A process for the production of sorbitol by hydrogenation of glucose

Abstract

The application discloses a method for preparing sorbitol by hydrogenation of glucose, which comprises the following steps: mixing glucose aqueous solution and a catalyst, filling hydrogen and heating to carry out hydrogenation reaction to obtain sorbitol; the catalyst is selected from one of Ni x Co 1‑x / La2O3 catalyst, Ni / La2O3 catalyst or Co / La2O3 catalyst, wherein x in the catalyst Ni x Co 1‑x / La2O3 is 0.1-0.9. The method provided by the application can realize efficient conversion of glucose and high-selectivity preparation of sorbitol under the action of non-noble metal catalyst and under mild conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sugar alcohol preparation, and in particular to a method for preparing sorbitol by hydrogenation of glucose. BACKGROUND

[0002] Sorbitol is a fine chemical with high added value and is widely used in food, medicine, cosmetics, chemical industry and many other fields. In the food industry, sorbitol is the most commonly used sugar alcohol, and it is currently the first largest variety of sugar alcohol production in China, accounting for the largest market share among similar polyols. In 2021, the production of sugar alcohol in China reached 1,543,800 tons, of which the production of sorbitol was 1,136,000 tons, accounting for 73.58%.

[0003] Currently, sorbitol is mainly obtained by catalytic hydrogenation of glucose. The reported glucose hydrogenation catalyst systems are mainly heterogeneous catalysis. The earliest catalyst to achieve industrialization is Raney-Ni catalyst, but the harsh reaction conditions, flammability during storage and use, and leaching of active metals are the main reasons for limiting its further application. In recent years, the development of supported catalysts has attracted much attention in order to overcome the above shortcomings of Raney-Ni. Among them, Ru and other noble metal supported catalysts show excellent activity, but the high cost limits the large-scale use of such catalysts. Chinese invention patent CN1214333A discloses a Ni-Fe-P-Al alloy catalyst, which can achieve a glucose conversion rate of 100% and a sorbitol selectivity of 99.2%, but the reaction conditions of the catalyst are relatively harsh, which requires a higher temperature (140℃). Chinese invention patent CN111302893A discloses a supported copper-nickel alloy catalyst, which can achieve a selectivity of 93.3% when the reaction temperature is 100℃, but the glucose conversion rate is only 85.2%, which needs to be further improved.

[0004] Therefore, it is of great significance to develop a cheap and efficient non-noble metal catalyst to catalyze the hydrogenation of glucose to prepare sorbitol with high conversion rate and high selectivity under mild reaction conditions. SUMMARY

[0005] The purpose of the present application is to provide a method for catalyzing the hydrogenation of glucose to prepare sorbitol, which can achieve efficient conversion of glucose and high selectivity preparation of sorbitol under mild conditions with the action of a non-noble metal catalyst.

[0006] The present application provides the following technical solutions:

[0007] A method for catalyzing the hydrogenation of glucose to prepare sorbitol, which comprises mixing a glucose aqueous solution and a catalyst, charging hydrogen and heating to perform hydrogenation reaction to obtain sorbitol; the catalyst is selected from Ni x Co1-x one or more of Ni / La2O3catalyst, Ni / La2O3catalyst or Co / La2O3catalyst, wherein the catalyst Ni x Co 1-x x in the Co / La2O3is 0.1-0.9.

[0008] The temperature of the hydrogenation reaction is 60-100℃; the time of the hydrogenation reaction is 0.5-8h. Preferably, to obtain higher selectivity of sorbitol, the temperature of the hydrogenation reaction is 70-90℃; considering that prolonging the reaction time can improve the conversion rate of glucose and the yield of sorbitol, the time of the hydrogenation reaction is 6-8h.

