Preparation method and application of black soldier fly sand biomass carbon-based solid acid catalyst

Abstract

The present invention relates to a preparation method and application of a black soldier fly worm sand biomass carbon-based solid acid catalyst. The preparation method comprises the following steps: first, the black soldier fly worm sand is sieved with a sieve, and then the sieved black soldier fly worm sand is added to a sodium hydrosulfide solution and stirred and soaked for several hours. The pretreated black soldier fly worm sand is washed three times with deionized water and dried in an oven for 24 hours. Finally, the pretreated and dried worm sand is pyrolyzed and carbonized at high temperature in a nitrogen atmosphere for several hours to obtain a biochar-based solid acid catalyst material. The present invention uses biomass worm sand as raw material, which is cheap and easily available, reduces the production cost of solid acid catalysts and biodiesel, and improves the utilization value of renewable resources. In the present invention, the carbon-based material is pretreated with a sodium hydrosulfide solution, which not only improves the acid catalytic activity of the catalyst, but also improves the pore structure of the catalyst, thereby improving the catalytic activity of the carbon-based material as a whole, and is expected to become a highly competitive clean process route.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst preparation, and in particular relates to a method for preparing a black soldier fly sand biomass carbon-based solid acid catalyst and application thereof 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] Currently, most studies on improving the catalytic activity of biochar-based solid acids involve sulfonation on activated carbon supports. However, this method is complex, time-consuming, and prone to equipment corrosion. Therefore, developing simple, low-cost biochar-based solid acid catalysts with highly active sites to more efficiently produce biodiesel is of particular interest. Summary of the Invention

[0005] In order to address the deficiencies of the prior art, the present invention aims to provide a method for preparing a black soldier fly worm sand biomass carbon-based solid acid catalyst 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 worm litter biomass carbon-based solid acid catalyst comprises first sieving the black soldier fly worm litter with a sieve, then stirring and soaking the sieved black soldier fly worm litter in a sodium hydrosulfide solution for several hours. The pretreated black soldier fly worm litter is then washed three times with deionized water and dried in an oven for 24 hours. Finally, the pretreated and dried worm litter is pyrolyzed and carbonized at high temperature in a nitrogen atmosphere for several hours to obtain a biochar-based solid acid catalyst material.

[0008] The present invention utilizes sodium hydrosulfide solution to soak the biomass carbon material, which not only improves the acid catalytic activity of the catalyst, but also improves the pore structure of the catalyst, thereby improving the catalytic activity of the catalyst as a whole.

[0009] In a third aspect, a carbon-based solid acid catalyst of the black soldier fly sand biomass is used in the preparation of biodiesel.

[0010] In a fourth aspect, a method for preparing biodiesel is provided, which uses black soldier fly oil and methanol as raw materials and performs an exchange reaction under the catalysis of the above-mentioned black soldier fly sand biomass carbon-based solid acid catalyst.

[0011] The present invention provides the following beneficial effects: the disclosed black soldier fly sand biomass carbon-based solid acid catalyst utilizes sodium hydrosulfide as a pretreatment agent, significantly improving the activity of the biomass carbon-based catalyst; the carbon-based raw material is widely available and inexpensive; and the disclosed black soldier fly sand biomass carbon-based solid acid catalyst is a high-performance biodiesel catalyst, contributing significantly 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 biomass carbon-based solid acid catalyst 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 method for preparing a black soldier fly sand biomass carbon-based solid acid catalyst 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) The pre-treated insect sand dried in step (3) was placed in a tubular furnace, and the heating addition 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;

[0022] (5) 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 separated from the catalyst by centrifuge at 3000 r / min. 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%.

[0023] Example 2

[0024] A method for preparing a black soldier fly sand biomass carbon-based solid acid catalyst comprises the following steps:

[0025] (1) First, the black soldier fly sand was sieved with an 80-mesh sieve, and the sieved fine sand was collected;

[0026] (4) 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;

[0027] (5) After separating the pretreated insect sand, rinse it with deionized water three times and then dry it in an oven at 80°C for 24 h;

[0028] (4) placing the pretreated insect sand dried in step (3) in a tubular furnace, turning on the heating addition mode, heating rate of 15 ° C / min, target temperature of 400 ° C, carbonization time of 3 h, and obtaining the black soldier fly insect sand biomass carbon-based solid acid catalyst;

[0029] (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%.

[0030] Example 3

[0031] A method for preparing a black soldier fly sand biomass carbon-based solid acid catalyst comprises the following steps:

[0032] (1) First, the black soldier fly sand was sieved with a 60-mesh sieve, and the sieved fine sand was collected;

[0033] (6) Prepare 3.5 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;

[0034] (7) 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;

[0035] (4) placing the pretreated insect sand dried in step (3) in a tubular furnace, turning on the heating addition mode, heating rate of 20 ° C / min, target temperature of 500 ° C, carbonization time of 4 h, and obtaining the black soldier fly insect sand biomass carbon-based solid acid catalyst;

[0036] (5) 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 biomass carbon-based solid acid catalyst, characterized in that: The steps include: (1) Sieve the black soldier fly sand with a sieve; (2) adding the sieved insect sand to a sodium hydrosulfide solution and stirring at 40-80° C. and 300-1000 rpm for 2-4 hours; the mass fraction of the black soldier fly insect sand is 1 wt.%-10 wt.%, and the concentration of the sodium hydrosulfide solution is 1 mol / L-5 mol / L; (3) Wash the soaked insect litter with deionized water three times and dry it in an oven for 24 hours; (4) Under a nitrogen atmosphere, the temperature was raised to 300-500°C at a rate of 10-30°C / min for a carbonization time of 2-4 h to obtain a biochar-based solid acid catalyst.

2. A black soldier fly sand biomass carbon-based solid acid catalyst, characterized by: Prepared by the preparation method according to claim 1.

3. Use of the black soldier fly sand biomass carbon-based solid acid catalyst according to claim 2 in the preparation of biodiesel.

4. A method for preparing biodiesel, characterized in that: Black soldier fly oil and methanol are used as raw materials, and an ester exchange reaction is carried out under the catalysis of the catalyst described in claim 2; wherein the molar ratio of methanol to insect oil is 6:1-15:1, the amount of catalyst added is 1.5%-8% of the mass of oleic acid, the reaction temperature is 40-70°C, and the reaction time is 3-6 hours.

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