CZ306084B6 - Nanocatalyst for the production of biofuels, process of its preparation and use - Google Patents

Abstract

In the present invention, there is disclosed a nanocatalyst for the production of biofuels containing 95 to 99.3 percent by weight of crystalline titanium oxide with particle size in the range of 15 to 70 nm, wherein the nanocatalyst specific surface area is in the range of 70 to 220 me2/g, the average size of pores is in the range of 1.5 to 5 nm and the pore volume in the range of 0.19 to 0.7 cme3/g. Disclosed is also a process for preparing the above-described nanocatalyst, the process being characterized in that a solution of a titanium salt (Tie4+) is heated for a period of 1 hour to a temperature in the range of 90 to 100 degC. Subsequently, 110 to 195 g of urea are added under perpetual agitation and the reaction mixture is brought to boil and maintained on that temperature under perpetual agitation until pH value in the range of 3 to 8.2 is achieved. Then, the reaction mixture is mixed for a period of 30 minutes and is let to ripen for a period of 12 hours at the laboratory temperature. Subsequently, dewatering, filtering off and drying for a period of 12 hours at a temperature in the range of 100 to 120 degC follows. Finally, the obtained product can be calcined. The nanocatalyst for the preparation of biofuels according to the present invention can be used for aldol condensation reaction of furfural with acetone.

Description

Nano catalyst for the production of biofuels, method of its production and use

Field of technology

The invention relates to a nanocatalyst for the production of biofuels, to a process for its preparation and to its use in chemical technology, in particular the aldol condensation reaction of acetone with furfural.

Prior art

A key reaction in the production of synthetic fuels is the aldol condensation reaction of furfural with acetone (Kubíčka, D .; Kikhtyanin, O. Catalysis Today, 2015, 243, 10-22), which takes place in the presence of either basic or acid catalysts. The most efficient industrially available methods use solutions of bases (NaOH or KOH) or mineral acids (H2SO4) as catalysts. The disadvantage of these catalysts is that they pose a major environmental threat due to wastewater production and equipment corrosion (Kikhtyanin, O .; Kubicka, D .; Cejka, J., Catalysis Today, 2015, 243, 158-162).

Solid catalysts of an acid-base nature are considered a promising alternative to homogeneous catalysts for the aldol condensation reaction of furfural and acetone. Solid catalysts based on Al-Mg compounds, hydrotalcites, metal oxides or mixed basic oxides are considered to be the most promising. The disadvantages of such catalysts are their high sensitivity to ambient CO ₂ , which transforms them into a catalytically inactive form, and the lack of reliable methods for restoring their catalytic properties after regeneration.

Zeolites as catalysts for the aldol condensation reaction of acetone and furfural have a lower sensitivity to CO ₂ , but are difficult to regenerate and their activity in the aldol condensation reaction of acetone and furfural is lower than that of hydrotalcites. Their disadvantage is also the fact that they are rapidly deactivated due to the formation of coke during the reaction.

The essence of the invention

The above-mentioned disadvantages are at least partially eliminated by the nanocatalyst for the production of biofuels, characterized in that it contains 95 to 99.3% by weight. crystalline titanium dioxide with a particle size of 15 to 70 nm, the specific surface area of the nanocatalyst being 70 to 220 m ² / g, an average pore size of 1.5 to 5 nm and a pore volume of 0.19 to 0.7 cm ³ / g.

Process for the production of a nanocatalyst for the production of biofuels is characterized in that the titanium salt solution (Ti ⁴⁺ ) is heated for 1 hour at 90-100 ° C, then 110-195 g of urea are added with stirring, the weight ratio of titanium contained in titanium salt to urea is 0.08 to 0.12: 1, then the reaction mixture is brought to a boil and maintained at this temperature with stirring to pH 3 to 8.2, then the reaction mixture is stirred for 30 minutes, then it is aged for 12 hours at room temperature, then the suspension is drained, filtered and at least dried for 12 hours at 100 to 120 ° C.

A preferred method of manufacturing a nanocatalyst for the production of biofuels is characterized in that the dried suspension is calcined at a temperature of 150 to 550 ° C.