[0009] The hydrogen pressure is 1-4.5MPa. The hydrogen pressure can ensure excellent conversion efficiency, and also takes into account economic and safety considerations. Preferably, the hydrogen pressure is 3-4MPa. When the hydrogen pressure is in this range, higher glucose conversion rate and sorbitol selectivity can be obtained; and when the hydrogen pressure is greater than 4MPa, there is no significant difference in the conversion rate of glucose, so the hydrogen pressure does not need to be increased, further reducing the cost and safety problems.

[0010] The glucose to catalyst feed ratio is 3.6-14.4:1. Preferably, to achieve efficient conversion of glucose, while taking into account cost considerations, the amount of catalyst used is 30-45mg.

[0011] Preferably, the catalyst is Ni x Co 1-x Ni / La2O3catalyst or Ni / La2O3catalyst, wherein the catalyst Ni x Co 1-x x in the Co / La2O3is 0.4-0.8.

[0012] Further preferably, the catalyst is Ni 0.8 Co 0.2 Co / La2O3, the temperature of the hydrogenation reaction is 80-90℃, the time of the hydrogenation reaction is 4-8h, the hydrogen pressure is 3.5-4.5MPa, and the glucose to catalyst feed ratio is 3.6-4.8:1. Under the above conditions, the glucose conversion rate is at least 85.8% and the selectivity of sorbitol is at least 93.2%.

[0013] Further preferably, the catalyst is Ni 0.8 Co 0.2Ni / La2O3, the temperature of the hydrogenation reaction is 80-90℃, the time of the hydrogenation reaction is 6-8h, the hydrogen pressure is 3.5-4.5MPa, and the feed ratio of glucose to catalyst is 3.6-4.8:1. Under the above conditions, the conversion rate of glucose is at least 90%, and the selectivity of sorbitol is at least 93.2%.

[0014] Further preferably, the catalyst is Ni 0.8 Co 0.2 Ni / La2O3, the temperature of the hydrogenation reaction is 80℃, the time of the hydrogenation reaction is 6-8h, the hydrogen pressure is 4-4.5MPa, and the feed ratio of glucose to catalyst is 3.6-4.8:1. Under the above conditions, the conversion rate of glucose is at least 93%, and the selectivity of sorbitol is at least 95%.

[0015] Further preferably, the catalyst is Ni 0.8 Co 0.2 Ni / La2O3, the temperature of the hydrogenation reaction is 80℃, the time of the hydrogenation reaction is 6-8h, the hydrogen pressure is 4MPa, and the feed ratio of glucose to catalyst is 4.8:1. Under the above conditions, the conversion rate of glucose is at least 93.2%, and the selectivity of sorbitol is at least 96.5%.

[0016] The preparation method provided by the present application has low required temperature, low hydrogen pressure, high product selectivity, and is non-toxic, harmless and environmentally friendly.

[0017] In the present application, Ni x Co 1-x The preparation method of the Ni / La2O3 catalyst, the Ni / La2O3 catalyst and the Co / La2O3 catalyst is as follows:

[0018] (1) Dissolve lanthanum nitrate hexahydrate, nickel nitrate hexahydrate or / and cobalt nitrate hexahydrate and citric acid to obtain a mixed solution;

[0019] (2) Stir the mixed solution to a temperature of 80-100℃ until a gel state is formed to obtain a gel mixture;

[0020] (3) Dry the gel mixture and then calcine it in a muffle furnace at 600-800℃ for 5-8h;

[0021] (4) Reduce the product obtained in step (3) by passing H2 at 350-600℃ for 2-4h, cool it to 30-50℃ and pass a mixed gas of nitrogen and oxygen, or air, to passivate it for 0.5-1h to obtain a Ni x Co 1-x / La2O3 catalyst, a Ni / La2O3 catalyst or a Co / La2O3 catalyst.

