Preparation method and application of black soldier fly sand carbon catalyst with acid-base bifunctional

Abstract

The present application relates to a kind of preparation method and its application with acid-base bifunctional black soldier fly sand carbon-based catalyst, the main body of catalyst is black soldier fly sand biomass carbonization material, the modification component used is sodium hydrosulfide reagent and copper sulfate reagent, its preparation method is as follows: first, black soldier fly sand is screened using screen, then the screened black soldier fly sand is added to sodium hydrosulfide solution and stirred and soaked for a period of time, to obtain the pretreated black soldier fly sand, wash 3 times with deionized water, and dry in oven for 24h. Again, the sodium hydrosulfide pretreated sand is added to copper sulfate solution and stirred and soaked for a period of time, to obtain the pretreated black soldier fly sand, wash 3 times with deionized water, and dry in oven for 24h. Finally, the pretreated and dried sand is pyrolyzed and carbonized in nitrogen atmosphere for a period of time, to obtain the acid-base bifunctional biochar-based catalyst material.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst preparation, and particularly relates to a preparation method of a black soldier fly sand carbon-based catalyst with acid and base dual functions and application of the catalyst in biodiesel. Background Art

[0002] Renewable bioenergy sources, such as biodiesel, are becoming increasingly important in the current energy landscape. Biodiesel is a clean, renewable energy product with potential for large-scale deployment. Black soldier fly insects offer unique advantages, including high oil content, rapid growth, minimal land occupation, and reduced carbon dioxide emissions. Therefore, converting black soldier fly oil into biodiesel has significant potential for development.

[0003] Catalysts for esterification reactions often use diatomaceous earth, macroporous resins, and graphene oxide as carriers. However, these catalysts have drawbacks such as high cost and high-temperature resin deactivation. Waste resource utilization is crucial for achieving green agriculture and sustainable development. Biomass carbon-based solid acid catalysts, with their low cost, large specific surface area, rich surface functional groups, and renewability, have sparked in-depth research by numerous researchers. Black soldier fly sand is rich in active nutrients such as carbon, nitrogen, and potassium, and possesses numerous catalytically active sites after carbonization, making it an ideal biomass carbon-based feedstock.

[0004] At present, conventional solid acid catalysts have a high tolerance to the acid value and moisture content of the feedstock oil, but the reaction rate is slow. Solid base catalysts have a fast reaction rate, but have high requirements for the acid value and moisture content of the feedstock oil, otherwise saponification reaction will occur, affecting separation and causing catalyst loss. Therefore, the development of carbon-based catalysts with acid-base dual functions combines the advantages of strong acid and water resistance of acid catalysts and fast reaction rate of base catalysts. It is considered to be a novel and promising technology for producing biodiesel using high-acid value feedstocks. Summary of the Invention

[0005] In order to address the deficiencies of the prior art, the purpose of the present disclosure is to provide a method for preparing a black soldier fly sand carbon-based catalyst with acid-base dual functions and its application in the preparation of biodiesel. The prepared catalyst has high catalytic performance, is reusable and has low production cost.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0007] In one aspect, a method for preparing a black soldier fly sand carbon-based catalyst with dual acid and base functions is disclosed. The black soldier fly sand is first screened with a sieve, then the screened black soldier fly sand is added to a sodium hydrosulfide solution and stirred and soaked for several hours. The pretreated black soldier fly sand is then washed three times with deionized water and dried in an oven for 24 hours. The sodium hydrosulfide pretreated sand is then added to a copper sulfate solution and stirred and soaked for several hours. The pretreated black soldier fly sand is then washed three times with deionized water and dried in an oven for 24 hours. Finally, the pretreated and dried sand is pyrolyzed and carbonized at high temperature in a nitrogen atmosphere for several hours to obtain a biochar-based catalyst material with dual acid and base functions.