Use of a nanocatalyst for the production of biofuels for the aldol condensation reaction of furfural with acetone.

The basic component of the nanocatalyst for the production of biofuels according to the invention is crystalline titanium dioxide.

-1 CZ 306084 B6

Titanium salts are used to prepare the titanium salt solution (Ti ⁴⁺ _{), eg TiCl 4} , Ti ₂ (SO ₄ ) ₃ , TiOSO ₄ .xH ₂ SO ₄ .xH ₂ O, TiO [CH ₃ COCH = C (O- ) CH ₃ ] ₂ , TiOSO ₄ .xH ₂ O and Ti (OC ₃ H ₇ ) ₄ .

The nanocatalyst for the production of biofuels according to the invention is a white, very fine, fluffy powder.

The production method of the nanocatalyst for the production of biofuels according to the invention can be implemented in conventional chemical reactors or devices.

The nanocatalyst for the production of biofuels according to the invention can be used for the aldol condensation reaction of furfural with acetone in the production of biofuels.

The nanocatalyst used for biofuel production can be recycled by calcination at 450 ° C, steam saturation and drying at 100 ° C.

Examples of embodiments of the invention

Example 1

In a rotary reactor, 300 ml of a solution containing 60 g of TiOSO ₄ are prepared. The solution is heated to 90-100 ° C for 1 hour, which facilitates the hydrolysis of the titanium salt. Then, in the initial phase of vigorous stirring of the solution, 150 g of urea are added rapidly and the reaction mixture is then brought to boiling and kept at this temperature with constant stirring to a pH of about 3. The mixture is then stirred for 30 minutes and then allowed to mature. for 12 hours at room temperature. Finally, the suspension is drained, filtered and dried for 12 hours at 100-120 ° C. The obtained nanocatalyst for the production of biofuels is a white, very fine, fluffy powder.

Tab. 1. Nanocatalyst for biofuel production - sample 1

Pointer Value TiO ₂ content (% by weight) 95.8 Specific surface area (m ² / g) 216 Average pore size (nm) 2 Pore volume (cm ³ / g) 0.438 Particle size (nm) 14.8

Example 2

The preparation of the nanocatalyst for biofuel production was carried out according to Example 1, but the reaction mixture of 71.9 g Ti ₂ (SO ₄ ) ₃ and 110 g urea was kept at boiling temperature up to pH about 7. The obtained nanocatalyst for biofuel production is again white, very fine , fluffy powder.

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Tab. 2. Nanocatalyst for biofuel production - sample 2

Pointer Value TiO ₂ content (% by weight) 95.6 Specific surface area (m ² / g) 180 Average pore size (nm) 3.8 Pore volume (cm ³ / g) 0.61 Particle size (nm) 16.5

Example 3

The preparation of the nanocatalyst for the production of biofuels was again carried out according to Example 1, but the reaction mixture of 71.3 g of T1Cl4 and 195 g of urea was kept at a boiling point up to a pH of about 8.2. The obtained nanocatalyst for the production of biofuels is again a white, very fine, fluffy powder.

Tab. 3. Nanocatalyst for biofuel production - sample 3

Pointer Value T1O2 content (% by weight) 95.1 Specific surface area (m ² / g) 158 Average pore size (nm) 3 Pore volume (cm ³ / g) 0.35 Particle size (nm) 19.2

Example 4

The preparation of the nanocatalyst for the production of biofuels was again carried out according to Example 1, but the powder obtained was calcined at 150 ° C for 2 hours. The calcined nanocatalyst for biofuel production is again a white, very fine, fluffy powder.

Tab. 4. Nanocatalyst for biofuel production - sample 1/150

Pointer Value TiO ₂ content (% by weight) 97.6 Specific surface area (m ² / g) 210 Average pore size (nm) 3.5 Pore volume (cm ³ / g) 0.358 Particle size (nm) 14.8

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Example 5

The preparation of the nanocatalyst for the production of biofuels was again carried out according to Example 1, but the powder obtained was calcined at 250 ° C for 2 hours. The calcined nanocatalyst for biofuel production is again a white, very fine, fluffy powder.