[0022] Ni x Co1-x The preparation method of the La2O3catalyst, the Ni / La2O3catalyst and the Co / La2O3catalyst is specifically as follows:

[0023] Preparation of the NiCo / La2O3catalyst

[0024] According to the proportion of Ni and Co in the catalyst, 10 mmol of lanthanum nitrate hexahydrate, 10 xmmol of nickel nitrate hexahydrate, 10(1-x) mmol of cobalt nitrate hexahydrate (wherein x = 0.1-0.9) and 10 mmol of citric acid are dissolved in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stirred at room temperature for 1.5-3 h to form a uniform transparent solution. Then, the temperature is raised to 80-100 °C and stirred for 1-3 h until a gel state is formed to obtain a gel mixture. The gel mixture is placed in an oven at 100-120 °C overnight for drying, and the viscous dark solid after drying is placed in a muffle furnace and calcined at 600-800 °C for 5-8 h. Finally, H2is introduced at 350-600 °C for 2-4 h, the temperature is lowered to 30-50 °C and a mixed gas of nitrogen and oxygen, or air, is introduced for passivation for 0.5-1 h to obtain the NiCo / La2O3catalyst. According to the content of Ni and Co in the catalyst, the catalyst is recorded as Ni x Co 1-x / La2O3.

[0025] Preparation of the Ni / La2O3catalyst

[0026] According to the proportion of Ni and Co in the catalyst, 10 mmol of lanthanum nitrate hexahydrate, 10 xmmol of nickel nitrate hexahydrate, 10(1-x) mmol of cobalt nitrate hexahydrate (wherein x = 0.1-0.9) and 10 mmol of citric acid are dissolved in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stirred at room temperature for 1.5-3 h to form a uniform transparent solution. Then, the temperature is raised to 80-100 °C and stirred for 1-3 h until a gel state is formed to obtain a gel mixture. The gel mixture is placed in an oven at 100-120 °C overnight for drying, and the viscous dark solid after drying is placed in a muffle furnace and calcined at 600-800 °C for 5-8 h. Finally, H2is introduced at 350-600 °C for 2-4 h, the temperature is lowered to 30-50 °C and a mixed gas of nitrogen and oxygen, or air, is introduced for passivation for 0.5-1 h to obtain the NiCo / La2O3catalyst. According to the content of Ni and Co in the catalyst, the catalyst is recorded as Ni

[0027] Preparation of the Co / La2O3catalyst

[0028] Take 10 mmol of lanthanum nitrate hexahydrate, 10 mmol of cobalt nitrate hexahydrate and 10 mmol of citric acid, and dissolve them in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stir at room temperature for 3 h to form a uniform transparent solution. Then heat to 80-100℃ and stir for 1-3 h until a gel state is formed to obtain a gel mixture. Place the gel mixture in an oven at 100-120℃ overnight to dry, and place the viscous dark solid after drying in a muffle furnace at 600-800℃ for 5-8 h. Finally, reduce at 350-600℃ for 2-4 h by passing in H2, cool to 30-50℃ and pass in a mixture of nitrogen and oxygen gas, or air passivation for 0.5-1 h, to obtain a Co / La2O3 catalyst.

[0029] Compared with the prior art, the beneficial effects of the present application are reflected in:

[0030] (1) The catalyst in the present application has high glucose hydrogenation activity, and under optimized reaction conditions, the glucose conversion rate can reach 96.2% or more, and the sorbitol selectivity can reach 97.9% or more;

[0031] (2) The reaction temperature in the present application is mild, which is not easy to generate by-products, and the hydrogen pressure is low, the hydrogenation process is safe and pollution-free, and the requirement for production equipment is small;

[0032] (3) The catalyst in the present application is easy to recycle and reusable, has the advantages of low cost, stable performance, green environmental protection, etc.;

[0033] (4) The present application provides an effective way for the high-value utilization of biomass sugar, and has good social and economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Figure 1 is a crystal phase structure analysis chart of the catalyst in Example 1-5. DETAILED DESCRIPTION

[0035] The present application will be further described below through specific examples, and all raw materials involved in the implementation examples are commercially available or can be obtained by simple laboratory treatment.

