Method for preparing biodiesel based on ladle slag and metakaolin
By using ladle slag and metakaolin powder to prepare catalyst powder, the problems of large equipment investment, high energy consumption and pollution in the existing biodiesel production process are solved, efficient and low-cost biodiesel production are achieved, and waste resource utilization and environmental protection are promoted.
Patent Information
- Application Number
- CN202411924002.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-03-28
AI Technical Summary
In the existing biodiesel production process, fixed equipment investment is large, energy consumption is high, and reaction products are difficult to separate from catalysts, resulting in environmental pollution and other problems.
Catalyst powder is prepared by ladle slag and metakaolin powder, and biodiesel is produced through heating reaction, cooling, standstill separation, rotary distillation and other steps.
It reduces the cost of catalysts and improves the yield of biodiesel. It has simple process, low cost, easy separation of products, and high catalyst activity. It realizes waste resource utilization and reduces pollution and carbon emissions.
Smart Images
Figure CN119709279A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of solid waste resource utilization, and particularly relates to a method for preparing biodiesel based on ladle slag and metakaolin. Background Art
[0002] Biodiesel is a product made from animal and plant oils, microorganisms and various waste oils, and is converted into fatty acid monoalkyl esters by transesterification with alcohols (such as methanol, ethanol, etc.). In recent years, it has attracted great attention due to its biodegradability, compatibility with diesel engines, high energy density, high combustion efficiency, and renewability. Compared with traditional petroleum, biodiesel has low nitrogen and sulfur content, produces less harmful gases during combustion, is environmentally friendly, and has a higher flash point. It is safer during transportation, storage and use. It is one of the effective ways to solve the problem of increasingly depleted petroleum resources and has important practical significance and economic value. A key step in its development and application is to explore cost-effective catalysts so that the density, viscosity and flash point of biodiesel are within the biodiesel standard range. At present, liquid alkalis such as NaOH, KOH, various carbonates, organic alkalis, etc. are mostly used in industry as catalysts to mix with methanol and oil to form a homogeneous reaction system, but there are problems such as large fixed equipment investment, high energy consumption, difficulty in separating reaction products and catalysts, and generation of a large amount of wastewater to pollute the environment. Summary of the invention
[0003] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for preparing biodiesel based on ladle slag and metakaolin.
[0004] To achieve the above object, the technical solution adopted by the present invention is:
[0005] A method for preparing biodiesel based on ladle slag and metakaolin, comprising the following steps: mixing catalyst powder, cooked tung oil and methanol, heating for reaction, cooling to obtain a product, mixing the product with water, standing for separation, removing a lower layer product, obtaining an upper layer product, and finally rotary distilling the upper layer product to remove a solvent to obtain biodiesel;
[0006] The method for preparing the catalyst powder comprises the following steps:
[0007] (1) mixing ladle slag and metakaolin powder uniformly to obtain a mixture;
[0008] (2) adding NaOH powder to Na2SiO3 solution and stirring evenly to obtain an alkaline solution activator;
[0009] (3) mixing the mixture and the alkaline solution activator and stirring to obtain a uniform slurry;
[0010] (4) Pour the slurry into a mold for molding, vibrate to eliminate bubbles, seal the mold with a plastic film, and then demould after curing;
[0011] (5) The demoulding product is crushed and then calcined to obtain catalyst powder.
[0012] The ladle slag described in the present invention is the slag produced by steelmaking in a ladle refining furnace.
[0013] As a preferred embodiment of the present invention, the mass of the catalyst powder is (2.1-2.8) wt% of the mass of the tung oil; and the volume ratio of the methanol to the tung oil is (2-3):1.
[0014] As a preferred embodiment of the present invention, the temperature of the heating reaction is 80-90°C and the time is 1-1.5h.
[0015] As a preferred embodiment of the present invention, the filtrate pressure of the rotary distillation is 250-350 Pa, the temperature is 90° C., and the rotation speed is 25 / min.
