst includes one or more of silicon dioxide, γ-alumina, zirconium dioxide, cerium dioxide, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, ion exchange resin.

[0042] Preferably, the solid acid catalyst includes one or more of silicon dioxide, γ-alumina, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, ion exchange resin.

[0043] More preferably, the solid acid catalyst includes one or more of γ-alumina, zeolite molecular sieve, ion exchange resin.

[0044] Preferably, the zeolite molecular sieve includes one or more of HZSM5, HZSM11, HY, Hβ, HMOR, SAPO-34.

[0045] In the above step 1, the mass ratio of distilled water to biomass raw material is 50:1-2:1.

[0046] Preferably, in the above step 1, the mass ratio of distilled water to biomass raw material is 20:1-5:1.

[0047] In the above step 1, the hydrolysis reaction temperature is 120-250℃.

[0048] Preferably, in the above step 1, the hydrolysis reaction temperature is 150-220℃.

[0049] More preferably, in the above step 1, the hydrolysis reaction temperature is 160-210℃.

[0050] In the above step 1, the hydrolysis reaction time is 4-10h.

[0051] Preferably, in the above step 1, the hydrolysis reaction time is 4-6h.

[0052] In the above step 1, the mass concentration of the concentrated solution is 10%-30%.

[0053] Preferably, in the above step 1, the concentrated solution has a mass concentration of 10%-20%.

[0054] In the above step 2, the acid is selected from one or more of formic acid, acetic acid, propionic acid, and hydrochloric acid.

[0055] In the above step 2, the acid solution has a mass concentration of 1%-30%.

[0056] Preferably, in the above step 2, the acid solution has a mass concentration of 3%-10%.

[0057] In the above step 2, the mass ratio of the acid solution to the concentrated solution is 1:1-10:1.

[0058] Preferably, in the above step 2, the mass ratio of the acid solution to the concentrated solution is 1:1-5:1.

[0059] In the above step 2, the mass ratio of the chitosan to the concentrated solution is 1:10-1:100.

[0060] In the above step 2, the hydrothermal treatment temperature is 160-220°C.

[0061] Preferably, in the above step 2, the hydrothermal treatment temperature is 180-210°C.

[0062] In the above step 2, the hydrothermal treatment time is 4-20h.

[0063] Preferably, in the above step 2, the hydrothermal treatment time is 5-10h.

[0064] In the above step 3, the base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, and potassium ethoxide.

[0065] In the above step 3, the mass ratio of the base to the doped carbon material is 1:1-10:1.

[0066] Preferably, in the above step 3, the mass ratio of the base to the doped carbon material is 1:1-5:1.

[0067] More preferably, in the above step 3, the mass ratio of the base to the doped carbon material is 1:1-3:1.

[0068] In the above step 3, the inert gas used in the carbonization process includes one or more of nitrogen, helium, and argon.

[0069] Preferably, in the above step 3, the inert gas used in the carbonization process includes one or more of nitrogen and argon.

[0070] In the step 4, the acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, and phosphoric acid. The oxidizing agent is one or more of hydrogen peroxide (mass concentration 30 wt%) and sodium hypochlorite (effective chlorine 6%).

[0071] In the step 4, the mass ratio of the acid to the carbon material is 1:1-10:1.

[0072] In the step 4, the mass ratio of the acid to the carbon material is 1:1-10:1.

[0073] In the step 4, the mass ratio of the oxidizing agent to the carbon material is 1:1-10:1.

[0074] In the step 4, the treatment temperature is 60-90℃.

[0075] In the step 4, the treatment time is 4-10h.

[0076] Advantages

[0077] The method for continuously preparing a nitrile compound provided by the application can be continuously produced and has high efficiency. The catalyst used in the method has high activity, good stability, and long service life. BRIEF DESCRIPTION OF DRAWINGS

[0078] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0079] Figure 1 A schematic diagram of a fixed bed reaction device for the method for continuously preparing a nitrile compound according to an embodiment of the application;

[0080] Figure 2 A schematic diagram of a fluidized bed reaction device for the method for continuously preparing a nitrile compound according to an embodiment of the application.

[0081] Figure 3 The results of the ammonia temperature programmed desorption test of the catalyst product for preparing Example 6, Comparative Example 1, and Comparative Example 2. DETAILED DESCRIPTION

[0082] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to describing the present disclosure, it should be understood that the term used in the specification and the appended claims should not be construed as specific to general and dictionary meanings and should be interpreted as having a meaning and concept corresponding to the technical level of the present disclosure based on the principle that the inventor is allowed to define the terms as long as the definition of the inventor does not depart from the spirit of the disclosure. Therefore, the description herein merely describes preferred embodiments and does not limit the scope of the disclosure and should be understood as the other equivalent embodiments and modifications can be made thereto without departing from the spirit of the disclosure.

