A catalyst applied to biomass pyrolysis and a pyrolysis method

Abstract

The application belongs to the technical field of biomass energy, and particularly relates to a catalyst applied to biomass pyrolysis and a pyrolysis method. The catalyst comprises sodium carbonate and polyferric sulfate. The application uses the compound of sodium carbonate and polyferric sulfate as the catalyst, can reduce the pyrolysis temperature of biomass, improve the pyrolysis rate, and greatly reduce the industrial energy consumption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of biomass energy, and particularly relates to a catalyst applied to biomass pyrolysis and a pyrolysis method. BACKGROUND

[0002] With the rapid economic development, clean energy utilization has attracted widespread attention. At present, biomass resources are considered to be the best choice to replace fossil fuels, and have advantages such as wide source, large resource quantity and low pollution. Distiller's grains are the remaining residues after brewing, which are mainly produced by grains and other fermented and distilled processes, including unextracted solid substances and liquid residues. With the continuous progress of biotechnology, the conversion and utilization of distiller's grains have attracted widespread attention. Generally, they are converted into fertilizers, fuels and other high-value products through fermentation, enzymatic hydrolysis and other means. However, in the actual application process, the conversion and reuse of distiller's grains still face problems such as complex operation and high cost, which limit their further widespread application.

[0003] Biomass contains rich renewable resources and has the characteristics of green and low carbon. Through the use of catalysts, it can be converted into high-value products such as bio-oil and synthesis gas, which not only helps to reduce the dependence on fossil fuels, but also promotes the development of renewable energy. However, the catalysts currently applied to biomass have many defects, for example, high-performance catalysts are often expensive, increasing the cost; under high temperature or long-time operation conditions, they are easy to deactivate or change structure, resulting in a decrease in catalyst performance and affecting production efficiency; the catalysts have poor catalytic activity and low efficiency at low temperature. Therefore, how to improve the performance of the catalysts is of great significance for expanding the application of biomass. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defects of the catalysts applied to biomass in the prior art, such as the need for pyrolysis under high temperature conditions, poor low-temperature pyrolysis effect and low pyrolysis yield, so as to provide a catalyst applied to biomass pyrolysis and a pyrolysis method.

[0005] To this end, the present application provides the following technical solutions.

[0006] The present application provides a catalyst applied to biomass pyrolysis, comprising: sodium carbonate and polyferric sulfate.

[0007] The mass ratio of the sodium carbonate to the polyferric sulfate is (1-10):(1-10);

[0008] Preferably, the biomass comprises at least one of distiller's grains and rice husks.

[0009] The present application also provides a pyrolysis method of biomass, comprising the following steps:

[0010] (1) preparing a mixed solution by using a catalyst; the catalyst comprises sodium carbonate and polyferric sulfate;

[0011] (2) spraying the mixed solution on the surface of the biomass, drying, and pyrolyzing.

[0012] The mass ratio of the catalyst to the biomass is (1-10):100; and / or,

[0013] The concentration of the mixed solution is 20-40wt%.

[0014] The spraying pressure is 0.2-1Mpa. During the spraying process, controlling the spraying pressure can better control the flow rate of the mixed solution, and controlling the spraying pressure can make the particle size of the mist droplets formed by the mixed solution be 50-100μm.

[0015] The drying temperature is 70-90℃, and the time is 12-16h.

[0016] The pyrolysis temperature is 250-400℃, and the time is 30-60min.

[0017] The heating rate of the pyrolysis is 10-20℃ / min.

[0018] Further, when the spraying is performed, the step of stirring the biomass is further included;

[0019] Preferably, the stirring speed is 60-100r / min.

[0020] The biomass comprises at least one of rice husk and vinasse;

[0021] Preferably, the biomass comprises vinasse.

[0022] The technical scheme of the present application has the following advantages:

[0023] 1. The catalyst applied to the pyrolysis of biomass provided by the present application comprises sodium carbonate and polyferric sulfate. The present application uses sodium carbonate and polyferric sulfate as a catalyst, which can reduce the pyrolysis temperature of biomass, improve the pyrolysis rate, and greatly reduce the industrial energy consumption.