[0016] As a preferred embodiment of the present invention, the mass ratio of the ladle slag to the metakaolin powder is (1-9):1.
[0017] If the ladle slag content is reduced, the catalytic effect of the prepared catalyst powder is weakened, and the biodiesel yield is reduced. If the metakaolin content is reduced, it is not conducive to the production of catalyst powder and the uniform distribution of metal ions in the catalyst, the catalytic effect of the catalyst is weakened, and the biodiesel yield is reduced.
[0018] As a preferred embodiment of the present invention, the modulus of the Na2SiO3 solution is 3-3.5, and the mass ratio of NaOH powder to Na2SiO3 solution is (0.6-1.5):1.
[0019] As a preferred embodiment of the present invention, the mixture and the alkaline solution activator are mixed in a mass ratio of (0.9-1.7):1.
[0020] As a preferred embodiment of the present invention, the curing temperature is 80° C. and the curing time is 48 hours.
[0021] As a preferred embodiment of the present invention, the calcination temperature is 300-700°C, the time is 6 hours, and the calcination heating rate is 5°C / min.
[0022] The present invention obtains catalyst powder by means of calcination, so that the pore structure and specific surface area of the catalyst are significantly increased, and the stability of the catalyst structure is improved, so that the catalyst has stable activity.
[0023] Compared with the prior art, the present invention has the following beneficial effects: the present invention uses industrial solid waste ladle slag and metakaolin as raw materials to prepare catalyst powder, and uses the catalyst powder as a catalyst for producing biodiesel, thereby reducing the catalyst cost and effectively increasing the yield of biodiesel. In addition, the preparation method has the advantages of simple process, low cost, easy product separation, high catalyst activity, and high biodiesel yield, realizes waste resource utilization, contributes to pollution reduction and carbon reduction, green development, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 The XRD patterns of the catalyst powders prepared in Example 1 and Example 2.
[0025] Figure 2 FTIR spectra of the catalyst powders prepared in Example 1 and Example 2.
[0026] Figure 3 The SEM image and EDS analysis image of the catalyst powder in Example 1.
[0027] Figure 4 The SEM image and EDS analysis image of the catalyst powder in Example 2.
[0028] Figure 5 These are physical pictures of the biodiesel prepared in Examples 1 and 2. The left picture is a physical picture of the biodiesel prepared in Example 1, and the right picture is a physical picture of the biodiesel prepared in Example 2. DETAILED DESCRIPTION
[0029] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.
[0030] The ladle slag powder used in the embodiments of the present invention and the comparative examples was purchased from Lingshou County Shihang Building Materials Co., Ltd., and specifically included the following components in percentage by mass: SiO2: 54.78%, Al2O3: 27.21%, Fe2O3: 5.44%, MgO: 1.08%, CaO: 4.22%, SO3: 0.43% and other impurities; the loss on ignition was 1.66.
[0031] Example 1
[0032] A method for preparing biodiesel based on ladle slag and metakaolin comprises the following steps:
[0033] (1) Weigh 19.6g of ladle slag powder. (Purchased from Lingshou County Shihang Building Materials Co., Ltd., the specific composition content is as written in the composition report: SiO2: 54.78% Al2O3: 27.21% Fe2O3: 5.44% MgO: 1.08% CaO: 4.22% SO3: 0.43% ignition loss 1.66)
[0034] (2) Weigh 4.9 g of metakaolin powder.
[0035] (3) uniformly mixing the ladle slag and metakaolin powder of step (1) and step (2).
[0036] (4) Weigh 4.8 g of silicon dioxide particles and 1.5 g of sodium oxide particles and mix them in a beaker.
[0037] (5) Weigh 9.6 g of deionized water into a beaker and dissolve the solid mixture from step (4) to obtain 15.9 g of a sodium silicate solution having a modulus of 3.3.
[0038] (6) Weigh 15.9 g of sodium hydroxide solid, dissolve it into the sodium silicate solution obtained in step (5), stir evenly, seal with plastic wrap and store at room temperature for 24 h.