[0083] In the present disclosure, the terms "comprise" and "comprising", "include" and "including", "have" and "having", "contain" and "containing" or other similar forms are open-ended and intended to mean including, but not limited to. For example, a composition or article that comprises a list of elements is not limited to only those elements but can include other elements not expressly listed or inherent to such composition or article. Further, unless expressly stated to the contrary, the term "or" means an inclusive "or" and not an exclusive "or". For example, any of the following are satisfied: A or B, where A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and A and B are both true (or exist). In addition, in the present disclosure, the terms "comprise", "include", "have", and "contain" should be interpreted as having been specifically disclosed and encompassing "consist of" and "consist essentially of" closed or semi-closed conjunctions.

[0084] In the present disclosure, all features or conditions defined in the form of a numerical range or a percentage range are intended to be merely for convenience and brevity. Accordingly, the description of a numerical range or a percentage range should be interpreted as having been specifically disclosed and encompassing all possible sub-ranges and individual numerical values within the range, particularly integer numerical values. For example, the range description of "1 to 8" should be interpreted as having been specifically disclosed all sub-ranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, etc., particularly sub-ranges defined by all integer numerical values, and as having been specifically disclosed individual numerical values such as 1, 2, 3, 4, 5, 6, 7, 8, etc. within the range. The aforementioned interpretation method applies to all contents of the present disclosure, regardless of the extent of the range, unless otherwise indicated.

[0085] If a number or other numerical values or parameters are expressed in a range, a preferred range, or a series of upper and lower limits, it should be understood that all ranges formed by any pair of the upper limit or the preferred value of the range and the lower limit or the preferred value of the range have been specifically disclosed herein, regardless of whether the ranges are separately disclosed. In addition, if a range of numerical values is mentioned herein, unless otherwise stated, the range should include its endpoints and all integers and fractions within the range.

[0086] In this document, the use of the term "about" to modify the numerical limitations of a variable means that the value of the variable can vary from the stated numerical value by no more than the tolerance level of the variable. For example, the number 40.0 is understood to encompass a range from 39.50 to 40.49.

[0087] For the purpose of clarifying the present application, portions unrelated to the description are omitted in the drawings, and throughout the specification, the same or similar components are denoted by the same reference numerals.

[0088] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the purpose of explanation, and thus the present application is not necessarily limited to those shown in the drawings.

[0089] Throughout the specification, when it is mentioned that a certain element is "connected" to another element, it includes not only "direct connection" but also "indirect connection" between the other components. In addition, when it is mentioned that a certain element "includes" a certain component, it means that the element can further include other components rather than excluding other components, unless explicitly described to the contrary.

[0090] The following examples are merely set forth as examples of embodiments of the present application and should not be construed as limiting the present application in any way, and it will be understood by those skilled in the art that modifications can be made without departing from the spirit and scope of the present application.

[0091] Except for special description, the raw materials used in the present application are commercially available, and the methods and devices used are conventional methods and devices in the art.

[0092] In the following examples, salicylamide, methyl salicylate, p-hydroxybenzamide, methyl p-hydroxybenzoate, dimethyl 1,4-cyclohexanedicarboxylate, 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxamide, dimethyl 1,2-cyclohexanedicarboxylate, dimethyl 1,2-cyclopentanedicarboxylate, n-hexanoic acid, n-pentanoic acid, n-octanoic acid, sebacic acid, suberic acid, terephthalic acid, phthalic acid, benzoic acid, methyl benzoate, sodium hydroxide, potassium hydroxide were purchased from Sinopharm Chemical Reagent Co., Ltd.; high-purity nitrogen, high-purity helium were purchased from Qingdao Dehai Weiyeh Technology Co., Ltd.; corn cob, corn straw, peanut shell were purchased locally.

[0093] In the method for preparing nitrile compounds according to the present application, nitrile compounds are obtained from acid / ester / amide as raw materials through dehydration / amination dehydration reaction. The product obtained after separation in step 3 is analyzed and detected by gas chromatography (GC) through a 0.22 μm filter membrane. The low-boiling-point product is qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS) and standard GC retention time comparison to determine that the reaction product is mainly nitrile product. The low-boiling-point substance is quantitatively determined by Shimadzu-GC 2020 gas chromatography, and quantitatively analyzed by comparison with the retention time and peak area size of the standard. The relevant calculation formula is as follows:

[0094]

[0095]

[0096]

[0097]

[0098]

[0099] wherein the flow rate of the raw material is g / min, and the amount of the catalyst is g. Figure 1 A schematic diagram of a fixed bed reaction device for the method for continuously preparing nitrile compounds according to an embodiment of the present application is shown in FIG. 1. Figure 1 wherein the reaction tube is filled with the catalyst according to the present application. First, the carrier gas is introduced into the reaction tube by controlling the flow rate with a mass flow meter to create a carrier gas atmosphere, and then the heating furnace can be heated to activate the catalyst. Then, the temperature of the reaction tube is maintained, and the raw material is pumped into the reaction tube through the feed pump, and the product containing nitrile compounds is generated under the catalysis of the catalyst in the carrier gas atmosphere. After condensation and gas-liquid separation, the product of nitrile compounds can be collected.

