Method and device for producing nicotinamide through continuous 3-cyanopyridine enzyme hydrolysis

Abstract

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a method and device for producing nicotinamide through continuous cyanopyridine enzyme hydrolysis. 3-cyanopyridine and a buffer solution are mixed as a raw material solution in a hydrolysis reactor, and 3-cyanopyridine is hydrolyzed under the catalytic action of hydrolase to produce nicotinamide; wherein a hydrolase supplementing system, a hydrolase transferring system and an inactivated enzyme filtering system are arranged in the hydrolysis reactor. A filter screen is arranged in an inner cavity of the hydrolysis reactor and divides the hydrolysis reaction area into an upper section and a lower section, the upper section of the hydrolysis reaction area is provided with a hydrolase supplementing system and a hydrolase transferring system, and the lower section of the hydrolysis reaction area is provided with an inactivated enzyme filtering system; fresh hydrolase enters the upper section of the hydrolysis reaction area through the hydrolase supplementing system, the hydrolase transferring system directly transfers the hydrolase with reduced activity in the upper section of the hydrolysis reaction area to the lower section of the hydrolysis reaction area, and the inactivated enzyme filtering system filters the inactivated hydrolase in the lower section of the hydrolysis reaction area and then discards the inactivated hydrolase. Therefore, the replacement of the hydrolase and the graded utilization of different enzyme activities are completed. The method provided by the invention realizes continuous production of nicotinamide through enzymatic hydrolysis of 3-cyanopyridine by a biological method, the production operation condition is stable and easy to control, the reaction period is shortened, and the problems of intermittent production, complex and difficult control of process operation conditions and reduction of enzyme activity of hydrolase caused by continuous increase of product concentration in a traditional biological method are avoided. And the quality of products is uneven.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemical industry, and particularly relates to a method and a device for continuously hydrolyzing cyanopyridine to produce nicotinamide. Background Art

[0002] Nicotinamide, also known as nicotinamide, is an important water-soluble vitamin in the vitamin B family. In the biological oxidative respiratory chain, nicotinamide plays a key role in transferring hydrogen atoms, participating in and regulating the metabolic processes of carbohydrates, fats and proteins. Due to its unique physiological functions, nicotinamide plays an indispensable role in maintaining the integrity of the skin, digestive tract and nervous system. As a vitamin, nicotinamide has a significant anti-rough skin disease effect and has a unique therapeutic effect on certain skin diseases and neurological disorders. In addition, nicotinamide is also widely used in feed additives and food nutritional enhancers to prevent pellagra and cardiovascular diseases. At the same time, nicotinamide is also an important intermediate for the synthesis of certain medicines and pesticides, and has extremely high industrial application value. At present, there are mainly chemical and biological methods for the hydrolysis of 3-cyanopyridine. The chemical method is to catalyze the hydrolysis of 3-cyanopyridine to nicotinamide under the action of catalysts such as acids, alkalis and metal oxides. However, there are a series of problems in the chemical production of nicotinamide. First, this method mostly uses intermittent reactor operation, resulting in high operating costs, long production cycle, and unstable product quality. Secondly, the traditional chemical method needs to be carried out under high temperature and high pressure conditions, which consumes a lot of energy. In the separation and extraction process, solvent extractants need to be used, which may lead to the problem of residual solvents in the subsequent separation process, thereby affecting the purity and safety of the product. The biological method uses a specific strain of bacteria to hydrolyze 3-cyanopyridine to obtain nicotinamide under suitable reaction conditions. Although the product produced by the biological method has high purity, this method also has the limitation of intermittent production, and the operating conditions are complex and difficult to control, which affects the reaction efficiency and product quality. In summary, the existing chemical method and biological method have shortcomings in the production of nicotinamide. The chemical method has problems such as difficult separation, high energy consumption, and large environmental pollution; while the biological method has the problem of unstable product quality. In addition, both the chemical method and the biological method are intermittent operations. Therefore, it is necessary to develop a more efficient, environmentally friendly and continuous nicotinamide production method with stable product quality. Summary of the invention

[0003] In view of the above problems, the object of the present invention is to provide a method for producing nicotinamide by continuous enzymatic hydrolysis of 3-cyanopyridine, which realizes the continuous production of nicotinamide by bio-enzymatic hydrolysis of 3-cyanopyridine, and the conversion rate of 3-cyanopyridine can reach more than 99%.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for continuously hydrolyzing 3-cyanopyridine to produce nicotinamide by enzymatic hydrolysis: 3-cyanopyridine is mixed with a buffer solution as a raw material liquid in a hydrolysis reactor, and 3-cyanopyridine is hydrolyzed to produce nicotinamide under the catalytic action of a hydrolase; wherein a hydrolase supplement system, a hydrolase transfer system and an inactivated enzyme filtration system are provided in the hydrolysis reactor.