[0039] (7) The mixture of step (3) and step (6) was stirred at a liquid-to-solid ratio of 1.3 to obtain a uniform slurry.
[0040] (8) The slurry is poured into a mold for molding, and bubbles are eliminated by vibration. The mold is sealed with a plastic film, placed in a constant temperature box for curing at 80°C for 48 hours, and then demolded to obtain a block.
[0041] (9) The block obtained in step (8) was crushed and ground and placed in a crucible, and calcined in a muffle furnace at a heating rate of 5°C / min and a final temperature of 300°C for 6 h to obtain a catalyst powder, which was recorded as M20.
[0042] (10) Add 300 mL of cooked tung oil and 660 mL of methanol into a spherical flask equipped with a reflux device.
[0043] (11) Take 7.7 g of the catalyst powder described in step (9) (its mass is 2.67 wt% of the total mass of cooked tung oil), add it into the round-bottom flask with reflux device described in step (9), and react in a water bath at 85° C. for 1 h under magnetic stirring at a speed of 10 r / min to obtain a biodiesel product.
[0044] (12) Cool the biodiesel product obtained in step (11) at room temperature, add it and deionized water into a separatory funnel, filter out the propylene glycol in the lower layer after stratification, and repeat the process until the lower layer liquid is clear.
[0045] (13) The product obtained in step (12) is filtered, and the filtrate is subjected to rotary distillation at a pressure of 300 Pa, a temperature of 90° C., and a rotation speed of 25 / min for 1.5 h to remove unreacted methanol and water to obtain biodiesel.
[0046] (14) The biodiesel yield Y is calculated using the following formula:
[0047] Y=W 生物柴油 / W 熟桐油 ×100%.
[0048] The calculated biodiesel yield Y is 91.3%.
[0049] Example 2
[0050] A method for preparing biodiesel based on ladle slag and metakaolin comprises the following steps:
[0051] (1) Weigh 11.6 g of ladle slag powder.
[0052] (2) Weigh 17.4 g of metakaolin powder.
[0053] (3) uniformly mixing the ladle slag and metakaolin powder of step (1) and step (2).
[0054] (4) Weigh 6.4 g of silicon dioxide particles and 2.0 g of sodium oxide particles and mix them in a beaker.
[0055] (5) Weigh 17.9 g of deionized water into a beaker and dissolve the solid mixture from step (4) to obtain 18.9 g of a sodium silicate solution having a modulus of 3.3.
[0056] (6) Weigh 18.9 g of sodium hydroxide solid, dissolve it into the sodium silicate solution obtained in step (5), stir evenly, seal with plastic wrap and store at room temperature for 24 h.
[0057] (7) The mixture of step (3) and step (6) was stirred at a liquid-to-solid ratio of 1.3 to obtain a uniform slurry.
[0058] (8) The slurry is poured into a mold for molding, and bubbles are eliminated by vibration. The mold is sealed with a plastic film, placed in a constant temperature box for curing at 80°C for 48 hours, and then demolded to obtain a block.
[0059] (9) The block obtained in step (8) was crushed and ground and placed in a crucible, and calcined in a muffle furnace at a heating rate of 5°C / min and a final temperature of 700°C for 6 h to obtain a catalyst powder, which was recorded as M40.
[0060] (10) Add 300 mL of cooked tung oil and 660 mL of methanol into a spherical flask equipped with a reflux device.
[0061] (11) Take 7.7 g of the catalyst powder described in step (9) (its mass is 2.67 wt% of the total mass of cooked tung oil), add it into the round-bottom flask with reflux device described in step (9), and react in a water bath at 85° C. for 1 h under magnetic stirring at a speed of 10 r / min to obtain a biodiesel product.
[0062] (12) Cool the biodiesel product obtained in step (11) at room temperature, add it and deionized water into a separatory funnel, filter out the propylene glycol in the lower layer after stratification, and repeat the process until the lower layer liquid is clear.