[0100] Figure 2 A schematic diagram of a fluidized bed reaction device for the method for continuously preparing nitrile compounds according to an embodiment of the present application is shown in FIG. 2. Figure 2 wherein the reaction tube is filled with the catalyst according to the present application. First, the carrier gas is introduced into the reaction tube by controlling the flow rate with a mass flow meter to create a carrier gas atmosphere, and then the heating furnace can be heated to activate the catalyst. Then, the temperature of the reaction tube is maintained, and the raw material is pumped into the reaction tube through the feed pump, and the product containing nitrile compounds is generated under the catalysis of the catalyst in the carrier gas atmosphere. After condensation and gas-liquid separation, the product of nitrile compounds can be collected.

[0101] Example

[0102] Preparation Example 1

[0103] 1. Dry 150g of corn cob, after being crushed by a crusher, 15g of HZSM5 catalyst is added to a ball mill to be ground into a fine powder of 200-400 mesh, which is then added to a reaction kettle, 800ml of distilled water is added, the reaction kettle is sealed and heated to 200℃, and hydrolysis is carried out for 6h. After the reaction is completed, the temperature is lowered, the pressure is released, and then the filtrate is distilled and concentrated to obtain 143ml of concentrated solution.

[0104] 2. 200ml of 10% formic acid solution is added to the concentrated solution in step 1 under vigorous stirring, 5g of chitosan is added, and then the mixture is uniformly mixed and added to an autoclave, which is then treated at 180℃ for 10h. After cooling and releasing the pressure, the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110℃ for 12h to obtain a doped carbon material.

[0105] 3. 20g of the doped carbon material obtained in step 2 is added with 60g of potassium hydroxide, which is then stirred and mixed uniformly, and then placed in a tube furnace and heated to 500℃ under an inert gas atmosphere for carbonization treatment for 5h.

[0106] After the carbonization is completed, the temperature is lowered, and the obtained material is washed with distilled water until the filtrate is neutral, and then dried at 110℃ for 12h.

[0107] 4. 10g of the doped carbon material obtained in step 3 is added with 100ml of 20wt% nitric acid aqueous solution, which is then heated to 60℃ for 6h. After the treatment is completed, the temperature is lowered and filtered, and then the material is washed with distilled water until the filtrate is neutral, and then dried at 110℃ for 12h. After cooling, the catalyst 1 is obtained.

[0108] Preparation Example 2

[0109] 1. Dry 150g of bamboo shoots, after being crushed by a crusher, 15g of HY catalyst is added to a ball mill to be ground into a fine powder of 200-400 mesh, which is then added to a reaction kettle, 800ml of distilled water is added, the reaction kettle is sealed and heated to 200℃, and hydrolysis is carried out for 6h. After the reaction is completed, the temperature is lowered, the pressure is released, and then the filtrate is distilled and concentrated to obtain 140ml of concentrated solution.

[0110] 2. 200ml of 10% acetic acid solution is added to the concentrated solution in step 1 under vigorous stirring, 5g of chitosan is added, and then the mixture is uniformly mixed and added to an autoclave, which is then treated at 180℃ for 10h. After cooling and releasing the pressure, the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110℃ for 12h to obtain a doped carbon material.

[0111] 3. Take 20 g of the doped carbon material obtained in step 2, add 60 g of potassium hydroxide, stir and mix uniformly, then place in a tube furnace, heat to 600°C under inert gas atmosphere for carbonization treatment for 5 h, after carbonization, cool down, and the obtained material is washed with distilled water until the filtrate is neutral, and dried at 110°C for 12 h.

[0112] After carbonization, cool down, and the obtained material is washed with distilled water until the filtrate is neutral, and dried at 110°C for 12 h.

[0113] 4. Add 100 ml of hydrochloric acid with a concentration of 30 wt% to 10 g of the doped carbon material obtained in step 3, heat to 70°C for 6 h, after treatment, cool down and filter, wash the material with distilled water until the filtrate is neutral, and dry at 110°C for 12 h. After cooling, take out to obtain catalyst 2.

[0114] Preparation Example 3

[0115] 1. Dry 300 g of peanut shells, crush them with a pulverizer, and add 30 g of Hβ catalyst to a ball mill to grind into fine powder of 200-400 mesh, add 1500 ml of distilled water to a reaction kettle, seal the reaction kettle, heat to 200°C, and perform hydrolysis reaction for 6 h, after reaction, cool down, release pressure, and perform vacuum filtration, and distill and concentrate the filtrate to obtain 380 ml of concentrated solution.

[0116] 2. Add 400 ml of 10% hydrochloric acid solution to the concentrated solution in step 1 under vigorous stirring, add 10 g of chitosan, mix uniformly, add to an autoclave, and perform hydrothermal treatment at 180°C for 10 h, cool down, release pressure, and wash the obtained product with anhydrous ethanol and deionized water for 3 times respectively, and dry at 110°C for 12 h to obtain a doped carbon material.

[0117] 3. Take 20 g of the doped carbon material obtained in step 2, add 60 g of potassium hydroxide, stir and mix uniformly, then place in a tube furnace, heat to 600°C under inert gas atmosphere for carbonization treatment for 5 h, after carbonization, cool down, and the obtained material is washed with distilled water until the filtrate is neutral, and dried at 110°C for 12 h.