[0006] A filter is provided in the inner cavity of the hydrolysis reactor to divide the hydrolysis reaction zone into an upper section and a lower section. The upper section of the hydrolysis reaction zone is provided with a hydrolase replenishment system and a hydrolase transfer system, and the lower section of the hydrolysis reaction zone is provided with an inactivated enzyme filtration system; fresh hydrolase enters the upper section of the hydrolysis reaction zone through the hydrolase replenishment system, the hydrolase transfer system directly transfers the hydrolase with decreased activity in the upper section of the hydrolysis reaction zone to the lower section of the hydrolysis reaction zone, and the inactivated enzyme filtration system filters the inactivated hydrolase in the lower section of the hydrolysis reaction zone and then scraps it, thereby completing the replacement of the hydrolase and the graded utilization of different enzyme activities.

[0007] The inactivated enzyme filtration system is first turned on after the hydrolysis reaction has been carried out for 2h-6h, and then turned on once every 1h, and the operation time of each turn-on is 10-20min;

[0008] The hydrolase transfer system is turned on after the inactivated enzyme filtration system is turned off, and each operation time is 10-20 minutes;

[0009] The hydrolase supplement system is opened after the hydrolase transfer system is closed, and the amount of supplemented hydrolase is 20%-35% of the total mass of the hydrolase in the hydrolysis reactor, preferably 24%.

[0010] The reaction liquid after the hydrolysis of 3-cyanopyridine is divided into a reflux liquid and a nicotinamide product, and the reflux liquid is returned to the hydrolysis reactor to continue the reaction; the flow ratio of the reflux liquid to the nicotinamide product is 4-10:1, preferably 5:1.

[0011] The raw material liquid also contains nicotinamide mother liquor, which is the filtrate obtained after the nicotinamide product solution is concentrated and nicotinamide crystals are precipitated. The filtrate contains nicotinamide and buffer solution components and can be reused.

[0012] The temperature of the raw material liquid is 20-50°C, preferably 35°C, the hydrolysis reaction temperature is 25°C-30°C, the pH value of the raw material liquid is 6.0-8.0, and the pH value of the hydrolysis reaction is 6-9.

[0013] The hydrolase is a suspension of Escherichia coli, and the concentration of the hydrolase is 5%-40%.

[0014] The buffer solution is a mixed solution of dipotassium hydrogen phosphate and potassium dihydrogen phosphate, the dosage ratio of dipotassium hydrogen phosphate to potassium dihydrogen phosphate is 1.0-1.5:1, and the dosage of the buffer solution is 50-70% of the weight of the raw material solution.

[0015] A device used in the method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis, the device comprises a raw material liquid mixing tank 1, a hydrolysis reactor 4, an enzyme inactivation filter 7, a buffer tank 9, and a hydrolyzate filter 11;

[0016] A filter screen A is provided at the upper part of the inner cavity of the hydrolysis reactor 4 to divide the hydrolysis reactor 4 into a hydrolysis product discharge area and a hydrolysis reaction area. The upper part of the filter screen A is the hydrolysis product discharge area, and the lower part of the filter screen A is the hydrolysis reaction area. A filter screen B is provided at the middle part of the inner cavity of the hydrolysis reactor 4 to divide the hydrolysis reaction area into an upper section and a lower section.

[0017] The hydrolysis reactor 4 is provided with an inlet A, an inlet B, an inlet C, an inlet D and an outlet A, an outlet B, and an outlet C; the inlet A is connected to the upper section of the hydrolysis reaction zone, and the inlet B, the inlet C, and the inlet D are all connected to the lower section of the hydrolysis reaction zone; the outlet A is connected to the hydrolysis product discharge zone, the outlet B is connected to the upper section of the hydrolysis reaction zone, and the outlet C is connected to the lower section of the hydrolysis reaction zone;

[0018] The buffer tank 9 is provided with 1 inlet and 2 outlets;

[0019] The inlet of the raw liquid mixing tank 1 is connected to the raw liquid pipeline, the outlet of the raw liquid mixing tank 1 is connected to the inlet B of the hydrolysis reactor 4 through the raw liquid feed pump 2, the fresh hydrolase pipeline is connected to the inlet A of the hydrolysis reactor 4 through the enzyme suspension pump 3, the outlet A of the hydrolysis reactor 4 is connected to the inlet of the buffer tank 9, one outlet of the buffer tank 9 is connected to the inlet C of the hydrolysis reactor 4 through the hydrolysis circulation pump 8, the other outlet of the buffer tank 9 is connected to the inlet of the hydrolysis solution filter 11 through the hydrolyzate extraction pump 10, and the outlet of the hydrolyzate filter 11 is connected to the subsequent concentration and crystallization process;

[0020] The outlet B of the hydrolysis reactor 4 is connected to the inlet D of the hydrolysis reactor 4 through the enzyme filtration pump 6, and the outlet C of the hydrolysis reactor 4 is connected to the inlet D of the hydrolysis reactor 4 through the enzyme filtration pump 6 and the inactivated enzyme filter 7 in sequence.

[0021] A valve is provided on the pipeline connecting the outlet B of the hydrolysis reactor 4 and the enzyme filtration pump 6;

[0022] A valve is provided on the pipeline connecting the outlet C of the hydrolysis reactor 4 and the enzyme filtration pump 6;

[0023] A valve is provided on the pipeline connecting the outlet of the enzyme filtration pump 6 and the inactivated enzyme filter 7;

[0024] A valve is provided on the pipeline connecting the outlet of the enzyme filtration pump 6 and the inlet D of the hydrolysis reactor 4 .

