Catalyst applied to biomass pyrolysis and pyrolysis method

Abstract

The invention 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 sodium carbonate and the polyferric sulfate are compounded as the catalyst, so that the pyrolysis temperature of the biomass can be reduced, the pyrolysis rate is increased, and the industrial energy consumption is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass energy, and in particular relates to a catalyst and a pyrolysis method for biomass pyrolysis. Background Art

[0002] With the rapid economic development, the utilization of clean energy has received extensive attention. At present, biomass resources are considered to be the best choice to replace fossil fuels, with the advantages of wide sources, large resources and low pollution. Wine lees, as the remaining residue after brewing, are mainly produced by the fermentation and distillation process of grains, including unextracted solid matter and liquid residues. With the continuous advancement of biotechnology, the conversion and utilization of wine lees biomass has received extensive attention. Generally, it is converted into high-value-added products such as fertilizers and fuels through fermentation, enzymolysis and other means. However, in the actual application process, the conversion and reuse of wine lees still faces the problems of complex operation and high cost, which limits its further widespread application.

[0003] Biomass contains abundant renewable resources and has the characteristics of being green and low-carbon. It can be converted into high-value products such as bio-oil and synthesis gas by using catalysts, which not only helps to reduce dependence on fossil fuels, but also promotes the development of renewable energy. There are many defects in the catalysts currently used in biomass. For example, high-performance catalysts are often expensive, which increases costs; they are easily deactivated or structurally changed under high temperature or long-term operation conditions, resulting in a decrease in catalyst performance and affecting production efficiency; catalysts have poor catalytic activity and low efficiency at low temperatures. How to improve catalyst performance is of great significance to expanding the application of biomass. Summary of the invention

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

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

[0006] The invention 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 invention also provides a biomass pyrolysis method, comprising the following steps:

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

[0011] (2) Spraying the mixed solution on the surface of 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 liquid, and controlling the spraying pressure can make the particle size of the droplets formed by the mixed liquid 50-100μm.

[0015] The drying temperature is 70-90° C. and the drying time is 12-16 hours.

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

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

[0018] Furthermore, when the spraying is performed, the step of stirring the biomass is also included;

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

[0020] The biomass comprises at least one of rice husk and distiller's grains;

[0021] Preferably, the biomass comprises distillers grains.

[0022] The technical solution of the present invention has the following advantages:

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

[0024] 2. The pyrolysis method of biomass provided by the present invention comprises (1) preparing a catalyst into a mixed liquid; the catalyst comprises sodium carbonate and polyferric sulfate; (2) spraying the mixed liquid on the surface of the biomass, drying, and pyrolyzing. The present invention uses a compound of sodium carbonate and polyferric sulfate as a catalyst, disperses the catalyst on the surface of the biomass in a highly dispersed form, prepares a biomass material loaded with a catalyst, and then pyrolyzes it, which significantly reduces the pyrolysis temperature and time of the biomass, achieves a high-temperature pyrolysis effect at a relatively low temperature, shortens the pyrolysis time, and promotes the biomass material to generate biomass carbon under the action of a heat source, without affecting the yield and calorific value after carbonization. The present invention also provides a method for recycling vinasse, which broadens the application scenarios of vinasse, not limited to feed, etc.

[0025] The main components of the wine lees and rice husks of the present invention are cellulose and hemicellulose, and sodium carbonate and polyferric sulfate are used as catalysts to help reduce the cracking temperature and time of cellulose and hemicellulose, thereby reducing the energy consumption of the cracking process and more effectively utilizing the wine lees and rice husks. The biochar obtained after pyrolysis of the biomass of the present invention can be used as raw materials such as CO synthesis gas, green methanol and activated carbon.

[0026] 3. The biomass pyrolysis method provided by the present invention controls the particle size of the droplets formed by the mixed liquid during the spraying process, which can ensure the dispersion effect of the catalyst on the biomass surface, so that it is evenly attached to the biomass surface for pyrolysis. This spraying method is more conducive to later industrial applications. DETAILED DESCRIPTION

[0027] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0028] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0029] Wine lees are the residue left after brewing wine. Recycling them as resources can increase the added value of products. At present, the conversion and recycling of wine lees faces 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 production efficiency and is not suitable for treating wine lees. To this end, the present invention provides the following technical solutions.

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

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

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

[0033] The combination of sodium carbonate and polyferric sulfate as a catalyst can reduce the pyrolysis temperature of biomass, increase the pyrolysis rate, and reduce energy consumption, solving many problems existing in the application of existing technologies to biomass catalysts, as well as the defect that existing biomass catalysts are not suitable for processing biomass such as wine grains and rice husks.