[0118] 4. Add 100 ml of sodium hypochlorite aqueous solution (effective chlorine 6%) to 15 g of the doped carbon material obtained in step 3, heat to 60°C for 6 h, after treatment, cool down and filter, wash the material with distilled water until the filtrate is neutral, and dry at 110°C for 12 h. After cooling, take out to obtain catalyst 3.

[0119] Preparation Example 4

[0120] 1. Dry 300g of peanut shells were ground by a grinder and mixed with 30g of Hβ catalyst in a ball mill to form a fine powder with a particle size of 200-400 mesh. The powder was added to a reaction kettle, 1500ml of distilled water was added, the reaction kettle was sealed and heated to 200°C, and a hydrolysis reaction was performed for 6h. After the reaction was completed, the temperature was lowered, the pressure was released, and the filtrate was distilled and concentrated to obtain 369ml of a concentrated solution.

[0121] 2. 400ml of a 10wt% formic acid solution was added to the concentrated solution obtained in step 1 under vigorous stirring, 6g of chitosan was added and mixed uniformly, and then the mixture was added to an autoclave and hydrothermally treated at 180°C for 10h. After cooling and releasing the pressure, the obtained product was washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110°C for 12h to obtain a doped carbon material.

[0122] 3. 20g of the doped carbon material obtained in step 2 was mixed with 60g of potassium hydroxide, and then placed in a tube furnace and heated to 600°C under an inert gas atmosphere for carbonization treatment for 5h. After the carbonization was completed, the temperature was lowered, and the obtained material was washed with distilled water until the filtrate was neutral, and then dried at 110°C for 12h.

[0123] 4. 18g of the doped carbon material obtained in step 3 was added to 100ml of a 20wt% sulfuric acid solution, heated to 80°C and treated for 6h. After the treatment was completed, the temperature was lowered, the material was filtered and washed with distilled water until the filtrate was neutral, and then dried at 110°C for 12h. After cooling, the catalyst 4 was obtained.

[0124] Preparation Example 5

[0125] 1. Dry 300g of peanut shells were ground by a grinder and mixed with 30g of Hβ catalyst in a ball mill to form a fine powder with a particle size of 200-400 mesh. The powder was added to a reaction kettle, 1500ml of distilled water was added, the reaction kettle was sealed and heated to 200°C, and a hydrolysis reaction was performed for 6h. After the reaction was completed, the temperature was lowered, the pressure was released, and the filtrate was distilled and concentrated to obtain 369ml of a concentrated solution.

[0126] 2. 400ml of a 10wt% formic acid solution was added to the concentrated solution obtained in step 1 under vigorous stirring, 6g of chitosan was added and mixed uniformly, and then the mixture was added to an autoclave and hydrothermally treated at 180°C for 10h. After cooling and releasing the pressure, the obtained product was washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110°C for 12h to obtain a doped carbon material.

[0127] 3. Take 20 g of the doped carbon material obtained in step 2, add 60 g of sodium hydroxide, stir and mix uniformly, then place in a tube furnace, heat to 600°C under a nitrogen gas atmosphere for carbonization treatment for 5 h, after the carbonization is completed, cool down, and the obtained material is washed with distilled water until the filtrate is neutral, and dried at 110°C for 12 h.

[0128] 4. Add 100 ml of a 20 wt% nitric acid aqueous solution to 15 g of the doped carbon material obtained in step 3, heat to 60°C for 6 h, after the treatment is completed, cool down, filter, wash the material with distilled water until the filtrate is neutral, and dry at 110°C for 12 h. After cooling down, catalyst 5 is obtained.

[0129] Preparation Example 6

[0130] 1. Dry 300 g of corn cob, crush with a pulverizer, add 30 g of Nb2O5 to a ball mill, and mill into a fine powder of 200-400 mesh, add to a reaction kettle, add 1500 ml of distilled water, seal the reaction kettle, heat to 200°C, and perform hydrolysis for 6 h, after the reaction is completed, cool down, release the pressure, and perform reduced pressure filtration, and distill and concentrate the filtrate to obtain 341 ml of a concentrated solution.

[0131] 2. Add 400 ml of a 10% by mass acetic acid solution to the concentrated solution described in step 1 under vigorous stirring, add 5 g of chitosan, mix uniformly, add to an autoclave, and perform hydrothermal treatment at 180°C for 10 h, cool down, release the pressure, and after washing the obtained product with anhydrous ethanol and deionized water three times each, dry at 110°C for 12 h to obtain a doped carbon material.

[0132] 3. Take 20 g of the doped carbon material obtained in step 2, add 60 g of sodium hydroxide, stir and mix uniformly, then place in a tube furnace, heat to 600°C under a nitrogen gas atmosphere for carbonization treatment for 5 h, after the carbonization is completed, cool down, and the obtained material is washed with distilled water until the filtrate is neutral, and dried at 110°C for 12 h.