[0025] The connecting pipelines of the device are all provided with control valves and flow meters.

[0026] Both the raw liquid mixing tank 1 and the hydrolysis reactor 4 are provided with temperature control equipment.

[0027] The principle of the present invention is:

[0028] After the raw material 3-cyanopyridine, buffer solution and nicotinamide reflux liquid are mixed and preheated in the raw material liquid mixing tank, they enter the hydrolysis reactor through the raw material liquid feed pump. At the same time, the hydrolase suspension is added to the hydrolysis reactor through the enzyme suspension pump. In the hydrolysis reactor, 3-cyanopyridine is converted into nicotinamide under the catalytic action of the hydrolase. The hydrolyzed reaction liquid enters the buffer tank and is divided into two streams at the bottom of the buffer tank. One stream enters the reflux pipeline as the reflux liquid, and re-enters the hydrolysis reactor for reaction under the action of the hydrolysis circulation pump; the other stream passes through the hydrolyzate extraction pump, is filtered through the hydrolyzate filter, and then concentrated and crystallized; the hydrolyzate in the hydrolysis reactor A filter is provided in the part to separate the hydrolysis area into an upper section and a lower section. The upper section is provided with a hydrolase replenishment system and a hydrolase transfer system, and the lower section is provided with an inactivated enzyme filtration system. The inactivated enzyme filtration system filters the inactivated hydrolase in the lower section of the hydrolysis reactor and scraps it. The hydrolase transfer system directly transfers the hydrolase with decreased activity in the upper section of the hydrolysis reactor to the lower section of the hydrolysis reactor. Fresh hydrolase is added to the upper section of the hydrolysis reactor through an enzyme suspension pump, thereby completing the replacement of the hydrolase and ensuring the stability of the device operation. At the same time, it ensures the recycling of nicotinamide mother liquor, reduces the use of buffer solution, and greatly reduces the amount of wastewater.

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] The method of the invention realizes the continuous production of nicotinamide by bio-enzymatic hydrolysis of 3-cyanopyridine, the production operation conditions are stable and easy to control, the reaction cycle is shortened, and the problems of intermittent production by traditional bio-methods, complex and difficult to control process operation conditions, and a decrease in the activity of the hydrolase due to the continuous increase in product concentration, resulting in uneven product quality, are avoided.

[0031] The present invention provides a hydrolase supplement system, a hydrolase transfer system and an inactivated enzyme filtering system, so that the hydrolase can be supplemented, transferred and scrapped in time, so that the activity of the hydrolase in the hydrolysis reactor is maintained at a high level, a faster catalytic hydrolysis speed is achieved, and the amount of enzyme used is reduced.

[0032] The setting of the reflux pipeline of the present invention can flexibly control the residence time of the raw material liquid to ensure a high conversion rate of the raw material; continuously extract qualified nicotinamide solution to avoid the accumulation of products and the continued hydrolysis to produce impurities, so that the product purity is high, the by-products are small, and the quality is improved. At the same time, the recycling of nicotinamide mother liquor reduces the amount of waste liquid discharged, reduces energy consumption and environmental pollution, and can greatly improve production efficiency and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1It is a process flow chart of the present invention, in which: 1-raw material liquid mixing tank, 2-raw material liquid feed pump, 3-enzyme suspension feed pump, 4-hydrolysis reactor, 5-filter screen, 6-enzyme filtration pump, 7-inactivated enzyme filter, 8-hydrolysis circulation pump, 9-buffer tank, 10-hydrolyzate extraction pump, 11-hydrolyzate filter. DETAILED DESCRIPTION

[0034] In order to make the technical solution and effects of the present invention clearer, the technical solution of the present invention is further defined through the following specific implementation methods, and the scope of protection required includes but is not limited to the description.

[0035] like Figure 1 As shown, the device of this embodiment includes a raw liquid mixing tank 1, a hydrolysis reactor 4, an inactivated enzyme filter 7, a buffer tank 9, and a hydrolyzate filter 11;

[0036] A filter screen A is provided at the upper part of the inner cavity of the hydrolysis reactor 4 to divide the hydrolysis reactor 4 into a hydrolysis product discharge area and a hydrolysis reaction area. The upper part of the filter screen A is the hydrolysis product discharge area, and the lower part of the filter screen A is the hydrolysis reaction area. A filter screen B is provided at the middle part of the inner cavity of the hydrolysis reactor 4 to divide the hydrolysis reaction area into an upper section and a lower section.