[0034] In a second aspect, the present invention provides a method for pyrolyzing biomass, comprising the following steps:

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

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

[0037] When pyrolyzing biomass, the present invention first disperses the catalyst on the biomass surface to obtain a biomass material loaded with the catalyst, and then pyrolyzes it, which significantly reduces the biomass pyrolysis temperature and time, achieves a high-temperature pyrolysis effect at a relatively low temperature, shortens the pyrolysis time, promotes the biomass material to generate biomass carbon under the action of a heat source, does not affect the yield and calorific value after carbonization, and improves the product added value of biomass such as distiller's grains and rice husks. The biochar obtained after pyrolysis can be used as a raw material for CO synthesis gas, green methanol, activated carbon, and the like.

[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 catalyst to 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 between any two 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 between any two values.

[0042] As an optional implementation manner, the drying temperature is 70-90° C. and the drying time is 12-16 hours.

[0043] The pyrolysis temperature is 250-400° C. and the time is 30-60 min.

[0044] The heating rate of the pyrolysis is 10-20°C / min.

[0045] As an optional embodiment, during the spraying, the step of stirring the biomass is also included;

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

[0047] It should be noted that stirring is started while spraying, and the stirring time is the spraying time. Stirring is stopped when all the mixed liquid is sprayed onto the biomass surface.

[0048] As an optional embodiment, the biomass includes at least one of rice husk and distiller's grains;

[0049] Preferably, the biomass comprises distillers grains.

[0050] The sodium carbonate used in the following examples is produced by Maclean; the polyferric sulfate is produced by Maclean.

[0051] Example 1

[0052] This embodiment provides a method for pyrolyzing biomass, using sodium carbonate and polyferric sulfate as catalysts, comprising the following steps:

[0053] (1) A certain amount of sodium carbonate and polyferric sulfate were weighed in a mass ratio of 3:1, placed in 200 ml of water, and ultrasonicated for 30 min to completely disperse them to obtain a 30 wt% mixed solution.

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

[0055] Example 2

[0056] This embodiment provides a method for pyrolyzing biomass, using sodium carbonate and polyferric sulfate as catalysts, comprising the following steps:

[0057] (1) A certain amount of sodium carbonate and polyferric sulfate were weighed in a mass ratio of 1:1, placed in 200 ml of water, and ultrasonicated for 30 minutes to completely disperse them to obtain a 30 wt% mixed solution.

[0058] (2) Using wine lees as biomass, the total mass of sodium carbonate and polyferric sulfate and the mass ratio of wine lees is 6:100, and the above-mentioned mixed solution is sprayed on the surface of wine lees. The spraying pressure is 0.8Mpa, the flow rate of the mixed solution is 0.7m / S, and the droplet size of the mixed solution during the spraying process is 50-100μm. The biomass is stirred during the spraying process, and the stirring speed is 60r / min. Stirring is continued until the spraying is completed, and then placed in a 90℃ oven and dried for 14h to obtain wine lees loaded with catalyst. Then, the temperature is raised to 280℃ at a heating rate of 15℃ / min in a nitrogen atmosphere, and then pyrolyzed for 60min, and the wine lees carbon yield and the time to reach the stable carbon yield are recorded. The results are shown in Table 1.

[0059] Example 3

[0060] This embodiment provides a method for pyrolyzing biomass, using sodium carbonate and polyferric sulfate as catalysts, comprising the following steps:

[0061] (1) A certain amount of sodium carbonate and polyferric sulfate were weighed in a mass ratio of 3:5, placed in 200 ml of water, and ultrasonicated for 30 minutes to completely disperse them to obtain a 30 wt% mixed solution.

[0062] (2) Using wine lees as biomass, the mass ratio of the total mass of sodium carbonate and polyferric sulfate to wine lees is 8:100, and the above-mentioned mixed solution is sprayed onto the surface of wine lees. The spraying pressure is 0.6 MPa, the flow rate of the mixed solution is 0.6 m / S, and the droplet size of the mixed solution during the spraying process is 50-100 μm. The biomass is stirred during the spraying process at a speed of 60 r / min. The stirring is continued until the spraying is completed, and then placed in a 90°C oven and dried for 12 hours to obtain wine lees loaded with catalysts. Then, the temperature is raised to 300°C at a heating rate of 15°C / min under a nitrogen atmosphere, and then pyrolyzed for 60 minutes. The wine lees carbon yield and the time to reach a stable carbon yield are recorded. The results are shown in Table 1.

[0063] Example 4

[0064] This embodiment provides a method for pyrolyzing biomass, using sodium carbonate and polyferric sulfate as catalysts, comprising the following steps:

[0065] (1) A certain amount of sodium carbonate and polyferric sulfate were weighed in a mass ratio of 3:7, placed in 200 ml of water, and ultrasonicated for 30 min to completely disperse them to obtain a 30 wt% mixed solution.