[0133] 4. Add 100 ml of a 40 wt% sulfuric acid aqueous solution to 15 g of the doped carbon material obtained in step 3, heat to 60°C for 6 h, after the treatment is completed, cool down, filter, wash the material with distilled water until the filtrate is neutral, and dry at 110°C for 12 h. After cooling down, catalyst 6 is obtained.

[0134] Comparative Example 1

[0135] 1. Dry 300g of corn cob is ground by a grinder and mixed with 30g of Nb2O5, then put into a ball mill to grind into fine powder with a size of 200-400 mesh. The powder is put into a reactor, 1500ml of distilled water is added, the reactor is sealed and heated to 200℃, and the hydrolysis reaction is carried out for 6h. After the reaction is completed, the temperature is lowered, the pressure is released, and the filtrate is distilled and concentrated to obtain 341ml of concentrated solution.

[0136] 2. 400ml of acetic acid solution with a mass percentage concentration of 10% is added to the concentrated solution in step 1 under vigorous stirring, and then put into an autoclave and hydrothermally treated at 180℃ for 10h. After cooling and releasing the pressure, the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110℃ for 12h to obtain a doped carbon material.

[0137] 3. 20g of the doped carbon material obtained in step 2 is mixed with 60g of sodium hydroxide, and then put into a tube furnace and heated to 600℃ under nitrogen gas atmosphere for carbonization treatment for 5h. After the carbonization is completed, the temperature is lowered, and the obtained material is washed with distilled water until the filtrate is neutral, and then dried at 110℃ for 12h.

[0138] 4. 15g of the doped carbon material obtained in step 3 is mixed with 100ml of 40wt% sulfuric acid aqueous solution, heated to 60℃ for 6h, and then cooled and filtered. The material is washed with distilled water until the filtrate is neutral, and then dried at 110℃ for 12h. After cooling, the comparative catalyst 1 is obtained.

[0139] Comparative Example 2

[0140] 1. Dry 300g of corn cob is ground by a grinder and mixed with 30g of Nb2O5, then put into a ball mill to grind into fine powder with a size of 200-400 mesh. The powder is put into a reactor, 1500ml of distilled water is added, the reactor is sealed and heated to 200℃, and the hydrolysis reaction is carried out for 6h. After the reaction is completed, the temperature is lowered, the pressure is released, and the filtrate is distilled and concentrated to obtain 341ml of concentrated solution.

[0141] 2. 400ml of acetic acid solution with a mass percentage concentration of 10% is added to the concentrated solution in step 1 under vigorous stirring, and then put into an autoclave and hydrothermally treated at 180℃ for 10h. After cooling and releasing the pressure, the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110℃ for 12h to obtain a doped carbon material.

[0142] 3. Take 20 g of the doped carbon material obtained in step 2, add 60 g of sodium hydroxide, stir to mix uniformly, and then place in a tube furnace, heat to 600°C under a nitrogen gas atmosphere, and perform carbonization treatment for 5 h. After the carbonization is completed, cool down, wash the obtained material with distilled water until the filtrate is neutral, and then dry at 110°C for 12 h to obtain a comparative catalyst 2.

[0143] Characterization of the catalyst product

[0144] 1. Catalyst elemental analysis

[0145] Table 1 below is the elemental analysis results of the catalyst products prepared in preparation examples 1-6 and comparative examples 1-2.

[0146] Table 1: Catalyst elemental analysis

[0147] Carbon (wt%) Nitrogen (wt%) Oxygen (wt%) Hydrogen (wt%) Preparation Example 1 79.3 10.6 3.7 1.9 Preparation Example 2 78.2 10.0 4.3 1.1 Preparation Example 3 78.5 9.2 3.3 1.3 Preparation Example 4 77.3 10.1 3.2 1.9 Preparation Example 5 79.1 8.3 3.3 1.8 Preparation Example 6 80.6 9.3 3.2 1.4 Comparative Example 1 84.6 1.7 5.2 1.9 Comparative Example 2 81.6 9.0 2.9 1.1

[0148] From the elemental analysis results, it can be seen that during the synthesis of the carbon-based catalyst material, the nitrogen element in chitosan can be well doped into the carbon material, and the nitrogen content in the synthesized doped carbon material is about 10wt%. In comparative example 1 without adding chitosan, the nitrogen content in the obtained carbon material is low, which shows that the above synthesis method can dope the nitrogen element in chitosan into the carbon material.

[0149] 2. Quantitative detection of catalyst surface groups

[0150] Boehm titration method was used to quantitatively detect the surface groups of the prepared catalyst, and the method is as follows:

[0151] Preparation work:

[0152] 1. Deionized water is first boiled in an oil bath at 160°C for a few minutes and stored in a sealed state.

[0153] 2. Prepare NaOH, HCl, Na2CO3, and NaHCO3 standard titration solutions, and determine the concentration of the standard titration solution.

[0154] Boehm titration method:

[0155] 1. Take 3 portions of 1.0 g or so of the sample and place them in 3 conical flasks with stoppers (plastic material and thoroughly dried), and add 50 mL of 0.05 mol / L NaOH, Na2CO3, and NaHCO3 solution to each conical flask.