[0024] 2. The pyrolysis method of biomass provided by the present application, the pyrolysis method comprises (1) preparing a mixed solution of a catalyst; the catalyst comprises sodium carbonate and polyferric sulfate; (2) spraying the mixed solution on the surface of the biomass, drying and pyrolyzing. The present application uses sodium carbonate and polyferric sulfate as a catalyst, disperses the catalyst in a high-dispersion form on the surface of the biomass, prepares biomass material loaded with the catalyst, and then pyrolyzes, thereby significantly reducing the pyrolysis temperature and time of the biomass, achieving the pyrolysis effect of high temperature at a lower temperature, shortening the pyrolysis time, promoting the generation of biomass carbon from the biomass material under the action of a heat source, and not affecting the yield and calorific value after carbonization. The present application also provides a method for recycling distiller's grains, which widens the application scenarios of the distiller's grains and is not limited to feed and the like.

[0025] The main components of the distiller's grains and rice husks in the present application are cellulose and hemicellulose, and sodium carbonate and polyferric sulfate are used as catalysts, which helps to reduce the pyrolysis temperature and time of cellulose and hemicellulose, thereby reducing the energy consumption in the pyrolysis process and more effectively utilizing the distiller's grains and rice husks. The biochar obtained by pyrolysis of the biomass in the present application can be used as a raw material for CO synthesis gas, green methanol and activated carbon.

[0026] 3. The pyrolysis method of biomass provided by the present application, the present application controls the particle size of the mist droplets formed in the spraying process, which can ensure the dispersion effect of the catalyst on the surface of the biomass, so that the catalyst is uniformly attached to the surface of the biomass for pyrolysis. This spraying method is more conducive to the later industrial application. DETAILED DESCRIPTION

[0027] The following examples are provided to better further understand the present application and are not limited to the best mode of the present application, and do not constitute a limitation on the content and scope of protection of the present application. Any person who obtains any product identical or similar to the present application under the inspiration of the present application or by combining the present application with other prior art features falls within the scope of protection of the present application.

[0028] In the examples, the specific experimental steps or conditions are not specified, and can be performed according to the conventional experimental steps described in the literature. The reagents or instruments used are not specified by the manufacturer, and are conventional reagent products that can be obtained by purchase.

[0029] Distiller's grains are the remaining residues after brewing, and resource recycling thereof can improve the product added value. At present, the conversion and recycling of distiller's grains face the problems of complex operation and high cost. In addition, the catalysts used in the prior art for biomass have poor catalytic performance, which affects the production efficiency and is not suitable for processing distiller's grains. Therefore, the present application provides the following technical solutions.

[0030] In a first aspect, the present application provides a catalyst for biomass pyrolysis, comprising: sodium carbonate and polyferric sulfate.

[0031] The mass ratio of the sodium carbonate and the polyferric sulfate is (1-10):(1-10);

[0032] Preferably, the biomass includes at least one of distiller's grains and rice husks.

[0033] The sodium carbonate and the polyferric sulfate are compounded as a catalyst, which can reduce the pyrolysis temperature of biomass, improve the pyrolysis rate, and reduce energy consumption, solving many problems existing in the prior art and overcoming the defects of the existing biomass catalysts which are not suitable for processing biomass such as distiller's grains and rice husks.

[0034] In a second aspect, the present application provides a method for pyrolysis of biomass, comprising the following steps:

[0035] (1) preparing a mixed solution of a catalyst; the catalyst includes sodium carbonate and polyferric sulfate;

[0036] (2) spraying the mixed solution on the surface of the biomass, drying, and pyrolyzing.