[0063] (13) The product obtained in step (12) is filtered, and the filtrate is subjected to rotary distillation at a pressure of 300 Pa, a temperature of 90° C., and a rotation speed of 25 / min for 1.5 h to remove unreacted methanol and water to obtain biodiesel.
[0064] (14) The biodiesel yield Y is calculated using the following formula:
[0065] Y=W 生物柴油 / W 熟桐油 ×100%.
[0066] The calculated biodiesel yield Y is 93.6%.
[0067] according to Figure 1 It can be seen that the catalysts prepared in Examples 1 and 2 contain calcium silicate phase (CSH), sodium silicate phase (NSH), sodium aluminosilicate phase (NASH) and sodium calcium aluminosilicate phase (NCSH). Among them, the NSH phase in the M20 catalyst prepared in Example 1 is the main phase, and amorphous NCSH phase and CSH phase appear next to the main phase. The NSH phase is the main phase in the M40 catalyst prepared in Example 2, and more NASH phase and a small amount of NCSH phase are produced. As the content of metakaolin increases, the content of NASH phase increases. The amorphous NASH phase is formed after the metakaolin particles react with the alkali activator, which forms water-soluble silicon monomers and aluminum monomers and diffuses outward to undergo polycondensation to form a gel phase. Therefore, M40 has a better catalytic effect than M20.
[0068] according to Figure 2 It can be seen that at 3430-3450cm -1 and 1650cm -1 The bands at 1440-1450cm are due to the stretching and bending vibrations of -OH. These peaks represent the adsorption of water molecules, and the intensity of the adsorption peaks of the above water molecules decreases slightly with the addition of metakaolin and the formation of NCSH phase and NASH phase. -1 The band at is due to the stretching vibration of the OCO bond, showing that CO3 2- The formation of the band is due to atmospheric CO2 production, and the intensity of this band decreases with the formation of the NASH phase. 972-1023cm-1 The band is due to the asymmetric stretching vibration of the Si-OT bond (T is tetrahedral Al or Si), which is the main band used to detect changes in catalyst formation. With the formation of the NASH phase, it moves to a lower wavenumber. The formation of this band indicates the enhancement of the catalyst generation reaction and the formation of a highly cross-linked catalyst gel framework. Therefore, the M40 catalyst is more stable than the M20 catalyst.
[0069] according to Figure 3 It can be seen that the microstructure of the catalyst powder prepared in Example 1 presents well-crystallized coarse block and agglomerated grains, and the porosity between the grains is large. The edges of the block grains are relatively rough and composed of small grains, and the whole presents irregular and amorphous characteristics; the grain size is about 5μm. The formation of the gel network leads to the formation of small pores between the gels, which means that the catalyst powder prepared in Example 1 has a larger specific surface area. EDS shows that Na + , Ca 2+ 、Al 3+ The content of catalytic metal ions is relatively high, meeting the basic requirements for being a biodiesel catalyst.
[0070] according to Figure 4 It can be seen that a large number of NASH phase and CASH phase long plate particles were found on the microstructure surface of the catalyst powder prepared in Example 2 as catalyst enhancers, which increased the stability of the catalyst. The increase in the content of metakaolin promoted the formation of the gel phase in the polycondensation reaction. The formation of the gel network tended to form small pores between the gels, and the overall porosity increased; the particle size of the crystals was about 5μm. EDS showed that Na + , Ca 2+ 、Al 3+ The content of metal ions that play a catalytic role is high, and the catalyst has a certain catalytic activity. With the increase of the content of metakaolin, the catalyst generation reaction is enhanced, which is conducive to the formation of a highly cross-linked catalyst gel framework. The catalyst is more resistant to friction, impact and gravity, and is not easy to break and wear during use. In addition, the chemical composition and chemical state of the catalyst are stable during the catalytic process. In the process of using it as a catalyst for producing biodiesel, the active components and additives do not react or lose. The catalyst can be recycled and the yield of biodiesel has not been significantly reduced. However, if only metakaolin powder or ladle slag powder is used as a raw material for preparing the catalyst, not only the yield of preparing biodiesel is significantly reduced, but also the stability is poor and it cannot be recycled.