[0037] The hydrolysis reactor 4 is provided with an inlet A, an inlet B, an inlet C, an inlet D and an outlet A, an outlet B, and an outlet C; the inlet A is connected to the upper section of the hydrolysis reaction zone, and the inlet B, the inlet C, and the inlet D are all connected to the lower section of the hydrolysis reaction zone; the outlet A is connected to the hydrolysis product discharge zone, the outlet B is connected to the upper section of the hydrolysis reaction zone, and the outlet C is connected to the lower section of the hydrolysis reaction zone;

[0038] The buffer tank 9 is provided with 1 inlet and 2 outlets;

[0039] The inlet of the raw liquid mixing tank 1 is connected to the raw liquid pipeline, the outlet of the raw liquid mixing tank 1 is connected to the inlet B of the hydrolysis reactor 4 through the raw liquid feed pump 2, the fresh hydrolase pipeline is connected to the inlet A of the hydrolysis reactor 4 through the enzyme suspension pump 3, the outlet A of the hydrolysis reactor 4 is connected to the inlet of the buffer tank 9, one outlet of the buffer tank 9 is connected to the inlet C of the hydrolysis reactor 4 through the hydrolysis circulation pump 8, the other outlet of the buffer tank 9 is connected to the inlet of the hydrolysis solution filter 11 through the hydrolyzate extraction pump 10, and the outlet of the hydrolyzate filter 11 is connected to the subsequent concentration and crystallization process;

[0040] The outlet B of the hydrolysis reactor 4 is connected to the inlet D of the hydrolysis reactor 4 through the enzyme filtration pump 6, and the outlet C of the hydrolysis reactor 4 is connected to the inlet D of the hydrolysis reactor 4 through the enzyme filtration pump 6 and the inactivated enzyme filter 7 in sequence.

[0041] A valve is provided on the pipeline connecting the outlet B of the hydrolysis reactor 4 and the enzyme filtration pump 6;

[0042] A valve is provided on the pipeline connecting the outlet C of the hydrolysis reactor 4 and the enzyme filtration pump 6;

[0043] A valve is provided on the pipeline connecting the outlet of the enzyme filtration pump 6 and the inactivated enzyme filter 7;

[0044] A valve is provided on the pipeline connecting the outlet of the enzyme filtration pump 6 and the inlet D of the hydrolysis reactor 4 .

[0045] The connecting pipelines of the device are all provided with control valves and flow meters.

[0046] Both the raw liquid mixing tank 1 and the hydrolysis reactor 4 are provided with temperature control equipment.

[0047] The process parameters of the equipment used in the following embodiments of the present invention are as follows: the diameter of the hydrolysis reactor 4 is 500 mm and the height is 2800 mm; the filter is a five-layer stainless steel wire mesh sintered filter purchased from Suzhou Lianwang Electronics Co., Ltd.; the volume of the buffer tank 9 is 2000 L, and the diameter of the cyanopyridine hydrolase expressed by the Escherichia coli used in the embodiment of the present invention is 0.5-3 μm, the amount of the hydrolase accounts for about 15% of the volume of the hydrolysis reactor 4, and the reflux ratio is 5:1.

[0048] The buffer solution used in the embodiment of the present invention is a mixed solution of dipotassium hydrogen phosphate and potassium dihydrogen phosphate, and the weight ratio of dipotassium hydrogen phosphate to potassium dihydrogen phosphate is 1.2:1.

[0049] Example 1

[0050] The recombinant E. coli BL21 / pET24-PtNHase (purchased from General Biosystems Co., Ltd.) was inoculated into 10 mL of LB medium containing 50 μg / mL kanamycin, and cultured overnight at 37°C and 180 r / min. The above overnight culture was inoculated into LB medium containing 50 μg / mL kanamycin at an inoculum of 1%, and cultured for 3 hours at 37°C and 180 r / min, and 0.4 mM IPTG was added, induced at 25°C for 12 hours, and centrifuged at 10000 rpm for 20 minutes to collect 9.2 g of E. coli suspension.

[0051] Example 2

[0052] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650 L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5 kg), and then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate stabilizes, the enzyme filtration pump 6 is started, and the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4 are opened. After running for 20 minutes without a filter, the enzyme filtration pump 6 is turned off, and part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 is transferred to the lower section of the reactor.

[0053] The raw material 3-cyanopyridine is fed into the raw material liquid mixing tank 1 at 0.6 L / s and the buffer solution is fed into the raw material liquid mixing tank 1 at 1.0 L / s to mix with the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it is fed into the hydrolysis reactor 4 at 1.6 L / s through the raw material liquid feed pump 2 and mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0, and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and the nicotinamide product is extracted at a flow rate of 1.6 L / s.

[0054] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: open the inlet A pipeline of the hydrolysis reactor 4, start the enzyme suspension pump 3, and supplement 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg, which is 24% of the total mass of the hydrolase in the hydrolysis reactor).

[0055] During the reaction, the raw material normalization was less than 1% and the nicotinamide content was about 38.5% every hour. The yield was about 98.0%. The hydrolyzate was filtered through a hydrolysis filter 11 to remove protein, and then concentrated and crystallized. The crystals were vacuum dried at 35-45° C. The nicotinamide normalization was finally obtained to be greater than 99.5%.

[0056] Example 3

[0057] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650 L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5 kg), and then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate stabilizes, the enzyme filtration pump 6 is started, and the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4 are opened. After running for 20 minutes without a filter, the enzyme filtration pump 6 is turned off, and part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 is transferred to the lower section of the reactor.