[0037] In the present application, the catalyst is first dispersed on the surface of the biomass to obtain a biomass material loaded with the catalyst, and then pyrolysis is performed, which significantly reduces the pyrolysis temperature and time of the biomass, achieves high-temperature pyrolysis effect at a lower temperature, shortens the pyrolysis time, promotes the generation of biomass carbon from the biomass material under the action of a heat source, does not affect the yield and calorific value after carbonization, improves the product added value of biomass such as distiller's grains and rice husks, and the bio-carbon obtained after pyrolysis can be used as raw material for CO synthesis gas, green methanol, and activated carbon.

[0038] As an optional embodiment, the mass ratio of the catalyst to the biomass is (1-10):100; and / or,

[0039] The concentration of the mixed solution is 20-40wt%.

[0040] The spraying pressure is 0.2-1Mpa.

[0041] As an example, the mass ratio of the catalyst to the biomass is 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, or a range value between any two numerical values. The spraying pressure is 0.2Mpa, 0.3Mpa, 0.4Mpa, 0.5Mpa, 0.6Mpa, 0.7Mpa, 0.8Mpa, 0.9Mpa, 1Mpa, or a range value between any two numerical values.

[0042] As an optional embodiment, the drying temperature is 70-90℃, and the time is 12-16h.

[0043] The temperature of the pyrolysis is 250-400℃, and the time is 30-60min.

[0044] The temperature increasing rate of the pyrolysis is 10-20℃ / min.

[0045] As an optional embodiment, when the spraying is performed, the step of stirring the biomass is further included.

[0046] Preferably, the rotating speed of the stirring is 60-100r / min.

[0047] It should be noted that the stirring is started at the same time when the spraying is performed, and the stirring time is the spraying time. The stirring is stopped after all the mixed solution is sprayed onto the surface of the biomass.

[0048] As an optional embodiment, the biomass includes at least one of rice husk and vinasse.

[0049] Preferably, the biomass includes vinasse.

[0050] The manufacturer of sodium carbonate used in the following examples is from Macklin, and the manufacturer of polyferric sulfate is from Macklin.

[0051] Example 1

[0052] The present embodiment provides a pyrolysis method of biomass, using sodium carbonate and polyferric sulfate as catalysts, including the following steps:

[0053] (1) A certain amount of sodium carbonate and polyferric sulfate are weighed according to the mass ratio of 3:1, and are placed in 200ml water, ultrasonic for 30min, so as to be completely dispersed, and 30wt% mixed solution is obtained.

[0054] (2) Vinasse is used as biomass, the mass ratio of the total mass of sodium carbonate and polyferric sulfate to the mass of vinasse is 4:100, the above mixed solution is completely sprayed onto the surface of vinasse, the spraying pressure is 0.5Mpa, the flow rate of the mixed solution is 0.5m / S, the droplet size of the mixed solution is 50-100μm during the spraying process, the biomass is stirred during the spraying process, the rotating speed of the stirring is 60r / min, the stirring is continuously performed until the spraying is completed, and then it is placed in an oven at 80℃, and is dried for 16h, so as to obtain vinasse loaded with catalyst. Then, it is pyrolyzed for 60min after being heated to 300℃ at a temperature increasing rate of 10℃ / min under nitrogen atmosphere, the carbon yield of vinasse and the time to reach stable carbon yield are recorded, and the results are shown in Table 1. The carbon yield is obtained by calculating the mass before and after pyrolysis.

[0055] Example 2

[0056] The embodiment provides a pyrolysis method of biomass, taking sodium carbonate and polymeric ferric sulfate as catalysts, and comprises the following steps:

[0057] (1) A certain amount of sodium carbonate and polymeric ferric sulfate are taken according to the mass ratio of 1:1, and are placed in 200ml water, and are ultrasonically treated for 30min, so that they are completely dispersed, and 30wt% mixed solution is obtained.