[0071] Comparative Example 1
[0072] A method for preparing biodiesel based on ladle slag comprises the following steps:
[0073] (1) Weigh 24.5 g of ladle slag powder.
[0074] (2) Weigh 4.8 g of silicon dioxide particles and 1.5 g of sodium oxide particles and mix them in a beaker.
[0075] (3) Weigh 9.6 g of deionized water into a beaker and dissolve the solid mixture from step (2) to obtain 15.9 g of a sodium silicate solution with a modulus of 3.3.
[0076] (4) Weigh 15.9 g of sodium hydroxide solid, dissolve it into the sodium silicate solution obtained in step (3), stir evenly, seal with plastic wrap and store at room temperature for 24 h.
[0077] (5) The mixture of step (1) and step (4) is stirred at a liquid-to-solid ratio of 1.3 to obtain a uniform slurry.
[0078] (6) The slurry is poured into a mold for molding, and bubbles are eliminated by vibration. The mold is sealed with a plastic film, placed in a constant temperature box for curing at 80°C for 48 hours, and then demolded to obtain a block.
[0079] (7) The block obtained in step (6) is crushed and ground and placed in a crucible, and calcined in a muffle furnace at a heating rate of 5°C / min and a final temperature of 300°C for 6 hours to obtain a catalyst powder.
[0080] (8) Add 300 mL of cooked tung oil and 660 mL of methanol into a spherical flask equipped with a reflux device.
[0081] (9) Take 7.7 g of the catalyst powder described in step (7) (its mass is 2.67 wt% of the total mass of cooked tung oil) and add it to the round-bottom flask with reflux device described in step (8). Under magnetic stirring at a speed of 10 r / min, react in a water bath at 85° C. for 1 h to obtain a biodiesel product.
[0082] (10) The biodiesel product obtained in step (9) is cooled at room temperature and added to a separatory funnel with deionized water. After stratification, the propylene glycol in the lower layer is filtered out, and the process is repeated until the lower layer is clear.
[0083] (11) The product obtained in step (10) is filtered, and the filtrate is subjected to rotary distillation at a pressure of 300 Pa, a temperature of 90° C., and a rotation speed of 25 / min for 1.5 h to remove unreacted methanol and water to obtain biodiesel.
[0084] (12) The biodiesel yield Y is calculated using the following formula:
[0085] Y=W 生物柴油 / W 熟桐油 ×100%.
[0086] The calculated biodiesel yield Y is 68.7%.
[0087] Comparative Example 2
[0088] A method for preparing biodiesel based on metakaolin comprises the following steps:
[0089] (1) Weigh 24.5 g of metakaolin powder.
[0090] (2) Weigh 4.8 g of silicon dioxide particles and 1.5 g of sodium oxide particles and mix them in a beaker.
[0091] (3) Weigh 9.6 g of deionized water into a beaker and dissolve the solid mixture from step (2) to obtain 15.9 g of a sodium silicate solution with a modulus of 3.3.
[0092] (4) Weigh 15.9 g of sodium hydroxide solid, dissolve it into the sodium silicate solution obtained in step (3), stir evenly, seal with plastic wrap and store at room temperature for 24 h.
[0093] (5) The mixture of step (1) and step (4) is stirred at a liquid-to-solid ratio of 1.3 to obtain a uniform slurry.
[0094] (6) The slurry is poured into a mold for molding, and bubbles are eliminated by vibration. The mold is sealed with a plastic film, placed in a constant temperature box for curing at 80°C for 48 hours, and then demolded to obtain a block.