[0058] The raw material 3-cyanopyridine is fed into the raw material liquid mixing tank 1 at 0.52 L / s and the buffer solution is fed into the raw material liquid mixing tank 1 at 0.87 L / s to mix with the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it enters the hydrolysis reactor 4 through the raw material liquid feed pump 2 at 1.39 L / s and is mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0 and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and extraction is started at a flow rate of 1.39 L / s.

[0059] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0060] During the process, samples were taken every hour for analysis and the raw material normalization was less than 1%, the nicotinamide content was about 38.8%, and the yield was about 98.9%.

[0061] Example 4

[0062] First, open the enzyme suspension feed pump 3 to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5kg), then close the suspension pump 3, start the hydrolysis circulation pump 8, and after the flow rate stabilizes, start the enzyme filtration pump 6, open the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4, run without a filter for 20 minutes, then close the enzyme filtration pump 6, and transfer part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 to the lower section of the reactor.

[0063] The raw material 3-cyanopyridine is fed into the raw material mixing tank 1 at 0.58 L / s, the buffer solution is fed into the raw material mixing tank 1 at 0.6 L / s and the nicotinamide mother liquor is fed into the raw material mixing tank 1 at 0.43 L / s to mix the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it is fed into the hydrolysis reactor 4 at 1.61 L / s through the raw material liquid feed pump 2 and mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0 and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and extraction is started at a flow rate of 1.61 L / s.

[0064] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0065] During the process, samples were taken every hour for analysis and the raw material normalization was less than 0.8%, the nicotinamide content was about 39.8%, and the yield was about 98.5%.

[0066] Example 5

[0067] First, open the enzyme suspension pump 3 to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5kg), then close the suspension pump 3, start the hydrolysis circulation pump 8, and after the flow rate stabilizes, start the enzyme filtration pump 6, open the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4, run without a filter for 20 minutes, then close the enzyme filtration pump 6, and transfer part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor to the lower section of the reactor.

[0068] The raw material 3-cyanopyridine and the buffer solution were fed into the raw material mixing tank 1 at 0.52 L / s and 0.87 L / s, respectively, to mix with the raw material liquid. After the raw material was preheated to 35°C and the pH value was 7.5, the raw material liquid was fed into the hydrolysis reactor 4 at 1.39 L / s through the raw material liquid feed pump 2 and mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system was 7.0 and the reaction temperature was 25°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 was started, the reflux ratio was controlled at 5:1, and the nicotinamide product was extracted at a flow rate of 1.39 L / s.

[0069] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0070] During the process, samples were taken every hour for analysis and the raw material normalization was less than 4.6%, the nicotinamide content was about 36.9%, and the yield was about 93.96%.

[0071] Example 6

[0072] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650 L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5 kg), and then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate stabilizes, the enzyme filtration pump 6 is started, and the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4 are opened. After running for 20 minutes without a filter, the enzyme filtration pump 6 is turned off, and part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 is transferred to the lower section of the reactor.

[0073] The raw material 3-cyanopyridine is fed into the raw material liquid mixing tank 1 at 0.52 L / s and the buffer solution is fed into the raw material liquid mixing tank 1 at 0.87 L / s to mix with the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it enters the hydrolysis reactor 4 through the raw material liquid feed pump 2 at 1.39 L / s and is mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0, and the reaction temperature is 30°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and the nicotinamide product is extracted at a flow rate of 1.39 L / s.

[0074] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0075] During the process, samples were taken every hour for analysis and the raw material normalization was less than 3.8%, the nicotinamide content was about 37.25%, and the yield was about 94.9%.

[0076] Example 7

[0077] First, open the enzyme suspension pump 3 to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5kg), then close the suspension pump 3, start the hydrolysis circulation pump 8, and after the flow rate stabilizes, start the enzyme filtration pump 6, open the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4, and then close the enzyme filtration pump 6. Run for 20 minutes without passing through the filter, and transfer part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 to the lower section of the reactor.

[0078] The raw material 3-cyanopyridine is fed into the raw material mixing tank 1 at 0.6 L / s and the buffer solution is fed into the raw material mixing tank 1 at 0.87 L / s to mix with the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it is fed into the hydrolysis reactor 4 at 1.47 L / s through the raw material liquid feed pump 2 and mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0 and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and the nicotinamide product is extracted at a flow rate of 1.47 L / s.

[0079] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0080] During the process, samples were taken every hour for analysis and the raw material normalization was less than 5%, the nicotinamide content was about 36.63%, and the yield was about 93.4%.

[0081] Example 8

[0082] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650 L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5 kg), and then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate stabilizes, the enzyme filtration pump 6 is started, and the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4 are opened. After running for 20 minutes without a filter, the enzyme filtration pump 6 is turned off, and part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 is transferred to the lower section of the reactor.

[0083] The raw material 3-cyanopyridine is fed into the raw material mixing tank 1 at 0.56 L / s and the buffer solution is fed into the raw material mixing tank 1 at 0.87 L / s to mix with the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it enters the hydrolysis reactor 4 through the raw material liquid feed pump 2 at 1.43 L / s and is mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0, and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and the nicotinamide product is extracted at a flow rate of 1.43 L / s.