[0058] (2) Taking distiller's grains as biomass, the mass ratio of the total mass of sodium carbonate and polymeric ferric sulfate to the mass of distiller's grains is 6:100, the mixed solution is sprayed onto the surface of the distiller's grains, the spraying pressure is 0.8Mpa, the flow rate of the mixed solution is 0.7m / S, the droplet size of the mixed solution is 50-100μm during the spraying process, the biomass is stirred during the spraying process, the stirring speed is 60r / min, the stirring is continuously performed until the spraying is completed, then the biomass is placed in a 90℃ oven, and is dried for 14h, and the catalyst-loaded distiller's grains are obtained. Then, the distiller's grains are pyrolyzed under a nitrogen atmosphere at a temperature rising rate of 15℃ / min to 280℃ for 60min, the carbon yield of the distiller's grains and the time for reaching the stable carbon yield are recorded, and the results are shown in Table 1.

[0059] Example 3

[0060] The embodiment provides a pyrolysis method of biomass, taking sodium carbonate and polymeric ferric sulfate as catalysts, and comprises the following steps:

[0061] (1) A certain amount of sodium carbonate and polymeric ferric sulfate are taken according to the mass ratio of 3:5, and are placed in 200ml water, and are ultrasonically treated for 30min, so that they are completely dispersed, and 30wt% mixed solution is obtained.

[0062] (2) Taking distiller's grains as biomass, the mass ratio of the total mass of sodium carbonate and polymeric ferric sulfate to the mass of distiller's grains is 8:100, the mixed solution is sprayed onto the surface of the distiller's grains, the spraying pressure is 0.6Mpa, the flow rate of the mixed solution is 0.6m / S, the droplet size of the mixed solution is 50-100μm during the spraying process, the biomass is stirred during the spraying process, the stirring speed is 60r / min, the stirring is continuously performed until the spraying is completed, then the biomass is placed in a 90℃ oven, and is dried for 12h, and the catalyst-loaded distiller's grains are obtained. Then, the distiller's grains are pyrolyzed under a nitrogen atmosphere at a temperature rising rate of 15℃ / min to 300℃ for 60min, the carbon yield of the distiller's grains and the time for reaching the stable carbon yield are recorded, and the results are shown in Table 1.

[0063] Example 4

[0064] The embodiment provides a pyrolysis method of biomass, taking sodium carbonate and polymeric ferric sulfate as catalysts, and comprises the following steps:

[0065] (1) A certain amount of sodium carbonate and polymeric ferric sulfate were weighed according to a mass ratio of 3:7, and were placed in 200 ml of water, and were ultrasonically dispersed for 30 min to obtain a 30 wt% mixed solution.

[0066] (2) The total mass of sodium carbonate and polymeric ferric sulfate was 1:10 of the mass of the distiller's grains, and the mixed solution was sprayed onto the surface of the distiller's grains, the spraying pressure was 0.9 MPa, the flow rate of the mixed solution was 0.8 m / S, the droplet size of the mixed solution was 50-100 μm during the spraying process, the biomass was stirred at a stirring speed of 80 r / min during the spraying process, and after 20 min of continuous stirring, the biomass was placed in an oven at 70°C for 14 h of drying. The distiller's grains loaded with the catalyst were obtained. Then, the distiller's grains were pyrolyzed under a nitrogen atmosphere at a temperature increasing rate of 15°C / min to 320°C for 60 min, and the carbon yield of the distiller's grains and the time for reaching a stable carbon yield were recorded. The results are shown in Table 1.

[0067] Example 5

[0068] The present example provides a method for pyrolysis of biomass, using sodium carbonate and polymeric ferric sulfate as catalysts, comprising the following steps:

[0069] (1) A certain amount of sodium carbonate and polymeric ferric sulfate were weighed according to a mass ratio of 9:1, and were placed in 200 ml of water, and were ultrasonically dispersed for 30 min to obtain a 30 wt% mixed solution.