[0036] Example 1

[0037] Take 10 mmol of lanthanum nitrate hexahydrate, 8 mmol of nickel nitrate hexahydrate, 2 mmol of cobalt nitrate hexahydrate and 10 mmol of citric acid to dissolve in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stir at room temperature for 3 h to form a uniform transparent solution. Then heated to 80℃ and stirred for 3h until a gel state is formed, to obtain a gel mixture. The gel mixture is placed in an oven at 120℃ overnight to dry, and the viscous dark solid after drying is placed in a muffle furnace at 800℃ for 8h. Finally, reduce at 500℃ for 2h, cool to 30℃ and pass through air passivation for 0.5h, to obtain the NiCo / La2O3 catalyst, recorded as Ni 0.8 Co 0.2 / La2O3.

[0038] The hydrogenation performance of the catalyst was investigated by preparing sorbitol from glucose hydrogenation. Take 45 mg of catalyst, 3 mL of 0.4M glucose aqueous solution into 8 mL of high-pressure reaction kettle. The reaction temperature is 80℃, the hydrogen pressure is 4.0MPa, and the reaction time is 6h. The conversion rate of glucose and the selectivity of sorbitol were determined by high performance liquid chromatography with differential detector. The results of catalyst activity evaluation are shown in Table 1.

[0039] The crystal phase structure of the prepared catalyst was analyzed by Japanese science Miniflex 600X ray diffractometer, and the determination results are shown in the following table. Figure 1 .

[0040] Example 2

[0041] Take 10 mmol of lanthanum nitrate hexahydrate, 6 mmol of nickel nitrate hexahydrate, 4 mmol of cobalt nitrate hexahydrate and 10 mmol of citric acid to dissolve in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stir at room temperature for 2 h to form a uniform transparent solution. Then heated to 90℃ and stirred for 2h until a gel state is formed, to obtain a gel mixture. The gel mixture is placed in an oven at 110℃ overnight to dry, and the viscous dark solid after drying is placed in a muffle furnace at 800℃ for 7h. Finally, reduce at 500℃ for 3h, cool to 30℃ and pass through air passivation for 0.5h, to obtain the NiCo / La2O3 catalyst, recorded as Ni 0.6 Co 0.4 / La2O3.

[0042] The hydrogenation performance evaluation method of the catalyst is the same as that of Example 1, and the evaluation results are shown in Table 1.

[0043] The crystal phase structure of the prepared catalyst was analyzed by Japanese science Miniflex 600X ray diffractometer, and the determination results are shown in the following table. Figure 1 .

[0044] Example 3

[0045] Take 10 mmol of lanthanum nitrate hexahydrate, 4 mmol of nickel nitrate hexahydrate, 6 mmol of cobalt nitrate hexahydrate and 10 mmol of citric acid, dissolve them in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stir at room temperature for 1.5 h to form a uniform transparent solution. Then heat to 85°C and stir for 2.5 h until a gel state is formed to obtain a gel mixture. The gel mixture is placed in an oven at 100°C overnight to dry, and the viscous dark solid after drying is placed in a muffle furnace at 600°C for 6 h. Finally, reduce at 450°C for 2 h, cool to 30°C and pass air to passivate for 1 h to obtain the NiCo / La2O3 catalyst, which is recorded as Ni 0.4 Co 0.6 / La2O3.

[0046] The hydrogenation performance evaluation method of the catalyst is the same as that in Example 1, and the evaluation results are shown in Table 1.

[0047] The crystal phase structure of the prepared catalyst is analyzed by using a Japanese Rigaku Miniflex 600 X-ray diffractometer, and the determination results are shown in the attached Figure 1 .