[0084] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0085] During the process, samples were taken every hour for analysis and the raw material normalization was less than 3.6%, the nicotinamide content was about 37.2%, and the yield was about 94.7%.

[0086] Example 9

[0087] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650 L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5 kg), and then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate stabilizes, the enzyme filtration pump 6 is started, and the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4 are opened. After running for 20 minutes without a filter, the enzyme filtration pump 6 is turned off, and part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 is transferred to the lower section of the reactor.

[0088] The raw material 3-cyanopyridine and the buffer solution were fed into the raw material mixing tank 1 at 0.52 L / s and 0.87 L / s, respectively, to mix with the raw material liquid. After the raw material was preheated to 35°C and the pH value was 7.5, it was fed into the hydrolysis reactor 4 at 1.39 L / s through the raw material liquid feed pump and mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system was 7.0 and the reaction temperature was 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 was started, the reflux ratio was controlled at 4:1, and the nicotinamide product was extracted at a flow rate of 1.39 L / s.

[0089] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0090] During the process, samples were taken every hour for analysis and the raw material normalization was less than 2%, the nicotinamide content was about 36.8%, and the yield was about 93.8%.

[0091] Example 10

[0092] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650 L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5 kg), and then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate stabilizes, the enzyme filtration pump 6 is started, and the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4 are opened. After running for 20 minutes without a filter, the enzyme filtration pump 6 is turned off, and part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 is transferred to the lower section of the reactor.

[0093] The raw material 3-cyanopyridine is fed into the raw material mixing tank 1 at 0.52 L / s and the buffer solution is fed into the raw material mixing tank 1 at 0.87 L / s to mix with the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it enters the hydrolysis reactor 4 through the raw material liquid feed pump 2 at 1.39 L / s and is mixed with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0, and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 6:1, and the nicotinamide product is extracted at a flow rate of 1.39 L / s.

[0094] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0095] During the process, samples were taken every hour for analysis and the raw material normalization was less than 1%, the nicotinamide content was about 38.5%, and the yield was about 98.13%.

[0096] Comparative Example 1

[0097] The difference from Example 3 is that the filter screens A and B, the hydrolase transfer system and the inactivated enzyme filtration system are not provided in the hydrolysis reactor, specifically:

[0098] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5kg), then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate is stable, the raw material 3-cyanopyridine is fed into the raw material liquid mixing tank 1 at 0.52L / s and the buffer solution is fed into the raw material liquid mixing tank 1 at 0.87L / s to mix the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it is fed into the hydrolysis reactor 4 at 1.39L / s through the raw material liquid feed pump 2 to mix with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0, and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and extraction begins at a flow rate of 1.39L / s. The enzyme in the hydrolyzate is intercepted and discharged through the hydrolyzate filter 11.

[0099] After the reaction was carried out for 3 hours, the hydrolase supplement system was continuously turned on, specifically: the inlet A pipeline of the hydrolysis reactor 4 was opened, and the enzyme suspension pump 3 was turned on to continuously supplement 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) at 0.014L / s.

[0100] During the process, samples were taken every hour for analysis, and the raw material normalization gradually increased from 1% to 12%, the nicotinamide content was around 35.49%, and the yield was about 89.72%.

[0101] Comparative Example 2

[0102] The difference from Example 3 is that the filter screen B, the hydrolase transfer system and the inactivated enzyme filtration system are not provided in the hydrolysis reactor, specifically:

[0103] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 and the buffer tank 9 with 1650L of enzyme suspension (enzyme concentration 5%, actual enzyme 82.5kg), then the suspension pump 3 is turned off, and the hydrolysis circulation pump 8 is started. After the flow rate is stable, the raw material 3-cyanopyridine is fed into the raw material liquid mixing tank 1 at 0.52L / s and the buffer solution is fed into the raw material liquid mixing tank 1 at 0.87L / s to mix the raw material liquid. After the raw material is preheated to 35°C and the pH value is 7.5, it is fed into the hydrolysis reactor 4 through the raw material liquid feed pump 2 at 1.39L / s to mix with the reflux liquid of the hydrolysis circulation pump 8 to participate in the enzyme catalytic reaction. The pH value of the reaction system is 7.0, and the reaction temperature is 28°C. After reflux operation for 10 minutes, the hydrolyzate extraction pump 10 is started, the reflux ratio is controlled at 5:1, and extraction begins at a flow rate of 1.39L / s.

[0104] After 3 hours of reaction, the hydrolase supplement system is started, specifically: open the inlet A pipeline of the hydrolysis reactor 4, start the enzyme suspension pump 3, and supplement 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg). After running for 12 hours, the system needs to be stopped and cleaned once.

[0105] During the process, samples were taken every hour for analysis and the raw material normalization was less than 3.6%, the nicotinamide content was about 36.36%, and the yield was about 92.68%.