[0095] (7) The block obtained in step (6) is crushed and ground and placed in a crucible, and calcined in a muffle furnace at a heating rate of 5°C / min and a final temperature of 300°C for 6 hours to obtain a catalyst powder.
[0096] (8) Add 300 mL of cooked tung oil and 660 mL of methanol into a spherical flask equipped with a reflux device.
[0097] (9) Take 7.7 g of the catalyst powder described in step (7) (its mass is 2.67 wt% of the total mass of cooked tung oil) and add it to the round-bottom flask with reflux device described in step (8). Under magnetic stirring at a speed of 10 r / min, react in a water bath at 85° C. for 1 h to obtain a biodiesel product.
[0098] (10) The biodiesel product obtained in step (9) is cooled at room temperature and added to a separatory funnel with deionized water. After stratification, the propylene glycol in the lower layer is filtered out, and the process is repeated until the lower layer is clear.
[0099] (11) The product obtained in step (10) is filtered, and the filtrate is subjected to rotary distillation at a pressure of 300 Pa, a temperature of 90° C., and a rotation speed of 25 / min for 1.5 h to remove unreacted methanol and water to obtain biodiesel.
[0100] (12) The biodiesel yield Y is calculated using the following formula:
[0101] Y=W 生物柴油 / W 熟桐油×100%.
[0102] The calculated biodiesel yield Y is 64.6%.
[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.
Claims
1. A method for preparing biodiesel based on ladle slag and metakaolin, characterized in that: The method comprises the following steps: mixing catalyst powder, tung oil and methanol, heating and reacting the mixture, cooling the mixture to obtain a product, mixing the product with water, standing the mixture for separation, removing the lower layer product, retaining the upper layer product, and finally rotating the upper layer product for distillation to remove the solvent and obtain biodiesel; The method for preparing the catalyst powder comprises the following steps: (1) mixing ladle slag and metakaolin powder uniformly to obtain a mixture; (2) adding NaOH powder to Na2SiO3 solution and stirring evenly to obtain an alkaline solution activator; (3) mixing the mixture obtained in step (1) and an alkaline solution activator and stirring to obtain a uniform slurry; (4) Pour the slurry into the mold and vibrate to eliminate bubbles, then seal it, and finally demould it after curing; (5) The demoulding product is crushed and then calcined to obtain catalyst powder.
2. The method for preparing biodiesel based on ladle slag and metakaolin according to claim 1, characterized in that: The mass of the catalyst powder is (2.1-2.8) wt% of the mass of the tung oil; the volume ratio of the methanol to the tung oil is (2-3):
1.
3. The method for preparing biodiesel based on ladle slag and metakaolin as claimed in claim 1, characterized in that: The heating reaction temperature is 80-90°C and the time is 1-1.5h.
4. The method for preparing biodiesel based on ladle slag and metakaolin as claimed in claim 1, characterized in that: The filtrate pressure of the rotary distillation is 250-350 Pa, the temperature is 90° C., and the rotation speed is 25 r / min.
5. The method for preparing biodiesel based on ladle slag and metakaolin as claimed in claim 1, characterized in that: The mass ratio of the ladle slag to the metakaolin powder is (1-9):
1.
6. The method for preparing biodiesel based on ladle slag and metakaolin as claimed in claim 1, characterized in that: The modulus of the Na2SiO3 solution is 3-3.5, and the mass ratio of NaOH powder to Na2SiO3 solution is (0.6-1.5):
1.
7. The method for preparing biodiesel based on ladle slag and metakaolin as claimed in claim 1, characterized in that: The mixture and the alkaline solution activator are mixed in a mass ratio of (0.9-1.7):
1.
8. The method for preparing biodiesel based on ladle slag and metakaolin as claimed in claim 1, characterized in that: The curing temperature is 80° C. and the curing time is 48 hours.
9. The method for preparing biodiesel based on ladle slag and metakaolin as claimed in claim 1, characterized in that: The calcination temperature is 300-700°C, the time is 6 hours, and the calcination heating rate is 5°C / min.