[0070] (2) The total mass of sodium carbonate and polymeric ferric sulfate was 2:100 of the mass of the distiller's grains, and the mixed solution was completely sprayed onto the surface of the distiller's grains, the spraying pressure was 0.5 MPa, the flow rate of the mixed solution was 0.5 m / S, the droplet size of the mixed solution was 50-100 μm during the spraying process, the biomass was stirred at a stirring speed of 60 r / min during the spraying process, and after continuous stirring until the end of the spraying, the biomass was placed in an oven at 80°C for 16 h of drying. The distiller's grains loaded with the catalyst were obtained. Then, the distiller's grains were pyrolyzed under a nitrogen atmosphere at a temperature increasing rate of 10°C / min to 300°C for 60 min, and the carbon yield of the distiller's grains and the time for reaching a stable carbon yield were recorded. The results are shown in Table 1.

[0071] Comparative Example 1

[0072] The present comparative example provides a method for pyrolysis of biomass, which is different from Example 1 in that zinc sulfate is used instead of polymeric ferric sulfate.

[0073] Comparative Example 2

[0074] The present comparative example provides a method for pyrolysis of biomass, which is different from Example 1 in that ferrous sulfate is used instead of polymeric ferric sulfate.

[0075] Comparative Example 3

[0076] This comparative example provides a biomass pyrolysis method, which is different from Example 1 in that the polymeric ferric sulfate is removed.

[0077] Comparative Example 4

[0078] This comparative example provides a biomass pyrolysis method, which is different from Example 1 in that the sodium carbonate and polymeric ferric sulfate are removed.

[0079] Table 1: Test results of each example and comparative example

[0080] Example Carbon yield (%) Time required to reach a stable carbon yield (min) Example 1 70.2 40 Example 2 72.4 32 Example 3 72.8 31 Example 4 73.0 30 Example 5 70.2 34 Comparative Example 1 65.2 42 Comparative Example 2 68.4 45 Comparative Example 3 69.7 41 Comparative Example 4 61 51

[0081] According to the results in Table 1, the present application uses sodium carbonate and polymeric ferric sulfate as a complex catalyst for biomass pyrolysis, which can improve the carbon yield and shorten the time to reach a stable carbon yield. From Comparative Examples 1-2, compared with zinc sulfate or ferrous sulfate, the present application has a synergistic effect between sodium carbonate and polymeric ferric sulfate, which can significantly improve the carbon yield and reduce the pyrolysis time. From Comparative Examples 3-4, using single sodium carbonate or polymeric ferric sulfate as a catalyst, the pyrolysis yield is low and the time is long, which further shows that the use of sodium carbonate and polymeric ferric sulfate in the present application has a significant effect.

[0082] Obviously, the above examples are only examples for clarity, and are not limitations on the embodiments. Based on the above description, other different forms of changes or variations can also be made by those of ordinary skill in the art. Here, it is not necessary and impossible to exhaust all embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for pyrolysis of biomass, characterized in that, Includes the following steps: (1) The catalyst is prepared into a mixture; the catalyst includes sodium carbonate and polyferric sulfate; (2) The mixture is sprayed onto the surface of biomass, dried, and pyrolyzed; The mass ratio of sodium carbonate to polyferric sulfate is (1-10):(1-10); The mass ratio of the catalyst to the biomass is (1-10):100; The concentration of the mixture is 20-40 wt%; The pyrolysis temperature is 250-400℃ and the time is 30-60 min.

2. The pyrolysis method according to claim 1, characterized in that, The spraying pressure is 0.2-1 MPa.

3. The pyrolysis method according to claim 1, characterized in that, The drying temperature is 70-90℃, and the time is 12-16h.

4. The pyrolysis method according to claim 1, characterized in that, The heating rate of the pyrolysis is 10-20℃ / min.

5. The pyrolysis method according to claim 1, characterized in that, The spraying process also includes a step of stirring the biomass.

6. The pyrolysis method according to claim 5, characterized in that, The stirring speed is 60-100 r / min.

7. The pyrolysis method according to any one of claims 1-6, characterized in that, The biomass includes at least one of rice husks and distiller's grains.

8. The pyrolysis method according to claim 7, characterized in that, The biomass includes distiller's grains.