[0106] Comparative Example 3

[0107] The difference from Example 3 is that the hydrolyzate is not refluxed, specifically:

[0108] First, the enzyme suspension pump 3 is turned on to fill the hydrolysis reactor 4 with 550 L of enzyme suspension (enzyme concentration 15%, actual enzyme 82.5 kg), then the suspension pump 3 is turned off, the enzyme filtration pump 6 is started, the outlet B pipeline and the inlet D pipeline of the hydrolysis reactor 4 are opened, and after running for 20 minutes without a filter, the enzyme filtration pump 6 is turned off, and part of the hydrolytic enzyme in the upper section of the hydrolysis reaction zone of the hydrolysis reactor 4 is transferred to the lower section of the reactor.

[0109] The raw material 3-cyanopyridine and the buffer solution were fed into the raw material liquid mixing tank 1 at 0.52 L / s and 0.87 L / s, respectively, to mix the raw material liquid. After the raw material was preheated to 35°C and the pH value was 7.5, it was fed into the hydrolysis reactor 4 at 1.39 L / s through the raw material liquid feed pump 2 to participate in the enzyme catalytic reaction. The pH value of the reaction system was 7.0, the reaction temperature was 28°C, and extraction began at a flow rate of 1.39 L / s.

[0110] After the reaction is carried out for 3 hours, the inactivated enzyme filtering system is turned on for the first time, and then turned on once every 1 hour, and the operation time of each opening is 20 minutes, specifically: the enzyme filtering pump 6, the inactivated enzyme filter 7, the outlet C pipeline and the inlet D pipeline of the hydrolysis reactor 4 are turned on, so that the inactivated hydrolase in the lower section of the hydrolysis reaction zone of the hydrolysis reactor 4 is circulated and filtered by the inactivated enzyme filter 7 for 20 minutes, and the discharged hydrolase is about 16-20kg; the hydrolase transfer system is turned on after the inactivated enzyme filtering system is turned off, and the operation time of each opening is 20 minutes, specifically: after the inactivated hydrolase is discharged, the pipeline is switched, the outlet C pipeline of the hydrolysis reactor 4 and the inactivated enzyme filter 7 are turned off, and the outlet B pipeline of the hydrolysis reactor 4 is turned on to directly pump the hydrolase with decreased activity in the upper section of the hydrolysis zone of the hydrolysis reactor into the lower section of the hydrolysis zone of the hydrolysis reactor, and the operation is carried out for 20 minutes, and the amount of the transferred hydrolase is 16-28kg (20%-35%). The hydrolase supplement system is opened after the hydrolase transfer system is closed, specifically: the inlet A pipeline of the hydrolysis reactor 4 is opened, the enzyme suspension pump 3 is turned on, and 50L of enzyme suspension (enzyme concentration 40%, actual supplemented enzyme 20kg) is supplemented.

[0111] During the process, samples were taken every hour for analysis and the raw material normalization was less than 6.5%, the nicotinamide content was about 36.01%, and the yield was about 91.47%.

[0112] Table 1

[0113]

[0114]

[0115] As shown in Table 1, when filter screen A and B, hydrolase transfer system and inactivation enzyme filtration system are not provided in the hydrolysis reactor of comparative example 1, hydrolase can only be filtered by the hydrolyzate filter, and the amount of enzyme in the hydrolysis reactor is constantly reduced, and the continuous supplementation of hydrolase is required, resulting in a low utilization efficiency of the hydrolase in the reactor, while causing an increase in the use amount of the enzyme. When filter screen B, hydrolase transfer system and inactivation enzyme filtration system are not provided in the hydrolysis reactor of comparative example 2, the inactivated hydrolase accumulates in the reactor, affecting the mixing of fresh enzyme and raw material, causing the reaction speed to slow down, and because the reactor volume is limited, the inactivated enzyme needs to be regularly stopped to clean up, which not only affects the continuous operation, but also causes an increase in the use amount of the enzyme. Reflux line is not provided in comparative example 3, and the raw material that is not fully reacted cannot be circulated to continue the reaction, resulting in a low raw material conversion rate, and a reduction in product yield. Therefore, the present invention can timely supplement, transfer and scrap the hydrolase by setting the hydrolase supplement system, the transfer hydrolase system and the inactivated enzyme filtering system, so that the activity of the hydrolase in the hydrolysis reactor is maintained at a high level, a faster catalytic hydrolysis rate is achieved, and the amount of enzyme used is reduced. At the same time, the setting of the reflux pipeline can flexibly control the residence time of the raw material liquid to ensure a higher conversion rate of the raw material; the qualified nicotinamide solution is continuously extracted to avoid the accumulation of products and the continued hydrolysis to produce impurities, so that the product purity is high, the by-products are few, and the quality is improved.

Claims

1. A method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis, characterized in that: 3-cyanopyridine is mixed with a buffer solution as a raw material liquid in a hydrolysis reactor, and 3-cyanopyridine is hydrolyzed to produce nicotinamide under the catalytic action of a hydrolase; wherein a hydrolase supplement system, a hydrolase transfer system and an inactivated enzyme filtration system are provided in the hydrolysis reactor.