[0048] Example 4

[0049] Take 10 mmol of lanthanum nitrate hexahydrate, 2 mmol of nickel nitrate hexahydrate, 8 mmol of cobalt nitrate hexahydrate and 10 mmol of citric acid, dissolve them in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stir at room temperature for 1.5 h to form a uniform transparent solution. Then heat to 80°C and stir for 2 h until a gel state is formed to obtain a gel mixture. The gel mixture is placed in an oven at 100°C overnight to dry, and the viscous dark solid after drying is placed in a muffle furnace at 700°C for 8 h. Finally, reduce at 550°C for 3 h, cool to 30°C and pass air to passivate for 1 h to obtain the NiCo / La2O3 catalyst, which is recorded as Ni 0.2 Co 0.8 / La2O3.

[0050] The hydrogenation performance evaluation method of the catalyst is the same as that in Example 1, and the evaluation results are shown in Table 1.

[0051] The crystal phase structure of the prepared catalyst is analyzed by using a Japanese Rigaku Miniflex 600 X-ray diffractometer, and the determination results are shown in the attached Figure 1 .

[0052] Example 5

[0053] Take 10 mmol of lanthanum nitrate hexahydrate, 10 mmol of nickel nitrate hexahydrate and 10 mmol of citric acid and dissolve them in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stir at room temperature for 2 h to form a uniform transparent solution. Then heat to 90°C and stir for 3 h until a gel state is formed to obtain a gel mixture. Place the gel mixture in an oven at 100°C overnight to dry, and place the viscous dark solid after drying in a muffle furnace at 750°C for 6 h. Finally, reduce at 600°C for 3 h with H2, cool to 30°C and pass air through for 0.5 h to obtain the Ni / La2O3 catalyst.

[0054] The hydrogenation performance evaluation method of the catalyst is the same as in Example 1, and the evaluation results are shown in Table 1.

[0055] The crystal phase structure of the prepared catalyst is analyzed by a Japanese Rigaku Miniflex 600 X-ray diffractometer, and the determination results are shown in Table 2. Figure 1 .

[0056] Example 6

[0057] Take 10 mmol of lanthanum nitrate hexahydrate, 10 mmol of cobalt nitrate hexahydrate and 10 mmol of citric acid and dissolve them in a mixed solution of 12 mL of water and 4 mL of anhydrous ethanol, stir at room temperature for 2 h to form a uniform transparent solution. Then heat to 90°C and stir for 3 h until a gel state is formed to obtain a gel mixture. Place the gel mixture in an oven at 110°C overnight to dry, and place the viscous dark solid after drying in a muffle furnace at 700°C for 7 h. Finally, reduce at 600°C for 3 h with H2, cool to 40°C and pass air through for 1 h to obtain the Co / La2O3 catalyst.

[0058] The hydrogenation performance evaluation method of the catalyst is the same as in Example 1, and the evaluation results are shown in Table 1.

[0059] The crystal phase structure of the prepared catalyst is analyzed by a Japanese Rigaku Miniflex 600 X-ray diffractometer, and the determination results are shown in Table 2. Figure 1 .

[0060] Table 1 Evaluation results of the activities of different catalysts

[0061]

[0062]

[0063] Example 7

[0064] Take 45 mg of Ni 0.8 Co 0.2Ni / La2O3 catalyst, 3 mL of 0.4 M glucose aqueous solution was added into 8 mL of a high-pressure reactor. The reaction temperature was 80 °C, the hydrogen pressure was 4.0 MPa, and the reaction time was 0.5-8 h. The conversion of glucose and the selectivity of sorbitol were determined by high performance liquid chromatography with a differential detector. The results of catalyst activity evaluation are shown in Table 2:

[0065] Table 2 Activity evaluation results of different reaction times

[0066]

[0067] Example 8

[0068] Take 45 mg Ni 0.8 Co 0.2 / La2O3 catalyst, 3 mL of 0.4 M glucose aqueous solution was added into 8 mL of a high-pressure reactor. The reaction temperature was 60-100 °C, the hydrogen pressure was 4.0 MPa, and the reaction time was 6 h. The conversion of glucose and the selectivity of sorbitol were determined by high performance liquid chromatography with a differential detector. The results of catalyst activity evaluation are shown in Table 3:

[0069] Table 3 Activity evaluation results of different reaction temperatures

[0070]

[0071]

[0072] Example 9

[0073] Take 45 mg Ni 0.8 Co 0.2 / La2O3 catalyst, 3 mL of 0.4 M glucose aqueous solution was added into 8 mL of a high-pressure reactor. The reaction temperature was 80 °C, the hydrogen pressure was 1.0-4.5 MPa, and the reaction time was 6 h. The conversion of glucose and the selectivity of sorbitol were determined by high performance liquid chromatography with a differential detector. The results of catalyst activity evaluation are shown in Table 4:

[0074] Table 4 Activity evaluation results of different reaction temperatures

[0075]

[0076] Example 10

[0077] Take 15-60 mg Ni 0.8 Co 0.2The 0.4 M aqueous glucose solution 3 mL was added into 8 mL of the high-pressure reactor. The reaction temperature was 80 °C, the hydrogen pressure was 4.0 MPa, and the reaction time was 6 h. The conversion of glucose and the selectivity of sorbitol were determined by high performance liquid chromatography with differential detector. The results of the activity evaluation of the catalysts are shown in Table 5:

[0078] Table 5 Activity evaluation results of different catalyst dosages

[0079]

[0080] The above detailed description of the specific embodiments of the present application has described the technical solutions and beneficial effects of the present application. It should be understood that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, supplement, and equivalent replacement within the principle range of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing sorbitol by hydrogenation of glucose, characterized in that, The method involves mixing a glucose aqueous solution and a catalyst, then introducing hydrogen gas and heating to perform a hydrogenation reaction to obtain sorbitol; the catalyst is selected from Ni... x Co 1-x One of the following: a Ni / La2O3 catalyst, a Ni / La2O3 catalyst, or a Co / La2O3 catalyst, wherein the catalyst is Ni x Co 1-x In La2O3, x ranges from 0.1 to 0.

9. The hydrogenation reaction is carried out at a temperature of 60-100℃ and for a time of 0.5-8 hours. The feed ratio of glucose to catalyst is 3.6-14.4:1; The catalyst is prepared by: (1) Dissolve lanthanum nitrate hexahydrate, nickel nitrate hexahydrate and / or cobalt nitrate hexahydrate in citric acid to obtain a mixed solution; (2) Heat the mixed solution to 80-100℃ and stir until a gel is formed to obtain a gel mixture; (3) After drying the gel mixture, calcine it in a muffle furnace at 600-800℃ for 5-8 hours; (4) Reduce the product obtained in step (3) with H2 at 350-600℃ for 2-4 hours, cool it down to 30-50℃ and passivate it with a mixture of nitrogen and oxygen or air for 0.5-1 hours to obtain Ni. x Co 1-x / La2O3 catalyst, Ni / La2O3 catalyst or Co / La2O3 catalyst.

2. The method for preparing sorbitol by hydrogenation of glucose according to claim 1, characterized in that, The hydrogen pressure is 1-4.5 MPa.

3. The method for preparing sorbitol by hydrogenation of glucose according to claim 1, characterized in that, The catalyst is Ni x Co 1-x / La2O3, x is 0.4-0.8; or the catalyst is Ni / La2O3.

4. The method for preparing sorbitol by hydrogenation of glucose according to claim 1, characterized in that, The catalyst is Ni 0.8 Co 0.2 The hydrogenation reaction of / La2O3 takes place at a temperature of 80-90℃ for 4-8 hours, with a hydrogen pressure of 3.5-4.5 MPa and a glucose-to-catalyst ratio of 3.6-4.8:

1.

5. The method for preparing sorbitol by hydrogenation of glucose according to claim 1, characterized in that, The catalyst is Ni 0.8 Co 0.2 The hydrogenation reaction of / La2O3 takes place at a temperature of 80-90℃ for 6-8 hours, with a hydrogen pressure of 3.5-4.5 MPa and a glucose-to-catalyst ratio of 3.6-4.8:1.

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