[0156] 2. Place the conical flasks on a shaker for 4 h, and then place them at room temperature for 24 h (the longer the better).

[0157] 3. Filter the activated carbon slurry once, and take 20 mL of the filtrate.

[0158] 4. To 20 mL filtrate, add 20 mL, 0.05 mol / L of hydrochloric acid (add Na2CO3 filtrate to 40 mL of hydrochloric acid, add Na2CO3, NaHCO3 filtrate to hydrochloric acid after boiling to remove CO2 therein again).

[0159] 5. Use phenolphthalein as an indicator, and use 0.05 mol / L of standard NaOH titration solution to back titrate the excess acid to a light red solution

[0160] Amount of alkali consumed:

[0161] a = (V * CNaOH + 20 * Co - 20 * CHCl) * 2.5 / M (NaOH, NaHCO3 calculation formula)

[0162] a = (V * CNaOH + 20 * Co - 40 * CHCl) * 2.5 / M (Na2CO3 calculation formula)

[0163] Calculation formula explanation:

[0164] The concentration Co in the formula is based on equivalent concentration, and since Na2CO3 is a double proton base, when calculating Na2CO3, Co should be the molar concentration of Na2CO3 multiplied by 2.

[0165] V is the volume of NaOH consumed, Co is the concentration of the added alkali solution, CHCl is the concentration of the hydrochloric acid solution used, and M is the mass of the activated carbon.

[0166] Calculation:

[0167] The number of carboxyl groups is represented by the amount of NaHCO3 consumed aNaHCO3; the number of lactone groups is represented by the difference between the amounts of Na2CO3 and NaHCO3 consumed aNa2CO3-aNaHCO3; and the number of phenolic hydroxyl groups is represented by the difference between the amounts of NaOH and Na2CO3 consumed aNaOH-aNa2CO3.

[0168] Table 2 below is the surface group number analysis results of the catalyst products prepared in Preparation Examples 1-6 and Comparative Examples 1-2.

[0169] Table 2: Catalyst surface group number

[0170]

[0171] From the above Table 2, it can be seen that the doped carbon material catalysts synthesized in the present application all have abundant surface groups, and the amounts of carboxyl groups, lactone groups and phenolic hydroxyl groups on the surface of the catalyst material are about 0.5-0.6 mmol / g, 0.6-0.7 mmol / g, 0.1 mmol / g, respectively. In the comparative example 2 without using acid or oxidant treatment, the amounts of surface groups carboxyl groups, lactone groups and phenolic hydroxyl groups in the obtained carbon material are 0.33 mmol / g, 0.21 mmol / g, 0.06 mmol / g, respectively, which are obviously lower than the contents of other carbon materials described in the present application, indicating that the acid / oxidant treatment can greatly enrich the number of groups on the surface of the carbon material.

[0172] 3. Detection of adsorption capacity of catalyst product

[0173] NH3-TPR characterization of the catalyst product was carried out on a Micromeritics AutoChem 2920 type chemisorption instrument. The specific experimental steps are as follows: 0.1 g of sample was loaded into a U-shaped quartz tube, purged under Ar gas atmosphere at 150℃ for 2 h, then cooled to 100℃, and adsorbed 5wt% NH3 / Ar mixed gas at 100℃ for 2 h. Then switch to Ar atmosphere to purge the physically adsorbed ammonia for 1 h, after the baseline is flat, then heat to 800℃ at a rate of 10℃ / min. NH3 signal was recorded using a TCD detector. The results are shown in Figure 3

[0174] As can be seen from Figure 3 , the NH3-TPD comparison results of catalyst 6 and comparative catalyst 2 are shown in the above figure, from which it can be seen that the comparative catalyst 1 has a clear NH3 desorption peak at 200℃, showing certain weak acid sites. Comparative catalyst 2 has a desorption peak at a higher temperature (about 440℃) in addition to the NH3-desorption peak near 200℃, showing stronger acidity. Catalyst 6 has a stronger NH3 desorption peak at 230℃, from which it can be seen that the acid / oxidant treatment can significantly enhance the acidity of the catalyst surface, and the desorption temperature of NH3 is significantly increased, indicating that the catalyst has stronger acid strength and higher acid amount. This result is consistent with the catalyst surface group content results obtained by the above Boehm titration test, showing that the acid / oxidant treatment can significantly increase the number of groups on the surface of the catalyst.

[0175] Test example 1

[0176] The preparation method of continuous synthesis of nitrile compounds in a fixed bed reactor is as follows:

[0177] ​The reaction tube of the fixed bed reactor has a size of inner diameter 12 mm, outer diameter 21 mm, and length 400 mm, and is filled with about 10 g of the catalyst prepared according to the present application. First, nitrogen is passed into the reaction tube at a flow rate of 20 ml / min by controlling the flow rate with a mass flow meter to create a carrier gas atmosphere, and then the heating furnace can be heated to 400°C to activate the catalyst. Then, the temperature of the reaction tube is adjusted to the reaction temperature, and the raw material is pumped into the reaction tube by a feed pump, and the product containing the nitrile compound is generated by the reaction in the carrier gas atmosphere and in the presence of the catalyst. After condensation and gas-liquid separation, the product of the nitrile compound can be collected for detection.