2. The method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 1, characterized in that: A filter is provided in the inner cavity of the hydrolysis reactor to divide the hydrolysis reaction zone into an upper section and a lower section. The upper section of the hydrolysis reaction zone is provided with a hydrolase replenishment system and a hydrolase transfer system, and the lower section of the hydrolysis reaction zone is provided with an inactivated enzyme filtration system; fresh hydrolase enters the upper section of the hydrolysis reaction zone through the hydrolase replenishment system, the hydrolase transfer system directly transfers the hydrolase with decreased activity in the upper section of the hydrolysis reaction zone to the lower section of the hydrolysis reaction zone, and the inactivated enzyme filtration system filters the inactivated hydrolase in the lower section of the hydrolysis reaction zone and then scraps it, thereby completing the replacement of the hydrolase and the graded utilization of different enzyme activities.

3. The method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 1, characterized in that: The inactivated enzyme filtration system is first turned on after the hydrolysis reaction has been carried out for 2h-6h, and then turned on once every 1h, and the operation time of each turn-on is 10-20min; The hydrolase transfer system is turned on after the inactivated enzyme filtration system is turned off, and each operation time is 10-20 minutes; The hydrolase supplement system is opened after the hydrolase transfer system is closed, and the amount of supplemented hydrolase is 20%-35% of the total mass of the hydrolase in the hydrolysis reactor.

4. The method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 1, characterized in that: The reaction liquid after the hydrolysis of 3-cyanopyridine is divided into reflux liquid and nicotinamide product, and the reflux liquid is returned to the hydrolysis reactor to continue the reaction; the flow ratio of the reflux liquid to the nicotinamide product is 4-10:

1.

5. The method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 1, characterized in that: The temperature of the raw material liquid is 20-50°C, the temperature of the hydrolysis reaction is 25°C-30°C, the pH value of the raw material liquid is 6.0-8.0, and the pH value of the hydrolysis reaction is 6-9.

6. The method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 1, characterized in that: The hydrolase is a suspension of Escherichia coli, and the concentration of the hydrolase is 5%-40%.

7. The method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 1, characterized in that: The buffer solution is a mixed solution of dipotassium hydrogen phosphate and potassium dihydrogen phosphate, the weight ratio of dipotassium hydrogen phosphate to potassium dihydrogen phosphate is 1.0-1.5:1, and the amount of the buffer solution is 50-70% of the weight of the raw material solution.

8. A device used in the method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 1, characterized in that: The device comprises a raw material liquid mixing tank (1), a hydrolysis reactor (4), an inactivated enzyme filter (7), a buffer tank (9), and a hydrolyzate filter (11); A filter screen A is provided at the upper part of the inner cavity of the hydrolysis reactor (4), which divides the hydrolysis reactor (4) into a hydrolysis product discharge area and a hydrolysis reaction area; a filter screen B is provided at the middle part of the inner cavity of the hydrolysis reactor (4), which divides the hydrolysis reaction area into an upper section and a lower section; The hydrolysis reactor (4) is provided with an inlet A, an inlet B, an inlet C, an inlet D and an outlet A, an outlet B, and an outlet C; the inlet A is connected to the upper section of the hydrolysis reaction zone, the inlet B, the inlet C, and the inlet D are all connected to the lower section of the hydrolysis reaction zone; the outlet A is connected to the hydrolysis product discharge zone, the outlet B is connected to the upper section of the hydrolysis reaction zone, and the outlet C is connected to the lower section of the hydrolysis reaction zone; The buffer tank (9) is provided with one inlet and two outlets; The inlet of the raw liquid mixing tank (1) is connected to the raw liquid pipeline, the outlet of the raw liquid mixing tank (1) is connected to the inlet B of the hydrolysis reactor (4) through the raw liquid feed pump (2), the fresh hydrolase pipeline is connected to the inlet A of the hydrolysis reactor (4) through the enzyme suspension pump (3), the outlet A of the hydrolysis reactor (4) is connected to the inlet of the buffer tank (9), one outlet of the buffer tank (9) is connected to the inlet C of the hydrolysis reactor (4) through the hydrolyzate circulation pump (8), the other outlet of the buffer tank (9) is connected to the inlet of the hydrolyzate filter (11) through the hydrolyzate extraction pump (10), and the outlet of the hydrolyzate filter (11) is connected to the subsequent concentration and crystallization process; The outlet B of the hydrolysis reactor (4) is connected to the inlet D of the hydrolysis reactor (4) through the enzyme filtration pump (6), and the outlet C of the hydrolysis reactor (4) is connected to the inlet D of the hydrolysis reactor (4) through the enzyme filtration pump (6) and the inactivated enzyme filter (7) in sequence.

9. The device used in the method for producing nicotinamide by continuous 3-cyanopyridine enzymatic hydrolysis according to claim 8 is characterized in that: A valve is provided on the pipeline connecting the outlet B of the hydrolysis reactor (4) and the enzyme filtration pump (6); A valve is provided on the pipeline connecting the outlet C of the hydrolysis reactor (4) and the enzyme filtration pump (6); A valve is provided on the pipeline connecting the outlet of the enzyme filtration pump (6) and the inactivated enzyme filter (7); A valve is provided on the pipeline connecting the outlet of the enzyme filtration pump (6) and the inlet D of the hydrolysis reactor (4).

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