Tab. 5. Nanocatalyst for biofuel production - sample 1/250

Pointer Value TiO ₂ content (% by weight) 98.2 Specific surface area (m ² / g) 187 Average pore size (nm) 3.6 Pore volume (cm ³ / g) 0.528 Particle size (nm) 20.7

Example 6

The preparation of the nanocatalyst for the production of biofuels was again carried out according to Example 1, but the powder obtained was calcined at 350 ° C for 2 hours.

Tab. 6. Nanocatalyst for biofuel production - sample 1/350

Pointer Value TiO ₂ content (% by weight) 98.8 Specific surface area (m ² / g) 175 Average pore size (nm) 4.9 Pore volume (cm ³ / g) 0.688 Particle size (nm) 17.2

Example 7

The preparation of the nanocatalyst for the production of biofuels was again carried out according to Example 1, but the powder obtained was calcined at 450 ° C for 2 hours.

Tab. 7. Nanocatalyst for biofuel production - sample 1/450

Pointer Value TiO ₂ content (% by weight) 99.0 Specific surface area (m ² / g) 120 Average pore size (nm) 1.9 Pore volume (cm ³ / g) 0.327 Particle size (nm) 51.6

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Example 8

The preparation of the nanocatalyst for the production of biofuels was again carried out according to Example 1, but the powder obtained was calcined at 550 ° C for 2 hours.

Tab. 8. Nanocatalyst for biofuel production - sample 1/550

Pointer Value TiO ₂ content (% by weight) 99.3 Specific surface area (m ² / g) 74 Average pore size (nm) 1.6 Pore volume (cm ³ / g) 0.194 Particle size (nm) 68.4

Example 9

The use of the nanocatalyst for the production of biofuels for the aldol condensation of furfural and acetone was carried out in a 200 ml stirred batch reactor (Parr autoclave) at 100 ° C.

1.0 g of powdered nanocatalyst for biofuel production is mixed with a mixture of 19.75 g of acetone and 3.25 g of furfural (i.e. molar ratio of acetone: furfural = 10: 1) and then placed in an autoclave. After the start of heating, the desired temperature of 100 ° C was reached in about 60 minutes. This temperature is then maintained in the autoclave for a further 2 hours.

Tab. 9. Catalytic properties of nanocatalyst for biofuel production in aldol condensation reaction of furfural and acetone

Sample Furfural conversion,% 1 93.1 2 90.5 3 90.0 1/150 94.4 1/250 92.7 1/350 93.5 1/450 91.7 1/550 84.3

The nanocatalyst used for biofuel production can be recycled by calcination at 500 ° C, steam saturation and drying at 100 ° C. The recycled nanocatalyst for biofuel production has a conversion efficiency in the aldol condensation reaction of furfural with acetone of 90%.

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Industrial applicability

The process for the production of a nanocatalyst for the production of biofuels according to the invention is industrially applicable in the production of catalysts. The nanocatalyst for biofuel production is industrially applicable for the aldol condensation reaction of furfural with acetone, which is a key reaction in biofuel production.

Claims (4)

PATENT CLAIMS A nanocatalyst for the production of biofuels, characterized in that it contains 95 to 99.3% by weight. crystalline titanium dioxide with a particle size of 15 to 70 nm, the specific surface area of the nanocatalyst being 70 to 220 m ² / g, an average pore size of 1.5 to 5 nm and a pore volume of 0.19 to 0.7 cm ³ / g. Process for the production of a nanocatalyst according to Claim 1, characterized in that the titanium salt solution (Ti ⁴⁺ ) is heated for 1 hour at a temperature of 90 to 100 ° C, then 110 to 195 g of urea are added with stirring. of titanium contained in the titanium salt to urea is 0.08 to 0.12: 1, then the reaction mixture is brought to a boil and kept at this temperature with stirring to pH 3 to 8.2, then the reaction mixture is stirred for 30 minutes , then it is aged for 12 hours at room temperature and then the suspension is drained, filtered and at least dried for 12 hours at 100 to 120 ° C. Process for the production of a nanocatalyst according to Claim 2, characterized in that the dried suspension is calcined at a temperature of 150 to 550 ° C. Use of a nanocatalyst for the production of biofuels according to claim 1 for the aldol condensation reaction of furfural with acetone.