[0008] The present invention utilizes sodium hydrosulfide and copper sulfate solutions to soak biomass carbon materials for pretreatment, which not only improves the acid-base catalytic activity of the catalyst, but also improves the pore structure of the catalyst, thereby improving the catalytic activity and stability of the catalyst as a whole.

[0009] The third aspect is the application of a black soldier fly sand carbon-based catalyst with acid-base dual functions in the preparation of biodiesel.

[0010] In a fourth aspect, a method for preparing biodiesel is provided, wherein black soldier fly oil and methanol are used as raw materials and an exchange reaction is carried out under the catalysis of the above-mentioned black soldier fly sand carbon-based catalyst having acid-base dual functions.

[0011] The present invention provides the following beneficial effects: the disclosed black soldier fly sand biomass carbon-based catalyst utilizes sodium hydrosulfide and copper sulfate solution as pretreatment agents, significantly improving the activity of the biomass carbon-based catalyst; the carbon-based raw materials are widely available and inexpensive; and the disclosed dual-acid and base carbon-based catalyst, derived from black soldier fly sand, is a high-performance biodiesel catalyst, significantly contributing to reducing biodiesel production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which constitute a part of the present disclosure, are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation to the present disclosure.

[0013] Figure 1 This is an SEM photograph of the black soldier fly sand carbon-based catalyst with acid-base dual functions prepared in Example 1 of the present disclosure. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples, for which specific conditions are not specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the methods of the present invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0016] Example 1

[0017] A black soldier fly sand carbon-based catalyst with acid-base dual functions comprises the following steps:

[0018] (1) First, the black soldier fly sand was sieved with a 60-mesh sieve, and the sieved fine sand was collected;

[0019] (2) Prepare 1 mol / L sodium hydrosulfide solution, add 5 g of sieved fine insect sand to 100 mL of sodium hydrosulfide solution, and stir at 50°C for 3 h at a stirring speed of 500 rpm;

[0020] (3) After the pretreated insect sand was separated, it was rinsed with deionized water three times and then dried in an oven at 80°C for 24 h;

[0021] (4) Prepare a 3 mol / L copper sulfate solution, then add 1 g of the material obtained in step (3) to 100 mL of the copper sulfate solution, and stir at 50° C. for 3 h at a stirring speed of 500 rpm;

[0022] (5) The pre-treated insect sand dried in step (4) was placed in a tubular furnace, and the heating mode was turned on. The heating rate was 10 ° C / min, the target temperature was 350 ° C, and the carbonization time was 3 h. The black soldier fly insect sand biomass carbon-based solid acid catalyst was obtained. The SEM of the obtained product is as follows Figure 1 As shown;

[0023] (6) 10.5 g of methanol, 20 g of insect oil, and 1.5 g of the catalyst obtained in step (4) were added to a three-necked flask and refluxed at 60° C. for 4 h. The reaction product was centrifuged at 3000 r / min to separate the catalyst. The product was placed in a separatory funnel and allowed to stand for 2 h. The upper layer was biodiesel and the lower layer was glycerol. The biodiesel was washed with deionized water until neutral. The transesterification product was evaporated to separate the remaining deionized water and methanol in the biodiesel. The transesterification efficiency was measured by GC and was 94.4%.

[0024] Example 2

[0025] A method for preparing a black soldier fly sand carbon-based catalyst with acid-base dual functions comprises the following steps:

[0026] (1) First, the black soldier fly sand was sieved with an 80-mesh sieve, and the sieved fine sand was collected;

[0027] (2) Prepare 2 mol / L sodium hydrosulfide solution, add 7 g of sieved fine insect sand to 100 mL of sodium hydrosulfide solution, and stir at 60°C for 3 h at a stirring speed of 600 rpm;

[0028] (3) After the pretreated insect sand was separated, it was rinsed with deionized water three times and then dried in an oven at 80°C for 24 h;