[0066] (2) Using wine lees as biomass, the total mass of sodium carbonate and polyferric sulfate and the mass ratio of wine lees was 1:10, and the above-mentioned mixed solution was sprayed onto the surface of wine lees. The spraying pressure was 0.9 MPa, the flow rate of the mixed solution was 0.8 m / S, and the droplet size of the mixed solution during the spraying process was 50-100 μm. The biomass was stirred during the spraying process at a speed of 80 r / min. After continuous stirring for 20 minutes, it was placed in a 70°C oven and dried for 14 hours. The wine lees loaded with the catalyst were obtained. Then, the temperature was raised to 320°C at a heating rate of 15°C / min under a nitrogen atmosphere and then pyrolyzed for 60 minutes. The wine lees carbon yield and the time to reach a stable carbon yield were recorded. The results are shown in Table 1.

[0067] Example 5

[0068] This embodiment provides a method for pyrolyzing biomass, using sodium carbonate and polyferric sulfate as catalysts, comprising the following steps:

[0069] (1) A certain amount of sodium carbonate and polyferric sulfate were weighed in a mass ratio of 9:1, placed in 200 ml of water, and ultrasonicated for 30 min to completely disperse them to obtain a 30 wt% mixed solution.

[0070] (2) Using wine lees as biomass, the total mass of sodium carbonate and polyferric sulfate and the mass ratio of wine lees is 2:100, and the above-mentioned mixed liquid is completely sprayed onto the surface of wine lees. The spraying pressure is 0.5 MPa, the flow rate of the mixed liquid is 0.5 m / S, and the droplet size of the mixed liquid during the spraying process is 50-100 μm. The biomass is stirred during the spraying process, and the stirring speed is 60 r / min. Stirring is continued until the spraying is completed, and then placed in an 80°C oven and dried for 16 hours. The wine lees loaded with catalyst are obtained. Then, the temperature is raised to 300°C at a heating rate of 10°C / min under a nitrogen atmosphere, and then pyrolyzed for 60 minutes. The wine lees carbon yield and the time to reach stable carbon yield are recorded. The results are shown in Table 1.

[0071] Comparative Example 1

[0072] This comparative example provides a method for pyrolyzing biomass, which differs from Example 1 in that zinc sulfate of equal mass is used instead of polyferric sulfate.

[0073] Comparative Example 2

[0074] This comparative example provides a method for pyrolyzing biomass, which differs from Example 1 in that ferrous sulfate of equal mass is used instead of polyferric sulfate.

[0075] Comparative Example 3

[0076] This comparative example provides a biomass pyrolysis method, which differs from Example 1 in that polyferric sulfate is removed.

[0077] Comparative Example 4

[0078] This comparative example provides a biomass pyrolysis method, which differs from Example 1 in that sodium carbonate and polyferric sulfate are removed.

[0079] Table 1 Test results of various embodiments and comparative examples

[0080] Example Carbon yield (%) Time required to reach 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 of Table 1, the present invention uses sodium carbonate and polyferric sulfate as biomass pyrolysis catalysts, which can shorten the time to reach a stable carbon yield while improving carbon yield. From Comparative Examples 1-2, compared with zinc sulfate or ferrous sulfate, the present invention has a synergistic effect between sodium carbonate and polyferric sulfate, which can significantly improve carbon yield and reduce pyrolysis time. From Comparative Examples 3-4, using a single sodium carbonate or polyferric sulfate as a catalyst, the pyrolysis yield is low and the time is long, which further illustrates that the composite use effect of sodium carbonate and polyferric sulfate of the present invention is significant.

[0082] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A catalyst for biomass pyrolysis, characterized in that: include: Sodium carbonate and polyferric sulfate.

2. The catalyst according to claim 1, characterized in that The mass ratio of the sodium carbonate to the polyferric sulfate is (1-10):(1-10); Preferably, the biomass comprises at least one of distiller's grains and rice husks.

3. A method for pyrolyzing biomass, characterized in that: The following steps are involved: (1) preparing a catalyst mixed solution; the catalyst comprising sodium carbonate and polyferric sulfate; (2) Spraying the mixed solution on the surface of biomass, drying and pyrolyzing.

4. The pyrolysis method according to claim 3, characterized in that The mass ratio of the catalyst to the biomass is (1-10):100; and / or, The concentration of the mixed solution is 20-40wt%.

5. The pyrolysis method according to claim 4, characterized in that The spraying pressure is 0.2-1Mpa.

6. The pyrolysis method according to any one of claims 3 to 5, characterized in that: The drying temperature is 70-90° C. and the drying time is 12-16 hours.

7. The pyrolysis method according to any one of claims 3 to 6, characterized in that: The pyrolysis temperature is 250-400° C. and the time is 30-60 min.

8. The pyrolysis method according to any one of claims 3 to 7, characterized in that: The heating rate of the pyrolysis is 10-20°C / min.

9. The pyrolysis method according to any one of claims 3 to 8, characterized in that: When performing the spraying, the method further includes the step of stirring the biomass; Preferably, the stirring speed is 60-100 r / min.

10. The pyrolysis method according to any one of claims 3 to 7, characterized in that: The biomass comprises at least one of rice husk and distiller's grains; Preferably, the biomass comprises distillers grains.