[0178] The preparation method for continuously synthesizing the nitrile compound in the fluidized bed reactor is as follows:

[0179] The reaction tube of the fluidized bed reactor has a size of upper section inner diameter 100 mm, upper section outer diameter 108 mm, upper section length 300 mm, lower section inner diameter 40 mm, lower section outer diameter 48 mm, and lower section length 200 mm, and is filled with 300 g of the catalyst prepared according to the present application. First, the fluidization gas is passed into the reaction tube at a gas velocity of 5 L / min by controlling the flow rate with a mass flow meter to create a catalyst fluidization state, and then the heating furnace is heated to 400°C to activate the catalyst. Then, the temperature of the reaction tube is adjusted to the reaction temperature, and the raw material is fed into the reaction tube by a feed pump (liquid), a solid feeder (solid), or a mass flow meter (gas), and the product containing the nitrile compound is generated by the reaction in the fluidization gas atmosphere and in the presence of the catalyst. After condensation and gas-liquid separation, the product of the nitrile compound can be collected for detection.

[0180] The specific reaction conditions, reactants, and main products and their selectivity are shown in Table 3 below.

[0181] Table 3

[0182]

[0183]

[0184]

[0185]

[0186] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for continuously preparing a nitrile compound from an acid / ester / amide as a raw material, the method comprising the following steps: Step 1. Add catalyst to a continuous reactor and heat to 300-600 o C under inert atmosphere for 1-6 h after catalyst activation temperature and adjust to 160-450 o C reaction temperature; Step 2. Maintaining the reaction pressure in the continuous reactor at 0.1-3 MPa, the raw material is fed into the reactor for reaction; In the step 2, the raw material is selected from the following reaction formula: wherein R and R1 are each independently selected from hydrogen, C1-C6 alkyl; R2 and R3 are each independently selected from hydrogen, hydroxyl, C1-C6 alkyl, C1-C6 alkoxy; n is an integer between 2-15; In the step 2, if the raw material is an acid and / or an ester, an ammonia source raw material needs to be added to the reaction system, the ammonia source raw material is one or more of ammonia, aqueous ammonia, methanol solution of ammonia, tetrahydrofuran solution of ammonia, ethanol solution of ammonia, toluene solution of ammonia, urea, ammonium carbonate, ammonium bicarbonate; In the step 1, the catalyst is prepared by a method comprising the following steps: a) After the dry biomass raw material is crushed by a crusher, it is added to a ball mill together with a solid acid catalyst to be ball milled into a fine powder of 200-400 mesh, and then added to a reaction kettle, distilled water is added, the reaction kettle is sealed and heated to 150-250℃, and the hydrolysis reaction is carried out for 4-10 h, after the reaction is completed, the temperature is lowered, the pressure is released, and then the filtrate is concentrated by distillation to 20% of the original volume to obtain a concentrated solution, the biomass material is selected from one or more of corn cob, corn straw, sawdust, peanut shell, bamboo shoot, and the solid acid catalyst is selected from one or more of silicon dioxide, γ-alumina, zirconium dioxide, cerium dioxide, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, ion exchange resin; b) The acid solution is added to the concentrated solution in step a) under vigorous stirring, mixed uniformly, then chitosan is added, transferred into a hydrothermal kettle, and treated at 160-220℃ for 4-20 h, cooled, and then the obtained product is washed with anhydrous ethanol and deionized water for 3 times respectively, and then dried at 110℃ for 12 h to obtain a doped carbon material; c) The doped carbon material obtained in step b) is added with an alkali, stirred and mixed uniformly, then placed in a tube furnace, heated to 300-700℃ under an inert gas atmosphere for carbonization treatment for 4-20 h, after the carbonization is completed, the temperature is lowered, and the obtained material is washed with distilled water until the filtrate is neutral, and then dried at 110℃ for 12 h; d) The doped carbon material obtained in step c) is mixed with an acid or an oxidizing agent, stirred and mixed uniformly, heated to 60-90℃ for treatment for 4-10 h, after the treatment is completed, the temperature is lowered, filtered, and then the material is washed with distilled water until the filtrate is neutral, and then dried at 110℃ for 12 h.

2. The method for continuously producing a nitrile compound according to claim 1, characterized by, The method further comprises: step 3. After the reaction product of step 2 is condensed and gas-liquid separated, the product is obtained.

3. The method of continuously producing a nitrile compound according to claim 1, wherein In the step 1, the catalyst activation temperature is 300-500 o C, the reaction temperature is 160-400 o C, the inert atmosphere is one or more of nitrogen, helium, argon.

4. The method for continuously producing a nitrile compound according to claim 1, characterized by, In the step 2, the reaction pressure is 0.1-1 MPa.

5. The method of continuously producing a nitrile compound according to claim 1, wherein In the step 2, the raw material, R and R1 are each independently selected from hydrogen, C1-C4 alkyl; R2 and R3 are each independently selected from hydrogen, hydroxyl, C1-C4 alkyl, C1-C4 alkoxy.