[0029] (4) Prepare a 3 mol / L copper sulfate solution, then add 3 g of the material obtained in step (3) to 100 mL of the copper sulfate solution, and stir at 60° C. for 4 h at a stirring speed of 600 rpm;

[0030] (5) The pretreated insect sand dried in step (4) is placed in a tubular furnace, and the heating addition mode is turned on, the heating rate is 15°C / min, the target temperature is 400°C, and the carbonization time is 3h, to obtain the black soldier fly insect sand biomass carbon-based solid acid catalyst;

[0031] (5) 12 g of methanol, 15 g of insect oil, and 1.5 g of the catalyst obtained in step (4) were added to a three-necked flask and refluxed at 65° C. for 4 h. The reaction product was centrifuged at 2000 r / min to separate the catalyst. The product was placed in a separatory funnel and allowed to stand for 2 h. The upper layer was biodiesel and the lower layer was glycerol. The biodiesel was washed with deionized water until neutral. The transesterification product was evaporated to separate the remaining deionized water and methanol in the biodiesel. The transesterification efficiency was measured by GC and was 95.3%.

[0032] Example 3

[0033] A method for preparing a black soldier fly sand carbon-based catalyst with acid-base dual functions comprises the following steps:

[0034] (1) First, the black soldier fly sand was sieved with a 60-mesh sieve, and the sieved fine sand was collected;

[0035] (2) Prepare 4 mol / L sodium hydrosulfide solution, add 5 g of sieved fine insect sand to 100 mL of sodium hydrosulfide solution, and stir at 60°C for 4 h at a stirring speed of 800 rpm;

[0036] (3) After the pretreated insect sand was separated, it was rinsed with deionized water three times and then dried in an oven at 80°C for 24 h;

[0037] (4) Prepare 2 mol / L copper sulfate solution, then take 1.5 g of the material obtained in step (3)

[0038] Add to 100 mL of copper sulfate solution and stir at 50 °C for 3.5 h at a stirring speed of 600 rpm;

[0039] (5) The pretreated insect sand dried in step (3) is placed in a tubular furnace, and the heating addition mode is turned on, the heating rate is 20°C / min, the target temperature is 500°C, and the carbonization time is 4h, to obtain the black soldier fly insect sand biomass carbon-based solid acid catalyst;

[0040] (6) 11 g of methanol, 16 g of insect oil, and 2.0 g of the catalyst obtained in step (4) were added to a three-necked flask and refluxed at 55°C for 4 h. The reaction product was centrifuged at 3000 r / min to separate the catalyst. The product was placed in a separatory funnel and allowed to stand for 2 h. The upper layer was biodiesel and the lower layer was glycerol. The biodiesel was washed with deionized water until neutral. The transesterification product was evaporated to separate the remaining deionized water and methanol in the biodiesel. The transesterification efficiency was measured by GC and was 91.4%.

Claims

1. A method for preparing a black soldier fly sand carbon-based catalyst with acid and base dual functions, characterized in that: The steps include: (1) Sieve the black soldier fly sand with a 60-80 mesh screen; (2) Add the sieved insect sand to a 1-5 mol / L sodium hydrosulfide solution and stir at 40-80°C and 300-1000 rpm for 2-4 hours; (3) After soaking, the insect sand was washed with deionized water three times and dried in an oven at 80°C for 24 h; (4) soaking the dried insect sand obtained in step (3) in a 1-5 mol / L copper sulfate solution for 2-4 hours, wherein the concentration ratio of the sodium hydrosulfide solution to the copper sulfate solution is 3:1-1:3; (5) In a nitrogen atmosphere, the temperature is raised to 300-600°C at a rate of 10-40°C / min, and pyrolysis and carbonization are performed for 2-5 hours to obtain an acid-base bifunctional carbon-based catalyst.

2. A black soldier fly sand carbon-based catalyst with acid and base dual functions, characterized by: Prepared by the method of claim 1.

3. Use of the catalyst according to claim 2 in the preparation of biodiesel.

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