6. The method of continuously producing a nitrile compound according to claim 1, wherein In the step 2, n is an integer between 2-10 in the raw material. R and R1are each independently selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl; R2and R3are each independently selected from the group consisting of hydrogen, hydroxyl, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, methoxy, ethoxy, n-propyloxy, iso-propyloxy, n-butyloxy, sec-butyloxy, tert-butyloxy.

7. The method of continuously producing a nitrile compound according to claim 1, wherein In the step 2, n in the raw material is an integer between 2 and 8.

8. The method of continuously producing a nitrile compound according to claim 1, wherein In the step 2, n in the raw material is an integer between 2 and 6.

9. The method of continuously producing a nitrile compound according to claim 1, wherein In the step 2, the molar ratio of the raw material acid and / or ester to ammonia is 1:1-1:20, and the reaction space velocity is 0.05-8 h -1 .

10. The method of continuously producing a nitrile compound according to claim 1, characterized by, In the step 2, the molar ratio of the raw material acid and / or ester to ammonia is 1:2-1:10, and the reaction space velocity is 0.1-4 h -1 .

11. The method of continuously producing a nitrile compound according to claim 1, wherein In the step 2, the molar ratio of the raw material acid and / or ester to ammonia is 1:3-1:

8.

12. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, the filter cake obtained after the reaction in step a) is subjected to suction filtration, the filter cake contains the solid acid catalyst, the filter cake is calcined at 350-550 ℃ for 3-6 h to remove organic matter, and the solid acid catalyst is obtained, and the obtained solid acid catalyst is recycled and utilized.

13. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, the biomass material in step a) is selected from one or more of corn cob, corn straw, peanut shell.

14. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, the biomass material in step a) is selected from one or more of corn cob and corn straw.

15. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, the solid acid catalyst is selected from one or more of silicon dioxide, γ-alumina, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, ion exchange resin.

16. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, the solid acid catalyst is selected from one or more of γ-alumina, zeolite molecular sieve, ion exchange resin.

17. The method of continuously producing a nitrile compound according to claim 15 or 16, wherein In the preparation method of the catalyst, the zeolite molecular sieve is selected from one or more of HZSM5, HZSM11, HY, Hβ, HMOR, SAPO-34.

18. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, in step a): The mass ratio of the distilled water to the biomass raw material is 50:1-2:1; The hydrolysis reaction temperature is 120-250 ℃; The hydrolysis reaction time is 4-10 h; The mass concentration of the concentrated solution is 10%-30%.

19. The method of claim 1, wherein the nitrile compound is prepared continuously. In the preparation method of the catalyst, in step a): The mass ratio of the distilled water to the biomass raw material is 20:1-5:1; The hydrolysis reaction temperature is 150-220 ℃; The hydrolysis reaction time is 4-6 h; The mass concentration of the concentrated solution is 10%-20%.

20. The method of claim 1, wherein the nitrile compound is prepared continuously. In the preparation method of the catalyst, in step a), the hydrolysis reaction temperature is 160-210 ℃.

21. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, in step b): The acid is selected from one or more of formic acid, acetic acid, propionic acid, and hydrochloric acid; The mass concentration of the acid solution is 1%-30%; The mass ratio of the acid solution to the concentrated solution is 1:1-10:1; The mass ratio of the chitosan to the concentrated solution is 1:10-1:100; The hydrothermal treatment temperature is 160-220 ℃; The hydrothermal treatment time is 4-20 h.

22. The method of claim 1, wherein the method is continuous. In the preparation method of the catalyst, in step b): The mass concentration of the acid solution is 3%-10%; The mass ratio of the acid solution to the concentrated solution is 1:1-5:1; The hydrothermal treatment temperature is 180-210℃; The hydrothermal treatment time is 5-10 h.

23. The method of claim 1, wherein the nitrile compound is prepared continuously. In the step c) of the preparation method of the catalyst: The base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, and potassium ethoxide; The mass ratio of the base to the doped carbon material is 1:1-10:1; The inert gas used in the carbonization process is selected from one or more of nitrogen, helium, and argon.

24. The method of claim 1, wherein the nitrile compound is prepared continuously. In the step c) of the preparation method of the catalyst: The mass ratio of the base to the doped carbon material is 1:1-5:1; The inert gas used in the carbonization process is selected from one or more of nitrogen and argon.

25. The method of claim 1, wherein the nitrile compound is prepared continuously. In the step c) of the preparation method of the catalyst, the mass ratio of the base to the doped carbon material is 1:1-3:

1.

26. The method of claim 1, wherein the nitrile compound is prepared continuously. In the step d) of the preparation method of the catalyst: The acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, and phosphoric acid; the oxidizing agent is one or more of 30wt% hydrogen peroxide and sodium hypochlorite with effective chlorine of 6%; The mass ratio of the acid to the carbon material is 1:1-10:1; The mass ratio of the oxidizing agent to the carbon material is 1:1-10:1; The treatment temperature is 60-90℃; The treatment time is 4-10 h.

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